Bottom trawl fishing footprints on the world’s continental shelves
Date
2018-10-08
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Publisher
National Academy of Sciences
Abstract
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 highresolution
spatial data are unavailable. If SAR was ≤0.1, as in 8 of
24 regions, therewas >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.
Description
Publication history: Accepted - 23 August 2018; Published online - 8 October 2018.
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Article
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Keywords
fisheries, effort, footprint, habitat, seabed
Citation
Amoroso, R. O., Pitcher, C. R., Rijnsdorp, A. D., McConnaughey, R. A., Parma, A. M., Suuronen, P., Eigaard, O. R., Bastardie, F., Hintzen, N. T., Althaus, F., Baird, S. J., Black, J., Buhl-Mortensen, L., Campbell, A. B., Catarino, R., Collie, J., Cowan, J. H., Jr., Durholtz, D., Engstrom, N., Fairweather, T. P., Fock, H. O., Ford, R., Gálvez, P. A., Gerritsen, H., Góngora, M. E., González, J. A., Hiddink, J. G., Hughes, K. M., Intelmann, S. S., Jenkins, C., Jonsson, P., Kainge, P., Kangas, M., Kathena, J. N., Kavadas, S., Leslie, R. W., Lewis, S. G., Lundy, M., Makin, D., Martin, J., Mazor, T., Gonzalez-Mirelis, G., Newman, S. J., Papadopoulou, N., Posen, P. E., Rochester, W., Russo, T., Sala, A., Semmens, J. M., Silva, C., Tsolos, A., Vanelslander, B., Wakefield, C. B., Wood, B. A., Hilborn, R., Kaiser, M. J. and Jennings, S. (2018) ‘Bottom trawl fishing footprints on the world’s continental shelves’, Proceedings of the National Academy of Sciences, 115(43), pp. E10275–E10282. doi: 10.1073/pnas.1802379115.