Age and lunar cycle predict harbor porpoise bycatch in the south-western Baltic Sea

PeerJ

article

Dennis Brennecke¹  Magnus Wahlberg²  Anita Gilles¹  Ursula Siebert¹ 

[1] Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation;University of Southern Denmark, Department of Biology, Marine Biological Research Centre;Leibniz Institute for Science and Mathematics Education

关键词: Harbor porpoise;    Phocoena phocoena;    Fisheries;    Bycatch;    Baltic Sea;    Abiotic factors;    Lunar cycle;    Marine mammals;    Cetacean;   

DOI  :  10.7717/peerj.12284

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The harbor porpoise, Phocoena phocoena, is the only cetacean regularly occurring in the Baltic Sea. During the last decades, several anthropogenic activities have affected porpoises in the Baltic region. Most notably is bycatch in static fishing gear, such as gill nets, which is the main human-induced cause of death in odontocetes. There is still considerable uncertainty about which factors influence the amount of bycatch. In the present study, we reviewed bycatch data collected from 1987 to 2016 from the south-western Baltic Sea. There was a significant difference in bycatch due to seasonality and region, and there was a higher bycatch rate in juveniles than in adults. The only abiotic factor associated with bycatch was the lunar cycle, with more animals bycaught during a full moon. These results improve our understanding of which biotic and abiotic factors are associated with bycatch of Baltic harbor porpoises, which can be used to strengthen conservation endeavors such as managing fishing efforts.

【 授权许可】

CC BY