Mixed‐stock analysis using Rapture genotyping to evaluate stock‐specific exploitation of a walleye population despite weak genetic structure

• DOI: 10.1111/eva.13209
• Publication Date: 2021-02-20T14:01:53Z
• Authors: Peter T. Euclide; Tom MacDougall; Jason M. Robinson; Matthew D. Faust; Chris C. Wilson; Kuan‐Yu Chen; Elizabeth A. Mars...; Wesley Larson; Stuart Ludsin
• Keywords: Stock (firearms); Selective breeding; Rapture

Abstract Mixed‐stock analyses using genetic markers have informed fisheries management in cases where strong differentiation occurs among local spawning populations, yet many are supported by multiple, weakly differentiated stocks. Freshwater exemplify this problem, with populations multiple stocks of young evolutionary age and isolated across small spatial scales. Consequently, attempts to conduct mixed‐stock inland often been unsuccessful. Advances genomic sequencing offer the ability discriminate weak population structure, providing necessary resolution assignment previously indistinguishable We used data a analysis eastern Lake Erie's commercial recreational walleye ( Sander vitreus ) estimate relative harvest (pairwise F ST < 0.01). Using RAD‐capture (Rapture), we sequenced genotyped individuals from western basin at 12,081 loci 95% reassignment accuracy, which was not possible past microsatellite markers. A baseline assessment 395 11 identified three reporting groups refined previous assessments gene flow Genetic 1,075 harvested indicated that constituted majority during peak fishing season (July–September), whereas comprised much early (May–June). Clear structure composition existed; catches more easterly sites contained origin than did westerly sites. Our study provides important stock contribution estimates for Erie fishery demonstrates utility facilitate exploited fish having or limited existing resources.