Year Established: 2016 Start Date: 2016-03-01 End Date: 2017-02-28
Total Federal Funds: $10,000 Total Non-Federal Funds: $20,200
Principal Investigators: J Marsden, Carrie Kozel
Abstract: Recruitment failure of lake trout (Salvelinus namaycush) in the Great Lakes and Lake Champlain has been attributed to the consumption of alewife (Alosa pseudoharengus) by adult lake trout, eventually leading to Thiamine Deficiency Complex (TDC) in fry. Thiamine deficiency results in early mortality and is likely hindering successful restoration of lake trout populations. Prior studies found that wild fry begin feeding before yolk-sac absorption but in hatchery-reared fry first feeding does not occur until after yolk-sac absorption. The objective of this study is to determine if early feeding by lake trout fry can ameliorate thiamine deficiency. We postulate that wild-hatched fry can mitigate thiamine deficiency through early feeding on natural prey. Eggs will be collected from 40 adult lake trout from Lake Champlain. After fertilization each family will be split in half, with one group treated with thiamine and the other left untreated. Eggs will be reared until hatching; then each group will be split again into fed and unfed groups. Fry groups will be kept under similar conditions; the fed group will be fed a mixture of zooplankton daily. Fry will be sampled weekly and thiamine levels will be quantified using HPLC. We predict that fed fry in both thiamine-treated and untreated groups will have higher thiamine than starved fry. Results of this research will have direct relevance to understanding obstacles to restoration of lake trout in the Great Lakes as well as Lake Champlain.