Bottom trawl fishing footprints on the world’s continental shelves

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Ricardo O. Amoroso, C. Roland Pitcher, Adriaan D. Rijnsdorp, Robert A. McConnaughey, Ana M. Parma, Petri Suuronen, Ole R. Eigaard, Francois Bastardie, Niels T. Hintzen, Franziska Althaus, Susan Jane Baird, Jenny Black, Lene Buhl-Mortensen, Alexander B. Campbell, Rui Catarino, Jeremy Collie, James H. Cowan Jr., Deon Durholtz, Nadia Engstrom, Tracey P. Fairweather, Heino O. Fock, Richard Ford, Patricio A. Gálvez, Hans Gerritsen, María Eva Góngora, Jessica A. González, Jan G. Hiddink, Kathryn M. Hughes, Steven S. Intelmann, Chris Jenkins, Patrik Jonsson, Paulus Kainge, Mervi Kangas, Johannes N. Kathena, Stefanos Kavadas, Rob W. Leslie, Steve G. Lewis, Mathieu Lundy, David Makin, Julie Martin, Tessa Mazor, Genoveva Gonzalez-Mirelis, Stephen J. Newman, Nadia Papadopoulou, Paulette E. Posen, Wayne Rochester, Tommaso Russo, Antonello Sala, Jayson M. Semmens, Cristina Silva, Angelo Tsolos, Bart Vanelslander, Corey B. Wakefield, Brent A. Wood, Ray Hilborn, Michel J. Kaiser, and Simon Jennings
• Other Authors: Amoroso, Ro, Roland Pitcher, C, Rijnsdorp, Ad, Mcconnaughey, Ra, Parma, Am, Suuronen, P, Eigaard, Or, Bastardie, F, Hintzen, Nt, Althaus, F, Jane Baird, S, Black, J, Buhl-Mortensen, L, Campbell, Ab, Catarino, R, Collie, J, H. Cowan Jr., J, Durholtz, D, Engstrom, N, Fairweather, Tp, Fock, Ho, Ford, R, Gálvez, Pa, Gerritsen, H, Eva Góngora, M, González, Ja, Hiddink, Jg, Hughes, Km, Intelmann, S, Jenkins, C, Jonsson, P, Kainge, P, Kangas, M, Kathena, Jn, Kavadas, S, Leslie, Rw, Lewis, Sg, Lundy, M, Makin, D, Martin, J, Mazor, T, Gonzalez-Mirelis, G, Newman, Sj, Papadopoulou, N, Posen, Pe, Rochester, W, Russo, T, Sala, A, Semmens, Jm, Silva, C
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: fisherie; effort; footprint; habitat; seabed; Settore BIO/07 - ECOLOGIA; Bering Sea; Gulf of Alaska; New Zealand; Alaska; Aleutian Islands
• Online Access: http://hdl.handle.net/2108/241141; https://doi.org/10.1073/pnas.1802379115; https://www.ncbi.nlm.nih.gov/pubmed/30297399

Bottom trawlers land around 19 million tons of fish and invertebrates annually, almost one-quarter of wild marine landings. The extent of bottom trawling footprint (seabed area trawled at least once in a specified region and time period) is often contested but poorly described. We quantify footprints using high-resolution satellite vessel monitoring system (VMS) and logbook data on 24 continental shelves and slopes to 1,000-m depth over at least 2 years. Trawling footprint varied markedly among regions: from <10% of seabed area in Aus- tralian and New Zealand waters, the Aleutian Islands, East Bering Sea, South Chile, and Gulf of Alaska to >50% in some European seas. Overall, 14% of the 7.8 million-km2 study area was trawled, and 86% was not trawled. Trawling activity was aggregated; the most intensively trawled areas accounting for 90% of activity comprised 77% of footprint on average. Regional swept area ratio (SAR; ratio of total swept area trawled annually to total area of region, a metric of trawling intensity) and footprint area were related, providing an approach to estimate regional trawling footprints when high- resolution spatial data are unavailable. If SAR was ≤0.1, as in 8 of 24 regions, there was >95% probability that >90% of seabed was not trawled. If SAR was 7.9, equal to the highest SAR recorded, there was >95% probability that >70% of seabed was trawled. Footprints were smaller and SAR was ≤0.25 in regions where fishing rates con- sistently met international sustainability benchmarks for fish stocks, implying collateral environmental benefits from sustainable fishing.