Date of Award
Dr. Alexey Nikitin
Dr. Mark Luttenton
Dr. Roderick Morgan
The brown trout, Salmo trutta, was first introduced to the Laurentian Great Lakes in 1887 from European broodstocks to found a recreational salmonid fishery; however, the origins of these progenitor lineages remain largely unknown. Trout from these regions are very specialized to their native habitats and matching North American stocks to similar watersheds may help increase survivability by introducing the stock to a more appropriate environment. The objective of this study was to determine the European origins of brown trout found in the Great Lakes. We analyzed 144 brown trout from ten watersheds across Michigan and Wisconsin and identified their strain assignment according to the MIDNR classification using their mtDNA ND-1 sequences. European progenitor lineages occurring within these strain assignments were then identified using the first 309 base pairs of the mtDNA control region. Nine ND-1 haplotypes were found in the four most recently stocked strains. A total of four different European lineages were identified by 5 SNPs in the mtDNA control region in the 144 brown trout samples. One unique control region haplotype which has not been described was observed and a phylogeny was constructed with known sequences. We found that the Sturgeon River strain largely shares the same progenitor lineage as Gilchrist Creek. Fishery managers can use this information to make informed decisions about stocking watersheds where certain strains might prosper or to choose to not stock strains due to poor performance and great dissimilarity between North American watersheds and the European progenitor’s native watershed.
Baisch, David, "Origin of Great Lakes Brown Trout, Salmo trutta: A Phylogeographic Analysis Using mtDNA Sequence Variation" (2012). Masters Theses. Paper 40.