Undergraduate Student: Kelsey Gibbons
Currently: Kelsey is a Ph.D. student at the University of Michigan.
In the early 1980s, the Beaver Island Archipelago supported a healthy fishery of smallmouth bass, Micropterus dolomieu. This fishery has since declined and the consequent
genetic effects and population structure are not known. To determine the number of populations, dispersal between them, and identify a bottleneck, scales were collected from
five sites on three of the islands in the archipelago. DNA was extracted from 180 samples, amplified, and analyzed at eight microsatellite loci. Doh found high rates of dispersal
between the sites, consistent with the Nm value found by GenePop of 3.8 migrants/ population/ generation. This high level of migration and dispersal suggests that all five sites
are part of one population. Our mean Fis value was high (Fis= 0.25) and mean heterozygosity (H=0.174) and allelic diversity (A=6.125) were low suggesting that the smallmouth are
inbred. BOTTLENECK found no deviations from mutation-drift equilibrium, but this test can only detect recent bottlenecks. Our results indicate that the smallmouth population in
the Beaver Island Archipelago experienced a major bottleneck in the past such that the population has returned to drift-mutation equilibrium. This bottleneck has resulted in a
significant reduction in heterozygosity and allelic diversity with a concomitant increase in inbreeding putting this population at risk for local extinction.
Funding provided by:
Central Michigan University and the
CMU Honors Program
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