**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
June 2012
ABSTRACT:
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.