Bottom trawl fishing footprints on the world’s continental shelves

AMOROSO, RICARDO O.; PITCHER, C. ROLAND; RIJNSDORP, ADRIAAN D.; MCCONNAUGHEY, ROBERT A.; PARMA, ANA M.; SUURONEN, PETRI; EIGAARD, OLE R.; BASTARDIE, FRANCOIS; HINTZEN, NIELS T.; ALTHAUS, FRANZISKA; BAIRD, SUSAN JANE; BUHL-MORTENSEN, LENE; CAMPBELL, ALEXANDER B.; COLLIE, JEREMY; COWAN, JAMES H.; DURHOLTZ, DEON; FAIRWEATHER, TRACEY P.; GÁLVEZ, PATRICIO A.; GÓNGORA, MARÍA EVA; GONZÁLEZ, JESSICA A.; HIDDINK, JAN G.; HUGHES, KATHRYN M.; JENKINS, CHRIS; KAINGE, PAULUS; KATHENA, JOHANNES N.; LESLIE, ROB W.; MAZOR, TESSA; GONZALEZ-MIRELIS, GENOVEVA; NEWMAN, STEPHEN J.; POSEN, PAULETTE E.; ROCHESTER, WAYNE; SILVA, CRISTINA; HILBORN, RAY; KAISER, MICHEL J.; JENNINGS, SIMON

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

NATL ACAD SCIENCES

Lugar: Washington DC, USA; Año: 2018 vol. 115 p. 10275 - 10282

0027-8424

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 Australian 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 consistently met international sustainability benchmarks for fish stocks, implying collateral environmental benefits from sustainable fishing.