Genetic Population Structure and Dynamics of nearctic Bering Cisco and Applied Mixed-Stock Analysis of the Yukon River Commercial Fishery

Abstract

Bering cisco (Coregonus laurettae) are anadromous salmonids with only three known spawning populations located in the Yukon, Kuskokwim, and Susitna river drainages, respectively in Alaska. Bering cisco are actively harvested in both subsistence and commercial fisheries in Alaska. The work presented herein was a genetic study conducted on Bering cisco with three main objectives: 1) to develop genetic markers for Bering cisco; 2) to evaluate the population structure of the Yukon, Kuskokwim, and Susitna spawning aggregations and 3) to use genetic mixed-stock analysis to estimate the contributions of baseline cisco populations to the Yukon Delta commercial harvest during 2010, 2011, and 2012. Toward this end a suite of 17 informative microsatellite (nuclear) loci was developed for the genetic analysis of Bering cisco and other related species. Results of the analysis indicated significant genetic divergence between all three populations, and supported the notion that there is at least one single stock in each river. Mixed-stock analysis for the Yukon River commercial harvest samples revealed that the majority of the fishery from 2010-2012 was comprised of Yukon River fish.