Genetic diversity of lake whitefish in lakes Michigan and Huron; sampling, standardization, and research priorities

We combined microsatellite DNA data from eight loci from two laboratories to increase the spatial extent of genetic inventories for lake whitefish Coregonus clupeaformis from lakes Huron and Michigan.  Spawning lake whitefish from a total of 10 sites were analyzed.  Genetic diversity was greatest between lakes, but significant structuring existed within lakes.  Low diversity among stocks may be a reflection of the recent colonization of the Great Lakes, but other factors such as population fluctuations and localized stresses such as lamprey predation or heavy exploitation may also have a homogenizing effect.  Our data suggested that interlacustrine gene flow exists and is asymmetrical; more genotypes associated with Lake Michigan were observed in Lake Huron.  As the picture of genetic diversity and population structure of lake whitefish in the Great Lakes region emerges, we need to develop methods to combine data types to identify important areas for biodiversity and conservation.  The incorporation of analytical techniques such as mixed stock analysis and GIS-based modeling has the potential to improve harvest models, predictions about impacts of new stresses and existing pressures, and to identify geographic regions that are important for biodiversity of species and ecosystems for an ecologically and economically important species.