Predicting site-specific overwintering of juvenile brown trout (Salmo trutta) using a habitat suitability index

Abstract

Brown trout (Salmo trutta) site-specific overwintering was studied in an ice-covered stream in northern Sweden. We monitored 238 individually tagged juvenile trout (body length 120-204 mm) from late summer until late winter using portable passive integrated transponder tag equipment and related it to a habitat suitability index. Minimum habitat suitability index explained a large portion (66.8%) of the variation in the proportion of individuals that remained and overwintered at specific sites from late summer until late winter. Our study design detected three scales of overwinter movements: (i) individuals that remained within their tagging site (site-scale movements); (ii) individuals that moved to other reaches (reach-scale movements), which were probably the most common; and (iii) individuals that left the study stream (stream-scale movements). There were no differences in size at tagging among individuals that adopted different scales of movements. We suggest that habitat suitability index can be used as a tool to predict site specific residency and, thus, habitat conditions in stream reaches during winter.

Published in

Canadian Journal of Fisheries and Aquatic Sciences
2009, Volume: 66, number: 4, pages: 540-546

SLU Authors

• Palm, Daniel

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

• Brännäs, Eva

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use
Fish and Aquacultural Science


Publication identifier

DOI: https://doi.org/10.1139/F09-016

Permanent link to this page (URI)

https://res.slu.se/id/publ/25328