Interhabitat and instream movements of large Atlantic salmon parr in a Newfoundland watershed in winter

Authors

  • M. J. Robertson,

    Corresponding author
    1. Cognitive and Behavioural Ecology Programme, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, A1C 5S7 Canada,
      †Present address: Department of Fisheries and Oceans, Science, Oceans and Environment, Box 5667, St. John’s, NL, A1C 5X1 Canada. Tel.: +1 709 772 6416; fax: +1 709 772 5315; email: robertsonmj@dfo-mpo.gc.ca
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  • K. D. Clarke,

    1. Department of Fisheries and Oceans, Box 5667, St. John’s, Newfoundland and Labrador, A1C 5X1 Canada and
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  • D. A. Scruton,

    1. Department of Fisheries and Oceans, Box 5667, St. John’s, Newfoundland and Labrador, A1C 5X1 Canada and
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  • J. A. Brown

    1. Ocean Sciences Centre, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, A1C 5S7 Canada
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†Present address: Department of Fisheries and Oceans, Science, Oceans and Environment, Box 5667, St. John’s, NL, A1C 5X1 Canada. Tel.: +1 709 772 6416; fax: +1 709 772 5315; email: robertsonmj@dfo-mpo.gc.ca

Abstract

Radio-telemetry was used to investigate movement of large, mainly mature male (80%) Atlantic salmon Salmo salar parr in Stoney River, Newfoundland during early winter (November; water temperature 6·0 ± 0·1° C) and mid-winter (January to February; 0·8 ± 0·0° C). Site fidelity of parr in early winter was low. Parr moved between fluvial and lacustrine habitats and were active throughout the diel cycle. Parr caught in fluvial habitats in mid-winter were smaller and younger than parr caught in early winter. Site fidelity of parr in mid-winter was greater than in early winter. Parr in mid-winter moved between fluvial and adjacent small lacustrine habitats, but avoided a larger pond inhabited by large piscivorous fishes. Instream movement rates in mid-winter were lower than in early winter and occurred primarily during hours of darkness (dawn, dusk and night). Fluvial habitats were relatively stable and ice-free throughout the study periods. These results suggested that large Atlantic salmon parr utilize a variety of habitats and remain active throughout the winter, even under stable environmental conditions.

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