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Research article2021Peer reviewedOpen access

Seal-induced losses and successful mitigation using Acoustic Harassment Devices in Estonian Baltic trap-net fisheries

Vetemaa, Markus; Paadam, Ulvi; Fjalling, Arne; Rohtla, Mehis; Svirgsden, Roland; Taal, Imre; Verliin, Aare; Eschbaum, Redik; Saks, Lauri


During the last decades the number of grey seals Halichoerus grypus has increased more than tenfold in the Baltic Sea. having reached 38 000 in 2019, which has created increasing problems to the coastal fisheries. In the current study, 151 Estonian coastal fishermen were interviewed to sum all direct and indirect monetary losses. The total cost of the damage caused by seals to the Estonian fisheries was around 0.9 million euros in 2009. With the aim of mitigating seal impact, Acoustic Harassment Devices (AHDs, Lofitech) were tested. This study presents quantitative data on seal damage in Estonian trap-net fisheries and analyses the results of the attempts made to mitigate the damage by means of AHDs. It can be concluded that AHDs provided sufficient protection against the seal attacks.


Acoustic Harassment Devices; coastal fisheries; trap nets; catch damage; Baltic Sea; grey seal

Published in

Proceedings of the Estonian Academy of Sciences
2021, Volume: 70, number: 2, pages: 207-214

    UKÄ Subject classification

    Fish and Aquacultural Science

    Publication identifier


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