n1 , a. 1. ; .. 10.? 1!... . ‘ If .t... . . I www.mrmfls... g... :3 _‘ hulk?! 4:... l a. £4».qu A. A9. . 4: I I . ROAM-W A \tfi . .. v.11- mums 3%.... $5. p . s. 35.2%”?! 93d“: #1". aII:\ 0.3. :4. 1.» Y v0.3 .1 It s .vn. 312‘! .171; It ’n’ . 21.9.... 2:! . r": ‘49:... d i .9! any)“. .. r i. ii . . 3.: .nnWanr 9.51.1. {Ansfitnouit {vulva .5 .. 5.2. 1|.Utx :. a». 1.... J Q: biymhflumrluiihé uh. M l. a». 9 .x #4.... O. .0... . t o :5 5.5.! :39. I... .1 .1}. Eli...‘ . J4: . 04. 3-! 52 a) .2 c: :3 .93 CO >25 CC c: Em [11.9 3f; 2 This is to certify that the dissertation entitled THE USE OF MACROINVERTEBRATES AS INDICATORS OF WETLAND QUALITY IN THE MUSKEGON RIVER WATERSHED, MICHIGAN presented by MOLLIE DAY MCINTOSH has been accepted towards fulfillment of the requirements for the Doctoral degree in Entomology fli/yz/afi’i/ Major Professor’s/Signature /Z/»7/o ? Date MSU is an affirmative-action, equal-opportunity employer .__._..-.—.----c--—.———.—.—-_.- PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE 6/07 p:/CIRC/DaleDue.indd—p.1 THE USE OF MACROINVERTEBRATES AS INDICATORS OF WETLAND QUALITY IN THE MUSKEGON RIVER WATERSHED, MICHIGAN By Mollie Day McIntosh A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Entomology 2007 ABSTRACT THE USE OF MACROINVERTEBRATES AS INDICATORS OF WETLAND QUALITY IN THE MUSKEGON RIVER WATERSHED, MICHIGAN By Mollie D. McIntosh Wetlands provide many functions, both ecological and economical; however, they are continuously threatened by numerous human activities. These activities (e.g., agriculture, development) subsequently generate environmental stressors (e.g., nutrients, road salt) that can impact the physical, chemical and biological integrity of wetland ecosystems. It is hypothesized that macroinvertebrate communities will vary with the presence and/or intensity of an environmental stressor; however, identifying these relationships can be difficult due to complex interactions among multiple human activities and stressors and wetland type and size. The main purpose of this study was to assess and characterize the macroinvertebrate community of inland wetlands of the Muskegon River Watershed, Michigan, and to understand how these communities respond to natural and human-induced changes in the environment, Ultimately the information from this research can add to a growing database on the use of macroinvertebrates as biological indicators of wetland ecosystem health, the identification of biological criteria used for water quality standards, predicting change in wetland structure and function, and in the regulation and protection of Michigan wetland ecosystems. This dissertation is dedicated to my parents, Candace and Michael McIntosh, who have always supported me throughout this journey. iii ACKNOWLEDGEMENTS I would first like to thank my advisor, Dr. Richard Merritt. Throughout my project he provided endless support, encouragement, and new opportunities that have made me a better scientist, person and future mentor. I must also thank Dr. Vanessa Lougheed, who not only served on my committee, but also helped with field logistics, data management and analyses for this project; her involvement made my experiences at MSU really fun and enjoyable. I am also grateful to all my committee members, including Drs. R. Jan Stevenson, Tom Burton and Mike Kaufman, who provided significant advice and support throughout this study. I would also like to thank the numerous individuals at MSU who played a significant role during my graduate years. Eric lBenbow and Ryan Klmbirauskas, my good friends, provided invaluable support and encouragement; without them, this journey would not have been so enjoyable. Todd White, Leia Watkins, Jennifer Schmitz and Rebecca Kolar, who worked numerous, long hours to process endless wetland samples for my project. Vanessa Lougheed, Chris Parker and Sarah LeSage should be commended for their tireless efforts in the field and at happy hour. Gary Parsons should also be recognized for his help and guidance in identifying insect specimens. Finally I would like to thank the members of the Merritt Lab, including JoAnna Lessard, Kelly Wessell, Jaree Johnson, Kristi Zurwaski, Osvaldo Hernandez, Ryan Kimbirauskas, Eric Benbow, Christian Lesage, Todd White and Matt Wessner; for making the lab a wonderful and always entertaining place to work. My family and friends should also be recognized for supporting me during my years at MSU. My parents, Candace McIntosh and Michael McIntosh, my sisters, Melissa Mitiska and Marielle McIntosh, Diana McIntosh and David Hulefeld, were there for me during all the good and stressful times and provided continuous encouragement; without them I would never have made it to this far — I am truly thankful and love them all very much. TABLE OF CONTENTS LIST OF TABLES ......................................................................................... viii LIST OF FIGURES ....................................................................................... xi CHAPTER 1 INTRODUCTION TO THE USE OF MACROINVERTEBRATES AS INDICATORS OF WATER QUALITY .......................................................... 1 CHAPTER 2 INFLUENCE OF SPATIAL SCALE ON WETLAND MACROINVERTEBRATE COMMUNITY RESPONSE TO ENVIRONMENTAL STRESSORS ............. 10 Abstract ................................................................................................. 1 1 Introduction...............; ............................................................................ 12 Methods ................................................................................................. 15 Study Location and Scale ....................................................... 15 Sample Collection ................................................................... 17 Statistical Analyses ................................................................. 1 9 Results ................................................................................................... 22 Environmental Variables ......................................................... 22 Macroinvertebrates ................................................................. 24 Environmental-Macroinvertebrate Response .......................... 27 Discussion ............................................................................................. 30 Ecosystem Scale .................................................................... 30 Class Scale ............................................................................. 33 Habitat Scale .......................................................................... 38 Tables .................................................................................................... 41 Figures ................................................................................................... 50 CHAPTER 3 UTILITY OF PRE-EXISTING MACROINVERTEBRATE METRICS IN MRW WETLANDS AT MULTIPLE SPATIAL SCALES .......................................... 59 Abstract ................................................................................................. 60 Introduction ............................................................................................ 61 Methods ................................................................................................. 64 Study Location and Scale ....................................................... 64 Sample Collection ................................................................... 67 Metric Calculation and Statistical Analyses ............................ 68 Results ................................................................................................... 70 Discussion ............................................................................................. 74 Conclusion ............................................................................................. 83 Tables .................................................................................................... 85 Figures ................................................................................................... 90 vi CHAPTER 4 INFLUENCE OF WETLAND SIZE AND WATER QUALITY ON ISOLATED MACROINVERTEBRATE COMMUNITIES .................................................. 92 Abstract ................................................................................................. 93 Introduction ............................................................................................ 94 Methods ................................................................................................. 97 Study Location and Scale ....................................................... 97 Sample Collection ................................................................... 98 Statistical Analyses ................................................................. 1 00 Results ................................................................................................... 102 Water Chemistry and Land-Use Land Cover .......................... 102 Macroinvertebrate Abundance ................................................ 103 Macroinvertebrate Diversity .................................................... 104 Macroinvertebrate Functional-Feeding Groups ...................... 105 Discussion ............................................................................................. 106 Conclusion ............................................................................................. 1 11 Tables .................................................................................................... 1 13 Figures ................................................................................................... 1 16 APPENDIX A: LIST OF COLLECTED MACROINVERTEBRATE TAXA FROM MUSKEGON RIVER WATERSHED INLAND MARSHES .................................................. 118 APPENDIX 8: RECORD OF DEPOSITION OF VOUCHER SPECIMENS .......................... 122 LITERATURE CITED ................................................................................... 133 vii LIST OF TABLES CHAPTER 2 Table 2.1: Principal componentanalysis (PCA) of 9 water chemistry variables at the ecosystem, class (lacustrine, palustrine, riverine) and habitat scale (emergent (E), submergent/floating (SIF)) in marsh wetlands. The percent variance explained by the first two principal components (PCs) of each PCA are listed for each scale. Water chemistry variables significantly correlated (p < 0.05) to each PC axis are listed (** = p < 0.001, * = p < 0.01). Water chemistry variables include pH, conductivity (cond), dissolved oxygen (DO), turbidity, total phosphorus (TP), ammonia (NH3), soluble reactive phosphorus (SRP), chloride (Cl), and mean depth (Depth) ............... 41 Table 2.2: Principal component analysis (PCA) of 6 land-use land-cover (LULC) variables at the ecosystem scale, class scale (lacustrine, palustrine, riverine) and habitat scale (emergent (E), submergent/floating (SIF)) in marsh wetlands. The percent variance explained by the first two principal components (PCs) of each PCA are listed for each scale. Land—use land-cover variables significantly correlated (p < 0.05) to each PC axis are listed (** = p < 0.001, * = p < 0.01). Land-use land-cover variables were relative proportions of urban, rangeland, agriculture, forest, water and wetland .............................................................................................. 42 Table 2.3: Mean(SE) values for all environmental variables at the ecosystem scale, class scale (lacustrine (L), palustrine (P), riverine (R)) and habitat scale (emergent (E), submergent/floating (SIF) in marsh wetlands. Water chemistry variables include, pH, conductivity (uS/cm), dissolved oxygen (DO mg/L), turbidity, total phosphorus (TP ug/L), nitrate (NH3 ug/L), soluble reactive phosphorus (SRP ug/L), chloride (Cl mg/L), and mean depth (cm). Land-use land-cover (LULC) variables were relative proportions of urban, rangeland, agriculture, forest, water and wetland. ANOVA results were presented for the class scale within each type of habitat; significant values (p < 0.05) and non-significant (ns) values are reported. Tukey HSD (p < 0.05) mean comparison results were shown among classes in each scale; different letters represent significant difference between wetland class ..................................... 43 Table 2.4: Mean (SE) values for 12 dominant macroinvertebrate taxa within each habitat (emergent (E), submergent/floating (SIF)) at the ecosystem scale and class scale (lacustrine (L), palustrine (P), viii riverine (R)) in marsh wetlands. ANOVA results were presented for the class scale within each type of habitat, p values are reported with significant values (p < 0.05, gray highlighted). Tukey HSD (p < 0.05) mean comparison results were shown among classes in each scale; different letters represent a significant difference between wetland class ..................................................................................... 44 Table 2.5: Macroinvertebrate taxa unique to the class or habitat scale in this study. Included are taxa class, order, family and generic level information, functional feeding group and habitat classification ......... 45 Table 2.6: Correspondence analysis (CA) of macroinvertebrate community at the ecosystem scale, class scale (lacustrine, palustrine, riverine) and habitat scale (emergent (E), submergent/floating (SIF)) in marsh wetlands. The percent variance explained by the first two CA axes are listed for each scale. Macroinvertebrates significantly correlated (p < 0.05) to each CA axis are listed (** = p < 0.001, * = p < 0.01) ............................................................................................ 46 Table 2.7: Pearson correlations (p < 0.05) between the first two axes of each correspondence analysis (CA 1 and CA 2) and the first two principal components (PC1 and P02) calculated from the principal component analysis of water chemistry values and from land-use land-cover (LULC) variables. Significant correlations (p value) at the ecosystem scale, class scale (lacustrine, palustrine, riverine) and habitat scale (emergent (E), submergent/floating (SIF)) in marsh wetlands ................................................................................. 47 Table 2.8: Significant relationships (correlations p < 0.05) between the principal component analysis (PCs) scores and correspondence analysis (CA) scores and the direction of each response (positive or negative) in each wetland class and habitat. The main chemical variables correlated to each PC axis (and the associated direction) are listed and macroinvertebrate taxa that respond to these changes in the PC are listed, taxa have either a positive (+) or negative (-) response ......................................................................... 48 Table 2.9: Canonical Correspondence analysis (CCA) of macroinvertebrate community at the ecosystem scale, class scale (lacustrine, palustrine, riverine) and habitat scale (emergent (E), submergent/floating (SIF)) in marsh wetlands. The CCA was constrained by water chemistry variables. The percent variance explained by the first two CCA and CA axes are listed for each scale .................................................................................................. 49 ix CHAPTER 3 Table 3.1: Various macroinvertebrate metrics used in the assessment of wetlands. The citation column lists studies that have utilized the metric. Each number represents the following citation: (1) Burton et al. 1999, (2) Helgen 2001, (3) Helgen and Gernes 2002), (4) Merritt et al. 2002 and 2006, (5) Apfelbeck 2001, (6) Uzarski et al. 2006 and (7) Kashian and Burton 2000 ...................................................... 85 Table 3.2: Ecosystem parameters and corresponding functional ratio ecosystem surrogates and expected ratios. (Modified from Cummins and Merritt, 1999 and Merritt et al. 2002) .......................... 87 Table 3.3: Macroinvertebrate metrics significantly different between reference and impacted wetlands of various class (lacustrine, palustrine, and riverine) and habitat (emergent, submergent). Median values are listed with Vlfilcoxon test scores and significance values of either p < 0.1 (*) or p < 0.05 (**). Those values left blank were non-significant according to these tests .................................... 88 CHAPTER 4 Table 4.1: Ecosystem parameters and corresponding functional ratio ecosystem surrogates and expected ratios utilized in this study. (Modified from Cummins and Merritt, 1999 and Merritt et al. 2002) .. 113 Table 4.2: Mean (SE) Shannon Index, Simpson Index, and Evenness Index values for each wetland treatment (impacted large, impacted small, reference large and reference small) for total wetland (T), emergent (E) and submergent (S) habitats. The only significant result (p < 0.05, *) was an interaction of wetland quality and size observed in the Evenness Index of the submergent habitat .............. 114 Table 4.3: Functional feeding group ratios representing ecosystem surrogates. Mean(SE) values for each wetland treatment (impacted large, impacted small, reference large and reference small) for total wetland (T), emergent (E) and submergent (S) habitats. The only significant effect (p < 0.05, *) of wetland size was observed in the top down ratio of the emergent habitat ............. 115 APPEDNIX A Table A1: List of macroinvertebrate taxon identified from inland marsh wetlands in the Muskegon River Watershed, Michigan ..................... 118 LIST OF FIGURES CHAPTER 2 Figure 2.1: Schematic illustration of three spatial scales (ecosystem, class and habitat) and levels within each scale that were analyzed in this study. The class scale is composed of three groups: lacustrine, palustrine, and riverine wetlands. The habitat scale is composed of two groups: emergent and submergent/floating habitats ................... 50 Figure 2.2: Principal component analysis of nine water chemistry variables and six land-use land-cover variables at the ecosystem level (n = 50 emergent sites). Each site is denoted by an open circle. (A) Water chemistry variables include pH, conductivity (Cond), dissolved oxygen (DO), turbidity (Turb), total phosphorus (TP), ammonia (NH3), soluble reactive phosphorus (SRP), chloride (Cl) and mean depth (Depth). (B) Land-use land-cover variables include relative proportions of urban, rangeland (Range), agriculture (Agricul), forest, water and wetland ................................. 51 Figure 2.3: Principal component analysis of (A) nine water chemistry variables and (8) six land-use land-cover variables at the ecosystem level (n = 50 emergent sites), with each site denoted by a letter representing the marsh class. (A) Water chemistry variables include pH, conductivity (Cond), dissolved oxygen (DO), turbidity (Turb), total phosphorus (TP), ammonia (NH3), soluble reactive phosphorus (SRP), chloride (Cl) and mean depth (Depth). (B) Land-use land-cover variables include relative proportions of urban, rangeland (Range), agriculture (Agricul), forest, water and wetland .............................................................................................. 53 Figure 2.4: Mean(SE) values for (A) macroinvertebrate abundance and (B) taxa richness for each habitat (emergent and submergent/floating) from marsh wetlands at the ecosystem and class scales (lacustrine, palustrine, and riverine). Significant differences in habitat (p < 0.05, denoted by *) were calculated by ANOVA at the ecosystem and each class scale. Tukey HSD mean comparison results were shown among classes at each habitat; different letters represent a significant difference (p < 0.05) between wetland class ..................................................................................... 56 Figure 2.5: Correspondence analysis of 57 macroinvertebrate taxa at the eCOSystem level in the emergent habitat (n = 50 sites), Each site is denoted by a letter representing the marsh class. Sites separate xi into a palustrine dominated group (long- dashed circle) and lacustrine and riverine dominated group (small-dashed circle) .......... 57 Figure 2.6: Canonical correspondence analysis of 57 macroinvertebrate taxa from 50 sites in the emergent habitat at the ecosystem level. Each site is denoted by aletter representing the marsh class. Sites separate into a palustrine dominated group (long- dashed circle) and lacustrine and riverine dominated group (small-dashed circle). The graph has been constrained by water chemistry variables that include pH, conductivity (Cond), dissolved oxygen (DO), turbidity (Turb), total phosphorus (TP), ammonia (NH3), soluble reactive phosphorus (SRP), chloride (Cl) and mean depth (Depth) ................ 58 CHAPTER 3 Figure 3.1: The relative composition (°/o) Gastropoda in emergent habitats of reference (R) and impacted (I) wetlands at the class scale (lacustrine, palustrine, and riverine). Solid lines within the box indicate are median values, the box values represent the inter- quartile ranges (25% and 75%), and the range bars indicate the maximum and minimum values. Significant differences (p < 0.05, denoted by ** or p < 0.1, denoted by *) were calculated by non- parametric ercoxon tests ................................................................. 90 Figure 3.2: A comparison of functional or ecosystem attribute ratios between reference (R) and impacted (I) emergent habitats of palustrine wetlands in the MRW. Solid lines within the box indicate are median values, the box values represent the inter-quartile ranges (25% and 75%), and the range bars indicate the maximum and minimum values. Significant differences (p < 0.05, denoted by ** or p < 0.1, denoted by *) were calculated by non-parametric Wilcoxon tests ................................................................................... 91 CHAPTER 4 Figure 4.1: Mean (SE) macroinvertebrate abundance (individuals per sample) for (A) total wetland, (B) emergent and (C) submergent habitats in isolated palustrine wetlands. All four wetland treatments are represented: small reference, large reference, small impacted and large impacted. A significant effect (*) of wetland quality (p < 0.05) and an interaction effect (p < 0.01) were observed in only the submergent habitat (C) ...................................................................... 1 16 xii Figure 4.2: Mean (SE) taxa richness (taxa per sample) for (A) total wetland, (B) emergent and (C) submergent habitats in isolated palustrine wetlands. All four wetland treatments are represented: small reference, large reference, small impacted and large impacted. No significant effects of wetland quality, wetland size or an interaction effect were observed in this study ............................... 117 xiii Chapter 1: Introduction to the Use of Macroinvertebrates as Indicators of Water Quality Chapter 1: Introduction to the Use of Macroinvertebrates as Indicators of Water Quality The Clean Water Act (CWA) was established to restore and maintain the chemical, physical and biological integrity of water bodies in the United States (Adamus 1996). In the past, the condition of a water body was determined mainly through physical and chemical measurements. These data were then compared to previous data from that site or a reference location, and subsequent management action was taken to improve the water body if necessary. Although many of these physical and chemical criteria can be easily measured, when collected in a rapid assessment (e.g., once a year) they provide only limited information on the current conditions of the water body (Danielson 1998). Typically when human activities degrade an aquatic ecosystem, effects can be observed through a change in the biota (Danielson 1998). Biological organisms, and thus biological measurements, can respond to short and long-term changes in the environment, providing temporal information useful in evaluating the integrity of a water body in a rapid assessment (Rosenberg and Resh 1993). The biological community present at the time of assessment is the cumulative result of the physical and chemical conditions over time. Organisms that respond to these changes in a predictable manner can act as biological indicators and are used to establish biological thresholds or criteria, and are monitored in rapid assessments. As a result, the EPA and numerous states have developedbiological criteria useful in assessing the condition of aquatic habitats, hence the term bioassessment. The use of all three criteria, physical, chemical and biological combined, provide for the most thorough assessments (Apfelbeck 2001). Biological assessments have successfully been created for stream, lake, and river systems; but few states have developed biological criteria and assessments for wetland ecosystems (Danielson 1998). Compared to these other aquatic habitats, less information is known about wetland biological communities. The presence/absence of biota, the interactions of these organisms with the biotic and abiotic environment, and individual organism traits (e.g., life histories, tolerance levels) are still unknown in wetlands and can make the identification of good biological indicators difficult. Natural temporal variability common to the chemical and physical wetland environment can also influence the biological community in both the short and long term; and the existence of numerous wetland types (e.g., coastal marshes, fens, swamps) make the establishment of standard biological criteria difficult for wetlands (Rader 2001 ). Despite the complexity, effort is still being given to develop biological criteria that can aid in the regulation and protection of wetland quality. Following the same trend, most aquatic research has focused on lake or stream habitats; however, within the past twenty-five years an increasing amount of research has been conducted on wetland ecosystems. Wetlands provide both economic and social benefits (e.g., flood prevention, groundwater recharge, water purification) and ecological significance (e.g., species diversity, unique wildlife habitats) (Wrssinger 1999, Mitsch and Gosselink 2000). However, over the past 200 years, approximately 50% of wetlands within the continental United States have been lost or converted to other types of land uses (e.g., agriculture, development) (Mitsch and Gosselink 2000). In Michigan, where this study was conducted, 50% of wetlands have also been lost, with the threat rising due to increased development (Mitsch and Gosselink 2000). Of those remaining wetlands, many are still endangered due to increases in human activity and lack of government protection. Increased human activity could lead to a decline in water quality from nutrient enrichment, sedimentation, and other types of pollution (Lemly and King 2000). A recent ruling in 2001, by the United State Supreme Court (Solid Waste Agency of Northern Cook County [SWANCC] vs. US. Army Corp of Engineers) has reduced the amount of protection for some wetlands. The court ruled that isolated waters were no longer, under certain circumstances, under the protection of the CWA; this decision makes isolated waters, especially isolated depression wetlands, potentially vulnerable to human disturbance (Tiner 2003a). Wetland managers, researchers, government officials and the general public have recognized this need to protect wetlands, and have become more active as a result. Biological assessments have been developed using fish, macroinvertebrates, zooplankton, plant and algal communities for assessing water quality; however, macroinvertebrates are the most commonly used group (Hellawell 1986, Rosenberg and Resh 1993). Macroinvertebrates play a fundamental role in the biological community of aquatic ecosystems. They facilitate the transport of energy by connecting primary producers and higher trophic levels in fobd webs. Therefore, shifts in macroinvertebrate structure could have cascading effects on other levels of the food web, and in return, shifts at other levels could have a direct influence on macroinvertebrate communities (Wrssinger 1999, Helgen 2001). Because of this connection, macroinvertebrates have been useful as management tools in the evaluation and monitoring of aquatic habitats. Additional reasons for using macroinvertebrates are (1) their ubiquitous nature, (2) range of response to environmental stressors by different species, (3) relative stationary nature, (4) their relatively long life cycles, (5) the ease in which macroinvertebrates are collected and the (6) relatively low costs involved with collections (Rosenberg and Resh 1993). All of these advantages apply to most aquatic habitats (e.g., streams and rivers); however, some do not yet apply to wetland ecosystems. For example, Batzer et al. (2001) maintained that many wetland macroinvertebrates are mobile, some life cycles can be quite short (1-2 months), and that much information is still unknown for certain taxa (e.g., response to pollution and taxonomy), thereby, limiting the use of macroinvertebrates in wetland assessments. For example, a study by King and Richardson (2002) found that family-level identification of wetland macroinvertebrate communities were not capable of detecting impairment and suggested that genus or species-level identification be utilized, especially within the dominant Chironomidae family. However, this type of identification, especially with the Chironomidae or Annelida can be difficult, require expertise, time consuming and more expensive (King and Richardson 2002), and for some taxa in some regions identification keys may not be available. In general, more research is needed on the general biology and ecology of macroinvertebrate communities in various types of wetlands over different spatial and temporal scales for us to better understand their use as assessment tools. Several studies, however, have successfully used macroinvertebrates in the assessment of wetland quality. Burton et al. (1999) developed a preliminary index of biotic integrity for coastal Great Lake wetlands using 14 invertebrate metrics. Additional evidence supporting the use of certain invertebrate indicators within costal freshwater wetlands were identified by Kashian and Burton (2000) and later validated by Uzarski et al. (2004). Cooper et al. (2006) found certain macroinvertebrate taxa to respond to land-use and water quality parameters in a drowned river mouth wetland on Lake Michigan, supporting the use of macroinvertebrates as indicators of human disturbance. In forested bottomland wetlands, macroinvertebrate communities were also found to be sensitive to human disturbance (e.g., highway roadways) and potentially useful in biological assessment (King et al. 2000). Helgen and Gernes (2001, 2002) developed two indices of biological integrity for vegetation and invertebrates to be used in monitoring the water quality of depressional wetlands in Minnesota, and in Montana, Apfelbeck (2001) found macroinvertebrates and diatoms to be useful in evaluating the biological integrity of perennial wetlands. In Australia, Chessman et al. (2002) successfully derived and tested a new biotic index for the Swan Coastal Plain using macroinvertebrate taxa. Due to taxonomic limitations, functional-group analyses can also provide insight to the assessment of aquatic ecosystems (Cummins 1974, Cummins and Merritt 2001). Merritt et al. (1996, 1999, 2002b) found that macroinvertebrate metrics, including functional group analyses, could be used as surrogates for ecosystem attributes in river oxbows and floodplain ecosystems in Florida. However, other studies have found the use of macroinvertebrates as biological indicators to be questionable in wetlands. Studies in the Prairie Pothole Region, have found weak relationships between macroinvertebrate communities and surrounding land use, suggesting that macroinvertebrate indicators might not be useful in this region (Tangen et al. 2003). Also, Vlfilcox et al. (2002) found that biological indicators (macroinvertebrates in addition to fish and plants) were inaccurate due to fluctuations in hydrology in drowned-river mouth wetlands. In general, all of these studies suggest that macroinvertebrates might be useful in developing biological criteria and bioassessment protocols, however, again more temporal and spatial research is needed in wetlands of various regional, class and water- level histories (Wilcox et al. 2002). Common trends in wetland ecology have long been desired; however, due to the large amount of variation that can be found in wetlands (e.g., hydrologic condition, type of vegetation, location) these general trends have been difficult to uncover and separating the natural variation from the human-induced variation makes this task even more complex (Rader 2001). As a result, the Environmental Protection Agency (EPA) has been working on conceptual models to illustrate the relationship between biological condition (e.g., macroinvertebrate attributes) and human disturbance in wetlands; thus, providing a framework to help states fulfill the biological requirements of the CWA by supporting aquatic life in wetlands. However, more research is needed to test this model by assessing actual relationships between biota (e.g., macroinvertebrate communities) and human disturbance (stressors) in the field. Ultimately, if useful relationships are found and tested, these guidelines could be a useful tool in the development of macroinvertebrate/wetland assessments for many states. This model will also provide consistency across states, scientifically defensible benchmarks, a common framework for evaluation, and protection of wetland habitats. To understand if relationships do exist between the wetland macroinvertebrate community and environmental stressors, more detailed investigations, at various spatial and temporal scales, are needed. The main purpose of this study was to assess and characterize the macroinvertebrate community of inland wetlands of the Muskegon River Watershed (MRW), Michigan, USA. To identify biological indicators, potential relationships were examined at several spatial scales between MRW environmental stressors and macroinvertebrate attributes (response indicators). i also investigated the variability of the macroinvertebrate community within and between wetlands and wetland habitats. This study has provided a better understanding of the macroinvertebrate community present in inland Michigan wetlands and how these communities respond to changes in the environment- information that can then be utilized in the development of wetland biocriteria for the MRW, assessment of MRW wetland integrity, predicting change in MRW wetland structure and function, and in the regulation and protection of MRW wetland ecosystems. The specific objectives of this study were divided into the following three chapters: 1.) To determine macroinvertebrate communities and stressor response relationships at multiple spatial scales 2.) To test the utility of pre-existing macroinvertebrate assessment metrics in MRW wetlands 3.) To assess stressor impact and wetland size on macroinvertebrate community structure and function in palustrine wetlands. Ultimately the information from this research can add to a growing database on the use of macroinvertebrates as biological indicators of wetland ecosystem health and integrity, the identification of biological criteria used for water quality standards in Michigan, and provide a model for other states. Chapter 2: Influence of Spatial Scale on Wetland Macroinvertebrate Community Response to Environmental Stressors 10 Chapter 2: Influence of Spatial Scale on Wetland Macroinvertebrate Community Response to Environmental Stressors Abstract Wetlands provide many functions, both ecological and economical; however, they are continuously threatened by numerous human activities. These activities (e.g., agriculture, development) subsequently generate environmental stressors (e.g., nutrients, road salt) that can impact the physical, chemical and biological integrity of wetland ecosystems. It is hypothesized that macroinvertebrate communities will vary with the presence and/or intensity of an environmental stressor; however, identifying these relationships can be difficult due to complex interactions among multiple human activities and stressors and wetland type and size. In an effort to understand this complexity, we identified relationships between macroinvertebrate communities and environmental stressors at three spatial scales: the ecosystem (marsh wetlands), class (riverine, palustrine, and lacustrine) and habitat (emergent and submergent vegetation). During the summer of 2002 and 2003, macroinvertebrates were collected from 57 inland marshes within the Muskegon River Watershed (Michigan, USA). Relationships between macroinvertebrate community abundance and environmental stressors were explored using several multivariate ordination and correlation techniques. Analyses showed spatially explicit variation among macroinvertebrate communities, with most variation explained at the class scale, 11 but dependent on habitat type. In general, differences among the wetland classes in emergent habitats indicated that palustrine marshes supported different macroinvertebrate communities compared to riverine and lacustrine marsh wetlands; the submergent/floating habitat did not differ among classes. Because of the large variation of macroinvertebrate assemblages among all spatial scales, it was not possible to identify useful biotic water quality indicators for general wetland bioassessment in this watershed. Specific assessments using macroinvertebrate communities may be needed for each class and habitat scale. Results from this multi-scale analysis will allow for the identification of more useful indicators of wetland health that provide a guideline for scale-defined wetland bioassessments. Introduction Over the past twenty-five years increasing research has been conducted on wetland ecosystems, due to their rapid disappearance, economic and social benefits (e.g., flood prevention, groundwater recharge, water purification) and ecological significance (e.g., species diversity, unique habitats) (Wrssinger 1999, Mitsch and Gosselink 2000). In the United States alone, approximately 50% of wetlands have been lost to development (e.g., urban, agricultural) leaving the quantity and quality of those remaining wetlands at risk and vulnerable to human activities (e.g., agriculture, mining, development) and subsequent environmental stressors, both contributing to wetland degradation (Mitsch and Gosselink 2000). 12 The Clean Water Act (CWA) was established to restore and maintain the chemical, physical and biological integrity of water bodies in the United States (Adamus 1996), however, most emphasis has focused on lake, stream, and river systems. Recent attention has shifted to developing similar CWA standards in wetlands by improving methods and programs that protect wetland quality. Biological indicators and their response to environmental stressors have long been identified and successfully used in biological assessment protocols in lotic ecosystems (King et al. 2000). Certain biota respond to both short and long- term changes in the physical, chemical and biological environment, and are thus good overall indicators of the environmental quality (Rosenberg and Resh 1993). Macroinvertebrate communities are most frequently used in these assessment protocols due to the following: (1) their role in facilitating energy transport by connecting primary producers and higher trophic levels of the food web, (2) their ubiquitous nature, (3) range of response to environmental stressors by different species, (4) relative stationary nature, (5) their relatively long life cycles, and (6) simple collection methods (Hellawell 1986, Rosenberg and Resh 1993, Wissinger 1999, Helgen and Gernes 2001). However, Batzer et al. (1999) point out that while these advantages apply to most aquatic habitats (e.g., streams and rivers), some do not yet apply to wetland ecosystems. For example, many wetland macroinvertebrates are mobile, some life cycles can be quite short (1-2 months), and that much information is still unknown (e.g., response to pollution and taxonomy), thereby, limiting the use of macroinvertebrates in wetland biological assessments (Batzer et al. 2001). 13 Environmental stressors on the macroinvertebrate community can be abiotic or biotic factors and are commonly induced by human activities; however, identification of these relationships can be difficult due to the complexity of wetlands and interactions among multiple human activities and stressor. Several studies, however, have identified these relationships and found that macroinvertebrates can be useful in wetland bioassessments (Burton et al. 1999, Kashian and Burton 2000, King et al. 2000, Apfelbeck 2001, Helgen and Gernes 2001, Chessman et al. 2002, Merritt et al. 2002b, Uzarski et al. 2004, Cooper et al. 2006) while others have found little response between macroinvertebrate communities and human activities (Tangen et al. 2003). Differences between these studies question the utility of macroinvertebrates as general indicators of wetland quality, and this may be due to high variability from independent or interactive effects of hydrology, region, seasonality, and wetland type, among others (Wilcox et al. 2002). In order to understand this complexity, these relationships must be addressed at multiple spatial scales. Macroinvertebrate communities and environmental variables can vary among scales; thus, the stressor-biotic response relationship should also be spatially explicit (e.g., wetland class, and habitat) (Downes et al. 1993, Boyero and Bosch 2004, Rios and Bailey 2006). An analysis that incorporates the role and importance of nested scales would allow for the better evaluation of stressor -macroinvertebrate community relationships (Kotliar and Wrens 1990), providing potential indicators of wetland health and sampling procedures at the appropriate scale for assessment. 14 The first objective of this study was to identify macroinvertebrate community response to environmental stressors at multiple spatial scales among inland Michigan wetlands. The following questions were addressed: (1) what types and how do environmental stressors influence wetland macroinvertebrate communities; (2) are macroinvertebrate communities good indicators of wetland health; (3) what macroinvertebrate metrics can be developed for inland wetland bioassessments. My second objective was to determine if macroinvertebrate communities and their relationships with environmental stressors differ among wetlands at each spatial scale. For each spatial scale of analysis the following questions were addressed: (1) which macroinvertebrate taxa are ubiquitous vs rare among wetlands at a particular spatial scale; (2) are relationships between macroinvertebrate communities and stressors spatially explicit; and (3) should each scale be evaluated separately in a bioassessment program for inland marshes in Michigan? I hypothesized that macroinvertebrate communities would differ among inland wetlands at each spatial scale and that relationships between environmental stressors and macroinvertebrate attributes (e.g., metrics) would be dependent on the scale of analysis. Methods Study Location and ficale The Muskegon River Watershed (MRW) begins in the north-central region of Michigan’s lower peninsula, and drains southwest into Lake Michigan. The 15 watershed is approximately 7000 km2 and includes 94 tributaries, 183 stream segments, hundreds of lakes and wetlands within 11 different counties (Torbick et al. 2006). Dominant land use varies from forest to agriculture/urban dominated areas within the Upper and lower regions of the watershed, respectively (Lougheed et al. 2007). The continuum of the MRW has been altered by 95 dams, has been impacted by human influence through logging and agriculture, and is predicted to have a 50% increase in urban land use within the next 35 years (Pijanowski et al. 2006). Inland wetlands (n = 57) were selected from within and near the MRW; most sites,(~ 42) were randomly selected, whereas remaining sites were purposely selected as described by Lougheed et al. (2007) to ensure that a gradient of sites with variable water quality were included in the study. Although the term wetland has been used to describe many types of aquatic habitats, hereafter, in this study the term wetland referred to only inland marsh ecosystems. All sites were surveyed prior to the field season to confirm wetland existence, accessibility, and to obtain landowner permission if necessary. To achieve our objectives, three spatial scales were designated for this study: the ecosystem scale, class scale, and habitat scale (Figure 1). The ecosystem (watershed) scale classified all sites into a single group for analyses. Within the ecosystem scale, all wetlands were further divided into the next scale based on wetland class: palustrine (depression, n=25), riverine (n=18), and lacustrine (n=14) wetlands (Figure 1). Within each class, habitats were nested as distinct Vegetation zones (habitats) (Figure 1): when present, two zones were 16 sampled in each marsh, the emergent (E) and submergent/floating (S/F; hereafter referred to as submergent) vegetation zones. The floating and submergent zones were combined due to little variation in macroinvertebrate composition (T. Burton, personal communication), and the inability to clearly distinguish and separate these zones in many wetlands. Sample Collection Inland marsh wetlands were sampled once between July and early August in 2002 and 2003. At each marsh site, three evenly spaced transects were established perpendicular to one side of the wetland, thus extending from the wet-meadow, or shore, into deep-water habitats. Along each transect, multiple random sampling points (marked by a 1m2 quadrant) were established and macroinvertebrates were collected from the first random point in each habitat zone. To ensure no disturbance in the macroinvertebrate community due to other sampling activities (e.g., algae or zooplankton), macroinvertebrates were collected at a random angle, 1—2 m from the main sampling quadrant. One macroinvertebrate sample consisted of two sets of three sweeps (~1m2) using a standard D-net (500 um) that was rinsed through a 500 um sieve to remove large pieces of vegetation, and then combined into a single composite sample and preserved in 100 °/o ethanol for laboratory identification. Each wetland was sampled only once giving a maximum of two composite samples per site (Halse et al. 2002). Although 57 sites were sampled, some had only one type of habitat; l7 therefore, a total of only 50 emergent composite samples and 50 submergent composite samples were collected and analyzed in this study. In the laboratory, macroinvertebrate composite samples were sieved and sub-sampled to reduce processing time. In the sub-sampling protocol, each sample was homogenized and divided into two equal proportions or sub- samples. All macroinvertebrates from one sub-sample were sorted and identified to the lowest practical taxonomic level using Merritt and Cummins (1996), Thorp and Covich (1991), Pennack (1989) and Larson et al. (2000). Most macroinvertebrate taxa were identified to the generic level, except for the Chironomidae, Oligocheata, and Hirudinea. For other taxa, large numbers of immature specimens were collected and could only be accurately identified to the family level; all taxa from these groups (Planorbidae, Libellulidae, Coenagrionidae, Corixidae, Notonectidae) were grouped at the family level. Macroinvertebrate counts were adjusted (doubled) to account for the sub- sampling protocol prior to statistical analyses. Environmental factors measured at each wetland included chemical and physical water variables. For water chemistry, a single 250ml sample was collected from an open habitat area and analyzed in the laboratory for total phosphorous (TP), soluble reactive phosphorus (SRP), ammonia (NH3), turbidity (Turb) and chloride (CL) using methods described by Lougheed et al. (2007). Field measurements of dissolved oxygen (DO), pH, conductivity and mean water depth were collected at every site with a YSI 556 multiprobe meter. Land-use land-cover‘(LULC) data for a 500 m buffer surrounding each wetland was 18 calculated using ArcGlS (Lougheed et al. 2007), categories determined were the percentage of agriculture, urban, rangeland, forested, water, and wetland within each buffer. Statistical Analysis We employed several multivariate statistical analyses that followed the methods outlined by Cooper et al. (2006) to identify macroinvertebrate response to environmental stressors at three spatial scales. In order to identify scale- dependent relationships, the habitat zones were analyzed separately. For the ecosystem scale analyses, 50 sites were used for each habitat. For class scale analyses, the number of sites included depended on the habitat type: lacustrine (E n=12; S/F n = 14), palustrine (E n=23; S/F n = 21), and riverine (E n=15; S/F n = 15). Differences between the two habitats were compared for both the ecosystem and class scale. Principal component analysis (PCA) was conducted to identify stressors among MRW sites at the ecosystem and class scale. For each scale, PCA were conducted on two environmental datasets: (1) nine water chemistry variables log- transformed and (2) six land-use land-cover (LULC) variables arcsine-square root-transformed. The PCA will identify gradients in each environmental dataset among the wetland sites. The first two gradients or principal components (PCs) from each PCA were correlated with each individual environmental variable from 19 the corresponding dataset in an effort to decompose the PCs as described by Cooper et al. (2006) and Uzarski et al. (2004). Pearson correlations were considered significant at p < 0.05; those environmental variables significant were considered as potential stressors in MRW wetlands. Correspondence analysis (CA) was conducted to identify patterns in the macroinvertebrate community at the ecosystem and class scale. For each scale, a CA was conducted on log-transfon'ned macroinvertebrate abundances, with 51 taxa groups in the emergent zone and 45 taxa groups in the submergent zone. These taxa represent only organisms that were present in more than 10% of the survey sites and 0.05% of the total macroinvertebrates collected (Cooper et al. 2006, Kratzer and Batzer 2007). The CA will identify gradients in macroinvertebrate abundance among the wetland sites. Pearson correlations (significance level p < 0.05) were then conducted between the first two gradients or CA axis scores and corresponding macroinvertebrate abundances in order to determine specific taxa abundance patterns in relation to the CA ordination at each scale. To relate macroinvertebrate community response to environmental factors, two methods were used, Pearson correlations and canonical correspondence analysis (CCA). Pearson correlations (significance level < 0.05), as described by Cooper et al. (2006), were conducted between the scores of the first and second CA of each scale and the corresponding scale site scores of the first two PCs. This method allowed relationships between biotic and abiotic variables to be determined in an unconstrained method (Cooper et al. 2006). 20 Canonical correspondence analysis (CCA) was then utilized to relate the macroinvertebrate community to the water chemistry variables, specifically to environmental stressors. The same data sets used in the PCA and CA analyses were used in the constrained CCA method for the ecosystem and class scale of each habitat. To identify specific differences at the ecosystem scale between habitat types (between emergent and submergent) and at the class scale (among lacustrine, palustrine and riverine wetlands) for each habitat type, one-way ANOVAs for both environmental datasets and macroinvertebrate abundances of the twelve dominant taxa were conducted, along with post-hoc multiple comparison Tukey HSD tests at the class scale (significance level of p < 0.05). For macroinvertebrates, one-way ANOVAs for total macroinvertebrate abundance and total taxa richness were conducted at the ecosystem and class scale, along with post-hoc multiple comparison Tukey HSD tests to identify specific differences among class scale for each habitat (significance level of p < 0.05). Macroinvertebrate abundance data was log-transformed to meet statistical requirements for these tests; taxa richness did not need transformation. Dominant taxa were identified as the 12 most abundant individuals within each habitat at the ecosystem scale. Ubiquitous and unique taxa were identified among the wetland scales. For this study, taxa were considered unique to a scale if it were absent in all but one level at the same scale and present in more than two sites within that level (e.g., absent from lacustrine and riverine wetlands but in more than two palustrine sites). 21 Principal component, correspondence, and canonical correspondence analyses were conducted using R version 2.5.0. Pearson correlations, ANOVA and Tukey HSD analyses were conducted using JMP IN version 5.1.2. Results Environmental Variables Ecosystem Scale At the ecosystem scale, the first two principal components (PCs) of the water chemistry and LULC ordination explained from 54-57% of the total variance among sites (Table 2.1 and 2.2). There were significant correlations between the first two PCs (PC1 and P02) and certain water chemistry variables (Table 2.1). This suggested that each PC axis represented the association of these variables and the significance indicated that it was a main exploratory variable in the PC. At the ecosystem scale, in both habitats, the water chemistry PC1 was negatively correlated with turbidity, total phosphorus, ammonia, and chloride and positively correlated with dissolved oxygen (Table 2.1, Figure 2.2a). The water chemistry PCZ was negatively correlated with pH, conductivity, chloride and positively correlated with dissolved oxygen (submergent zone only) (Table 2.1, Figure 2.2a). The first LULC PC was positively correlated with %forest and %wetland and negatively correlated with %rangeland and agriculture (Table 2.2, Figure 2.2b). The second LULC PC was positively correlated with %water and %urban (Table 2.2, Figure 2.2b). In the ecosystem PCA ordination 22 with site labeled by wetland class, there was no clear separation of classes based on water chemistry (Figure 2.3A) or LULC (Figure 2.38). No significant differences were observed in any environmental variables between habitats. Class Scale Individual PCA analyses at the class scale found from 60—72% of the variation was explained by the first two PCs of the water chemistry and LULC ordinations in lacustrine and palustrine wetlands, whereas only 51-53% of the variation was explained in riverine wetlands (Table 2.1 and 2.2). The water chemistry PC1 for both habitats in the lacustrine and palustrine wetlands were negatively correlated with chloride and conductivity, whereas in riverine wetlands, PC1s were positively correlated with total phosphorus and turbidity and negatively correlated with dissolved oxygen (Table 2.1). The second PC in all three classes were negatively correlated with pH; however, other significant variables differed among classes (Table 2.1). The PCs of the LULC ordination at the class scale identified different correlated variables for each class. Common trends in all three classes have either %wetland or %water correlated with only the first PC and %agriculture correlated with the second PC axis; however, the strength of these correlations varied (Table 2.2). In general, % agriculture and % urban seem to be the main factors of disturbance in lacustrine and palustrine wetlands. Scale comparisons among environmental variables were conducted (Table 2.3). Significant differences were observed among classes in both 23 habitats for pH, TP and % water (Table 2.3). However, % agriculture and % wetland were only significantly different among classes for emergent habitats. Post-hoc Tukey HSD tests showed submergent habitats in palustrine wetlands to have significantly lower pH values compared to lacustrine and riverine wetlands; no significant post-hoc differences were found between classes for the emergent zone (Table 2.3). Total phosphorus was significantly greater in palustrine marshes compared to riverine marshes in both habitats; however, % agriculture was only significantly greater in palustrine marshes compared to lacustrine marshes in the emergent habitats (Table 2.3). The % water was greater for lacustrine wetlands in both habitats; this was expected since this class of wetlands were defined by their location adjacent to lakes. Macroinvertebrates Ecosystem Scale A total of 182,688 macroinvertebrates were collected from three phyla, the dominant ones being Arthropoda (75%), Mollusca (33%) and Annelida (7%). The most dominant taxa were the Chironomidae (22.2%), Planorbidae (14%) and Amphipoda (Hyalella, 12%). At the ecosystem scale, taxa richness was greater in emergent than submergent habitats (Figure 2.4; df =99, F =34.6, p <0.001) and macroinvertebrate did not differ among habitats (df = 99, F =1.49, p = 0.23). The 12 most dominant taxa in the emergent and submergent/floating habitats are listed in Table 5. At the ecosystem level, Physidae (df = 99, F = 6.7, p < 0.01) and Sphaeridae (df = 99, F = 10.9, p < 0.001) were the only ubiquitous taxa to 24 have significantly greater abundances in the emergent zone (Table 2.4). A total of eleven taxa were found exclusively in emergent habitats and three only in submergent zones (Table 2.5). Correspondence analysis was utilized to identify patterns or gradients in the macroinvertebrate community. At the ecosystem scale, the first CA axis (CA1) in both habitats explained 13-15% of the variance in the macroinvertebrate community and combined with the second CA axis (CA2) explained only 23-25% of the total variation (Table 2.6); however, macroinvertebrates significantly correlated to these axes varied between habitats. Thus, each CA was a representation of the associated macroinvertebrates and the significance indicated that it was an important factor in determining the gradient of the CA axis. Those significant taxa may be responding to environmental changes in MRW wetlands and may act as good biological indicators in future assessments. In the emergent zone, the first CA was negatively correlated with taxa from the Odonata (Libellulidae, Coenagrionidae), Diptera (Dashylea, Bezzia) and Trichoptera (Oecetis, Oxytheira) and the second CA was negatively correlated with Amphipoda (Hyalella), Ephemeroptera (Caenis) and Mollusca (Viviparidae, Hydrobiidae) (Table 2.6). Whereas, in the submergent/floating zone CA1 was positively correlated with Mollusca (Viviparidae, Valavata) and Ephemeroptera (Caenis) and negatively correlated with Coleoptera (Haliplus) and Odonata (Lestidae). The second CA was positively correlated with lsopoda (Caecidotea) and Amphipoda (Gammarus) (Table 2.6). The ecosystem CA ordination, with sites labeled as class illustrated separation of marsh classes based on 25 macroinvertebrate composition (Figure 2.58). This separation of classes was visually observed in the emergent ordination (Figure 2.5B), but not the submergent ordination. This suggests that analyses at the class scale may better explain macroinvertebratecommunity structure in MRW wetlands. Class Scale Individual CA analyses at the class scale were able to explain more variation compared to the ecosystem scale, with the lacustrine macroinvertebrate community explaining over 40% of the variation, followed by the palustrine and riverine communities with 28-31% (Table 2.6). Several macroinvertebrate taxa were significantly correlated with the CA axes for each class, with no common trends among classes or between habitats (Table 2.6). At the class scale, a significant difference in macroinvertebrate abundance (df = 49, F = 3.41, p < 0.05) was observed in the emergent zone, with the highest mean abundance in palustrine followed by riverine and lacustrine wetlands (Figure 2.4A). However, post-hoc Tukey tests showed no significant difference among class means (Figure 2.4A). In addition, macroinvertebrate abundance in the submergent habitat was not significantly different between classes. Within each class no significant differences were observed between habitats (Figure 2.4A; lacustrine: df=24, F = 0.01, p = 0.92; palustrine: df=43, F = 2.86, p = 0.10; riverine: df=30, F = 0.001, p = 0.97). Total taxa richness of emergent habitats was significantly different (df=49, F = 5.41, p < 0.01) among classes, but not for submergent habitats (df=49, F = 26 1.16, p = 0.32) (Figure 2.4B). Tukey HSD tests found that taxa richness was significantly greater in palustrine compared to riverine wetlands in emergent habitats (Figure 2.5B). Within each marsh class, emergent habitat taxa richness was significantly greater than the submergent habitat (Figure 2.43; lacustrine: df=24, F = 9.57, p < 0.01; palustrine: df=43, F = 23.8, p < 0.001; riverine: df=30, F=494p<00$. Results from among class ANOVA analyses indicated significant abundance differences for the Chironomidae, Planorbidae, Hyalella, Copepoda, and Lymnaeidae in emergent habitats, and Hyalella, Caenis, Neoplea, Hyrdrachnida and Bezzia in submergent habitats (Table 2.4). In general, mean comparisons with Tukey HSD tests indicated that palustrine wetlands were significantly different from riverine and lacustrine wetlands in both habitats (Table 2.4). Copepoda in palustrine wetlands (df = 43, F = 4.31, p < 0.05) and Sphaeridae in palustrine and riverine wetlands (df = 30, F = 5.1, p < 0.05) were the only ubiquitous taxa to be significantly more abundant in the emergent zone compared to the other habitats (Table 2.4). Specific taxa were exclusively found within a single wetland class (Table 2.5). Environmental -Macroinvertebrate Response Ecosystem Scafi Significant Pearson correlations between the PCA and CA axes for each habitat at the ecosystem scale are presented in Table 2.7. The first CA axis for the emergent zone was negatively correlated with both water chemistry PC1 and 27 PCZ, whereas the first CA axis (CA1) in the submergent habitat was not significantly correlated. At the ecosystem scale all the water chemistry PC relationships had correlations below 0.5 (Table 2.7). For the LULC dataset, only the emergent CA2 axis was correlated with PC1; all other relationships were not significant. The CCA analyses at the ecosystem level explained only 15% and 8% of the variation in the relationship between the marcoinvertebrate community and environmental variables within the emergent and submergent habitat, respectively. The same patterns found in the ecosystem level PCAs and CAs were also found in CCAs for both habitats. Class Scale Significant correlations between either CA1 or CA2 and the water chemistry PC1 were observed at least once in each marsh class; all of these relationships had a significant correlation of +/- 0.59 or higher (Table 2.7). No significant correlations were observed at the class scale between the CA axes and water chemistry PC2. Significant relationships identified between gradients at the class scale in the environmental variable data (PCAs) and macroinvertebrate community (CAs) are listed in Table 2.8. In emergent habitats of both lacustrine and palustrine classes, increases in chloride and conductivity corresponded to in a shift from Corixidae, Cladocera, and Hydrophilidae (Berosus) dominated communities to Hyalella, Haliplidae, Stratiomyiidae (Odontomyia), Gastropoda (Valvatidae, Lymnaeidae, Planorbidae), and Lepidoptera (Munroessa) communities (Table 2.8). In the 28 submergent zone of the lacustrine and palustrine marshes, macroinvertebrate taxa had both positive and negative responses to increases in chloride, conductivity and ammonia; however, the responsive taxa were different from those in the emergent habitats. More specifically, in lacustrine marshes, a shift occurred from Libellulidae, Corixidae, Cladocera, Oxythein'a, and Baetidae to Hirudinea, Lymneaidae, and Hydrophilidae (Tropisternus) communities and in palustrine marshes, the macroinvertebrate community shifted from Haliplidae and Lepidoptera (Munroessa) to Hydrarchnida, Libellulidae, Copepoda, Caenis, and Coenagrionidae (Table 2.8). Riverine marsh macroinvertebrate communities significantly responded to different water chemistry variables, as total phosphorus and turbidity increased and dissolved oxygen decreased, a shift in taxa from Caenis and Trichoptera (Oecitis) to Copepoda, Oligocheata, Physidae, Hydroporinae, and Gammarus communities (Table 2.8). At the class scale, the most significant correlations between the LULC PC and CA axes were observed in the lacustrine and palustrine classes. All relationships between the CA axes and LULC PC1 had a significant correlation of +/- 0.5 or higher at the class scale (Table 2.7). Again no significant correlations were observed for the LULC P02. The ecosystem CCA ordination illustrated separation of the marsh class based on macroinvertebrate communities and water chemistry variables (Figure 2.6). This separation of the marsh class was found in the emergent zones (Figure 2.6) but was not as defined in for submergent habitats. The CCA analyses at the class scale explained more of the macroin‘vertebrate-environmental variable variance (24-37%) compared to 29 the ecosystem scale (8-15%) (Table 2.9), and most variation was explained in lacustrine classes (36-37%) (Table 2.9). The same patterns observed in the ecosystem level PCAs and CAs were also observed in the CCAs for both habitats Discussion Ecosystem Scale Principal components analysis was utilized to identify potential environmental stressors that may influence macroinvertebrate communities in MRW marshes. At the ecosystem scale, six of the nine water chemistry variables included in the analyses were significantly correlated to the first PC axes of both habitats, thus making it difficult to identify specific stressors. These results suggest that a single environmental variable was probably not responsible for site separation observed in ordinations at this scale. All water chemistry variables correlated to the first PC axes had negative relationships except for positive correlations with dissolved oxygen. These significant correlations indicated that environmental gradients exist among these sites and that these correlated variables could be potential stressors on macroinvertebrate communities in MRW inland marsh wetlands. Furthermore, these significant relationships were with variables that we would predict to change based on previous wetland studies. Studies have found impacted wetland areas to have higher chloride (Kashian and Burton 2000, Helgen and Gernes 2001, Cooper et 30 al. 2006), total phosphorus (Helgen and Gernes 2001), nitrogen/nitrate (Kashian and Burton 2000, Cooper et al. 2006), turbidity (Helgen and Gernes 2001), and SRP (Kashian and Burton 2000) values. Non-impacted wetland areas have been reported to have higher dissolved oxygen (Kashian and Burton 2000, Helgen and Gernes 2001, Cooper et al. 2006) and pH values (Cooper et al. 2006). Uzarski et al. (2004) found that wetland water chemistry was dependent on surrounding land-use; wetlands surrounded by agriculture had increased pH, temperature, turbidity, alkalinity, sulfate and dissolved oxygen (in the daytime), and wetlands surrounded by urban/road development had increased chloride, conductivity, nitrate and ammonium. At the ecosystem scale in this study, the main environmental variables indicated of a mixture of human disturbances, with the water chemistry PC1 representing an agricultural disturbance gradient and PC2 representing an urban/road disturbance axis. In the LULC analyses, four of the six variables were significantly correlated with PC1, again making the identification of exact environmental stressors difficult. We would predict that % developed land (including % rangeland and % agriculture), will increase with human disturbance similar to that found by Soandso et al. (2002) and Cooper et al. (2006); whereas % forest and % wetland- have been found to decrease with human disturbance (Cooper et al. 2006). However, response to surrounding land-use land-cover may not occur in all wetlands and could be region specific (Tangen et al. 2003). At the ecosystem scale in this study, the LULC PC1 and P02 may be indicative of a two different disturbance axes, one based on agricultural differences and another on 31 urban/road differences (Uzarski 2004). When marsh class, however, was superimposed on the ecosystem scale PCA ordinations (Figure 2.3), no clear separation of sites was observed in either habitat. This indicated that observed disturbance gradients may be affecting all three marsh classes in the MRW. It is noteworthy that some separation of lacustrine sites in the LULC ecosystem ordination was observed in relation to %water. This would be expected because this class of wetlands are defined by their position next to lake ecosystems. Correspondence analysis (CA) was utilized to identify patterns or gradients in the macroinvertebrate community based on abundance values. Multiple taxa, in both habitats, were correlated with the CA axes, indicating gradients in macroinvertebrate community abundance. The presence of these gradients indicated that these taxa are changing across sites; however, the exact reason for these changes are unknown from these analyses (and discussed further below). Macroinvertebrate taxa represented by the CA axes differed between habitats, indicated that community composition also differed between habitats or that stressors on these communities differed between habitats. Between habitat comparisons of the environmental variables and of dominant taxa/unique taxa suggested that these CA gradients could be due to both factors. The ecosystem CA ordination, with sites superimposed as marsh class (Figure 2.4B), illustrated separation of marsh class based on macroinvertebrate composition. This indicated that the gradients observed in the macroinvertebrate taxa (CA axes) at the ecosystem scale might be due to class instead of potential environmental stressors. This separation of marsh classes was visually 32 observed in the emergent ordination, but not the submergent ordination, which implied that submergent habitats are more similar among wetland class. At the ecosystem scale, gradients were identified in the environmental data and macroinvertebrate community; however, I was interested in determining if relationships existed between these two factors. Significant correlations in the emergent habitat between the PCA and CA axes identified relationships that may exist at the ecosystem scale; however the low value correlations (values < 0.5) of these relationships was probably due to the influence of marsh class observed in the CA emergent ordination. This was further supported by CCA analyses in the emergent zone (Figure 2.6); ordination clearly separated the palustrine class from the lacustrine and riverine class, indicating that main gradients at this scale may not be due to environmental stressors. Differences in the macroinvertebrate community and response may be a result of natural differences (e.g., physical, hydrological) between lacustrine, palustrine, and riverine marshes. In the submergent zone, no clear separation of class was observed in the CA or CCA ordinations and no significant correlations were observed between the PCAs and CAs, revealing that macroinvertebrate community composition in this zone was similar across class. Low correlations at the ecosystem level between the PCA and CA analyses also indicated that specific relationships may be better identified at the class scale and will be discussed in more detail below. Class scale 33 Principal component analyses (of both water chemistry and land-use land- cover data (LULC)) explained more variation among sites at the class scale, specifically in lacustrine and palustrine marshes, with gradients observed in mainly chloride, conductivity, ammonia and pH as seen in other wetland studies (Helgen and Gernes 2001, Gernes and Helgen 2002). Riverine marshes had the least variation explained of the three classes and lower variation compared to the ecosystem scale; gradients in this class were observed in total phosphorus, turbidity, dissolved oxygen and conductivity. According to Uzarski et al. (2004), these same environmental gradients may be indicative of more urban and road disturbance in lacustrine and palustrine habitats and agricultural disturbance in riverine wetlands. Cooper et al. (2006) found water chemistry in drowned river- mouth wetlands in Michigan to be extremely variable due to a range of hydrological and biological conditions. These same dynamic conditions could also have influenced riverine wetlands in the MRW. Among class comparisons in the emergent zone had more significant differences in water chemistry and LULC values compared to the submergent zone, with palustrine marshes having statistically different values from either lacustrine, riverine or both marshes. This indicates that environmental variables affecting palustrine wetlands may be more distinct, compared to more similar environmental variables in lacustrine and riverine marshes. Correspondence analysis at the class scale explained more variation in the marcoinvertebrate community compared to the ecosystem scale. A large variety of macroinvertebrate taxa were significantly correlated with the CA axes 34 among the three classes and among habitats in the three classes, therefore, making no clear indicator taxa evident across all marsh classes or habitats. The significant relationships identified between gradients in the environmental variable data (PCAs) and macroinvertebrate community (CAs) were stronger (higher) and thus more significant than relationships at the ecosystem scale which allowed for important variables in our stressor-response relationships to be identified in these MRW inland marshes. A variety of macroinvertebrate taxa had a negative response to increased environmental stressors, suggesting their potential use as indicators of marsh water quality. The Ephemeroptera (Baetidae, Caenis) in the submergent zones of three marsh classes and the Trichoptera (Oecitis, Oxytheiria) in the submergent zones of two marsh classes both responded negatively to increased values in chloride, conductivity, total phosphorus and decreased dissolved oxygen values. Both Ephemeroptera and Trichoptera have been considered good indicators of poor water quality in lotic ecosystems, and although fewer taxa are found in wetland ecosystems, other studies have found these taxa to be useful as wetland indicators of water quality in coastal and depression wetlands (Kashian and Burton 2000, Gernes and Helgen 2002, Uzarski et al. 2004). The Odonata, including Libellulidae and Coenagrionidae, also had a negative response to increased environmental stressors in only submergent zones of palustrine and lacustrine marshes. Although not used as indicators in lotic ecosystems, the Odonata are more diverse in wetlands and have been found to be sensitive to low water quality (Kashian and Burton 2000, Gernes and Helgen 35 2002, Uzarski et al. 2004, Cooper et al. 2006). The Corixidae have often been considered indicators of poor water quality and thus common in impacted wetlands (Gernes and Helgen 2002, Cooper et al. 2006); however, my study found this group to decrease in response to increased conductivity, chloride and ammonia in MRW wetlands. A variety of macroinvertebrate taxa had a positive response to increased environmental stressors. Amphipoda had a positive response to increased stressors, specifically Hyalella to increased conductivity and chloride in the emergent zone and Gammarus to increased total phosphorus and turbidity in the submergent zone. Other studies have also found Amphipoda to be ubiquitous in wetlands, however, their response to stressors varied from no change in Hyalella and Gammarus with increased impact (Cooper et al. 2006), to genus replacement (from Hyalella to Gammarus) with increased impact (Kashian and Burton 2000), and a decrease in abundance in Hyalella with increased impact (Uzarski et al. 2004). Uzarski (2004) found that although the Amphipoda ultimately decreased, its first response was an increase in abundance with intermediate levels of disturbance. Based on this, perhaps in our study the most disturbed sites were only at this intermediate level. ln this study and in others (Burton et al. 1999, Kashian and Burton 2000), the Gastropoda , including Valvatidae, Planorbidae, Lymnaeidae and Physa positively responded to increases in all significant environmental stressors in at least one habitat and one class. 36 Numerous macroinvertebrate taxa were ubiquitous across all spatial scales. Chironomidae were the most abundant taxa collected among all three marsh classes, as observed in other wetland studies (Kashian and Burton 2000, King and Richardson 2002), andat the family level did not appear to respond to environmental gradients in our wetlands. Similar results were found in costal wetlands by Burton (1999) in which Chironomidae showed no response to human disturbance. However, some wetland studies that have identified Chironomidae to further taxonomic levels (e.g., sub-family, genus, species) have found taxa that respond differently to environmental stressors (Kashian and Burton 2000, King and Richardson 2002). Further identification of the Chironomidae in this study may have lead to significant differences between and among wetlands at various spatial scales. Differences among wetland class were observed throughout this study, with the palustrine marsh often being separated from the other two marsh types. This separation was most evident in ordination techniques using the macroinvertebrate communities and thus palustrine macroinvertebrate communities are different compared to the riverine and lacustrine marsh communities. Similar communities in the lacustrine and riverine marshes could result from similar exposure to moving water through flooding events and wave exposure, whereas palustrine marshes tend to be more stagnant. Ordination techniques based on water chemistry and LULC did not separate marsh classes, indicating that other factors, such as these natural physical differences mentioned, may be driving the distribution of macroinvertebrates. This would 37 support the importance of hydrology in the development of bioassessment protocols (Wilcox et al. 2002) and the need to develop these protocols at the class scale in inland marshes of the MRW. Habitat Scale Aquatic vegetation can influence biotic communities within wetlands by providing a variety of habitat and food resources, shaping community interactions (e.g., predation), and altering abiotic conditions (Voights 1976, De Szalay and Resh 2000). In this study, the submergent zone appeared to be a more homogenous and stable habitat compared to the emergent zone. Mean macroinvertebrate abundance and total taxa richness were lower in submergent habitats, with no statistical differences observed among marsh class. In addition, only three unique taxa were identified from the submergent zone compared to 10 unique taxa in the emergent zone. More sensitive taxa, such as the Ephemeroptera, Trichoptera, and Odonata were only observed to be responsive to environmental stressors in this submergent habitat perhaps due to a more stable location, with deeper more permanent water during the year. The emergent habitat of marshes are usually more shallow with fluctuating water levels making them a less stable habitat (Murkin and Kadlec 1986, Burton et al.1999). This increased disturbance and high habitat heterogeneity available in emergent zones could be reasons for greater abundance, taxa diversity and more unique taxa (Murkin and Kadlec 1986). Voights (1976) found similar results with greater abundance in emergent compared to submergent zones, however, 38 they found the zone where emergent begins to mix with submergent zones to be the most abundant and diverse habitats. Cardinale et al. (1997) also found macroinvertebrate attributes (epiphytic Chironomidae abundance, biomass, and diversity) to be greater in the mixed zone of emergent (littoral) vegetation and open water habitats. They also found that plant growth and water level influenced their results over time, suggesting that seasonal influences could have an affect on wetland macroinvertebrate communities (Cardinale et al.1997). Our results indicate that macroinvertebrate communities in emergent habitats were more variable than submergent habitats; yet, both habitats had distinct taxa that responded to environmental stressors. This data supported work by Burton et al. (1999, 2004) in coastal wetlands, that vegetation type was an important factor in macroinvertebrate community structure. More research is needed on macroinvertebrate response to vegetation in inland wetlands, and studies over a gradient of vegetation types and in mixed-habitat zones may be helpful for future assessment protocols. Other potential influences on the macroinvertebrate community that were not taken into account for this study include both abiotic and biotic factors. Abiotic factors such as fluctuations in wetland hydrology and hydroperiod could influence plant communities and habitat availability thus modifying the composition, abundance and life histories of certain macroinvertebrate taxa (Wilcox et al. 2002). Additional chemical or physical factors, could also have influenced macroinvertebrate responses. The biotic community within each Wetland coUId also have direct and indirect affects on macroinvertebrate 39 communities. For example, the presence or absence of fish could impact the number and composition of macroinvertebrates due to increased predation (Tangen et al. 2003). 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Scale Class Order fiFamily Genus Class Lacustrine Insecta Diptera Ceratopogonidae Alluaudomyia Palustrine Insecta Coleoptera Dytiscidae Agabetes Insecta Coleoptera Dytiscidae Coptotomus Insecta Coleoptera Dytiscidae Dytiscus Insecta Coleoptera Dytiscidae Hydroporus Insecta Collembola Poduridae Insecta Diptera Chaoboridae Chaoborus Insecta Diptera Corethrellidae Corethrella Insecta Lepidoptera Pyralidae Acentria Mollusca Gastropoda Viviparidae Riverine Insecta Coleoptera Elmidae Dubiraphia Insecta Odonata Calopterygidae Caloptelyx Insecta Odonata Gomphidae Arigomphus Habitat Emergent Insecta Coleoptera Dytiscidae Celina Insecta Coleoptera Dytiscidae Dytiscus Insecta Coleoptera Dytiscidae Hydroporus Insecta Coleoptera Dytiscidae Rhantus Insecta Coleoptera Hydrophilidae Anacera Insecta Diptera Corethrellidae Corethrella Insecta Diptera Sciomyzidae Type 2 Insecta Diptera Sciomyzidae Type 3 Insecta Odonata Calopterygidae Calopterwr Insecta Odonata Libellulidae Pachydiplax Submergent Insecta Diptera Ephydridae Lemnaphila Insecta Trichoptera Hydroptilidae Agraylea Insecta Trichoptera Hydroptilidae Orthotn'chia 45 600-210 L606? £00600 .6380 60.00202 6030”: 60.3222 60.3.0.0 600.65 6.0620 60.30... 6531.6 60.352 .6350 60.0.66 20.0-.Iam L 53.3.. 803000 6600000 600050 L639: 30.0050 .65300m 60.3000 6003232 6006.00 60.06: ..60.0-0>_> 60000.... ..N50-.m_..n. 50.3mm: L 53000 5535.5 .6505). 5.5.0.63 560.020 .6595... ..E.0-Emm .6006: 800.05... .6506: .650600 :60.0§<0 L030<0 :E.06I N 008. <0 5.; L500002 60.350 L6.0.<..0 60.0030 16.3010 60.3.4.0 60.00%: :60602 L 6.58 63000 60.330 .6365 600020.). 600025 166.060.. 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":0 m “=0 m 0.0 m “:0 m 00..0>.m 00.50200 0050000.. 000.0 E0u0>000m W 0.000 0000 .0. 00.0.. 0.0 00x0 <0 0:0 <00 020 00.... 00. >0 00:.0.0x0 00:0..0> 0:00.00 00 0. .00.00..0> 0.0.0.000 .0002, >0 00:.0..0:00 00210.00 00 0. 0000.002, 00.0:. 0. 20.0. m:..0o=0:0m.0E0:0 0w. 0:00.900. 0.000 000.000 000 00002. 0:00:00 0:00:00: 0.000 000.0 0.000 0.0.0.0000 00. .0 >..:::.:.00 000.000.026.000. .0 200. 0.0>.0:0 00:00:0000000 .00.:0:00 .mN 0.00... 49 |_'_— Scale Ecosystem AII MRW wetlands n = 57 Class { i \ Lacustrine Palustrine Riverine Wetlands Wetlands Wetlands "=14 "=25 "=18 Habitat x F Emergent Emergent n = 12 V V n ' 15 Submergent! Submergent! Floating Floating “=14 n=15 Emergent Submergent! n = 23 Floating n=21 I Figure 2.1: Schematic illustration of three spatial scales (ecosystem, class and habitat) and levels within each scale that were analyzed in this study. The class scale is composed of three groups: lacustrine, palustrine, and riverine wetlands. The habitat scale is composed of two groups: emergent and submergent/floating habitats. 50 0.2 -6 —4 -2 0 2 d) O o .- 2 - -_ .. 0 —2 —4 COND ¢ PH _6 -0.6 :0.4 .02 0 (5.2 Comp. 11 Figure 2.2: Principal component analysis of nine water chemistry variables and six land-use land-cover variables at the ecosystem level (n = 50 emergent sites), Each site is denoted by an open circle. (A) Water chemistry variables include pH, conductivity (Cond), dissolved oxygen (DO), turbidity (Turb), total phosphorus (TP), ammonia (NH3), soluble reactive phosphorus (SRP), chloride (CI) and mean depth (Depth). (B) Land-use land-cover variables include relative proportions of urban, rangeland (Range), agriculture (Agricul), forest, water and wetland. 5| Figure 2.2 (cont’d) B —4 -2 O 2 4 0.4 -4 0.2 . 2 0 O Wetland l —2 Forest -O.2 -4 -0.4 $0 4 —0 2 0 0 2 -0 4 52 Figure 2.3: Principal component analysis of (A) nine water chemistry variables and (B) six land-use land-cover variables at the ecosystem level (n = 50 emergent sites), with each site denoted by a letter representing the marsh class. (A) Water chemistry variables include pH, conductivity (Cond), dissolved oxygen (DO), turbidity (Turb), total phosphorus (TP), ammonia (NH3), soluble reactive phosphorus (SRP), chloride (CI) and mean depth (Depth). (B) Land-use land- cover variables include relative proportions of urban, rangeland (Range), agriculture (Agricul), forest, water and wetland. 53 l L COND i L = Lacustrine P = Palustrine PH R = Riverine I T l i fifi -0.6 -O.4 -0.2 0 0.2 Comp. 1 54 Figure 2.3 (cont'd) Comp. 2 B. -4 0.4 0.2 p____ 0 Agncul P Wetland P l Range _02 Forest L = Lacustrine 1‘ P = Palustrine 5 R = Riverine l —O.4 l —0.4 —0.2 0 0.2 -0.4 Comp. 1 55 -4 Emergent I: Submergent 3500- 8 g 3000- 15 ‘6? g a. 2500- 0 E f, g 2000- '5 w 5 5 1500- e a g s, 1000- .5 a e V 500- g. A A Ecosystem Lacustrine Palustrine Riverine s: Emergent :lSubmergent Ecosystem Lacustrine Palusrtine Riverine Macroinvertebrate Taxa Richness Figure 2.4: Mean(SE) values for (A) macroinvertebrate abundance and (B) taxa richness for each habitat (emergent and submergent/floating) from marsh wetlands at the ecosystem and class scales (lacustrine, palustrine, and riverine). Significant differences in habitat (p < 0.05, denoted by *) were calculated by ANOVA at the ecosystem and each class scale. Tukey HSD mean comparison results were shown among classes at each habitat; different letters 56 CA2 1 P 2 l PP P‘9o"“'.'.fi.-.'.O, ' P '3.“ O’o : 9 Z P 0. pp R o l o‘ O. P RP ‘3 n R O i: P .~ P P O. R L: p L 0 P . P 0. p P P P: "a R P .' . L R U . - i -2 : L R ; L = Lacustrine :L R L L .0. i P = Palustrine . R 3 ; R = Riverine '. R R L '- ,’ '. ‘0 L L o. 9 G. ‘4 ‘2 .0. 0 2 ....4 0 O o. ) . o ’ CA1 Figure 2.5: Correspondence analysis of 57 macroinvertebrate taxa at the ecosystem level in the emergent habitat (n = 50 sites), Each site is denoted by a letter representing the marsh class. Sites separate into a palustrine dominated group (long- dashed circle) and lacustrine and riverine dominated group (small-dashed circle). 57 o""ln .c n,. 9 O O. ': L = Lacustrine : R R '0, ' P = Palustrine : L L .9. R = Riverine - - o. '- R ‘ PH ’. P P P L t p : i P P Pp —3 -2 -1 O l 2 3 CA 11 Figure 2.6: Canonical correspondence analysis of 57 macroinvertebrate taxa from 50 sites in the emergent habitat and at the ecosystem level. Each site is denoted by a letter representing the marsh class. Sites separate into a palustrine dominated group (long- dashed circle) and lacustrine and riverine dominated group (small-dashed circle). The graph has been constrained by water chemistry variables that include pH, conductivity (Cond), dissolved oxygen (DO), turbidity (Turb), total phosphorus (TP), ammonia (NH3), soluble reactive phosphorus (SRP), chloride (Cl) and mean depth (Depth). 58 Chapter 3: Utility of Pro-existing Macroinvertebrate Metrics in MRW Wetlands at Multiple Spatial Scales 59 Chapter 3: Utility of Pre-existing Macroinvertebrate Metrics in MRW Wetlands at Multiple Spatial Scales Abstract Methods to monitor the ecological health of wetlands are needed to protect these ecosystems from further human disturbances. One method of interest has been the use of biological indicators in the assessment of water quality. Macroinvertebrate communities are responsive to environmental change and thus provide a good indication of water quality in other aquatic habitats making their potential use in wetlands a logical and practical objective for wetland management and protection. Wetland macroinvertebrate metrics sensitive to disturbance have been determined for some wetland types and regions, however the use of these methods or metrics in all wetlands is relatively unknown. The objective of this study was to compare the utility of these pre-existing macroinvertebrate metrics in wetlands, specifically inland marshes in the Muskegon River Watershed (MRW) Michigan at multiple spatial scales, including the class scale (lacustrine, palustrine and riverine marshes) and habitat scale (emergent and submergent vegetation zones). Macroinvertebrates were collected from impacted and reference wetlands of the MRW and 50 macroinvertebrate metrics were calculated and compared between groups at the habitat scale Within each class. Of all metrics tested in this study, 27 had at least one significant difference (p < 0.10 or p < 0.05) in one class and habitat 60 combination, yet, those combinations that were significant varied from metric to metric. Few metrics were sensitive in all wetland classes or habitats, suggesting that these pre-existing macroinvertebrate metrics did not work equally well in MRW wetland assessments at different scales. Introduction Wetlands are threatened by various human activities (e.g., development, agriculture) and as a result have declined in quantity and quality over the years. Recent interest in protecting wetlands, including those still remaining, restored and newly created wetlands, have resulted in the development of assessment methods that can monitor the quality and identify degraded wetland ecosystems (van Dam et al. 1998, Rader 2001). One method of interest is the use of biota as indicators of wetland quality. Biological organisms, and thus biological measurements, can respond to short and long-term changes in the environment, providing temporal information useful in evaluating the integrity of a water body in an assessment (Rosenberg and Resh 1993). Organisms that respond to these changes in a predictable manner can act as biological indicators and are used to establish biological thresholds or criteria and are monitored in assessments. The success of these methods in other aquatic ecosystems (e.g., streams and lakes), in addition to the rapid, reliable and cost efficient manner in which these methods are conducted, make the concept of biological assessments in wetland ecosystems a logical and practical objective for wetland management and protection. 61 Macroinvertebrates have been useful as biological indicators in aquatic ecosystems due to their fundamental role in energy transport between primary producers and higher trophic levels in food webs. Shifts in macroinvertebrate structure could have cascading effects on other levels of the food web, and in return, shifts at other levels could have a direct influence on macroinvertebrate communities (Wrssinger 1999, Helgen and Gernes 2001). Because of this significant connection, macroinvertebrates have been useful as management tools in the evaluation and monitoring of aquatic habitats. Additional reasons for using macroinvertebrates are (1) their ubiquitous nature, (2) range of response to environmental stressors by different species, (3) relative stationary nature, (4) their relatively long life cycles and (5) the ease in which macroinvertebrates are collected (Rosenberg and Resh 1993). For these reasons macroinvertebrates are the most frequently used organisms in aquatic assessments (Hellawell 1986). All of these advantages apply to most aquatic habitats; however, some do not yet apply to wetland ecosystems. For example, Batzer et al. (2001) maintains that many wetland macroinvertebrates are mobile, some life cycles can be quite short (1-2 months), and that much information is still unknown for certain taxa (e.g., response to stressors and taxonomy), thereby, limiting the use of macroinvertebrates in wetland assessments. Several studies, however, have successfully used macroinvertebrates as biological indicators of wetland quality. Burton et al. (1999) developed a preliminary index of biotic integrity for coastal Great Lake wetlands based on macroinvertebrate metrics. This study was later supported by work in Lake 62 Huron costal wetlands by Kashian and Burton (2000) and later validated by Uzarski et al. (2004) in coastal wetlands of Lake Huron and Lake Michigan wetlands. Helgen and Gernes (2001, 2002) developed an index of biological integrity for macroinvertebrates in large depression wetlands in Minnesota, and in Montana, Apfelbeck (2001) found macroinvertebrates to be useful in evaluating the biological integrity of perennial wetlands. In Australia, Chessman et al. (2002) successfully derived and tested a new biotic index for the Swan Costal Plain using macroinvertebrate taxa diversity. Merritt et al. (1996, 1999, 2002b) found that macroinvertebrate functional-group metrics, instead of taxonomic based metrics, could be used in the assessment of wetlands, specifically in river oxbows and floodplain ecosystems in Florida. Other studies, however, have found macroinvertebrates to be non-responsive to human disturbances, making their ubiquitous use as biological indicators questionable in wetlands (Wilcox et al. 2002, Tangen et al. 2003). Multiple methods or metrics that assess macroinvertebrate communities have been developed and utilized in aquatic ecosystems; however, few comparisons of these methods have been made (Ravera 2001), especially in wetland ecosystems. Although many of these assessments have been successful in certain types of wetlands (e.g., coastal, depressional) and in specific regions (e.g., Great Lakes, Minnesota), the general use of these metrics in all wetlands is relatively unclear. As a result, the main objective of this study was to compare the utility of these pre-existing macroinvertebrate metrics in wetlands, specifically inland marshes in the Muskegon River Watershed (MRW) 63 Michigan. We also tested the utility of these metrics at multiple spatial scales. In general, the following questions can be answered from this study: (1) do existing macroinvertebrate metrics work in MRW wetlands; (2) how do these metrics compare; (3) do taxonomic or functional metrics work best in MRW wetlands; and (4) do the utility of these metrics vary with different spatial scale? We hypothesized that these pre-existing macroinvertebrate metrics work equally well in MRW wetland assessments at all scales. The results from this study will provide more information on macroinvertebrate communities in wetland ecosystems, how they respond to changes in the environment, and in the development of successful wetland assessment protocols in the MRW. Methods Mocation ancL Scale The Muskegon River Watershed (MRW) begins in the north-central portion of Michigan's lower peninsula, and runs in a southwest direction to the shoreline of Lake Michigan. The watershed is approximately 7000 km2 in size and includes 94 tributaries, 183 stream segments, hundreds of lakes and wetlands within 11 different counties (Torbick et al. 2006). Dominant land use varies from forest dominated to agriculture/urban dominated areas within the upper and lower regions of the watershed, respectively (Lougheed et al. 2007). The continuum of the MRW has been altered by 95 dams, and has been impacted by human influence through logging and agricultural byproducts and is predicted to have a 50% increase in urban land use within the next 35 years (Pijanowski et al. 2006). For all of our studies, inland marsh wetlands (n = 57) were selected from in and near the MRW; most sites (~42) were randomly selected, whereas remaining sites were purposely selected as described by Lougheed et al. (2007) to ensure a gradient of sites with variable water quality in the study. Of these sites, a subset (n=30) were selected for this study based on wetland class and impact (see below). All sites were surveyed prior to the field season to confirm wetland existence, accessibility, and to obtain landowner permission if necessary. To achieve our objectives, two spatial scales were designated for this study: the class scale and habitat scale. Three wetland classes were sampled: palustrine marshes (depression, n=12), riverine marshes (n=10), and lacustrine marshes (n=8). Each class was then further divided into the next scale based on habitat, which separated each marsh into distinct vegetation zones (habitats). When present, two zones were sampled in each marsh, the emergent and submergent/floating (now labeled as only submergent) vegetation zone. The floating and submergent zones were combined due to little difference in macroinvertebrate composition (T. Burton, personal communication), and the . inability to clearly distinguish and separate these zones in many wetlands. In order to test the utility of macroinvertebrate metrics, wetlands within each class were divided into a reference and impacted group. These groups were separated based on water chemistry measurements representing mainly agricultural and urban disturbance. Turbidity and eutrophication were ranked as 65 two of the top three mechanisms of impact for wetlands in the Great Lakes ecoregion (Detenbeck et al. 1999), and thus sites in this study were separated to represent this. Statistical tests comparing reference and impacted sites (t-tests for normal data and Wilcoxon tests for nonparametric data) confirmed differences in water chemistry. Lacustrine sites were significantly different in total phosphorus (ref = 11.9 ug/L, imp = 56 ug/L, t-test: t = 3.15, DF = 6, p < 0.01), turbidity (ref = 1.43 ntu, imp = 4.62 ntu, t-test: t = 2.75, DF = 6, p < 0.05) and soluble reactive phosphorous (ref = 3.23 ug/L, imp = 16.6 ug/L, Wilcoxon test: 2 = -2.16, S = 10, z < 0.05). Palustrine sites were significantly different (p < 0.05) in total phosphorus (ref = 15.6 ug/L, imp = 94.3 ng/L, t-test: t = 10.39, DF = 10, p < 0.0001), chloride (ref = 30 mg/L, imp = 76.8 mg/L, Wilcoxon test: 2 = -2.16, S = 25, p < 0.05), soluble reactive phosphorous (ref = 1.2 ug/L, imp = 15.7 pg/L, Wilcoxon test: 2 = -2.01, S = 26, z < 0.05) and % surrounding wetland land-use (ref = 12%, imp = 4%, t-test: t = -3.08, DF = 10, p < 0.01). Conductivity, turbidity, and % agriculture surrounding land-use were also significantly greater at a more relaxed level (p < 0.10), at impacted sites compared to reference palustrine sites. Riverine sites were significantly different in dissolved oxygen (ref = 7.73 mg/L, imp = 2.9, t-test: t = -2.79, DF = 8, p < 0.05), turbidity (ref = 1.43 ntu, imp = 4.62 ntu, t-test: t = 2.82, DF = 8, p < 0.05) and total phosphorus (ref = 8.9 ug/L, imp = 48.17 ug/L, t-test: t = 6.46, DF = 8, p < 0.0001). Sample Collection Inland marshes were sampled once between July and early August in 2002 and 2003. At each marsh site, three evenly spaced transects were established perpendicular to one side of the wetland, thus extending from the wet—meadow or shore into deep-water habitats. Along each transect, multiple random sampling points (marked by a quadrant) were established to facilitate sample collections from each habitat zone. All macroinvertebrates were collected from the first random point in each habitat zone. To ensure no disturbance in the macroinvertebrate community due to other sampling activities, macroinvertebrates were collected at a random angle, 1—2 m from the main sampling location (quadrant). One macroinvertebrate sample consisted of two sets of three sweeps using a standard D-net (500 um) and subsequently rinsed through a 500 um sieve to remove large pieces of vegetation. All three transect samples from the same habitat were combined into a single composite sample and preserved in 100 % alcohol for laboratory identification. Because each marsh was sampled only once, a maximum total of two composite samples were collected from each marsh site (Halse et al. 2002). A total of 30 emergent composite samples and 30 submergent composite samples were analyzed in this study. In the laboratory, macroinvertebrate composite samples were again sieved and sub-sampled to reduce processing time. In the sub—sampling protocol, each sample was homogenized and divided into two equal proportions or sub-samples. All macroinvertebrates from one sub-sample were sorted and 67 identified to the lowest practical taxonomic level using Merritt and Cummins (1996), Thorp and Covich (1991), Pennack (1989) and Larson et al. (2000). Most macroinvertebrate taxa were identified to the generic level, except for taxonomically difficult organisms such as the Chironomidae, Oligocheata, and Hirudinea. For other taxa, large numbers of immature specimens were collected and could only be accurately identified to the family level. All taxa from these groups (Planorbidae, Corixidae) were grouped at the family level for this study. Microinvertebrates, including Cladocera, Copepoda and Ostracoda, were not considered due to the sampling design in this study. Macroinvertebrate counts were subsequently adjusted to account for subsampling procedures prior to statistical analyses. Metric Calculation and Statistical Analysis Macroinvertebrate metrics that have been utilized in previous wetland assessments can be divided into five general categories: macroinvertebrate taxa richness, composition, tolerance, functional feeding, and diversity metrics (Table 3.1). All of these metrics (Table 3.1) have been found to respond predictably to changes in some type of wetland environment. Richness measures assess the number of taxonomically distinct individuals or groups of individuals within the community. Often taxonomic groups known to be sensitive to anthropogenic changes in aquatic environments are monitored through these measures (Burton et al. 1999, Kashian and Burton 2000, Helgen and Gernes 2001, Gernes and 68 Helgen 2002, Uzarski et al. 2004). It should be noted, however, that taxonomic resolution can affect the ability of these metrics to detect impairment, with more detailed taxonomy (e.g., species level) providing more accurate detection (King and Richardson 2002). Composition and tolerance metrics measure the relative proportion of macroinvertebrate taxa abundance within the community and often focus on tolerant and intolerant taxa to various stressors (Table 3.1) (Burton et al. 1999, Kashian and Burton 2000, Helgen and Gernes 2001, Gernes and Helgen 2002). Functional analyses rely on the separation of invertebrate taxa by functional relationships (e.g., similar feeding morphology). These functional taxa are then placed into ratios that provide surrogates of habitat assessment and overall ecological condition (Table 3.2) (Merritt et al. 1996, Merritt et al. 1999, Cummins and Merritt 2001, Merritt et al. 2002a). Another common category are diversity measures, which assess the number of species (or lowest taxonomic level) within a standard area (e.g., Simpson index and Shannon's index) (McCune and Grace 2002). All metrics listed in Table 3.1 were calculated in each class for each habitat (e.g., emergent lacustrine) of this study. Statistical analyses included non-parametric Wilcoxon tests that were conducted between impacted and reference sites (significance level of p < 0.05 or p < 0.01) at each class and habitat combination. Non-parametric tests were utilized due to smaller sample sizes, and the use of a majority of proportion data that was not normally distributed (Kashian and Burton 2000, Quinn and Keough 2002). All statistical analyses were conducted with JMP IN 5.1.2. 69 Results A total of 105,081 macroinvertebrates were collected from inland marsh wetlands of the Muskegon River Watershed (MRW). At the class scale, the majority of individuals were from palustrine sites (55%, n = 12), followed by 27% from riverine sites (n = 10) and 18% from lacustrine sites (n = 8). At the habitat scale, about 58,174 (55%) and 46,907 (45%) individuals were collected from the emergent and submergent zones, respectfully. Of these individuals, the class Insecta was the most abundant major taxonomic group, followed by the phylum Mollusca and class Crustacea. Of the 50 metrics that were tested in this study (Table 3.1), 27 tests had at least one significant difference (p < 0.10 or p < 0.05) in one class and habitat combination. For the taxa richness metrics, 8 of the 12 measures detected impairment in at least one class and habitat combination. For the total number of taxa, there were significantly greater taxa at both the generic and family level in the emergent habitats of impacted riverine wetlands (Table 3.3); however, no differences in total taxa numbers were observed in any other class or habitat. Taxa richness measures including sensitive taxa only, such as the Ephemeroptera, Odonata and Trichoptera, detected impairment in only riverine and lacustrine wetlands. The number of Ephemeroptera taxa and the number of Trichoptera taxa independently and combined were significantly greater in the submergent habitats of reference riverine wetlands (Table 3.3). In lacustrine wetlands, the“ number of Odonata taxa was significantly greater in both emergent 70 and submergent habitats at reference sites (Table 3.3). The number of Odonata and Trichoptera Taxa combined and the number of Ephemeroptera, Trichoptera, and Odonata (ETO) taxa combined were significantly greater in the submergent zone of only lacustrine wetlands (Table 3.3). It should also be noted that differences in these taxa richness measures were observed in only lacustrine and riverine wetlands; however, no differences were found in palustrine wetlands (Table 3.3). Of the 10 composition metrics, 7 measures detected impairment in at least one type of wetland class and habitat. The only metric to have significantly different results between impacted and reference wetlands in all three classes and habitat types was the metric measuring the relative proportion of Gastropoda (Table 3.3). The lacustrine wetlands had a higher proportion of Gastropoda in reference sites compared to impacted sites; however, the opposite was observed in the palustrine and riverine wetlands, with the impacted sites having a higher proportion of Gastropoda compared to reference (Figure 3.1). This same trend was observed in both emergent and submergent habitats (Table 3.3). The % Diptera and % Chironomidae also were significantly greater in reference sites compared to impacted in both habitats of palustrine and emergent only habitats in riverine wetlands (Table 3.3). The % Trichoptera were greater in both habitats of reference palustrine wetlands, whereas as % Mollusca + Crustacean were significantly lower in emergent zones of reference palustrine wetlands (Table 3.3). 71 Of the 13 tolerance metrics, 9 were significantly different in at least one type of wetland class and habitat. The lsopoda, generally tolerant taxa, were found in greater abundance in impacted wetlands compared to reference riverine wetlands, but only in the emergent habitats. Also, for the taxa Physa, the relative proportion was significantly greater in impacted sites of only submergent zones in palustrine and emergent and submergent zones in riverine wetlands (Table 3.3). Physa is also considered a tolerant taxa (Cooper et al. 2006). The dominant metrics (% dominant taxa, % two most dominant taxa, % 3 most dominant taxa) were greater in reference wetlands suggesting that dominant taxa were in greater abundance at these sites; however, each significant metric occurred in only one class and habitat combination and each combination among wetland class was different, indicating no clear pattern across the class or habitat scale (Table 3.3). Of the 13 functional feeding metrics, 9 detected impairment in at least one wetland class and habitat. A greater proportion of piercers, scrapers and total shredders were observed in impacted wetlands compared to reference wetlands (Table 3.3). For scrapers this difference was observed in both habitats of palustrine wetlands and for piercers and shredders this difference was observed in only emergent habitats of riverine wetlands. The photosynthesis to respiration (P/R) ratio was significantly greater in both habitats of palustrine impacted wetlands compared to reference wetlands, indicating that impacted sites are more autotrophic systems and reference sites are more heterotrophic systems (Table 3.2 and 3.3; Figure 3.2A). Differences in the amount of particulate organic matter, including the coarse particulate organic matter to fine particulate organic 72 matter (CPOM/FPOM) ratio and the suspended particulate organic matter to benthic particulate organic matter (SPOM/BPOM) ratio, were significant in emergent habitats only. The CPOM/FPOM ratio was significantly greater in impacted palustrine and riverine sites, indicating more shredder species at these sites; however, all ratio values were still below the criteria (> 0.25) for normal shredder riparian systems (Table 3.2 and 3.3; Figure 3.28). The SPOM/BPOM ratio was also significantly greater in emergent habitats of impacted palustrine wetlands, indicating more suspended material in these sites; however, again, all of these values were below the enrichment criteria (> 0.50) (Table 3.2 and 3.3, Figure 3.2C). The first habitat stability metric, based on functional feeding groups, indicated that significantly more stable habitat was available in impacted sites compared to reference sites in both habitats of palustrine wetlands (Table 3.2 and 3.3; Figure 3.20). The second habitat stability metric, based on macroinvertebrate habits, indicated the same results of more stable substrates in impacted palustrine wetlands in addition to emergent riverine habitats; however, it should be noted that a significant opposite results was found in lacustrine wetlands, with reference wetlands having more stable substrates (Table 3.2 and 3.3; Figure 3.2E). The benthic food ratio was significantly greater in reference wetlands compared to impacted wetlands in emergent palustrine wetlands only, indicating these wetlands have better food availability for wading birds and benthic fish, however, all values were still below the established criteria (> 0.60) for good food supply (Table 3.2 and 3.3; Figure 3.2F). 73 Discussion Numerous studies have begun to investigate the use of macroinvertebrates as biological indicators of wetland ecosystem health; yet many questions remain regarding the use of this approach in all wetlands. The main objective of this study was to compare the utility of these pre-existing macroinvertebrate metrics in detecting impacted verses reference wetlands, specifically within inland marshes in the Muskegon River Watershed (MRW) Michigan. In this study, impacted wetlands were influenced by agricultural disturbance with increased total phosphorus and turbidity. We also tested these metrics at two spatial scales, the class scale (lacustrine, palustrine and riverine wetlands) and the habitat scale (emergent and submergent habitats). Although this study has focused on only macroinvertebrate communities, other studies have also begun to investigate the use of other biota as potential indicators of wetland quality, including plants (Helgen and Gernes 2001, Wlssinger et al. 2001, Gernes and Helgen 2002, Lopez and Fennessy 2002, Lougheed et al. 2007), birds (Brown and Batzer 2001, Rivers and Cable 2003, Hierl et al. 2007), fish and amphibians (Simon et al. 2000), zooplankton (Lougheed and Chow- Fraser 2002, Lougheed et al. 2007), algae (Yangdong and Stevenson 1996, Stevenson 2001, Lougheed et al. 2007), and bacteria (Lemly and King 2000, McArthur 2001, Merkley et al. 2004). In general, differences in the macroinvertebrate community were observed between wetlands with dissimilar water quality. Of the 50 metrics that were tested in this study (Table 3.1), 27 metrics had at least one significant difference 74 in one class and habitat combination, yet, those combinations significant varied from metric to metric (Table 3.3). Few metrics were sensitive in all wetland classes or habitats, suggesting that that these pre-existing macroinvertebrate metrics did not work equally well in MRW wetland assessments at different scales and many of these metrics used in other studies (e.g., diversity indices, abundance values) were not sensitive at all in our study (Burton et al. 1999, Kashian and Burton 2000, Apfelbeck 2001, Uzarski et al. 2004). However, prior to a more thorough discussion of these metrics it should be noted that these results could be a true representation of the differences and natural variability in macroinvertebrate community response or other factors in the study design that might have had a significant role. For example, we cannot prove that observed differences were caused by chemical and agricultural differences alone, many other stressors not included in this study could also directly or indirectly have influenced these communities. Also, some MRW wetlands (or classes and habitats) classified as impacted in this study may not have stressor levels necessary to affect wetland macroinvertebrate communities. In wetlands, natural harsh conditions have made many wetland taxa tolerant to some degree of variability in the surrounding environment (King and Richardson 2002). Wetlands in more developed or disturbed areas outside the MRW may be at or above stressor threshold levels and subsequently have changed macroinvertebrate communities. If true, this would suggest that some macroinvertebrates metrics are not good biological indicators of early wetland degradation or stress. This also would suggest that significant metrics in this study may be the most 75 sensitive macroinvertebrate metrics in the MRW and as more development occurs in this watershed, these metrics may become more useful. Other factors in our sampling design, such as single sampling dates, number of sites, time of sampling, number of samples collected, etc. could also have influenced these results. More research, especially on significant metrics from this study will be needed prior to the use of any metrics in biological assessments in the MRW. In general, most wetland assessments have found total macroinvertebrate taxa richness to decrease in impacted wetlands (Burton et al. 1999, Kashian and Burton 2000, Helgen and Gernes 2001, Uzarski et al. 2004). In our study, no differences in the number of taxa were observed between impacted and reference sites except for an increase in taxa richness (at both the generic and family level) in emergent habitats of riverine wetlands. No differences observed in some wetlands may be an indication that impacted wetlands in the MRW are not at levels that affect macroinvertebrate communities, as previously discussed. However, it should be noted that although the number of taxa may not differ, the taxa present might; sensitive taxa in reference wetlands could be replaced with new tolerant taxa in impacted wetlands. Differences (and lack of differences) in taxa number in our study and other wetland studies could be due to the level of taxonomic resolution used. For example, a study by King and Richardson (2002) found that family-level identification of wetland macroinvertebrate communities were not capable of detecting impairment and suggested that genus or species- level identification be utilized, especially within the dominant Chironomidae family. Most wetland assessment studies have identified Chironomidae to 76 various levels including the family (Uzarski et al. 2004), sub-family or tribe (Kashian and Burton 2000, Uzarski et al. 2004), generic levels (Apfelbeck 2001, Helgen and Gernes 2001, Gernes and Helgen 2002) or species level (King and Richardson 2002). Further identification of the Chironomidae in this study may provide for better detection between reference and impacted sites with taxa richness metrics. However this type of identification, especially with the Chironomidae or other taxa (e.g., Annelida) can be difficult, require expertise, consume large quantities of time and be more expensive (King and Richardson 2002). Also, for some taxa identification keys in certain regions may not be available; making the utility of these metrics in rapid assessments questionable. A few studies also have found taxa richness to increase in response to disturbance. Rader and Richardson (1994) found increased taxa richness in nutrient enriched wetlands in the Everglades and King et al. (2000) found increased taxa richness in forested wetlands closer to highway disturbance. In these studies, disturbance provided more variety of habitat (e.g., more plants, structure); in the MRW riverine wetlands, the increased nutrient levels may directly and indirectly cause macroinvertebrate taxa to increase due to more habitat and food resource availability as suggested by the intermediate disturbance concept (Townsend et al. 1997). Certain taxa richness metrics detected significant differences in the macroinvertebrate community between impacted and reference sites in lacustrine and riverine wetlands, but not palustrine wetlands. Lacustrine and riverine wetlands are‘located adjacent to other aquatic habitats (lakes and rivers) and as 77 a result have the potential for waterflow through wave action or river movement that can provide habitat and food resources for more types of taxa. The edge habitats of these wetlands (e.g., the submergent zone) may support certain sensitive taxa commonly used in the assessment of these other aquatic habitats. These taxa may be more sensitive due to the dependence on waterfiow for movement of organic material, higher oxygen levels and potential removal of pollutants. This might explain the reduction in taxa number and sensitive taxa, including the number of Ephemeroptera, Trichoptera, and Odonata in mainly the submergent zone of lacustrine and riverine habitats. Similar results in Great Lake coastal wetlands found taxa richness of Ephemeroptera, Trichoptera and Odonata to be lower in impacted wetlands (Burton et al. 1999, Kashian and Burton 2000, Uzarski et al. 2004). Helgen and Gernes (2001, 2002) also found the number of total taxa, number of Odonata taxa, and number of ETSD (Ephemeroptera, Trichoptera, Sphaeriidae and dragonflies) to be reduced in impacted palustrine wetlands. The absence of this result in palustrine wetlands of this study could be due to the use of activity traps by Helgen and Gernes in collecting movable predators and perhaps differences in taxonomic resolution. Of all metrics tested in this study only one, the relative proportion of Gastropoda, could detect impairment in all wetland classes and habitats; however the response of this metric was different among wetland class. The relative composition of Gastropoda decreased in impacted lacustrine wetlands, whereas the relative composition increased in impacted palustrine and riverine wetlands. At'impacted sites, increased nutrients may result in increased algal 78 growth, which is the main food source for Gastropoda (Kashian and Burton 2000); this subsequently may have increased the relative composition of these taxa in palustrine and riverine wetlands of this study. The reduction of Gastropoda observed in impacted lacustrine wetlands could be due to a reduction in algal food resources, the presence of intolerant Gastropoda and the influence of additional stressors in lacustrine wetlands not measured in this study. However, other studies in coastal Great Lake wetlands, found opposite results, with impacted wetlands having greater relative composition of Gastropoda (Burton et al. 1999, Kashian and Burton 2000, Uzarski et al. 2004). Although this metric was responsive in all wetlands, the variation in response (positive and negative) based on wetland class suggests that more research is necessary. Of all the composition measures, the most significant metrics were observed in both habitats of palustrine wetlands, followed by emergent habitats of riverine wetlands. The relative proportion of Diptera, Chironomidae, and Trichoptera were greater in reference wetlands. Chironomidae, commonly the most dominant taxa in wetlands and the most common Dipteran taxa in our wetland samples, are generally thought of as tolerant taxa in aquatic ecosystems, however, other studies have found different sub-families (Kashian and Burton 2000), genera and species (King and Richardson 2002) within this family to have variable tolerances to environmental stressors. Perhaps the reduction observed in this study represents the loss of those sensitive Chironomidae taxa. Helgen and Gernes utilized a metric assessing the number 79 of Chironomidae taxa (generic level) in palustrine wetlands for this reason; however, this metric was not utilized in this study due to high taxonomic resolution required for this family. Kashian and Burton (2000), however, found the opposite result in Great Lake coastal wetlands, with approximately 20—40% increase in Chironomidae relative composition. King et al. (2000) found no differences in Chironomidae composition in reference compared to impacted forested wetlands. Most Trichoptera are considered sensitive in all aquatic habitats, similar reductions in the relative composition of this order have been observed in other wetland studies (Kashian and Burton 2000), however it has not been included in any assessment protocols. This could be due to the lower number of Trichoptera generally found in wetland ecosystems (Helgen and Gernes 2001). In inland lacustrine marshes we found no significant differences in these groups between impacted and reference wetlands. Of the tolerance/intolerance taxa, the most sensitive metrics were observed in palustrine and riverine wetlands. ln riverine wetlands, the relative composition of lsopoda was greater in impacted wetlands. Uzarski et al. (2004) and Burton et al. (1999) found opposite results with increased lsopoda composition in reference coastal wetlands. However, Kashian and Burton (Kashian and Burton 2000) found greater abundance of lsopoda in impacted coastal wetlands, yet, significant differences were small clue to high variability in collected samples. Increased abundance in our study may be due to increased nutrients and thus food resources in impacted wetlands. Differences between our study and coastal wetlands could be due to taxonomic differences or other 80 stressors not included in this study. In both palustrine and riverine wetlands, the relative composition of Physa was greater in impacted wetlands. Cooper et al. (2006) found similar results in a drowned-river mouth wetland. The positive response of these taxa in impactedwetlands could also explain trends observed in the relative composition of Gastropoda. The functional wetland metrics developed by Merritt and Cummins (Merritt et al. 1996, Merritt et al. 1999, Cummins and Merritt 2001, Merritt et al. 2002b) were made to assess the ability of wetlands to support bird and fish populations in Florida. Criteria established by these authors in their assessment protocols were developed specifically for that region and may not apply to all wetlands or stressors in MRW wetlands. Although these metrics may not be sensitive to all potential stressors, they can still provide an indication of changes in the ecological condition between reference and impacted wetlands. In our study, most impacted sites had higher functional group ratio values with overall greater variability, whereas reference sites had lower functional group ratio values with little variation among sites (Figure 3.2). This was true except for the benthic food ratio, in which greater food availability was present in reference wetlands. The low significance value, and large amount of variability between reference and impacted sites indicated that this metric might not clearly detect wetland impairment. In addition, the criteria level for this ratio set by Merritt et al. (1996, 1999, 2002), developed and tested specifically for riverine wetlands in Florida, was not relevant in this study. Similar results were observed with the CPOM/F POM and SPOM/BPOM ratio criteria. This indicated that these metrics 81 and the corresponding criteria may not be useful in detecting impairment in palustrine wetlands or all wetlands in the MRW. Further modification and testing of these metrics would be needed for their use in wetland assessment. In general, greater variability in impacted sites could be due to differences in the amount and number of stressors present at a site. The greater P/R ratios and % scraper values in impacted wetlands suggest that increased nutrient levels have stimulated more algal growth thus resulting in a more autotrophic system that can support more organisms dependent on periphyton as a food resource (Kashian and Burton 2000, Cummins and Merritt 2001, Merritt et al. 2002b). Greater values of habitat stability observed in impacted wetlands might again be the indirect result of increased nutrients stimulating plant and algal growth, which can provide more habitats for macroinvertebrates. Greater habitat stability was observed in impacted palustrine wetlands and impacted emergent riverine wetlands; however, in the submergent zone of lacustrine wetlands the opposite result was observed with greater stability in reference wetlands. This opposite result was probably due to the lower number of Gastropoda in impacted lacustrine wetlands, as discussed above. Kashian and Burton (2000) also found greater autotrophy, stable habitat and proportion of scrapers in impacted coastal wetlands. Merritt et al. (1996, 2002) found similar types of ecological conditions in areas with more light penetration; impacted wetlands in this study may have less canopy cover also providing for increased habitat through plant and algal growth. Increased values of CPOM and SPOM 82 could also be a result of increased nutrient and plant growth in impacted palustrine wetlands. Conclusions The results from this study suggest that macroinvertebrates may be useful in the biological assessment of MRW inland wetlands; however, the lack in consistency of most metrics among wetland class and habitats suggest that the same metrics may not be useful for all wetlands. In general, this lack in consistency is due to the high amount of variability observed in the macroinvertebrate community. This variability is even evident among the significant metrics with the overlap of inter-quartile ranges and medians of impacted and reference groups (Figure 3.1, Figure 3.2). The use of these metrics in all wetlands could be misleading and lead to inappropriate management decisions. The use of significant metrics from this study in future MRW tests may be possible but will require more research. Although no clear group of metrics were identified in this study, some general patterns in macroinvertebrate response among wetland class were observed from palustrine to riverine to lacustrine wetlands. Specifically, palustrine and lacustrine metrics were most dissimilar with wetland macroinvertebrates most sensitive to composition and functional measures in palustrine wetlands and taxa richness measures most sensitive in lacustrine wetlands. Riverine wetlands had an overlap of measures, with emergent riverine macroinvertebrate response more 83 similar to palustrine wetlands and submergent riverine community response more similar to lacustrine wetlands. These differences could be due to differences in vegetation; visual observation of these field sites would classify both habitats of palustrine and emergent riverine wetlands as having more dense vegetation, compared to both habitats of lacustrine and submergent riverine wetlands. These results suggest that wetland assessment based on wetland class (lacustrine, palustrine, and riverine) and habitat (emergent, submergent) may not be the best method of grouping, perhaps general assessment categories based on amount of vegetation or perhaps by more detailed types of vegetation may be acceptable for assessment purposes in these inland wetlands (Burton et al. 1999). More research on the macroinvertebrate community and relationships to the biological community (e.g., vegetation, algal communities) are needed to validate these measures. 84 Table 3.1: Various macroinvertebrate metrics used in the assessment of wetlands. The citation column lists studies that have utilized the metric. Each number represents the following citation: (1) Burton et al. 1999, (2) Helgen 2001, (3) Helgen and Gernes 2002), (4) Merritt et al. 2002 and 2006, (5) Apfelbeck 2001, (6) Uzarski et al. 2006 and (7) Kashian and Burton 2000. Metric I on Richness Total taxa (g) 1,2,3,5,6,7 Total taxa (f) 1,6,7 Ephemeroptera (E) taxa (g) 2, 7 Odonata (O) taxa (g) 1,2,3,6 Trichoptera (T) taxa (9) 2,7 Diptera taxa (g) 7 Odonata + Trichoptera taxa 2 Ephemeroptera + Trichoptera Taxa 1,6,7 EOT Taxa 2 POET 2,5 ETSD (E+T+Sphaeriidae+Dragonflies) 2,3 Number of Individuals 5,7 Composition Odonata (%) 1,6,7 Trichoptera (%) 2,7 Chironomidae (%) 2,5,7 Diptera (%) 2,7 POET/(POET + Chironomidae) 2 Gastropoda (%) 1,6,7 Sphaeriidae (%) 1,6,7 Amphipoda (%) 1,6,7 Mollusca + Crustacea (%) 1,5,6,7 Corixidae (%) 3 Tolerance! Intolerance Odonata (%) 1,2 Trichoptera (%) 2 Ephemeroptera (%) 2 EOT (%) 2 Oligocheata (%) 2 Gastropoda (%) 1,2,6 Amphipoda (%) 1,2 lsopoda (%) 6 ETSD 2,3 Dominant Taxa(%), Dom. 2 Taxa(%), Dom. 3 Taxa(%) 2.3 Physa snail abundance (%) 2 85 Table 3.1 (cont'd). 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Significant differences (p < 0.05. denoted by “ or p < 0.1. denoted by ') were calculated by non-parametric Vchoxon tests. 91 Chapter 4: Influence of Wetland Size and Water Quality on Isolated Macroinvertebrate Communities 92 Chapter 4: Influence of Wetland Size and Water Quality on Isolated Macroinvertebrate Communities Abstract Wetlands are biologically diverse ecosystems that provide many benefits of both economic and ecological significance; however, changes in the federal wetland regulatory program have made isolated wetlands more vulnerable to human disturbance. New regulations may be based on wetland size leaving small isolated wetlands more at risk. In order to protect these wetlands more information regarding the structure and function of biological communities within isolated wetlands of all sizes and the response of these communities to human activities is needed. The objective of this study was to compare macroinvertebrate communities among isolated wetlands of variable quality (impacted or non-impacted) and size (large or small). Four palustrine marshes were sampled from each possible combination of treatments (large impacted, large non-impacted, small impacted, and small non-impacted) from the Muskegon River Watershed, Michigan, USA, during July 2002. In addition, multiple habitats (emergent, submergent/floating) were sampled in each wetland, if present. In this study, we found little differences in the macroinvertebrate community between small and large wetlands and between impacted and reference wetlands. However, we did find different taxa exist in small and large 93 wetlands, and we did find more unique taxa in small wetlands. These results may be due to an interaction between wetland size and quality. This information could provide wetland managers evidence for the protection of all wetlands, both large and small. Introduction In 2001, the United States Supreme Court ruled that isolated, non- navlgable waters of the United States were no longer protected through the Clean Water Act based on the Migratory Bird Rule alone (Nadeau and Leibowitz 2003). The change in CWA jurisdiction and subsequent reduction in regulation may result in once protected isolated waters and non-protected isolated waters becoming more vulnerable to human disturbance (Christie and Hausmann 2003). Falling under this category of isolated waters are isolated wetlands, generally defined as wetlands surrounded by upland areas (Tiner 2003b). The extent of isolated wetlands through out the United States is unknown; however estimates in the Great Lakes Region, where this study was conducted, suggest that ~40- 80% of wetlands may be considered isolated (T iner 2003a). These changes in the federal wetland regulatory program have made isolated wetlands more vulnerable to human disturbance and subsequently more research is needed to understand the impact of disturbance on wetlands and to protect and better manage these ecosystems. 94 Over the past 200 years, over half of the wetlands in the United States have been destroyed due to human activities, mainly through the development of agricultural, urban and industrial areas (van Dam et al. 1998, Mitsch and Gosselink 2000). Loss of these wetland ecosystems may have resulted in subsequent loss of many economic and social benefits (e.g., flood prevention, groundwater recharge, water purification) and in loss of areas of ecological significance (e.g., species diversity, unique habitats) (Wrssinger 1999, Mitsch and Gosselink 2000). Methods to monitor and protect those remaining wetlands have been of great research interest, especially methods using macroinvertebrates as biological indicators of assessment (Burton et al. 1999, Merritt et al. 1999, Kashian and Burton 2000, Helgen 200‘l, Helgen and Gernes 2001, Chessman et al. 2002, Gernes and Helgen 2002, Merritt et al. 2002b, Tangen et al. 2003, Uzarski et al. 2004). Most of these studies have addressed macroinvertebrate communities in connected wetlands such as riverine and lacustrine wetlands; however, few studies (Helgen and Gernes 2001, Gernes and Helgen 2002) have addressed marcoinvertebrate community response to human disturbance in isolated wetlands. Often wetland regulation and protection are determined by wetland size, with preference given to large wetland ecosystems (Babbitt 2005). This is based on assumptions that smaller wetlands have shorter hydroperiods, identical species and less species compared to large wetlands and are independent from other wetlands (Snodgrass et al. 2000, Babbitt 2005). Whether these assumptions hold true is still unknown and could vary dependent on the type of 95 biota. Studies have found an increase in bird species richness (Brown and Dinsmore 1986), plant species richness (Lopez et al. 2002, Houlahan et al. 2006) and a slight increase in amphibian and predatory macroinvertebrate richness (Baber et al. 2004) with wetland size, yet other studies have found no relationship between amphibian species richness and wetland size (Snodgrass et al. 2000, Babbitt 2005). New regulations may be based on wetland size, leaving small isolated wetlands more at risk, making further studies investigating the relationship between wetland size and additional biological communities necessary in order to understand the potential significance of this new regulation. The objective of this study was to address patterns in the biological community of isolated wetlands, specifically, patterns in macroinvertebrate community structure within a single wetland class (palustrine or depression marshes) using an experimental approach. Macroinvertebrate attributes, including abundance, diversity, and functional-group analyses, were compared in wetlands and between habitats using two experimental factors: (1) stressor impact (wetlands classified as impacted or reference); and (2) wetland size (wetlands classified as large or small). I hypothesized that ( 1) in both large and small palustrine wetlands, reference wetlands will differ in macroinvertebrate community structure compared to impacted wetlands and that (2) macroinvertebrate community structure will differ between palustrine wetlands of different size. In general, I predicted that impacted wetlands, regardless of size, would have lower macroinvertebrate abundance, diversity, and a shift in invertebrate functional relationships compared to non-impacted wetlands. I also 96 predicted that large wetlands would have greater macroinvertebrate abundance and diversity and a shift in invertebrate functional relationships compared to small wetlands. The results of this study could provide valuable information for future wetland regulation, protection and management. Methods Mocation andecale The Muskegon River Watershed (MRW) begins in the north-central portion of Michigan's lower peninsula, and runs in a southwest direction to the shoreline of Lake Michigan. The watershed is approximately 7000 km2 in size and includes 94 tributaries, 183 stream segments, hundreds of lakes and wetlands within 11 different counties (Torbick et al. 2006). Dominant land use varies from forest dominated to agriculture/urban dominated areas within the upper and lower regions of the watershed, respectively (Lougheed et al. 2007). The continuum of the MRW has been altered by 95 dams, and has been impacted by human influence through logging and agricultural byproducts and is predicted to have a 50% increase in urban land use within the next 35 years (Pijanowski et al. 2006). Isolated wetlands, defined in this study as depression marshes surrounded by upland areas, were selected (n=16) from in and near the MRW (Lougheed et al. 2006) and surveyed prior to the field season to confirm wetland existence, accessibility, and to obtain landowner permission if necessary. Each wetland was selected and classified based on two experimental factors: (1) 97 stressor impact (wetlands classified as impacted or reference); and (2) wetland size (wetlands classified as large or small). Level of impact was determined by the amount of human activity through visual surveys surrounding each wetland and later confirmed with chemical and GIS analyses. In general, those wetlands with little human activity and forest-dominated surroundings were considered reference, and those with high human activity and agriculture-dominated surroundings were considered impacted. Wetlands < 0.5 hectares were considered small, and wetlands >1.2 hectares were considered large as defined by Lougheed et al. (2006). Therefore, a total of four wetland treatments (large impacted, large reference, small impacted and small reference) each with four sites, were sampled in this study. Sample Collection All marshes were sampled once between July and early August 2002. At each marsh site, three evenly spaced transects were established perpendicular to one side of the wetland, thus extending from the wet-meadow or shore into deep-water habitats. Along each transect, multiple random sampling points (marked by a quadrant) were established to facilitate sample collections from dominant vegetation habitats. For macroinvertebrate collections, two habitats (the emergent and submergent/floating, now labeled as only submergent in this paper, vegetation zones) were sampled in each marsh. The floating and submergent zones were combined due to little difference in macroinvertebrate composition, and the inability to clearly distinguish and separate these zones in 98 many wetlands (T. Burton, personal communication). In small wetlands, it was difficult to extend three parallel transects and not disrupt adjacent transects while sampling. As a result three transects were extended from the center of the wetland toward the bank. This allowed for three complete transects to be sampled properly with no disturbance. In wetlands where walking was prohibited or unsafe, boats were used to collect samples. All macroinvertebrates were collected from the first random quadrat in each habitat. To ensure no disturbance in the macroinvertebrate community due to other sampling activities, macroinvertebrates were collected at a random angle, 1-2 m from the main sampling quadrant where other variables (e.g., physical, plant, zooplankton, algae) were collected. One macroinvertebrate sample consisted of two sets of three sweeps using a standard D-net (500 pm) and subsequently rinsed through a 500 pm sieve to remove large pieces of vegetation. Since each marsh was sampled only once, a total of three samples were collected per habitat and a total of 6 samples per wetland. In the laboratory, macroinvertebrate samples were again sieved and sub- sampled to reduce processing time (King and Richardson 2002). In the sub- sampling protocol, each sample was homogenized and divided into two equal proportions or sub-samples. All macroinvertebrates from one sub-sample were sorted and identified to the lowest practical taxonomic level using Merritt and Cummins (1996), Thorp and Covich (1991), Pennack (1989) and Larson et al. (2000). Most macroinvertebrate taxa were identified to the generic level, except for taxonomically difficult organisms such as the Chironomidae, Oligocheata, and 99 Hirudinea. For other taxa, large numbers of immature specimens were collected and could only be accurately identified to the family level (e.g., Planorbidae, Corixidae, Notonectidae). Macroinvertebrate counts were subsequently adjusted to account for subsampling procedures prior to statistical analyses. Environmental variables collected for each wetland site included field (chemical and physical water variables, additional biological attributes) and laboratory (chemistry, GIS) measurements. For water chemistry, a single 250ml sample was collected from an open area of each marsh and analyzed in the laboratory for total phosphorous (TP), total nitrogen(TN), and reactive phosphorus (SRP), using methods described by Lougheed et al. (2007). Field measurements of dissolved oxygen (DO), pH, conductivity, and mean water depth were collected at every site with a YSI 556 multiprobe meter and measuring stick, respectively. Biological measurements on plant, algal, and zooplankton communities also were collected; however, these results are not reported in this study and can be found in Lougheed et al. (2006, 2007). Land- use, land-cover analyses were conducted with GIS maps as described by Lougheed et al. (2006) to obtain land-use and wetland size information. These data were collected to confirm the classification of wetland sites into correct treatment groups. Statistical Analysis 100 Common attributes used to characterize macroinvertebrate community structure were calculated in this study, including macroinvertebrate abundance (number of individuals per sample), and taxa richness (number of taxa per sample at the lowest practical taxonomic unit). Numerous diversity indices were calculated to characterize diversity within the macroinvertebrate community, including the Shannon Diversity Index, Simpson Index and Evenness Index as described by Burton et al. (1999). To better understand the ecological condition of these isolated wetlands, macroinvertebrate taxa were assigned into functional feeding and habit groups (Merritt and Cummins 1996, Cummins and Merritt 2001) and subsequently calculated into the selected functional group ratios (Table 4.1) that can serve as ecosystem surrogates for wetlands (Merritt et al. 1999, Cummins and Merritt 2001, Merritt et al. 2002b). These functional metrics were developed to assess the ability of wetlands to support bird and fish populations in Florida. Criteria established by these authors (Table 4.1) in their assessment protocols were developed specifically for that region and may not apply to our wetlands (inland marshes) or the stressors in our wetlands. Although these metrics may not be sensitive to some potential stressors, these metrics can still provide an indication of changes in the ecological condition between reference and impacted and small and large wetlands in this study. All attributes (abundance, diversity and functional) were calculated for each habitat type, including (1) total wetland, in which all samples from both habitats were included (6 samples per wetland); (2) emergent habitat, in which only emergent samples were included (3 samples 10] per wetland); and (3) submergent habitat, in which only submergent samples were included (3 samples per wetland). Comparisons for this study were calculated with a two-way ANOVA to test for effects and interactions in the macroinvertebrate data (abundance, diversity, functional-feeding analyses) (Quinn and Keough 2002). Non-normal data was transformed to meet test assumptions; if necessary, abundance data was log or fourth root transformed and proportion data was arcsin square-root transformed (Quinn and Keough 2002). Again, analyses were conducted three times, for each macroinvertebrate attribute: (1) total wetland (6 samples per wetland); (2) emergent habitat (3 samples per wetland); and (3) submergent habitat (3 samples per wetland). All analyses were conducted on JMP IN 5.1.2. Results Water Chemistry and Land-(1139 Land Cover Wetland sites had significant differences in chloride between impacted (59.46 +/- 17.6 mg/l) and reference sites (6.7 +/- 5.7 mg/l, t-test: n=16, t = 3.2, p < 0.01). Similar trends were observed in conductivity, with 310.79 +/- 59.1 9 pS/cm and 109.91 +/- 30.9 pS [cm in impacted and reference wetlands, respectively (t-test: n = 16, t = 2.33, p < 0.05). Impacted wetlands also had higher amounts of total phosphorus (TP) (64.69 +/— 17.6 pg/L) and total nitrogen (TN) (1.37 +/- .0-2 mg/L) compared to reference sites (TP: 31.52 +/- 6.2 pg IL, t = 1.47, p =0.16; TN: 1.12 +/- 0.11 mg/L, t = 1.11, p =0.28); however, these results 102 were not statistically significant. Impacted wetlands had ~40% greater developed (urban + agricultural) surrounding land use compared to reference wetlands (t = 5.59, p< 0.001). Whereas, reference wetlands had significantly greater forest (71%) and wetland areas (17%) compared to impacted wetlands (forest: 33%, t = -3.75, p < 0.001; wetland: 4%, = -2.91, p < 0.05). Wetland size was found to be significantly different (t—test: n = 16, t = 5.64, p < 0.0001), with small wetlands 0.3 +/- 0.06 hectares in size compared to at large wetlands 1.66 +/- hectares. Overall, wetlands were correctly assigned to treatment groups. Macroinverteliate Abundance In this study, ~89,000 macroinvertebrates were collected from isolated palustrine wetlands in the MRW. The community was dominated by Arthropoda (74%), followed by Mollusca (23%) and Annelida (2%). Of the Arthropoda, insects were most prevalent at 55%, followed by crustaceans (19%), including both micro- (e.g., Copepoda) and macro-organisms (e.g., Amphipoda). At the order level, the most dominant groups in all wetlands were the Diptera (27—35%), Gastropoda (11-20%), Copepoda (9-10%), Hemiptera, (7-10%) and Ephemeroptera (5-8%). For the total wetland analyses, mean macroinvertebrate abundance was greatest in impacted large wetlands and lowest in impacted small wetlands, however no significant effects of wetland quality (F = 1.02, p = 0.31), size (F = 0.01, p = 0.96) or interactions (F = 1.8, p = 0.19) were observed (Figure 4.1A). Similar results'were observed in the emergent zone, with ~30-40% greater 103 macroinvertebrate abundance in large impacted wetlands compared to all other treatments (Figure 4.1 B). In the submergent zone, we did observe a significant effect of wetland quality (F = 4.66, p < 0.05), along with a significant interaction between wetland quality and size (F #- 8.97, p < 0.01). This interaction effect is evident in Figure 4.1C, with high abundances in small compared to large reference wetlands and opposite results, of high abundances in large compared to small impacted wetlands. [Lacroin vertebrate fiversitv Total mean taxa richness was consistent across all treatments, ranging from 20-25 different taxa per sample with no significant difference in the main effects (quality: F = 0.16, p = 0.68; size: F = 0.02, p = 0.32) or an interaction (F = 1.01, p = 0.31) (Figure 4.2A). In the emergent zone even less variation was present between treatments, means ranging from 27-29 different taxa (Figure 4.28). In the submergent zone no significant difference was observed, however, the same interaction observed with the abundance data was also apparent in the taxa richness data (Figure 4.2C). It should be noted that the emergent habitats across all treatments had greater abundance and taxa richness than the submergent habitats (Figures 4.1 and 4.2). Various community diversity indices were calculated to test for differences among wetland treatments, with mean values reported in Table 4.2. We found no significant effects of wetland quality, size, or interactions in any of the three habitats for the Shannon-Diversity Index (range for all three habitats: F = 0.02 — 104 2.51, p = 0.95 - 0.12) or Simpson Index (range for all three habitats: F = 0.02 - 3.27, p = 0.87 — 0.08). The only statistically significant result was an interaction between wetland quality and size in the Evenness Index for the submergent habitat only (Table 4.2: F = 4.46, p s 0.05). Because taxa richness and diversity were mainly the same across wetland treatments, we examined each factor (quality and size) and each treatment (e.g., large impacted) for unique taxa. We considered unique taxa as organisms found in a minimum of two sites within a single wetland factor or treatment. The most unique taxa (6) were found in small wetlands compared to large wetlands (2 taxa); of these taxa in small wetlands, most were predators (5 taxa) belonging to the family Dytiscidae or Hydrophilidae. In impacted wetlands, 4 unique taxa were identified, one being lsospoda, a group often associated with increased disturbance (Burton et al. 1999, Kashian and Burton 2000). In reference wetlands, 3 unique taxa were identified, two of which are from insect orders (Odonata and Trichoptera) considered as less tolerant and indicators of good water quality (Burton et al. 1999, Kashian and Burton 2000, Helgen 2001, Helgen and Gernes 2001). Of the total taxa identified in this study, approximately 11% were found in either small or large and either impacted or reference wetlands. Of this percentage, study treatments had even fewer unique taxa, with only 2 unique macroinvertebrate taxa in small reference wetlands and one unique taxon in small impacted, large reference and large impacted wetlands. Macroinvertebrate Fynctional—Feeding Groups I 05 Functional group ratio means are listed in Table 4.3. The ratio of predators to available prey, or top—down control, was statistically greater in small wetlands compared to large wetlands in emergent habitats (F = 4.41, p < 0.05). This indicated that small isolated wetlands have a greater number of predators. Although no statistical differences were observed in the rest of the data, some general trends on the ecological condition among treatment wetlands were evident. Differences between impacted and reference wetlands were observed in the production/respiration (HR) and habitat stability (using macroinvertebrate habits) ratios. In general, the P/R ratio in all reference wetlands were lower compared to impacted wetlands, this indicated that reference wetlands may be more heterotrophic systems and impacted wetlands may be more autotrophic (Table 4.3). The exception was emergent habitats of impacted wetlands, which also indicated heterotrophy. A similar pattern was observed with the habitat stability ratio (based on macroinvertebrate habits), with less stable habitats in reference and emergent impacted wetlands and more stable habitats in impacted wetlands (Table 4.3). However, this ratio contradicted the additional habitat stability ratio (based on functional feeding groups) in which all wetlands had similar, higher values indicative of more stable substrates. Discussion Wetland ecosystems are threatened by various human activities and recent changes in wetland regulation have made these systems, specifically 106 isolated wetlands, more vulnerable. Without protection, many of these isolated wetlands, especially small sized systems, and the biological communities within may be overlooked, despite the numerous benefits these wetlands can provide. In order to protect these systems, more information regarding the structure and function of biological communities within isolated wetlands of all sizes and the response of these communities to human activities are needed. The objective of this study was to compare macroinvertebrate communities (including abundance, diversity, and functional relationships) among isolated wetlands of variable quality (impacted or reference) and size (large or small). We predicted that impacted wetlands, regardless of size, would have lower macroinvertebrate abundance, diversity, and a shift in functional relationships compared to reference wetlands. However, most of our results showed no statistical differences in abundance and diversity between impacted and reference wetlands. Other wetland studies have found similar results with a lack of macroinvertebrate response to environmental disturbances, such as increased land-use, nutrients and development (King et al. 2000, Steinman et al. 2003, Tangen et al. 2003). Environmental conditions in these impacted wetlands may not have reached the threshold limits for many naturally tolerant wetland macroinvertebrates, thus explaining the lack of significant change in abundance or diversity in our study (King and Richardson 2002). However, other wetland studies have found contrasting results. For example, both King and Brazner (1999) and Kashian and Burton (2000) found lower macroinvertebrate abundance and diversity at impacted wetlands; whereas, Rader and Richardson 107 (1994) found opposite results, with increased macroinvertebrate diversity in response to increased nutrients in the Florida Everglades. This latter study supports our significant findings of increased macroinvertebrate abundance in submergent habitats of large impacted wetlands compared to large reference wetlands. Increased nutrient input, combined with a suitable amount of available habitat (thus large impacted wetlands), may provide for increased plant and algal growth, which subsequently can provide increased food and habitat availability for more individuals (Wissinger 1999). Variation between all of these studies could be due to numerous factors such as wetland hydrology, wetland type, the amount and type of impact (e.g., type of nutrients), study design (e.g., taxonomic resolution) or a combination the above (King and Richardson 2002, VWcox et al. 2002). We also predicted that macroinvertebrate community structure would differ between large and small wetlands; however, in general we found no macroinvertebrate response due to wetland size. The only observed effect of size was on top-down control in emergent habitats, due to a greater number of predators in emergent habitats of small compared to large wetlands. Large reference wetlands in general, had the lowest mean abundance and diversity of treatments and thus might have fewer prey to support large predator populations. A second reason for lower macroinvertebrate predator abundance could be due to the presence of fish. We did not survey fish in these studies, however, the likelihood of fish presence was increased with wetland permanence as would be expected in large wetlands. Numerous studies have shown that fish can lower 108 the overall abundance, diversity, and biomass of macroinvertebrate populations and compete with large macroinvertebrate predators for prey; thus limiting the top-down control in these wetlands (Mallory et al. 1994, Wlssinger 1999, Zimmer et al. 2000, Tangen et al. 2003). In general, large numbers of predators can be typical in many wetland ecosystems and could be further supported by high prey turn-over (possibly induced by high nutrient levels of impacted sites) and the absence of fish (more common in small wetlands). The lack of fish common in small wetlands can often lead to increased diversity in macroinvertebrate predators (Vlfissinger 1999). This was evident in the 6 unique taxa, mainly predators, found only in small wetlands of this study. These small wetlands may provide important areas for insect diversity, not provided by large wetlands. More studies with more intensive taxonomic resolution (e.g., identification of Chironomidae to species) are required to identify these differences (King and Richardson 2002). Overall, a combination of biotic reasons (both prey levels and fish presence/absence) may explain the overall lower abundance and diversity in large reference wetlands and greater predator abundance and unique taxa in small wetlands. Additional functional analyses of macroinvertebrate communities can provide information regarding the ecological condition of these wetland ecosystems (Merritt et al. 1996, Merritt et al. 1999, Cummins and Merritt 2001, Merritt et al. 2002b); however, it should be noted that criteria established by these authors (Table 4.1) were based on a different region and type of wetland and may not apply to wetlands in this study. Additional studies would need to be 109 done to quantify and test these criteria in inland marshes in Michigan; however, the established criteria values of Merritt et al. (1996, 1999, 2002) in relation to our study results (Table 4.3) are included for discussion and comparison purposes. Increased levels of production to respiration or PIR ratios in our impacted wetlands indicated these systems were more autotrophic compared to reference wetlands. Increased urban and agricultural land-use around these sites in addition to increased nutrient run-off might explain these differences. However, the emergent zones in these impacted wetlands indicated more heterotrophic systems; which could be due to high amounts of decomposition and increased abundance of aquatic detritivores common in this type of habitat (Wrssinger 1999). Kashian and Burton (2000) found similar results with lower P/R ratios in reference compared to impacted costal wetlands in Lake Huron, Michigan, and a study in restored riverine marshes of the Kissimmee River- floodplain, Florida, found most vegetation habitats to be heterotrophic (Merritt et al. 1996). Observed differences in the two habitat stability metrics were probably due to the placement of the Bivalva, in either the denominator (habit metric) or numerator (functional feeding metric) of the ratio calculations. Merritt et al. (2002) suggested switching the Bivalva into a special case of burrower for river-oxbows in Florida; if changed in this study, both habitat metrics would have indicated similar amounts of stable substrate availability. An interaction effect between wetland quality and size (Figure 4.1 and 4.2) was observed numerous times in the abundance and diversity data. This interaction indicated that large impacted wetlands had greater abundance and 110 diversity compared to large reference wetlands, whereas, small wetlands had an opposite effect, in which reference wetlands had greater abundance and diversity compared to impacted wetlands. As already mentioned in this discussion, many abiotic and biotic factors may be playing a role in the treatments of this study. Abundance of macroinvertebrate communities in large wetlands responded positively with impact, probably due to available space for general biotic growth; whereas, small wetlands respond negatively with impact. This negative impact could be due to increased competition for habitat and food resources and decreased recovery levels after carrying capacities have been reached. Also, because smaller wetlands have a reduced area, less impact (e.g. accumulation of N or P) may be necessary to reach the tolerant threshold levels in which wetland macroinvertebrates respond. Macroinvertebrates in reference wetlands seem to respond positively in small sized wetlands and negatively in large wetlands; again, as mentioned above, this could be due to the absence and presence of fish predators, respectively. Without the pressure of fish predators, the macroinvertebrate community can diversify in small wetlands. Additional examination of these data, that include further taxonomic identification and similarity analyses may provide more information on observed patterns in this study. Conclusions 111 Often wetland regulation and protection are determined by wetland size, with preference given to large wetland ecosystems (Babbitt 2005). Assumptions made regarding small and large wetlands were not supported by this study, specifically, that macroinvertebrate communities have identical species in large and small wetlands and that less species are found in small compared to large wetlands (Snodgrass et al. 2000, Babbitt 2005). In this study, we found few differences in the macroinvertebrate community between small and large wetlands and between impacted and reference wetlands. However, we did find different taxa to exist in small and large wetlands, and we did find more unique taxa in small wetlands. These results may be due to an interaction between wetland size and quality. These results provide support that small wetlands are equally, if not more important, than large wetland ecosystems. This evidence, in addition to potential greater diversity in small wetlands, could help support equal protection, regulation and management of small and large isolated wetlands. More research is needed on wetland ecosystems in general. However, studies on small wetland diversity, biological interactions and connectivity to surrounding wetlands are needed. 112 2.0 A 00000308 90 0900000 00 v 000003000 000000000 00>O 00.00000 .0852 omd 00.0 ......... 0.000 000.00... 00000000 0.0000 00.0 . 00 0 0.000 00:00.... 00000000 0.030 00.0 A E0000 00.0 v .0000 0.0000050. 200000.000... 000000 00“. 0050 ..0 .002 0090000 0000.00.30 + 20.30000 + 0002,0000 .200E_.o + 00005.0 00200.60 00000.00 + 000000000 .000. . 00200.60 00000.... + 00000000 0.2028 .92 + .2000. 000000000 \ 00000.00 000000 + 0.00080 + 0000.0 02: 0000000 0:00:90 0001.000 00. 9 000000000 00 000050 0.... 0050005. 0.0000 .0000 00 00.0 00 005000.). .00000 >000; 0000.0 .0000. .000 0000.000 0.000 0.0.0.024. 00000 500.00 .05 0000 0.0: 000 0.00E000000E En. €300 00 .5 000005000 .000 .0 .0008 0200000 0260.00... 000.030 05.00.... 0000 000.000 00 00000 0:090 0.00800 0.00: 3.0080 05.00:. 009 00.000.— 000.602 00 00000 0:590 00.0000. 0000... ER. 809.009 0.020008 00 00.00000 0 00 00000090 0000000 00000 $0300. 8:00 03800 00.001 000.5 000.0000“. .0050: «00.09.0000: “00.00 0050005. 003080000 E000>000m .3000 .0 .0 0.005. 000 000. .0005. 000 00.5050 69.. 00000.2. .630. 0.5 0. 000.0: 0000. 00.0000 000 000000000 000000000 0000 .0000002 0000000008 000 00.0.0000 000.0008. ”0.0 0.00 ._. 113 Table 4.2: Mean (SE) Shannon Index, Simpson Index, and Evenness Index values for each wetland treatment (impacted large, impacted small, reference large and reference small) for total wetland (T), emergent (E) and submergent (S) habitats. The only significant result (p < 0.05, *) was an interaction of wetland quality and size observed in the Evenness Index of the submergent habitat. Diversity Impacted Impacted JReference Reference lndices Lflge Small Large Small Shannon Index T 2.11(.11) 2.04(.07) 2.00(.09) 2.16(.06) E 2.43(.07) 2.2(.07) 2.13(.12) 2.31(.05) S 1.78(.18) 1.84(.09) 1.87(.12) 2.00(.10) Simpson Index T 0.79(.04) 0.81(.02) 0.79(.03) 0.84(.01) E 0.87(.01) 0.81(.02) 0.79(.03) 0.84(.01) S 0.69(.06) 0.76(.02) 0.77(.03) 0.78(.03) Evenness T 0.67(.03) 0.68(.01) 0.69(.02) 0.68(.02) E 0.74(.03) 0.67(.02) 0.65(.03) 0.70(.02) S * 0.59(.05) 0.68(.02) 0.74(.02) .68(.03) 114 00.50 0.0000 .3020 60.5.0 0 00.0 A 08.0508 . . . . . . . . 50000 0 80000000 05 .00 .00 0 .00 .0. 0 .00 .00 0 .00 .0 0 .. 0 80000.0 30000.0 60000.0 80000.0 0 0260 000 .0902 80:00 @3000 .3000 6.0.00... 0 00000000 000008 00000000 0.0000 . . . . . . . . 00.. 000000.. .000 v 00056000 5.. .00 .00 0 .00 #0 0 E .00 0 .00 :0 0 m . 200000... 0000 02.5.. 02 8:90.00 00.000 £00000 0.5000 .0. 00.0 0 “HM“... .0003 .0300 .0103 8.00000 0 00.0 . . . . . . . . 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D Reference - Impacted n1 C. 2000- E g E. , (indivdualslsample) é .§ Mean Macroinvertebrate Abundance O Small —0— Reference +Impacted {l- Reference +Impacted 3 A g 2 ,1 g g g- 1500- 1500‘ ' 8 > a E 2% 1000‘ 1000‘ all u 3 :3 a .9 E 2 < .2 g g sool 500‘ V Small LaFgo v Sula" LaFge Figure 4.1: Mean (SE) macroinvertebrate abundance (individuals per sample) for (A) total wetland, (B) emergent and (C) submergent habitats in isolated palustrine wetlands. All four wetland treatments are represented: small reference, large reference, small impacted and large impacted. A significant effect (*) of wetland quality (p < 0.05) and an interaction effect (p < 0.01) were observed in only the submergent habitat (C). 116 Mean Taxa Rlchnless A. Total DReference -lmpacted 30. (D m m l E E .2 zo- -I- a: (B r: 5.. r: 10- (U Q) 2 l‘ v ' ' Small Large 35. LEI-Reference +lmpacted 3;. {Iv-Reference -o-Impacted 30- %- Id 30. 25- 25- 20- 20- 15- 15- " Small Large .. Small Large Figure 4.2: Mean (SE) taxa richness (taxa per sample) for (A) total wetland, (B) emergent and (C) submergent habitats in isolated palustrine wetlands. All four wetland treatments are represented: small reference, large reference, small impacted and large impacted. No significant effects of wetland quality, wetland size or an interaction effect were observed in this study. 117 APPENDIX A: LIST OF COLLECTED MACROINVERTEBRATE TAXA FROM MUSKEGON RIVER WATERSHED INLAND MARSHES 118 Table A1: List of macroinvertebrate taxon identified from inland marsh wetlands in the Muskegon River Watershed. Michigan. Class Order Family Genera Insecta Coleoptera Chrysomelidae immature Insecta Coleoptera Curculionidae immature Insecta Coleoptera Curculionidae Adult 1 Insecta Coleoptera Curculionidae Type 2 Insecta Coleoptera Dytiscidae Acilius Insecta Coleoptera Dytiscidae Agabus Insecta Coleoptera Dytiscidae Celina Insecta Coleoptera Dytiscidae Celina Insecta Coleoptera Dytiscidae Coptotomus Insecta Coleoptera Dytiscidae Desmopachria Insecta Coleoptera Dytiscidae Desmopachria Insecta Coleoptera Dytiscidae Dytiscus Insecta Coleoptera Dytiscidae Dytiscus Insecta Coleoptera Dytiscidae Hydraticus Insecta Coleoptera Dytiscidae Hydrovatus Insecta Coleoptera Dytiscidae Hygrotus Insecta Coleoptera Dytiscidae Hygrotus Insecta Coleoptera Dytiscidae Laccophilus Insecta Coleoptera Dytiscidae Liodessus Insecta Coleoptera Dytiscidae Matus Insecta Coleoptera Dytiscidae Neoporus Insecta Coleoptera Dytiscidae Rhantus Insecta Coleoptera Dytiscidae Uvarus Insecta Coleoptera Elmidae Dubiraphia Insecta Coleoptera Elmidae Macronychus Insecta Coleoptera Elmidae Stenelmis Insecta Coleoptera Gyrinidae Dineutus Insecta Coleoptera Haliplidae Haliplus Insecta Coleoptera Haliplidae Haliplus Insecta Coleoptera Haliplidae Peltodytes Insecta Coleoptera Haliplidae Peltodytes Insecta Coleoptera Helophoridae Helophorus Insecta Coleoptera Hydrophilidae Anacera Insecta Coleoptera Hydrophilidae Berosus Insecta Coleoptera Hydroptilidae Berosus Insecta Coleoptera Hydrophilidae Enochrus Insecta Coleoptera Hydrophilidae Enochrus Insecta Coleoptera Hydrochidae Hydrochus Insecta Coleoptera Hydrophilidae Hydrobius Insecta Coleoptera Hydrophilidae Paracymus Insecta Coleoptera Hydrophilidae Paracymus Insecta Coleoptera Hydrophilidae Tropisternus Insecta Coleoptera Hydrophilidae Tropisternus Insecta Coleoptera Noteridae Hydrocanthus Insecta Coleoptera Noteridae Hydrocanthus 119 Table A1 (cont'd) Class Order Family Genera Insecta Coleoptera Scirtidae Microcara Insecta Coleoptera Scirtidae Scirtes Insecta Coleoptera Staphylinidae Stenus Insecta Coleoptera Staphylinidae Stenus Insecta Coleoptera Curculionidae Tanysphyrus Insecta Collembola Entomobryidae Insecta Collembola Poduridae Insecta Collembola Sminthuridae Insecta Diptera Ceratopogonidae Pupae Insecta Diptera Ceratopogonidae Atrichopogon Insecta Diptera Ceratapogonidae Culicoides Insecta Diptera Ceratapogonidae Dashylea Insecta Diptera Ceratapogonidae lVlalIochohelea Insecta Diptera Ceratapogonidae Sphaeromias Insecta Diptera Chaoboridae Chaoborous Insecta Diptera Chironomidae Immature Insecta Diptera Chironomidae Pupae Insecta Diptera Culicidae Aedes Insecta Diptera Culicidae Anopheles Insecta Diptera Culicidae Mansonia Insecta Diptera Dixidae Dixella Insecta Diptera Ephydridae Parydra Insecta [Diptera Ephydridae Setacera Insecta Diptera Larvae Type 1 Insecta Diptera Sciomyzidae Sepedon Insecta Diptera Sciomyzidae Type 1 Insecta Diptera Sciomyzidae Type2 Insecta Diptera Sciomyzidae Type 3 Insecta Diptera Simuliidae Immature Insecta Diptera Stratiomyidae Odontomyia Insecta Diptera Stratiomyidae Stratiomys Insecta Diptera Tabanidae Chrysops Insecta Diptera Tabanidae Hybomitra Insecta Diptera Tabanidae Merycomyia Insecta Diptera Tipulidae Helius Insecta Diptera Tipulidae Ormosia Insecta Diptera Corethrellidae Corethrella Insecta Ephemeroptera Caenidae Caenis Insecta Ephemeroptera Ephemerellidae Eurylophella Insecta Hemiptera Naucoridae Pelocoris Insecta Hemiptera Belastomatidae Belastoma Insecta Hemiptera Gerridae Neogerris Insecta Hemiptera Hebridae Hebrus Insecta Hemiptera Hebridae Merragata Insecta Hemiptera Hydrometridae Hydrometra Insecta Hemiptera Mesoveliidae Mesovelia Insecta Hemiptera Nepidae Ranatra 120 Table A1 (cont'd) Class Order Family Genera Insecta Hemiptera Notonectidae Notonecta Insecta Hemiptera Pleidae Neoplea Insecta Hemiptera Veliidae Microvelia Insecta Lepidoptera Pyralidae Munroessa Insecta Lepidoptera Pyralidae Parapoynx Insecta Megaloptera Corydalidae Chauloides Insecta Megaloptera Sialidae Sialis Insecta Neuroptera Sisyridae Sisyra Insecta Odonata Aeshnidae Aeshna Insecta Odonata Aeshnidae Anax Insecta Odonata Calopterygidae Calopteryx Insecta Odonata Calopterygidae Hetaerina Insecta Odonata Coenagrionidae CoenagrionlEnallagma Insecta Odonata Coenagrionidae Enallagma Insecta Odonata Coenagrionidae Ischnura Insecta Odonata Corduliidae Cordulia Insecta Odonata Gomphidae Gomphus Insecta Odonata Lestidae Lestes Insecta Odonata Libellulidae Erythemis Insecta Odonata Libellulidae Leucorrhinia Insecta Odonata Libellulidae Libellula Insecta Odonata Libellulidae Pachydiplax Insecta Odonata Libellulidae Plathemis Insecta Odonata Libellulidae Sympetrum Insecta Trichoptera [Hydroptilidae Agraylea Insecta Trichoptera Hydroptilidae Orthotrichia Insecta Trichoptera Hydroptilidae Oxyethira Insecta Trichoptera Leptoceridae Pupae Insecta Trichoptera Leptoceridae Ceraclea Insecta Trichoptera Leptoceridae Leptocerus Insecta Trichoptera Leptoceridae Oecetis Insecta Trichoptera Leptoceridae Triaenodes Insecta Trichoptera Limnephilidae Grammotaulius Insecta Trichoptera Limnephilidae Mystacides Insecta Trichoptera Phryganeidae Fabria Annelida Hirudinea Crustacea Amphipoda Gammaridae Gammarus Crustacea Amphipoda Pontoporeiidae Monoporeia Crustacea lsopoda Asellidae Lirceus Mollusca Bivalva Sphaeridae Mollusca Gastropoda Hydrobiidae Amnicola Mollusca Gastropoda Lymnaeidae Lymnea Mollusca Gastropoda Lymnaeidae Stagnicola Mollusca Gastropoda Physidae Physa Mollusca Gastropoda Planorbidae Armiger Mollusca Gastropoda Planorbidae Gyraulus Mollusca Gastropoda Planorbidae Helisoma Mollusca Gastropoda Valvatidae Valvata . Mollusca Gastropoda Viviparidae Campeloma Mollusca Gastropoda Viviparidae Viviparus 121 APPENDIX B: RECORD OF DEPOSITION OF VOUCHER SPECIMENS 122 Appendix B Record of Deposition of Voucher Specimens* The specimens listed on the following sheet(s) have been deposited in the named museum(s) as samples of those species or other taxa, which were used in this research. Voucher recognition labels bearing the Voucher No. have been attached or included in fluid-preserved specimens. Voucher No.: 2007-03 Title of thesis or dissertation (or other research projects): THE USE OF MACROINVERTEBRATES AS INDICATORS OF WETLAND QUALITY IN THE MUSKEGON RIVER WATERSHED, MICHIGAN Museum(s) where deposited and abbreviations for table on following sheets: Entomology Museum, Michigan State University (MSU) Other Museums: lnvestigator’s Name(s) (typed) M IlieM Intosh Date 12/07I2007 *Reference: Yoshimoto, C. M. 1978. Voucher Specimens for Entomology in North America. Bull. Entomol. Soc. Amer. 24: 141-42. Deposit as follows: Original: Include as Appendix B in ribbon copy of thesis or dissertation. Copies: Include as Appendix B in copies of thesis or dissertation. Museum(s) files. Research project files. This form is available from and the Voucher No. is assigned by the Curator, Michigan State University Entomology Museum. 123 Appendix B Voucher Specimen Data of 9 Pages 3.0.02.5 0.9m. 00900:). 0:. E 000000 .0. 0008.800 00.0.. 0>000 0... 0020000. No 10.00,“ .oz 0.009 not-NF 0.00 0090.05. 0:85. .0003. 8.00.02 0..0.0m..00>0. 30000000 ._ 0.0000 .000...000 003. Page 1 322 F 00001000012. 0.00002 .2 078 .00 00.8022 80.00020 30.2 0 00001000012. 0.0802 .2 078 .00 03902: 00000.06 30.2 F 008103.35 0009.002 .2 0.8 .00 00.03.02: 000.0008 30.2 F 0000108012. 0.0800 .2 3-8 .00 08.0.0022 00000.08 392 F 00001-000012. 5.00.002 .2 078 .00 080.020 00000.06 30.2 F 00001000012. 005288.. .2 078 .00 030.020 8000...... 30.2 0 000010.001... 0.0800 .2 ..-8 .00 00000005000 80.00.30 30.2 F 00001000012. 3.8002 .2 078 .00 00000008000 80.8.0.0 392 N 00001000012. 0.0802 .2 00-8 .00 00.00.2000 000.0008 30.2 F 000015312. 8.0.0 .2 00-8 .00 00.000 00000.06 392 F 0081000012. 00.00.8000 .2 00-8 .00 00.000 00000.08 30.2 F 00001000012. 090588.. .2 00-8 .00 8000.0 80.00.20 30.2 F 008180012. 0.0.0.02. .2 00-8 .00 0:00... 00000.06 30.2 0 00001000012. 002.03% .2 8-8 .00 0 00? 000.02.00.00 30.2 F 00001000012. 0.0802 .2 00-8 .00 3.00... 000.02.00.00 30.2 0 00001000012. 30802 .2 00-8 .00 05.0.0.0. 000.00.30.00 30.2 F 008100.012. 0.0.52. .2 8-8 .00 0.0.0.0.... 80.00.0006 m m s .0000 00 m m M m Pm m m. m. m .000 0000.0 00.00.80 00088000 www.0.00 "00mg 09.0. 000.0 .0 00.00am m .w. 0 0 .0 0 m m. 0 .0. ”.0 0000.02 124 Appendix B Voucher Specimen Data 0.00 8.050 80000.2 200880.00 0.0.02.5 0.0.0 00000.2 0... 0. 000000 .0. 05.0.0000 00.0.. 0800 0... 002000”. BENF 0.00 000.522 0:85. 8002.. 0.0802 08.09.0022 Page 2 of 9 Pages .oz .0..o:o> 0.0000000: .. 0.0000 8:00.000 003. 30.2 F 008180012. 0.00.02. .2 00-8 .00 0000.00 000.....0000m 30.2 F 0081000012. 00.00.8000 .2 00-8 .00 0.00000. 000.0090»: 30.2 0.. 008108012. 0.00000 .2 00-8 .00 030200.01 00.009.00.00 30.2 F 0081000012. 0.0802 .2 .0-8 .00 00.000200 00000.00. 30.2 0 00001000212. 8000.002 .2 00-8 .00 00.02.00 00000.0: 30.2 0 0081000012. 00.00.8000 .2 00-8 .00 00.3.0: 000.0..0: 30.2 F 0000130012. 2.00082 .2 00-8 .00 00.0.0... 000.000.. 30.2 F 0000100012. 0.00000 .2 00-8 .00 00.00.00 000.0000 30.2 F 00001000212. 0000.002 .2 00-8 .00 08.00000 000.....0 30.2 F 008320212. 8000.002 .2 00-8 .00 000000002 0000.0 30.2 F 00810300012. 0.0.0 .2 00-8 .00 0.0000000 0.00.5.0 30.2 F 0081000012. 0.0802 .2 00-8 .00 00003 00000000 30.2 F 000.010.000.12. 8000.002 .2 00-8 .00 030020 00000000 30.2 F 00001000012. 0.0802 .2 .0-8 .00 00000002 00000020 30.2 0 0000100212. 8000.002 .2 00-8 .00 00.0:. 00000000 30.2 0 0081000012. 00.00.8000 .2 078 .00 00000.00: 00000000 30.2 F 008108012. 0.0.0.02. .2 078 .00 00.308000 00000.0 m m m e 00000000 000 m Mr” M w m m m m m % 0000.0 00.00.80 00088000000000.0003 80.0.0508 00.0000 0 m 0 0 0 0 0 m. 0 00 00.00802 125 Appendix B Voucher Specimen Data mama .9930 Enema: 30.0595 3.99.5 99w 55.6.2 9.. c. 58.8 .2 992.0me 35.. m>onm 9: 328mm BENF 9mm. 59222 2:22 335 Amvamz 305959... Page 3 of 9 Pages .oz .m..o:o> 5338: F. £36 .9858 $3. 322 F 85:39.12. 5.8.82 .2 5-8 .am 85.38.36 :92 m 88:32:; 3.882 .2 8-5 .3 32:5me 08.5.8.5 322 F 85:39.2 985.2 .2 5.15 .am 85% 58.2.2..qu :22 F 85:83:; 85588”. .2 3-5 .am 855 825.28% :ws. 9 85:38:; 8.3822 .2 5-5 .am metam- 32:3 392 F 85-2532 3882 .2 3-5 .8 8885.: 82:3 322 N 88:38:... 38052 .2 3-5 .% mascmueuxm 82.802 392 F 85:88:; 53882 .2 3-5 .3 £5289an 03.882 :22 F 85155512. 286; .2 915 .3 85333 32.28.52: :22 F 88:38:; 3882 .2 $25 .3. maEBmao: 32.28.52: :92 N 85153.3... 558.32 .2 :15 .9". masxuemo. 03:28.3. 322 m 85:88:? SEES-8”. .2 3-5 .% 8:589. 82.28.52: :22 F 85:89:; «.988 .2 3-5 .3 3593: 82.2862: 3w: F 85:88:; SEES-8”. .2 8-5 .3. 828.3: 8.26952: 392 F 88:39.12, 2.8.82 .2 5-5 .am 2585 32.2852: :ws. F «80:38:; 3.82.2 .2 3.5 .3 95.85. 82.2852: 322 F 85.3312. SEES-v.3. .2 3.5 .9. 385m 82.592: m m s .88 cm mmm Mr. m m m m. m w 835 352.8 mcmEBmamwwwgmu “enema. 5535505 8.0on m m w m m M m m m ,m. go .3252 126 Appendix B Voucher Specimen Data 060 .2230 .Eammas. 30.0225 3.20203 22w 08.50:... 0... E 200000 .2 808.00% 020.. m>00m 05 0020001 BENF 28 2020.05. 9:05. 8002.. .mvamz 01.282008. Page 4 of 9 Pages .0z .0...0:0> 380000: 2 202.0 .8223“. 00:. :m: N 88:28:... 2830 .2 3-8 .3 88.8 82...»..& 3.0.... F 88:885.... 859.82 .2 3-8 .3 88“. 828.33 :22 F 88:88:... 2830 .2 2-8 .3 2.8.0 82.8 :22 N 88:88:... 3882 .2 ~78 .3 8382 822.8 :92 F 85:28:... 2830 .2 2-8 .3 8.2.8:... 822.30 :92 F 88:88:... .2882 .2 078 .3 88... 822.5 :22 N 88:88:... 3882 .2 8-8 .3 8288.20 :92 N 88:88:... .3882 .2 8-8 .3 8288.20 3m... F 88:88:... 8882 .2 8-8 .3 8882.0 82.885 :22 F 88882:... 88282 .2 8-8 .3 8.8.823- 82883.80 :22 F 88:89:; 283.0 .2 m0-m0 .3 8.2.2.0082 82888880 :92 m 88:88:; 22.8.... .2 8-8 .3 8.880 828508880 :22 F 85:28.2. 85833. .2 8-8 .3 88.8.80 82888880 392 N 88:058.... 828.. .2 8-8 .3 8888...... 82888880 :92 N 88:08.3... 85832. .2 5-8 .3 8&5 82888880 392 m NONOImmelg 0.0.28.5 .2 mo-No dm 80.55023 :9... F 88:38:... 5.8.82 .2 8-8 .3 82.88 m m m e 02.00000 0:0 , m m M Mr. m m m m m $ 008.0 0209.00 805.083228 .83 50.2.0508 8.00% m m m. m M M m m. m a. ”.0 .8822 127 Appendix B Voucher Specimen Data 0.00 .2050 830022 30.00.25 3.82.... 08.0 8.0.8.... 0... c. .88.. .2 802.6000 020.. 0800 0... 00>.000m. BEN F 0.00 8250.2 0...0.2 .0098 30.002 0.209.008. Page 5 of 9 Pages .oz .0..0:o> 00000000.. .. 0.008 .0..0...000 003. :0.... F 88:83:... 8332 .2 8-8 .3 3.88.8 82.882 30.2 F 88:88:... 882.32 .2 8-8 .3 2.2.8.80 82:28.83 Ems. N N08308:; 88808.. .2 F080 3.. 88.0 82:80 :0.... F 88:058.... 88... .2 8-8 .3 288.0 82.8: :0.... F 88:88:... 3882 .2 8-8 .3 8...... 82.8: :05. F 88:80.1... 8.882 .2 8-8 .3 28882 82:83 30.2 F 88:98:... 8.83.2 .2 8-8 .3 8.88. 823an :0.... F 88:80.35 3.882 .2 8-8 .3 8380 82......ng 3m... F 88:83:... 88.88.. .2 8-8 .3 88.88 8228.88 30.... F 88:38:... 6.882 .2 8-8 .3 8.28.800 82828.3 :0.... F 88:83:... 880.92 .2 8-8 .3 232...... 82.2.3 :0.... F 88:28:... 8.83.2 .2 2-8 .3 M83 82.4-28.3 30.2 N 88:88:... «.830 .2 2-8 .3 89¢ 8288.8 30.2 N 88:88:... 8.880 .2 2-8 .3 .83 82028.8 :0.... F 88:28:... .88... .2 078 .3 8880 8238.8 m m s .0000 :0 - mmm w m m W. m m w 008 .0 00.00.60 80E.0000F..M.200 “00mm. :98. .050 .0 8.080 m m m. m M M m m. a a. no .0282 128 Appendix B Voucher Specimen Data 2mm. .9930 .8385. 30.0895 3.28.5 .28 896.2 8. c. 88.8 .8 mcmE_omam 3E. m>onm 9: 328mm BEN r Ema 59522 2:22 €098 @952 {23:83. Page 6 of 9 Pages .oz .m...o:o> 3888 t 935 .8363 83 322 F 88:28-2. 8.088 .2 8-8 .8 85‘ 82.82 :ws. e 88:83:; 889.82 .2 5-8 .8 888- 82:88. am: m 88:83:; 3.882 .2 5-8 .8. «5a 8.2.28 :92 F 88:88:; 88.82 .2 8.8 .8 £8- 82.8 :92 N 88:88:; 2882 .2 8-8 .8 8.20.86 82.880 :22 _. 888%qu SEES-8”. .2 8.8 .8 82088“. 8.2.8}. :92 w 88:83:; 3882 .2 8-8 .8 888%: 8.2.85. :22 F 88:83:; 85588”. .2 2-8 .8 £889.: 8o.._o> :92 v 88:88:; 3.882 .2 9-8 .8 8.0.82 820.0. :92 r 8810828. 889.82 .2 8-8 .8 282202 838882 :22 F 88:28:; 3882 .2 8-8 .8. 38:3. 8282 :22 .- 88:88:; 85588”. .2 8-8 .8 3.8082 828.682 :22 F 88:88:; 5.8882 .2 8-8 .8 E8883... 82.8692: 322 r 88182-2. 285; .2 8-8 .8 88852 82.8... :92 v 88:28:; 8.88.2 .2 8.8 .8 8.8: 82.8: :92 e 88:53:; 9.8.0 .2 8-8 .8 8882 89:8 :22 F 88:85:; SEES-0.3. .2 No-8 .3 «888.8 828E888 m m m e 3:830 ccm mmm m m m W W m m. 88.0 882.8 mcmE.omam.£.m.mu .83 coxmtmseo 8.0on M m «u. m M M ou- Nvu m cm. no .8832 129 Appendix B Voucher Specimen Data 0.00 .2050 .8308: 30.00.95 3.202.... 0.90 826.2 0... c. 888 .0. 808.0000 00.0.. 0>000 0c. 00>.000m BEN F 0.00 58.0.0.2 050.2 600.5 @0802 0.0.0989... Page 7 of 9 Pages .02 .0..0:0> 308000: .. 0.00:0- .0:0...000 0.0.3. :22 m 88808:... 5055080.. .2 8.3 .8 8.5.0820 82.08.02: 3w... F 88:225.]... 8.88.2 .2 8-0. .8 2.05.2.5 82.08.02: :w... m 88.2.8.4... 5.8.82 .2 8.2 .8 8.8.2.. 82.08.02... 3w... N 88:80.1; 3.882 .2 078 .8 53.8.58- 82.2.8... :05. F 88:88:; 5.8502 .2 2-8 .8 0.52.8... 82.2.8: 0w... F 881.211.... .8882 .2 1-8 .8 8.2.8.8. 82.2.8... 3w... F 88:88:; 505588.. .2 2-8 .8 22.00.... 82.2.8... :22 N 88:85-... 505588.. .2 N 78 .8 22:50.80. 82.2.8... :22 F 88i......n.s 30802 .2 F78 .8 0.5052... 82.2.00... :ws. F 8848.-.... 20080 .2 078 .8 8.8.. 82.8.. 00.2 F 88100813 8882 .2 8-8 .8 3.0500 825.500 30.5. N 88:53.... 2.8.0 .2 8-8 .8 2.8.00 82.3500 30.2 N 881082-... 588.82 .2 8-8 .8 5:558. 82:28:80 am... F 88:..sz.... 2880 .2 8-8 .8 858.85... 825058580 0w... F 88.23:... 5.8.502 .2 8-8 .8 858.82.888.80 82.2.8580 :92 F 88:82.3... 20080 .2 8-8 .8 8:08.01 82838.8 3.0.... F 88-83-; 589.82 .2 8-8 .8 80.8.80 82888.8 m m m e 00.50000 0:0 . m m m m m m m m. m .50.. 008 .0 00.00.60 80E_0000 .0..0.00 .000. 00x0. .050 .0 00.00% m m w m m m m m. a a. ”.0 .00E32 130 Appendix B Voucher Specimen Data 0.00 .9080 8.0.02.5 0.0.0 000.00.... 0.... 0. 000000 .9 0006.080 00.0.. 0>000 0... 002000”. BENF 0.00 83003.2 30.00.95 0090.05. 0505. .08.... 8.0502 0.0.8.8.... Page 8 of 9 Pages .02 .0..030> 2.000000: .. 0.00:0 .0..0...000 00:. :0.... F 88:88:... 0.0082 .2 00-0. .8 80.0 82080 :0.... F 88:08:... 0.880 .2 8-0. .8 0.8.08.0 82805.: 30.2 8 88:88:... 8.880 .2 8-0. .8 0.00.0E< 82.00.02: :0.... 0 88:80.1... 880.002 .2 8-0. .8 82.8.8 :0.... 0.. 88:...<2:... 88.002 .2 8-0. .8 0000.... 82.8.. :0.... 0 88882:... 0080.032 .2 8-0. .8 0.0.0080... 82.0.0038. 30.2 on 88:83:... 0080.002 .2 8.0. .8 00.05500 82.05500 00.... F 88:88:... 0055080.. .2 .0-.. .8 08.02.... am... N 88:28:... 0.00002 .2 .70. .00 0.80.. 8288...... :0.... F 08:22.24... 8880.2 .2 0.0. .8 80.880. 82.2085: 00.2 F 88:82.35 0.880 .2 8.0. .8 00.00.0550... 82.2085... :0... N 88802:... 008.032 .2 8.0. .8 80008.... 82.80.08 20.... F 88:88:... 0.0.8.... .2 8.0. .8 0.00000 8280.8. Ems. N Nomolmmzml... 0.00000 .2 00.0. .00 0300900.. 80008.00. Dws. F 88:85:... 0.0080 .2 00.0. .8 00.00.00 82.80.00. :0.... F 88:83:... 8.0082 .2 8.0. .8 80:0 82.80.08 m M: s .0000 :0 mmm m Pm m m m m w 0003.0 00.00.60 0..0....0000....0....0.00 “.208. 00x0. .050 .0 00.0000 0 m 0 0 M M m m. 0 0.. ”.0 .8252 131 Appendix B Voucher Specimen Data mama .2930 Sagas. 30.0E2cw £292: 99w amazes. 9: 5 gmoamu .2 2056on 09m: m>onm m5 umzmowm BEN? Ema F$950.2 2:22 68>: 3252 3039395 Page 9 of 9 Pages .oz .mcoao> Emmmoooc : 93% .2363 33 DwE dm 3w: dm DmE dm 3m: dm DwE dm DwE dm 3m: dm 3w: dm 3m: dm Dmi dm DmE dm :ws. me Nowoufizmu; 288.0 :2 9-2 .3 333.3 «3:335 :92 N Nomoufixmu; 2880 =2 8.? .3 «E9856 3.2.835 :22 :V NooouE