Effects of transferring glacier‐fed water to a clear‐water mountain river on the production and food organisms of brown trout ( Salmo trutta L.) in Southern Norway
Abstract The effects of transferring glacier‐fed water to a clear‐water river on production and food organisms of brown trout ( Salmo trutta L.) were investigated in a mountain river, in southern Norway. Production in unregulated fluvial habitat was 271.5 g 100 m −2 yr −1 compared with 103.1 g 100 m...
Published in: | Regulated Rivers: Research & Management |
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Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
1987
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Subjects: | |
Online Access: | http://dx.doi.org/10.1002/rrr.3450010206 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Frrr.3450010206 https://onlinelibrary.wiley.com/doi/pdf/10.1002/rrr.3450010206 |
Summary: | Abstract The effects of transferring glacier‐fed water to a clear‐water river on production and food organisms of brown trout ( Salmo trutta L.) were investigated in a mountain river, in southern Norway. Production in unregulated fluvial habitat was 271.5 g 100 m −2 yr −1 compared with 103.1 g 100 m −2 yr −1 in a glacier‐fed reach of the river. This difference was due to low fish density and recruitment rate. The growth rate, at least for younger fish (2+ to 4+ age groups), was significantly higher in the regulated reach of the river. The main difference in food composition was the low abundance of crustaceans Eurycercus lamellatus and Gammarus lacustris in the regulated reach. Trichopterans were the main diet component in both sites. |
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