Region 3 wild coregonine brood stock collection activities for FY 2020 in support of restoration activities on Lake Huron and Lake Ontario (2020)
Contributing Authors
Executive Summary
The U.S. Fish and Wildlife Services Midwest Region Fisheries Program carried out two projects in support of a multi-agency effort to restore coregonid populations in Lakes Huron and Ontario. The first project began in 2015 when USFWS began documenting the spawning locations of cisco (Coregonus artedi) in northern Lake Huron. In 2016 USFWS began collecting cisco from those northern Lake Huron populations in support of the development of a line of captive brood stock at the Jordan River National Fish Hatchery (NFH). From 2016 to 2020 cisco gametes were collected from two sites in Northern Lake Huron (Les Cheneaux Islands and Drummond Island) using short set gillnets (<4 hr) in shallow water (~6.5m) during cisco spawning in November (Figures 1 and 2). The gametes of approximately 100+ pairs of cisco were collected each year (Table 1). Fertilized eggs from each pair were transported to Jordan River NFH to support an experimental stocking and evaluation program authorized by the Lake Huron Committee in an attempt to reestablish cisco populations in Saginaw Bay. Additionally, in some years a small volume of eggs from each pair were sent to the Genoa NFH for disease testing, isolation, and brood line development. All fish that were used during gamete collections had samples taken for a genetic classification and the USFWS La Crosse Fish Health Center conducted the disease screening of production and brood lines. The goal of the second project was to collect bloater (C. hoyi) from Lake Michigan to begin the culture of a representative brood stock for stocking into Lake Ontario (Table 2). In 2018 and 2020 a commercial bottom trawler (Susie Q Fisheries, Two Rivers, Wisconsin) sampled spawning bloater in offshore water (>90m in depth) weekly during January and February. No sampling occurred during 2019 due to the federal shutdown. In 2021 collections were made between 1/12/2021 and 2/25/2021 with overnight, bottom set, 65mm bar gill-nets in waters ranging from 93m to 142m in depth just east of Kewaunee, WI. In each year, sampling continued until between 90 and 100 spawning pairs were collected, and all eggs were transferred to the Jordan River NFH for incubation. Each spawn pairing (family) consisted of one female crossed with two males. There were a total of 120 pairings used in 2018, whose progeny represent an effective population size (Ne) of 320 individuals (Kapuscinksi and Jacobson 2007). In 2020, a total 75 pairings were used which produced a separate progeny line with an estimated effective population size of 200. The 2021 year class suffered from low gamete quality due to the use of gillnets, however a total of 55 suitable pairings were available which resulted in a Ne of 110. All three resulting year classes of bloater are currently housed at Jordan River NFH and will be available to support bloater stocking efforts in Lake Ontario.