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Genetic Divergence of Nearby Walleye Spawning Groups in Central Lake Erie: Implications for Management
Author(s) -
Stepien Carol A.,
Snyder Matthew R.,
Knight Carey T.
Publication year - 2018
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1002/nafm.10176
Subject(s) - fishery , geography , drainage basin , population , species richness , ecology , biology , demography , cartography , sociology
Spawning‐site philopatry may lead to genetic differentiation among reproductive populations, despite their locations being in close proximity within single bodies of water. Identifying and maintaining locally differentiated spawning groups of Walleye Sander vitreus constitute an agency management priority of the multi‐agency Walleye Task Group advisory for the Great Lakes Fishery Commission. Although genetically separable spawning groups of Walleyes have been identified from several areas in the Great Lakes, those in central Lake Erie were previously unknown. The Ohio Division of Wildlife ( ODW ) collected Walleyes for the present analysis from two spawning groups in Lake Erie's central basin, located just 2 km apart—one in the Grand River, Ohio, and the other at the nearby central basin reef. The hypothesis of whether the two spawning groups were genetically different was tested by analyzing variation at 14 nuclear DNA microsatellite loci from Walleyes ( n = 147) reproducing in 2012 at the two sites and among three separate years (1996, 2003, and 2012) in the Grand River (to evaluate temporal trends). Results revealed relatively high genetic diversity in both spawning groups, with the reproductive population in the Grand River having significantly greater allelic richness and representation of private alleles. The Grand River Walleye runs showed a slight temporal decline in allelic richness from 1996 to 2003, which coincided with ODW reports of declining numbers of Walleyes reproducing there. The two spawning groups differed in genetic composition suggesting that they are closely related, yet are separable reproductive subpopulations, with both contributing to the overall diversity of Lake Erie Walleye. Their maintenance and integrity thus may need management attention and further monitoring.