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Comparative genetic and phenotypic analysis of lake trout morphotypes in Great Bear Lake, Lake Superior and other large lakes.

Historical lake trout populations in the upper Great Lakes,  particularly Lake Superior, consisted of several morphotypes  (Goodier, 1981). Much of this morphological diversity has been lost  due to sea lamprey predation, pollution and over-harvest (Burnham- Curtis et al., 1995). Considerable research has been done in recent  years to better understand these lake trout forms, in the interests  of eventual restoration. Unfortunately, much of the historical  morphological and genetic variation was lost before it could be  studied in detail using modern sensitive discriminatory methods.  Moreover, the processes that gave rise to lake trout morphotypes and  the mechanisms that perpetuate these forms are largely unknown.  Currently, three forms are distinguished within the Lake Superior  lake trout population, leans, humpers and siscowet, although there is  evidence of greater diversity in the population prior to stock  collapse (Goodier, 1981). With a lack of reliable historical data,  the need to understand other model systems is crucial to creating and  implementing lake trout restoration programs. Great Bear Lake, Great  Slave Lake, and Lake Mistassini are examples of model systems. Since  many of the processes that were historically important in promoting  and regulating morphological variation in the Great Lakes were likely  replicated in other similar systems, a comparative approach is the  most logical way to gain insights into the evolutionary dynamics of  the extirpated populations. We will be employing a complementary  morphological and genetic approach.     Our objectives are as follows: 1) Quantify morphological, genetic and  growth variation between morphotypes of lake trout from Great Bear  Lake and compare to Lake Superior morphotypes.  2) Quantify gene flow  among morphotypes within and between geographical regions of GBL and  compare to patterns seen in Lake Superior.  3) Determine whether  morphotypes in Great Bear Lake, Great Slave Lakes, Lake Nipigon, Lake  Superior are the result of parallel patterns of sympatric divergence,  or whether they have origins in different glacial refugia.  4) Test  for evidence of natural selection acting to promote phenotypic  diversity in lake trout.  

In progress
Start Date
End Date
Scope of Study
Field Investigation
Laboratory Investigation
Scale of Phenomena
Natural Ecological Processes
Resource Management
Lake Basin Connecting Channels
Lake Ontario
Lake Superior
State Province
Annex Numbers
Surveillance and Monitoring

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