**The title, authors, and abstract for this completion report are provided below. For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209**
Evaluating Genetic Relationships between the Lake Ontario Deepwater Sculpin Population and Upper Great Lakes Populations
2 West Virginia University, Division of Forestry and Natural Resources, P.O. Box 6125, Morgantown, WV 26506
3 Michigan State University, 13 Natural Resources Building, East Lansing, MI 48824
4 Michigan State University c/o USGS-Great Lakes Science Center, 1451 Green Road, Ann Arbor, MI 48105
5 USGS-Lake Ontario Biological Field Station, 17 Lake Street, Oswego, NY 13126
Deepwater sculpin, Myoxocephalus thompsonii, are an important part of deepwater ecosystems throughout the Laurentian Great Lakes. Once abundant in Lake Ontario, the population was thought to be extirpated by the 1960s. However, in recent years, individuals have been caught in the lake and it appears that there is recruitment. The origin of the current Lake Ontario population was unclear and could represent a resurgence of an undetected remnant population or recolonization by individuals from the Upper Great Lakes. Objectives of our study were to determine if the Lake Ontario population was genetically distinct from Upper Great Lakes deepwater sculpin and if the Lake Ontario population had low genetic diversity. Samples collected in two years (2009 and 2010) from three different regions (east, north, west) throughout Lake Ontario were analyzed at ten microsatellite loci. Additionally, samples from different regions in the Upper Great Lakes (n=613) and Lake Ontario museum specimens from 1942 (n=50) were analyzed at the same loci. Most sample groups in the Upper Great Lakes could not be genetically differentiated from each other (average FST=0.001). Allele frequencies of the current Lake Ontario population, however, were significantly different from the Upper Great Lakes groups and were more genetically similar to samples from the historic Lake Ontario population. The current Lake Ontario population had similar heterozygosity and number of alleles as the Upper Great Lakes groups. However, all three regions in Lake Ontario significantly deviated from Hardy-Weinberg equilibrium due to an excess of homozygotes. There was no sign of a genetic bottleneck in the population. These preliminary data suggest that the Lake Ontario population may not have been extirpated and is now experiencing a resurgence. From a genetic perspective, enhancement of the Lake Ontario population may not be necessary. The low levels of genetic differentiation observed among deepwater sculpin indicate that there is likely high dispersal. Therefore, if enhancement were to occur, Upper Great Lakes individuals may be a suitable source. Caution needs to be exercised, however, in case local adaptations remain in the Lake Ontario population.