Comparative Recruitment Dynamics of Alewife and Bloater in Lakes Michigan and Huron

Abstract

The predictive power of recruitment models often relies on the identification and quantification of external variables, in addition to stock size. In theory, the identification of climatic, biotic, or demographic influences on reproductive success assists fisheries management by identifying factors that have a direct and reproducible influence on the population dynamics of a target species. More often, models are constructed as one-time studies of a single population whose results are not revisited when further data become available. Here, we present results from stock recruitment models for Alewife Alosa pseudoharengus and Bloater Coregonus hoyi in Lakes Michigan and Huron. The factors that explain variation in Bloater recruitment were remarkably consistent across populations and with previous studies that found Bloater recruitment to be linked to population demographic patterns in Lake Michigan. Conversely, our models were poor predictors of Alewife recruitment in Lake Huron but did show some agreement with previously published models from Lake Michigan. Overall, our results suggest that external predictors of fish recruitment are difficult to discern using traditional fisheries models, and reproducing the results from previous studies may be difficult particularly at low population sizes.

Received March 22, 2013; accepted August 6, 2013

ACKNOWLEDGMENTS

The authors thank the scientific staff, captains, and crew for their efforts maintaining the long-term data sets on Lakes Michigan and Huron. David Warner, Derek Aday, and three anonymous reviewers provided helpful reviews of the manuscript. Funding for this work was provided by the U.S. Geological Survey, National Climate Change and Wildlife Science Center. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. This article is Contribution 1779 of the U.S. Geological Survey Great Lakes Science Center.