Genetic Diversity Among Great Lakes Cisco Species: Exploring Taxonomic and Population Boundaries

Ciscoes (Coregonus artedi, hoyi, kiyi, and zenithicus) once formed a diverse species flock that was an important part of the Great Lakes food web.  Now the deepwater forms of cisco are most abundant in Lake Superior, bloater and cisco are observed in lakes Huron and Michigan, and only cisco are observed in Lake Ontario. Prior to their collapse, there were questions about the taxonomic status and population structure of the species flock that were never completely resolved.  Recent changes to the community structure of lakes Michigan and Huron has generated interest in restoring a native fish community to promote healthy ecological function of the food web.  Understanding the population structure of current populations is necessary to inform management actions that involved establishment and use of stocking of hatchery fish.  To this end, mitochondrial and nuclear DNA diversity was assessed in a collection of contemporary ciscoes from the Great Lakes to determine levels of diversity and population structure of the remaining populations.  Microsatellite DNA variation indicated that there were differences among species.  There were also differences in levels of observed population structure between bloater and cisco.