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Inferred fish behavior its implications for hydroacoustic surveys in nearshore habitats

Fisheries Research

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https://doi.org/10.1016/j.fishres.2017.11.018

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Abstract

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.

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Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Inferred fish behavior its implications for hydroacoustic surveys in nearshore habitats
Series title:
Fisheries Research
DOI:
10.1016/j.fishres.2017.11.018
Volume:
199
Year Published:
2018
Language:
English
Publisher:
Elsevier
Contributing office(s):
Great Lakes Science Center
Description:
13 p.
First page:
63
Last page:
75
Country:
United States
Other Geospatial:
Lake Erie