Examining the potential for unrepresentative sampling during cisco Coregonus artedi gamete collections for the Saginaw Bay restoration effort – Year 2
Contributing Authors
Andrew Honsey (USGS, ahonsey@usgs.gov), Kevin McDonnell (USFWS), Amanda Ackiss (USGS), Wendylee Stott (DFO), Roger Gordon (USFWS), Todd Hayden (USGS) Dave Fielder (MIDNR), Chris Olds (USDA)
Project Description
The cisco Coregonus artedi restoration effort in Saginaw Bay utilizes gametes sourced from northern Lake Huron, in the Les Cheneaux Islands and Drummond Island region (LHTC 2007). Gametes have been collected from bays in the Les Cheneaux area and Whitney Bay (Drummond Island) since 2016 using short-set, small mesh gillnets set in 2-20 m of water. Sampling for cisco gametes occurs as soon as spawning adults become vulnerable to shallow gill nets (typically when water temperatures reach 5 oC) and ends when roughly 100 pairs of fish are collected. If genotypes and/or phenotypes of cisco spawners vary across the spawning season within an aggregation, or across spawning habitats (e.g., shallow versus deepwater habitats in the same region), it is possible that this approach results in unrepresentative samples of the diversity present in those spawning populations. Moreover, this approach limits our understanding of the duration of the cisco spawning season in northern Lake Huron.
We propose to (1) investigate whether the gamete collection protocols used for the Saginaw Bay cisco restoration effort representatively sample the total genetic and phenotypic diversity of the source population(s), and (2) estimate the duration of the cisco spawning period in northern Lake Huron. Results from this work will be relevant to management decisions related to cisco gamete collections and for genetic considerations of broodstock development. This work also complements ongoing efforts to genotype existing brood fish. This work builds on a proposal that was funded via the GLRI Great Lakes Basin Coregonine Restoration Template in FY 2022, which was originally proposed as a multi-year project. Specifically, this project year (if funded) aims to expand the spatial and temporal coverage of sampling conducted during gamete collections, thereby augmenting our understanding of cisco spawning behavior, diversity, and phenology and adding to the knowledge gained from the FY 2022 proposal (which focused on analyses of existing data). Funding for year one has been carried over to fiscal year 2023 and will be used to provide additional supplies and personnel time. Despite the delay in funding, our team has already begun compiling data and prioritizing samples for further genetic and morphometric analysis.