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Can the river location within a fjord explain the density of Atlantic salmon and sea trout?

Authors :
Vollset, Knut W.
Skoglund, Helge
Barlaup, Bjørn T.
Pulg, Ulrich
Gabrielsen, Sven-Erik
Wiers, Tore
Skår, Bjørnar
Lehmann, Gunnar B.
Source :
Marine Biology Research. Mar2014, Vol. 10 Issue 3, p268-278. 11p.
Publication Year :
2014

Abstract

The rivers that drain into the Hardangerfjord were historically known to have numerous populations of both sea trout (Salmo trutta) and Atlantic salmon (Salmo salar). After a decline in catches during the last decades many of the rivers have been closed for fishing. In this study we use snorkelling observations from rivers and catch statistics from 2004 to 2011 to describe the current situation and analyse the patterns of density of wild salmon, sea trout and escaped farmed salmon in the Hardangerfjord rivers. We hypothesize that some of the variance in density of salmon and sea trout can be explained by the location of the river in the fjord, with fish from rivers with a longer fjord exposure having a lower density. A median number of 3.5 salmon×ha−1and 14.9 sea trout×ha−1were observed in the rivers. Farmed salmon were observed in all rivers and constituted on average 23.3% of the total number of observed salmon. For salmon, there was an inverse log-linear relationship between density in the river and migration distance to coast, with a higher density in rivers with a shorter migration distance. For sea trout there was no evident relationship with location within the fjord. We suggest that the spatial patterns observed for salmon and sea trout can be related to the species-specific differences in habitat use within the fjord system. [ABSTRACT FROM PUBLISHER]

Details

Language :
English
ISSN :
17451000
Volume :
10
Issue :
3
Database :
Academic Search Index
Journal :
Marine Biology Research
Publication Type :
Academic Journal
Accession number :
91103406
Full Text :
https://doi.org/10.1080/17451000.2013.810761