Sampling Glacial Lake Littoral Fish Assemblages with Four Gears

Abstract

Littoral zone fish assemblages are important components of freshwater lakes. Monitoring of littoral fish assemblage structure is important because littoral fishes often comprise the majority of the entire fish assemblage, and fluctuations in the structure and abundance of the littoral fish assemblage can influence trophic interactions and fishery yields at the ecosystem level. Single-gear sampling designs, however, may only capture a subset of the fish assemblage, resulting in a skewed representation of fish assemblage structure. Use of multiple gears can be justified if they provide complementary fish assemblage information. Our objective was to compare glacial lake fish assemblage structure as represented by four gears and to assess whether the gears provide redundant or complementary fish assemblage information. Two northeastern South Dakota glacial lakes were sampled with a beach seine, benthic sled, drop net, and push trawl in August 2011. Results indicated that fish assemblage structure did not differ significantly among gears. However, fish assemblage descriptors (metrics of species richness, diversity, dominance, and evenness) and rates of species accumulation did differ among gears; in comparison with the drop net, the beach seine, benthic sled, and push trawl collected more individuals with qualitatively greater species richness and diversity at a faster rate. The beach seine collected the most individuals representing the greatest number of species with the least amount of sampling effort (i.e., fastest rate of species accumulation); thus, we recommend the use of beach seines for monitoring and assessment of littoral fish assemblages in glacial lakes.

Received March 16, 2012; accepted August 16, 2012

ACKNOWLEDGMENTS

Funding for this project was provided by Federal Aid in Sport Fish Restoration funds (Project F-15-R, Study 1518; administered by the South Dakota Department of Game, Fish and Parks) and by South Dakota State University. We thank B. Graff and J. Lindgren for field assistance, R. Klumb and D. Shuman for use of the push trawl, B. Blackwell for use of the beach seine, and M. Kaemingk for providing the drop net. We are also grateful to J. Breeggemann, D. Deslauriers, C. Hayer, M. Kaemingk, and T. Rapp for providing helpful reviews of earlier drafts of the manuscript.