Fine‐scale acoustic telemetry reveals unexpected lake trout,Salvelinus namaycush,spawning habitats in northern Lake Huron,North America |
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| Authors: | Thomas R. Binder Steven A. Farha Henry T. Thompson Christopher M. Holbrook Roger A. Bergstedt Stephen C. Riley Charles R. Bronte Ji He Charles C. Krueger |
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| Affiliation: | 1. Department of Fisheries and Wildlife, Center for Systems Integration and Sustainability, Michigan State University, Hammond Bay Biological Station, Millersburg, MI, USA;2. U.S. Geological Survey, Great Lakes Science Center, Ann Arbor, MI, USA;3. U.S. Geological Survey, Great Lakes Science Center, Hammond Bay Biological Station, Millersburg, MI, USA;4. U.S. Fish and Wildlife Service, Green Bay Fish and Wildlife Conservation Office, New Franken, WI, USA;5. Michigan Department of Natural Resources, Alpena Fishery Research Station, Alpena, MI, USA;6. Department of Fisheries and Wildlife, Center for Systems Integration and Sustainability, Michigan State University, East Lansing, MI, USA |
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| Abstract: | Previous studies of lake trout, Salvelinus namaycush, spawning habitat in the Laurentian Great Lakes have used time‐ and labour‐intensive survey methods and have focused on areas with historic observations of spawning aggregations and on habitats prejudged by researchers to be suitable for spawning. As an alternative, we used fine‐scale acoustic telemetry to locate, describe and compare lake trout spawning habitats. Adult lake trout were implanted with acoustic transmitters and tracked during five consecutive spawning seasons in a 19–27 km2 region of the Drummond Island Refuge, Lake Huron, using the VEMCO Positioning System. Acoustic telemetry revealed discrete areas of aggregation on at least five reefs in the study area, subsequently confirmed by divers to contain deposited eggs. Notably, several identified spawning sites would likely not have been discovered using traditional methods because either they were too small and obscure to stand out on a bathymetric map or because they did not conform to the conceptual model of spawning habitat held by many biologists. Our most unique observation was egg deposition in gravel and rubble substrates located at the base of and beneath overhanging edges of large boulders. Spawning sites typically comprised <10% of the reef area and were used consistently over the 5‐year study. Evaluation of habitat selection from the perspective of fish behaviour through use of acoustic transmitters offers potential to expand current conceptual models of critical spawning habitat. |
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| Keywords: | Laurentian Great Lakes positional acoustic telemetry spawning habitat selection spawning reefs VEMCO positioning system |
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