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Synchrony of alewife, Alosa pseudoharengus, year-class strength in the Great Lakes region

September 16, 2024
Fish recruitment is interannually variable and challenging to predict. Annual recruitment is often regionally synchronized among populations and identifying drivers of such synchrony may help shed light on recruitment dynamics. We investigated interannual variation of alewife Alosa pseudoharengus recruitment by estimating year-class strength for populations from three of the Laurentian Great Lakes (lakes Huron, Michigan, and Ontario) using annual assessment survey data from 1968 to 2022. We first determined the age when year-class strength was set for each dataset. We then used a mixed-modeling approach incorporating age, year-class, and sampling year to estimate year-class strength for each study lake. Thereafter, we evaluated regional synchrony in year-class strength across the three lakes and evaluated potential climatic drivers of synchrony. Our results suggest that alewife year-class strength is set by age-1. Our model-derived indices of alewife year-class strength were synchronized among the three lakes, and we identified spring-summer degree-days as a potential regional driver of synchrony. This analysis highlights the potential for strong influence of climatic conditions on fish recruitment in large freshwater systems.
Publication Year 2024
Title Synchrony of alewife, Alosa pseudoharengus, year-class strength in the Great Lakes region
DOI 10.1139/cjfas-2023-0322
Authors Les D. Warren, Andrew Edgar Honsey, David Bunnell, Paris D. Collingsworth, Darryl W. Hondorp, Charles P. Madenjian, David Warner, Brian Weidel, Tomas O. Höök
Publication Type Article
Publication Subtype Journal Article
Series Title Canadian Journal of Fisheries and Aquatic Sciences
Index ID 70258663
Record Source USGS Publications Warehouse
USGS Organization Great Lakes Science Center
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