A DISTRIBUTION STUDY OF THE BEBTBIC FAUNA OF A LIMITED SECTION OF AUGUSTA CREEK, KALAMAZOO COUNTY. MICHIGAN Donald A. Snitgan A THESIS Sabmitted to Michigan State University in partial fulfillment of the roquiromente f0r the degree of MASTER OF SCIENCE Department of Entomology 1964 AGRICULEDGMEHTS The author wishes to express his sincere thanks to all three persons who aided him in the preparation of this paper. Be especially appreciates the oppor- tunity given him by Dr. I.P. Hirofsky to work on this problem. He is greatly indebted to Mr. Eugene V. Surber for his invaluable suggestions on bottom sampling and sorting techniques. Great appreciation is extended to Dr. Gordon Guyer for his suggestions on sorting tech- niques, and his academic advice. 11 AB8IRACT A DISTRIBUTIOI STUDY OF THE MIC FAN OF A.LIKITED 836110. 0? AUGUSIA GREEK, IALAHAZOO GODITI, HICHIGAI ‘by Donald A. Bnitgen During the period of August, 1961 to June. 1962 a dis- tribution study was conducted on Augusta Creek. Kalamazoo County to deter-ins a correlation'between types and nmnbers of benthic fauna, batten eonpesitien, and seasonal changes. Also, a eonparison wss lads between the results of this study and those obtained ten years previously by letterolf (1951) to indicate the possible effect of a fish run which occurred during August, 1960. the section of Augusta Greek studied was that portion flowing through the V. I. Kellogg Forest. this part of the strean.has been the object of a prolonged inprovenent study begun in 1934. Samples were collected using the Surber square foot botto- sanpler and the Ethan dredge. the Eknan dredge was enployed to sample the soft batten, slow current areas where the Surber sanpler was ineffective. the samples were concentrated by sieving and preserved in pint Jars for later sorting and identification. A sectioning procedure was initiated into the sorting pro- eess which proved to be greatly time saving. the organises were identified to genus and species when possible. they have been recorded in the tables at a higher level of classificati n for convenience in making comparisons with other literature. There were a total of 26,171 bottom animals col- lected. Of this total 57% were obtained during January, February, and March. The Diptera were the most numerous comprising 67.2% of the total. The station contributing the most bottom organisms was Station III (fine gravel) with 27.2% of the total. The results indicate no major changes have occurred since Fetterolf's (1951) report. It appears, however, there has been a shift in the dominant group of organisms from the Mollusca to the Chironomidae. This shift has been accompanied by a change in the most productive type of bottom. In Fetterolf's (1951) studies, the sand bottom habitat produced the largest number of animals, and in 1961-1962 the fine gravel habitat yielded the greatest pcpulation density. TABLE OF CONTENTS INTRODUCTION. . . . . . . . . . . . LITERATURE REVIEH. . . . . . . . . DESCRIPTION OF SAMPLING AREA. . . . SAMPLING AND SORTIRG TECHNIQUES. . RESULTS. . . . . . . . . . . . . . DISCUSSION. . . . . . . . . . . o . SUMMARI. . . b . . . . . . . . . . LITERATURE CITED. . . . . o . . . . LIST OF FIGURES Page FIGURE I (Station I). . . . . . . . . . . 8 FIGURE 2 (Station 11). . . . . . . . . . . 9 FIGURE 3 (Station III). . . . . . . . o . 10 FIGURE 4 (Station IV). . . . . . . . . . . 11 FIGURE 5 (Station V). . . . . . . . o . . . 13 FIGURE 6 (Station VI). . . . . o . . o . . 14 FIGURE 7 (Modified Sunber Sampler). . . . 17 FIGURE 8 (Collecting and sorting equipment) 19 TABLE TABLE TABLE TABLE IABLE tABLE tABLE tABLE tAHLE ' tABLE TABLE TABLE tABLE TABLES XIV - XVII LIST OF TABLES I (Qualitative list of insects coll- ected from Augusta Creek during 1961-1962e)e e e e e e e e e e e (Percent distribution of total organisms collected). . . . o . II III (Distribution of total organisms according to bottom composition) IV (Monthly distribution of total or- ganisms collected). . . . . . . V (Quantitative list of insects collected on August 25, 1961). . VI (September 28, 1961). . . . . . . VII (December 1, 1961). . . . . . . VIII (January 24, 1962). . . . . . . 11 (February 25. 1962). . . . . . . X (March 20, 1962). . . . . . . . o XI (May 16, 1962). . . . . . . . . . XII (June 25, 1962). . . . . . . . . XIII (Monthly distribution of organisms per station). . . . . . . . . . . Page 2% 25 35 36. 37 (Data from Fetterolf, l951)..38-41 INTRODUCTIOH Huchigan's rivers and streams are used for industrial purposes, sewage disposal, and recreation. Iany biologists have studied the effects of these uses on aquatic fauna. Conversely, other'biolcgists have studied the contribution of aquatic fauna in the overball value of these lotic waters. One such study has been the productivity and distribution of‘benthic theme as potential fish food. the object of this study was to survey the aquatic bottmn animals of Augusta Creek to find a correlation between benthic fauna, bottom type, and seasonal changes. It was also of interest to determine the number of bottom animals as the stream recovered from a serious fish kill which occurred one year prior to this study. LITERATURE REVIEW the study of stream bottom biology was somewhat of a neglected science until about 50 years ago. Since then bottom fauna data has been reported in ever-increas- ing amounts. Early investigators had to meet the chalo lenge of inventing devices suitable for taking qualita- tive and quantitative stream bottom samples. Techniques also had to be devised fer sorting these samples and reporting the results. Procedural methods are still not standardized. Most stream fauna distribution studies have dealt with the total number and kinds of animals present (Cummins, 1962). Some investigators have, however, dealt with a particular group of organisms (Scott, 1958; Cummins, 1964). Some life history studies have contained data on micro- distribution of a particular group (Sorbet, 1957). Much work has been done on the physical limiting factors of benthic fauna distribution. ”Substrate, current velocity, and food materials have been shown to be of primary importance, although the way in which these interrelated parameters determine distribution remains to be completely delineated,” (Cummins, 1962). leedhan and Uhinger (1956) found no correlation between pcpulaticn density and bottom types, but striking correlations were observed with depth and speed of current. Hens and Uickliff (1940) feund in a stream bottom modification study that aquatic insects showed preference for partic- ular bottom types, the medium rubble in a riffle being the most productive. Pennak and Van Gcrpen (1947) found variations in benthic pepulations depending on bottom types; the rubble habitat being the most productive. Armitagc‘(l958) found on the Firehole River, Wyoming, the rUbble botto- had an average of 2.48 times more weight of organises than on bedrock. He postulated that alkalinity might be the chief factor determining the level of standing crap in a stream, but this level can be highly modified by the action of temperature and current and by the physical composition of the stream bottom. The methods vary by which different authors have indicated the abundance of benthic fauna in their particular studies. Pennak and Van Gerpen (1947) used number and grams per square meter. Hans and Wickliff (19AO) used number per square yard. Armitage (1958) enpressed his results in average number per square foot and average weight in milligrams per square foot. Waters (1961) reported his findings as volume of organisms per hour. The investigator setting out to conduct a stream bottom survey must decide upon an appropriate sampler. Some of the instruments that have been used are the Surber (1936) square foot bottom sampler, the Hess (1941) circular sampler, the Eknan (1911) dredge, the Petersen (1911) dredge, and the Ids (1940) cage-type trap for 3 collecting emerging adults. The use of a not designed to collect drift organisms was introduced by Waters (1962, 1961). Welsh (1948) described the use and limitations of nan: types of sanplers. Guyer and Hutscn (1955) described the use of funnel and tent-type traps for emerging adults. there is also the question of how many salples should be taken. leedhan and Usinger (1956) found in sampling a single riffle with a Surber sampler that 194 samples were required to give acceptable figures for total net weight of organisms and 73 samples were needed to give significant figures for total numbers at the 95% confidence level. Leonard (1939) found that samples from a similar area varied in species composition from 20' to 40 percent. He concluded, "One sample of the sort described may be depended upon to yield a reasonably accurate index of the amount of food organimss produced per unit area of uniform bottom, but cannot be expected to provide a comprehensive picture of the relative numbers of individual species throughout the larger areas from which the sample is collected." there are a number of variables which affect the standing crop of a strean's benthos. Waters (1962) found an incredible drift of organisms during the nighto The drift rate increased one hour after sunset, continued through the night, decreasing again at daybreak. The anount of drift was nudh lower in the winter than in 4 summer. Maciolek and leedhan (1951) found the greatest number of bottom fauna during February and the least during August. Needham (1934) found the greatest season- al abundance for weight and numbers in May and a lesser peak in November. Mechanical disturbances, such as children playing, was shown.by Wstere (1962) to affect the downstream drift of bottom animals. Samples taken in a California stream before and-after a flood showed a drastic reduction in the standing crap following the flood (leedhan and leedham, 1963). Barber (1930, 1936) and Needhan and Heedham (1963) have described suitable methods of concentrating and sorting samples. the selection of a preper‘mesh sieve has been discussed by Jonasson (1955). Anderson (1959) has reviewed some flotation techniques which make use of solutions of high density (sugar, calcium chloride) which float benthic organisms to the surface. Lauff(l961) described a device which agitates the sample with compressed air. the suspended organisms are then decanted off. DESCRIPTION OF 8AMPLING AREA Augusta Creek originates in Gilkey Lake in Barry County, and empties into the Kalamazoo River in Kalamazoo County. Investigations on it began in 1934 (Morofsky, Tack, and Lammien, 1949) with a stream alteration study designed to improve conditions for trout productivity. Over one hundred current altering devices were installed in order to increase the current velocity and remove silt overlaying the gravel bottom. A carefully control- led trout stocking and harvest census was carried out. A trout stocking program is still in Operation in the W. K. Kellogg Forest under the direction of Hr. Walter Lemmien, Resident Supervisor. Bottom samples were taken from that part of Augusta Creek which flows through the W. K. Kellogg Forest, Ross Township, T.lS, R.9W, Sections 21, 22, and 27, Kalamazoo County. The section of stream under consideration was approximately 1.8 miles long. Samples were collected from seven stations as follows: STATION I - Large stone (Figure 1) The bottom consisted of gravel on tsp of which were stones ranging up to 15 inches in diameter. There were also several large boulders in this area. The average depth. was nine inches, and the average width was 15 feet. The current velocity was 0.6 feet/second. The sampling station was well shaded by large trees, but had scanty brush cover 3‘Eeasurements offstream depth, width, and velocity were -taken at low water levelo 6 at stream edge, since this was a picnic area. STATION II - Coarse gravel (Figure 2) the bottom was gravel covered with stones ranging in size up to 5 inches in diameter. the maximum depth was 20 inches and the average width 12 feet. the current velocity was 0.3 feet/second. the stream had abundant ‘brush cover at this station. STATIC! III - Fine gravel (Figure 2 and 3) the bottom consisted of a mixture of fine gravel and stones up to 2 inches in diameter. the maximum depth was 11 inches andthg width averaged 17 feet. The current velocity was 1.3 feet/second. the water'here was fairly well shaded‘by‘brush and small trees. STATION IV - Riffles (Figure 4) this station was located Just downstream from a stone current-diverter. the bottom was gravel with scattered stones up to 12 inches in diameter. the maximum depth was 19 in- ches and the average width 16 feet. the current velocity was 1.7 feet/second. the water was well shaded by trees and brush. sumo: v - Sand (Figure 5) this area was situated Just downstream from a pool and was a deposition area. the bottom was fine gravel covered with sand and silt. the maximum depth was 15 inches and the average width 12 feet. the current velocity was 0.8 feet/second. the water here was largely exposed to the sun. Some shade was provided by a low brush cover along the banks. 7 Figure 1 STATION I- Large stone. (a) Sampling area. (b) Foot bridge. Area to left of stream is highly frequented picnic site. Figure 2 STATION 11- Coarse gravel. (a) Sampling area. (b) Fallen tree which acts as natural dam. (c) STATION III Figure 3 (a) Sampling area. Fine Gravel. STATION III- 10 Figure 4 STATION IV- Riffles. (a) Sampling area. (b) Part of stone current diverter. 11 STATION VI AND STATION VII - Silt and much (Figure 6) These two collecting sites were adjacent to each other and differed only in their bottom types. There was a stone diverter upstream from them and a low stone dam Just downstream. The bottom consisted of gravel where the current was swift and gravel covered by silt and muck where the current was slower. Thesilt area was located Where the current velocity was slow enough to allow the fine silt particles to set- tle out. The bottom here consisted of a mixture of silt and organic matter. The muck area was located adjacent to and downstream from the diverter and the bottom consisted of deep organ- ic debrié mixed with silt. ’ Thegmaximum depth in this part of the stream was 21 inches. "The water's depth from where the silt was taken was about 15 inches.. The depth of water where the muck was located was about 5-10 inches. The average width was 21 feet. The current velocity ranged from 1 foot/second in nidstream to zero behind the diverter. ‘2 Figure 5 STATION V— Sand. (a) Sampling area. (b) Pool. Figure 6 STATIONS VI - Silt; and VII - Muck. (a) Silt bottom. (b) Muck bottom. (0) Log current diverter. SAMPLING AND sosnue rscssmuss A modification of the Surber sampler, as shown in Figure 7, was used by earlier investigators to sample Augusta Creek. The device was constructed of cupper wire screen (part a, Figure 7) and galvanized metal. the galvanized metal sides are held parallel to the current. the copper screen front allows water-to flow through the apparatus, but excludes drift organisms from upstream. Bottom materials are dislodged and swept into a removable screen (part c, Figure 7). The bottom material is later removed from this retaining screen and placed into a oontainor'fbr future sorting9 This device was heavy and cumbersmne to use. The Surber (1936) square root bottom sampler (Figure 8) was employed in this study because of its relative effieiency (Leonard, 1939) and its ease in handling. Ease in handling is not so critical during the summer months, but it is of prime importance while taking samples during the winter period. The use of a Surber sampler is limited to areas where there is an appreciable current. Stations VI and VII with silt and muck and little or no current were sampled by en Ekman dredge (Figure 8). When using the Surber sampler it was placed firmly on the bottom. If there were gaps under the square foot frame they were filled in using small stones from out- side the square foot area. While holding the sampler eecurely to the bottom the material within the frame was , 15 thoroughly agitated. This was done violently enough to dislodge any animals clinging to the bottom or to stone, etc., so they would be swept into the net by the current. Care was taken to include matter in the corners of the frame. The contents of the not were next transferred to a galvanized pail (Figure 8), and the net rinsed and in- spected for any clinging organisms. g The next step was concentration of the sample by ) sieving. This step was standardized as much as possible. I The size of the mesh of the screen can appreciably alter I l the number of organisms recovered (Jonasson, 1955 . A number 40 mesh soil sieve was used for every Surber s} ler sorting (Figure 8). Some biologists use a number 23n:esh (Needham and Needham, 1963), but I found that some Chironomidae and Elmidae larvae passed through even the smaller number 40 mesh screen. The material in the pail was swirled vigorously with the hand and immediately decanted through the sieve. The contents of the sieve were rinsed by sloshing it up and down in the water. Care had to be taken not to submerge the upper rim of the sieve while carrying out this rinsing process. By rotat- ing the sieve, while holding it in the water, the contents were congregated to one side. It was then emptied into a wide-mouthed pint Jar with preservative. This process was repeated several times or until it appeared there were no more organisms being retained on the screen. The bulk 16 ........ ,7 ._n.. Figure 7 ledified Barber eupler. (a) dapper wire screen front. (b) Galvanised metal side. (a) Detachable retaining IOW- 17 material which was left in the pail was then quickly sorted in a white enamel pan (Figure 8) to recover any TriehOptera cases, snails, clams, etc. which were too dense to decant off. It was evident that most of the heavier organisms were decanted with the lighter matter. The Jar was then labeled,usually a little more pro- servative added, and stored until it could be sorted in the laboratory. In using the Ekman dredge the sampler was first ”cocked" and then placed upon the area from which a sam- ple was desired. This process was done by hand without a repe. Due to the light consistency of the silt and much the sampler would.have sunk had it been released. It was placed in the bottom to a depth of about two or three inches and then tripped. The sampler was then placed in a galvanized pail about one~fourth full of water. This was done immediately after the sampler was brought above the water otherwise escaping water carried many organisms with it. The collected material was left in the pail and taken to the Kellogg Biological Station at Gull Lake. Spilling was prevented during the winter by allowing a thin layer of ice to form on the surface of the water before transporting it by automobile. Upon arriving at the laboratory the samples were placed in a screen- bottomed wooden box. The screen size was 80 mesh. The sample was then rinsed with a garden hose which washed 18 ‘ v ._. ‘ .‘> \e‘ 5 .' . ' " , ' _ Qt e..ced , - . . ' A 1'," #575.) 7.": ‘ Figure 8 Collecting and sorting equipment. (a) Galvan- ized pail. (b) Ekman dredge. (c) #40 mesh soil sieve. (d) White enamel pan. (e) Surber square foot bottom sampler with the net folded. away all the fine inorganic matter. The material was then transferred to a wide-mouthed pint jar with pre- servative and labeled for future sorting. When the material was to be sorted it was emptied into a glass fingerbowl. Small amounts of this material (about a teaspoon full) were put into a Syracuse watch glass and examined with a dissecting microscope. the animals were identified to genus and species when possi- ble, counted, and preserved in glass vials. This sorting technique was extremely time consuming and a modification of it was put into use. A circle with a diameter equal to that of the bottom half of a glass petri dish was marked off on a white peice of cardboard. This circle was then subdivided into eight equal "pie slices.” Material was then taken from the finger bowl and placed into the petri dish. It was then stirred to accomplish random distribution of any organisms present. The petri dish was then placed over this subdivided cir- cle. The material from one of these “pie slices" was then transferred to a Syracuse watch glass, examined, sorted, identified, and preserved. the number of animals picked from the Syracuse watch glass was multiplied by eight. If the sample was taken with an Ekman dredge it was also multiplied by four since this sampler takes only i square foot of bottom sample. Larger animals such as crayfish, etc. were sorted directly and were not mult- iplied by eight. much time was saved by using this sorting procedure. 20 By using a dissecting microscope to observe the sample, many Chironomidae, Tipulidae, and Elmidae larvae one millimeter in length or less were recovered. These animals would have been missed had the sample been sorted in the field. A floating magnifying glass with self-contained fluorescent bulbs was found to be extremely helpful in finding the larger animals. The preservative used was a mixture of 10 parts - 95% ethanol; 10 parts - water: 1 part - formaldehyde. the formaldehyde concentration was low enough so that it was not irritating to the eyes and nose while observing the sample at close range. Its presence, however, prevented spoilage of the sample when large amounts of organic matter were included. 21 RESULTS fables V-III show by month and station the kinds and number of bottom organisms collected from Augusta Creek. It will be noted there are three months not listed between the period of August, 1961 and June, 1962. Samples were not collected during the months of October and lovember 1961 and April 1962. The October and lovember samples were not taken due to an incapacitating illness. in unusual occusunce rendered the taking of the April sample impossible. Upon entering the stream, it was discovered the bottom was completely covered with a green.'scum.“ An attempt was made to secure a sample with the Surber sampler, but the dislodged algae floated into and plugged the sampler's net. This caused the remaining matorial to flow around the net Opening and downstream. The algae were a mixture of filamentous blue-green (Qgcillstggis sp.) and s number of genera of diatoms. The diatoms seemed to be entangled in the fibers of the ngillatoris sp. By hey the growth of these algae hsd subsided sufficiently to allow samples to be taken. Also, the STATIC! IV (Riffle) sample for June, 1962 was accidentally destroyed and is therefore not listed. The organisms taken during the eight months totaled 26,171. Table IV shows the monthly distribution of this total. The number of bottom animals steadily increased from August to February when the stream reached its peak in.productivity. 0f the total organisms taken, 67$ were 22 collected during the months of January, February, and lsrdh. Table XIII shows the distribution of benthic fauna by station for each month. Table III shows the distribution of total organisms with respect to bottom type. Most of the animals were collected from the first four stations. The largest number of organisms were taken from a fine gravel bottom (STATION III). Table II shows the distribution of the total number of organisms by taxonomic groups. The Diptera contributed 67.89% to the total animals collected and of the Diptera 54.75% were Chironomidae. I Table I contains a taxonomic list of the aquatic insects collected both in bottom samplings and random samplings during 1961-1962. Some of the insects listed were taken in random samples but not in bottom samples. Table XIV-XV'shows Fetterolf's (1951) results frmn his summer samplings of 19510 Tables XVI-XVII show the percent distribution of bottom organisms in relation to bottom composition and distribution of total organisms by taxonomic groups according to Fetterolf's findings. These samplings were done with a modified Surber sampler (Figure 7)- 23 Table I Qualitative list of insects collected fmm Augusta Creek during 1961-1962 POD URIDAE PTERONPBC IDAE EPILEifi. RIDAE BABTIDAS HEPTAGE IE IIDE GOMPHIDAE AESC EWIDAE* LIBE IJJJLIDAS * AGRION IDA?) * S IALIDAE CORYDALIDAE RHYAC (PHILIDM mime YC HIDPE IEP'I'OCERIDAE HELIC OPSYC HIDAE PSYCHWYIIDAE * BHvIIDAE PSmI-IEN IDAE TEULIDAE DIXIDAE * SWEAR CHIRGVOMIDAE RHAG IONIDAE * Collected by dip mt only. an 2.0.932 Ptenonlrcn Teniogtem Ephemere, Heflnu M4 Insights, Tricomtuodes Stemmns 22225222502222 grist!" mu Ch-ulntdes CW W W In, W 52mm“, Oecetls Hellmhe W tloservms Ec rt. 1%, Antochs Duni S lullu Attnflx Tnble II Percent distribution of total crannie- collected GROUP PERCENT PODURIDAE ---------------------- ..-----..--..------ 0.02% P‘IZERONARCIDAE --------------- .. ---------- ........- 0.001; W..- ...................... .— ........... 0.h5 EPEEbERIDAE -------------------------------------- 0.60 BAETIDAE ---------------------------------------- 2.21 HEPTAGENIIDAE ..................................... 0311 001mm --------------------------- - ------------ 0A0 WAR -------------------------------------- 0.0015 SIALIDM ----------------------------------- -..-- 0.02 meILIDAE ----------------------------------- 0.16 mmrcam ----------------------------------- 1.16 HELICG’SYCHIDAE ----------------------------------- 0.03 mesmmm: ------------------------------------ 0.12 was ........................................... Ihi6 PSEPHBHIDAE ---------------------------------- ---- 0.38 TIPULIDAE --------------------------- .. ------------ 12.13 snmuram: ---------------------------------------- 0.26 CHIRONOLIDAE. ------------------------------------- 511.75 311.1101me --------------------------- - ----------- 0.75 momma.- ------------------------------------- 18.77 AMPHIPODA ----------------------------------------- 0.11 0301190011 ------------------------------------------ 0. 16 munsca ------------------------------------------ 2.27 rm ..-.. ..................................... 0.3h mmcaamAu ----------------------------------- 0.35 25 STflTION II III VI VII Table III Distribution of totsl ergodic. according to bottOI cowoeltlon Large stone Cour-s gravel Fine gml lefle Sllt Muck m 10.9% 21.0 27.2 19.8 3.7 7.1 10.3 TIthV Monthly dLstrLbutlou of total 15 .4;— 54. 1.3 organ isms collected 16.6 7.83 T___ mm, . “MB—T 7.85 -_—7.-...---7H_.-—. . . Sept. Dec. Jen. Feb. 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HSH Edam 30 ~me :1... Ease-H. HHH> 0.3.9 an? «MH How mm 5.3 39 m2. new .289 S m H. H $82259 wH m «H m «8.22% mm «H «m m pm 6 m aomnHHQa m m m aguma H H aaofimeé mHm mg a H w om 8 am 3.938830 3 m HIH m H mafionufiHm 55 NH mHm m Ham m5 mom 8H manuazofimo m: m H mm quufim m2. om H Hmu «we mHH mm mafiéfis mm m m mH H Efigmamm 8H H 8 E 2 MH mange a H m H m magma E m mm HH m mafimowwmosfim m m s m mafidmmouama H H 3358 H H ”2338..“ 3 m om m m 328% H H magmas m H 2 flamuammaw .1. mm 3 S m HH g #1819 I 1 BE. gnaw mma mEH 1 i 1 588 so HEB Her-um Heine 83. as; SE 83 SEE 8E oflqoo sea-H ........ mg 20an HH> S > E HHH HH H .......... H8538 3]. 89 .8 has; an .35 82. 3“ 4.... an mp8 Rem 33 was .32. H m m «gag a. HH «Basses H cu m mm Hm H 532 m H 3888 in H mm 2. mm «580% H fl S 328% oH H m cm: 33. 8... 8m sausages H a 8m mmm 8 .1... flags m m H 3.335% H 98 . mm 9 am sagas H Snowmgoflmm a a H $33.33 w 8 H .o. $35»ng S « mqfifimmofina H Eases mm H 3 3355.591 H am flag 3 3 amalgam 0H 0H Essa « a magmas 180a Engage mamas 11 1 EM; .8 g1 Hep-um H253 83- 5:: pH; 8.5 332 8E «:80 .83 ...... tans. 223m HH> E > an HHH HH H 3:33---.5543 warm mamH amaa mm H32 H? a? mmH one vaam H> pmm no» 4pm _HmmH H «H mm oH H moH cm H 3 mHn son an? m 4H HH « H He>eum Hessnm 85 5.32 a: .238 > >H HHH HH «8H .8 secs H 33 man Hdgoe ‘1 1‘1 <2Hm40¢mnwm E H H ............ zofiasm HHH Gupta «mom om: «hm 4am mum mam mm A S > 3 HHH S H 33333355§m «m9 .3 83. 35 Table XIII Monthly dintrlbut [on of organism per statlon Agni: STATION EDITOM TYPE PERCENT RANK I Large Itona 5.9% 6 II Cour-e gravel 9.11 5 III Flue grim]. 12.3 13 IV lefh 19.6 3 V Sand 27.2 1 VI 8111‘. 3.2 7 VII Mac! 21.9 2 Segtenber I Large stone 34.]. 7 II Course gavel 13.0 3 III Flue granl h1.0 1 IV lefle 19.2 2 V Sand 5.9 6 VI 83.13: 6.1 5 VII Muck 10.9 h Deco-bar I L-rga atone 12.5 5 II Coax-Io gravel. 1133 h III Flue gme]. 23.2 1 IV Riffle 23.0 2 V Sand (.6 6 VI 8113: 19.8 3 VII Muck 0.5 7 Janna I urge stone 6.6 h II Cour-u gravel 18.0 3 III Fine gm]. h1.5 1 IV lefle 23.8 2 V Sand 0.6 7 VI Sllt 6.5 5 VII Muck 3.0 6 36 Table XIII (Continued) Februag I Large atone 113A 1+ II Coarse gravel 15.9 3 III Flue gravel 3143.6 1 IV Rtffle 27.3 2 V Sand 0.1+ 6 VI Sllt 0.3 7 VII Muck 7.1 5 March I Large room 10.2 3 II Coarse gravel 3h.0 1 III Flue gravel 9.9 5 IV lef‘ha 12.2 1+ V Sand 15.5 7 VI 8111; 7.9 6 VII inch 21.6 2 m I Large stone 25.6 1 II Course gravel 22.3 2 III Flue gravel 21.8 3 IV lefle 21.6 h V Sand 13.1; 5 VI 8111; 3.8 6 VII Ruck 0.3 7 June I Large atom h.8 6 II Coarse gravel 28.6 1 III Fina gravel 15.9 1. IV ruffle (Sample destroyed) V Sand 10.1» 5 VI Sllt 18.0 3 VII Muck 22.3 2 37 .Joono Opusws< 3:8... use. .33.... :3 .3 us... :3 Sp 8 ”8.2.3 5. 39.3.; E on! 33.3. 839 .. omaa Odd Pm AH am (I): 8052 HH> «ma mm: emu mm N w H mm: Hod mp ah an On «A wannan v4r44rn1 a 1.88 Eng mam mg aofiunm padm canm «cam E > H: .32 .mm 82. 33a .ua83¢£.§u Sue >Hx canaB mam g-O SASS 9. Futthcnrdra wnd m 9-! l 1 ambanm H :: pa mam m Hat-um £6 Ham 8; H> > HHH $9 .mu «83¢ ES 588%.” up... 3.8 >N canda .mm as .QPSIVOOM 00m. .3. ans ao>iuw A