Recruitment of potadromous salmonid populations in the Great Lakes is a combination of annual plantings of hatchery reared fish and natural reproduction. Determining the input of smolts and juveniles from natural sources is critical to our understanding of these populations as they are both economically and recreationally important species. I found Bear Creek to be a potentially important contributor of potadromous salmonids to the Lake Michigan basin, producing approximately 15,000 Rainbow Trout smolts, 5,000 Chinook Salmon smolts, and 23,000 Coho Salmon smolts in addition to supporting 43,000 young-of-year Rainbow Trout, 9,200 young-of-year Brook Trout and 21,000 young-of-year Brown Trout. I concluded that while Bear Creek may produce lower numbers of individual species, the total sum of potadromous salmonids produced is roughly equivalent to other similarly sized Lake Michigan tributaries. I also evaluated microhabitat use by young salmonids in Bear Creek using the modified Chesson's Index. My results showed that young-of-year salmonids tended to select for near shore habitat with finer sediments, in slower moving shallow water that provided both overhead cover and woody debris. This is in contrast to age-1 Rainbow Trout, that selected for more midstream sections of the river with deeper and faster moving currents that still provided overhead cover and woody debris. I also showed that univariate descriptions of habitat preference may not provide an accurate picture of the true habitat utilization of these species.
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