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Inferred fish behavior its implications for hydroacoustic surveys in nearshore habitats

March 12, 2018

Population availability and vessel avoidance effects on hydroacoustic abundance estimates may be scale dependent; therefore, it is important to evaluate these biases across systems. We performed an inter-ship comparison survey to determine the effect of vessel size, day-night period, depth, and environmental gradients on walleye (Sander vitreus) density estimates in Lake Erie, an intermediate-scaled system. Consistent near-bottom depth distributions coupled with horizontal fish movements relative to vessel paths indicated avoidance behavior contributed to higher walleye densities from smaller vessels in shallow water (i.e., <15 m), although the difference decreased with increasing depth. Diel bank migrations in response to seasonally varying onshore-to-offshore environmental gradients likely contributed to day-night differences in densities between sampling locations and seasons. Spatial and unexplained variation accounted for a high proportion of total variation; however, increasing sampling intensity can mitigate effects on precision. Therefore, researchers should minimize systematic avoidance and availability related biases (i.e., vessel and day-night period) to improve population abundance estimates. Quantifying availability and avoidance behavior effects and partitioning sources of variation provides informed flexibility for designing future hydroacoustic surveys in shallow-water nearshore environments.

Citation Information

Publication Year 2018
Title Inferred fish behavior its implications for hydroacoustic surveys in nearshore habitats
DOI 10.1016/j.fishres.2017.11.018
Authors Mark R. DuFour, Christine M. Mayer, Song S. Qian, Christopher Vandergoot, Richard T. Kraus, Patrick Kočovský, David M. Warner
Publication Type Article
Publication Subtype Journal Article
Series Title Fisheries Research
Index ID 70195982
Record Source USGS Publications Warehouse
USGS Organization Great Lakes Science Center

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