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Research article - Peer-reviewed, 2018

Pontoon trap for salmon and trout equipped with a seal exclusion device catches larger salmons

Calamnius, Linda; Lundin, Mikael; Fjalling, Arne; Konigson, Sara

Abstract

The growing seal populations of the Baltic have led to more frequent interactions with coastal fisheries. The motivation for seals to interact with fishing gear is high. It provides high densities of fish. A successful means of mitigating the conflict is the pontoon trap. Seal visits here have been frequent. Seals have access to most parts of the trap system including the middle chamber, which is an overhead environment. Concerns have been raised about seals possible entanglement in this specific part of the trap. As a means of keeping seals from entering the middle chamber, two different Seal Exclusion Devices (SEDs) were tested. A diamond mesh SED and a square mesh SED, which was rotated 45 degrees. The aim was to compare the functionality of the different SEDs with respect to seal deterrent abilities and catch composition. The hypothesis tested were (i) that seals would not be able to enter the middle chamber, (ii) that the catch would increase and (iii) that the SED would deter larger fish from swimming into the middle chamber. Catch data and underwater film were collected. Larger salmons were caught in traps equipped with SEDs. The SEDs did not affect the number of caught fish or the total catch per soak day.

Published in

PLoS ONE
2018, volume: 13, number: 7, article number: e0201164
Publisher: PUBLIC LIBRARY SCIENCE

Authors' information

Calamnius, Linda
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Lundin, Mikael
Swedish University of Agricultural Sciences, Department of Wildlife, Fish and Environmental Studies
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources

UKÄ Subject classification

Fish and Aquacultural Science

Publication Identifiers

DOI: https://doi.org/10.1371/journal.pone.0201164

URI (permanent link to this page)

https://res.slu.se/id/publ/96334