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Modeling White Sucker (Catostomus commersonii) populations to assess commercial harvest influence on age structure

November 28, 2018

Commercial harvest of White Suckers Catostomus commersonii for bait in the American Lobster Homarus americanus industry is minimally regulated in Maine and there are concerns as to the influence of increasing harvest. We built a population model using parameters (i.e. age-specific mortality, age at maturity, and size-specific fecundity) from literature and field studies to investigate the theoretical effects of harvest mortality on age structure. Because stock-recruitment relations are poorly characterized for this species, we explored the influence of both Beverton-Holt and Ricker recruitment processes. Our base model closely resembled the empirical age structures reported from three unfished lakes in Maine, with four percent of fish in the modeled spawning run being age-10 or older. We assessed the additive effects of harvest mortality on age structure using the full range of possible mortalities. As expected, increased harvest mortality in the model resulted in a decline and disappearance of older age-classes such that few fish greater than age-10 remained in the population under a realistic harvest mortality scenario. This age-truncation was qualitatively comparable to data from aggregate age distributions reported from three commercially harvested lakes in Maine. Because the loss of older fish may compromise population viability, this model is a valuable guidance tool for managers to craft regulation of this growing fishery.

Citation Information

Publication Year 2019
Title Modeling White Sucker (Catostomus commersonii) populations to assess commercial harvest influence on age structure
DOI 10.1080/02705060.2018.1496951
Authors Joseph D. Zydlewski, Meg Begley, Stephen Coghlan Jr.
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Freshwater Ecology
Series Number
Index ID 70204461
Record Source USGS Publications Warehouse
USGS Organization Coop Res Unit Leetown

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