Changes in depth occupied by Great Lakes lake whitefish populations and the influence of survey design

Journal of Great Lakes Research
Lakehead University, IISD-Experimental Lakes Area, Michigan Department of Natural Resources, Ontario Ministry of Natural Resources and Forestry
By: , and 

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Abstract

Understanding fish habitat use is important in determining conditions that ultimately affect fish energetics, growth and reproduction. Great Lakes lake whitefish (Coregonus clupeaformis) have demonstrated dramatic changes in growth and life history traits since the appearance of dreissenid mussels in the Great Lakes, but the role of habitat occupancy in driving these changes is poorly understood. To better understand temporal changes in lake whitefish depth of capture (Dw), we compiled a database of fishery-independent surveys representing multiple populations across all five Laurentian Great Lakes. By demonstrating the importance of survey design in estimating Dw, we describe a novel method for detecting survey-based bias in Dw and removing potentially biased data. Using unbiased Dw estimates, we show clear differences in the pattern and timing of changes in lake whitefish Dw between our reference sites (Lake Superior) and those that have experienced significant benthic food web changes (lakes Michigan, Huron, Erie and Ontario). Lake whitefish Dw in Lake Superior tended to gradually shift to shallower waters, but changed rapidly in other locations coincident with dreissenid establishment and declines in Diporeia densities. Almost all lake whitefish populations that were exposed to dreissenids demonstrated deeper Dw following benthic food web change, though a subset of these populations subsequently shifted to more shallow depths. In some cases in lakes Huron and Ontario, shifts towards more shallow Dw are occurring well after documented Diporeia collapse, suggesting the role of other drivers such as habitat availability or reliance on alternative prey sources.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Changes in depth occupied by Great Lakes lake whitefish populations and the influence of survey design
Series title Journal of Great Lakes Research
DOI 10.1016/j.jglr.2015.09.014
Volume 41
Issue 4
Year Published 2015
Language English
Publisher International Association for Great Lakes Research
Publisher location Ann Arbor, MI
Contributing office(s) Great Lakes Science Center
Description 12 p.
First page 1150
Last page 1161
Country United States
Other Geospatial Lake Erie, Lake Huron, Lake Michigan, Lake Ontario, Lake Superior
Online Only (Y/N) N
Additional Online Files (Y/N) N