Footprints of fixed‐gear fisheries in relation to rising whale entanglements on the U.S. West Coast

• Published in: Fisheries Management and Ecology
• Main Authors: Feist, Blake E., Samhouri, Jameal F., Forney, Karin A., Saez, Lauren E.
• Other Authors: National Oceanic and Atmospheric Administration
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2021
• Subjects: Megaptera novaeangliae
• Online Access: http://dx.doi.org/10.1111/fme.12478; https://onlinelibrary.wiley.com/doi/pdf/10.1111/fme.12478; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/fme.12478

Abstract On the U.S. West Coast, reports of whales entangled in fishing gear increased dramatically in 2014. In this study, a time series of fishing activity maps was developed from 2009 to 2016 for the four fixed‐gear fisheries most commonly implicated in entanglements. Maps were generated using vessel monitoring system (VMS) data linked to port‐level landings databases, which were related to entangled whale reports over the same time period and with modelled distributions of humpback whales Megaptera novaeangliae Borowski. Over the full study period, neither marked increases in fishing activity nor changes in fisheries footprints within regions with high whale densities were detected. By contrast, a delayed fishery opening in California due to a harmful algal bloom in spring of 2016 led to ~5–7 times average levels of Dungeness crab Metacarcinus magister (Dana) fishing activity, which was consistent with a high rate of entanglement in that year. These results are consistent with current hypotheses that habitat compression caused by a marine heatwave increased the overlap of whales with fishing activity, despite minimal changes in the fisheries themselves. This study adds to literature on bycatch of protected species in otherwise sustainable fisheries, highlighting the value of using VMS data for reducing human–wildlife conflict in the ocean.