The sublethal physiological impacts of sea lamprey parasitism on their hosts are likely to have significant population management implications. Our prior study showed that lake trout exhibit sublethal responses to parasitism and that endocrine, immune and bioenergetics systems are affected. Furthermore, siscowets and leans respond differently to sea lamprey parasitism; siscowets mount an immune response and sacrifice lipid storage in their muscle to combat parasitism, where leans show an overt stress response and express genes related to circulatory compensation and bioenergetics. Both leans and siscowets show evidence of endocrine disruption because hormones that are important in regulating vitellogenin, a precursor to yolk protein, are reduced in response to parasitism. We also have molecular data that suggests sea lamprey alters their host physiology, which may affect individual growth trajectories. At the population level, these sublethal effects could impact growth (length-at-age), condition (weight-at-age), and reproduction (maturity-at-age, fecundity), and that life history adaptations (energy allocated to reproduction and growth) that are specific to each morphotype could influence responses. Current management of many upper Great Lakes lake trout populations rely on estimation of spawning stock biomass per recruit (SSBR) as biological reference point to generate safe harvest quotas from catch-at-age models. We have constructed preliminary models to link some of these sublethal responses to population relevant endpoints such as growth and reproduction (length, weight, maturity at age and egg production); such endpoints that can be directly incorporated into age-structured models to predict impact on populations (SSBR). Here, we propose a study that will allow us to improve our predictions by actually measuring long term effects of parasitism on growth and reproduction in a controlled lab environment and to determine impacts on recruitment in both morphotypes. We hypothesize that parasitism will impact reproduction, growth and recruitment potential and that there will be differences between the morphotypes.
Comparing the sublethal effects of sea lamprey parasitism on long term reproduction, growth and recruitment of siscowet and lean lake trout.
Michigan State University, Department of Fisheries and Wildlife, Quantitative Fisheries Center (N/A) $ 172,626.00USDEstimates
Funding 1 projects for a total of $172,626.00
University of Wisconsin - Steven's Point, Northern Aquaculture Demonstration Facility $ 61,106.00USDEstimates
Funding 1 projects for a total of $61,106.00
NOAA $ 0.00USDActual
Funding 11 projects for a total of $502,508.00