Implementation of exclusion devices to mitigate seal (Arctocephalus australis, Otaria flavescens) incidental mortalities during bottom-trawling in the Falkland Islands (Southwest Atlantic)

摘要

In the Falkland Islands, the South American fur seal and South American sea lion spatially overlap and interact with bottom-trawling fisheries. Until 2015, interactions of these species with the Patagonian bottom trawl squid fishery were uncommon. During the second fishing season 2017 a dramatic increase in seal interactions was observed, with a corresponding increase in incidental mortalities. Various mitigation measures were applied, seal exclusion devices (SEDs) fitted inside a net extension inserted between the trawl net and cod-end being the most efficient. The SEDs became mandatory in the fishery in September 2017. Since then, the number of seal mortalities remains negligible. SED efficiency is monitored by 100 % observer coverage. To the best of our knowledge, the Falkland Islands Patagonian squid fishery is currently the only trawl fishery in the Southwest Atlantic with full observer coverage and SED usage. It is hoped in the near future similar mitigation measures extend to other coastal countries whose fisheries also interact with these otariids.