gov.noaa.nmfs.inport:28425 eng UTF8 dataset Alaska Fisheries Science Center 7600 Sand Point Way N.E., Building 4 Seattle WA 98115 USA https://www.afsc.noaa.gov WWW:LINK-1.0-http--link Website Website for this organization information 0700-1700 Pacific Time resourceProvider McCarthy, Abigail abigail.mccarthy@noaa.gov pointOfContact 2026-03-04T19:17:17 ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data ISO 19115-2:2009(E) NPRB 1117 Cooperative research to develop new trawl footrope designs to reduce mortality of southern Tanner and snow crabs (Chionoecetes bairdi and C. opilio) incidental to Bering Sea bottom trawl fisheries NPRB 1117 Cooperative research publication NOAA/NMFS/EDM 28425 https://www.fisheries.noaa.gov/inport/item/28425 WWW:LINK-1.0-http--link Full Metadata Record View the complete metadata record on InPort for more information about this dataset. information documentDigital Alaska’s Bering Sea is home to some of the world’s most productive groundfish and crab stocks and the fisheries that depend on them. Their spatial overlap creates problems when bottom trawls affect crabs in their paths, either through capture and discard or damage to crabs that remain on the seafloor. We worked with Bering Sea bottom trawlers to develop and test changes to trawl footropes to minimize crab mortality, by reducing damage to crabs that are not caught, and maintaining low crab capture rates. A previous NPRB project (0711) showed that crab mortality from herding cables ahead of trawls could be greatly reduced with simple modifications to raise them above the seafloor. This project did the same for trawl footropes, the part of the trawl located between the leading edge of the trawl net and the seafloor. Such gear changes allow crab mortality to be reduced without restricting trawling to the few areas of the Bering Sea without crabs. The mortality of crabs encountering bottom trawls has long influenced management of both Bering Sea groundfish and crab fisheries. NPRB Project 711 (Rose et al. 2013) provided estimates of mortality rates for crabs that encounter, but escape, trawls and showed how these mortalities could be greatly reduced by slightly raising the trawl components (sweeps) that affect most such crabs. The current project applied similar methods and resources to design and test changes to trawl footropes, the other major trawl component that crabs encounter, to reduce the remaining mortality of crabs due to trawling. This project continued cooperative participation of a group of Bering Sea trawl captains in generating new footrope design concepts, reviewing research plans for practicality and relevance to their commercial fishery, and communicating results to their peers. Three principles were identified for reducing footrope effects on crabs: 1) lower weight-in-water, 2) less seafloor contact area, and 3) higher and wider spaces between contact points. Mortality rates for crabs following contact with footropes incorporating these footrope modifications were all substantially lower than an earlier design tested under NPRB project 711. Acceptable crab bycatch and fish escapement rates resulted from the field experiment. The Bering Sea bottom trawl fleet has adopted usage of the improved footropes. completed Towler, Rick rick.towler@noaa.gov pointOfContact Towler, Rick rick.towler@noaa.gov custodian unknown Tanner crab mortality snow crab trawl theme DOC/NOAA/NMFS/AFSC > Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Department of Commerce dataCentre Global Change Master Directory (GCMD) Data Center Keywords 2017-04-24 publication 8.5 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian AFSC/RACE/MACE: Reducing Trawl impacts to benthic habitat and invertebrates project InPort otherRestrictions Cite As: Alaska Fisheries Science Center, [Date of Access]: NPRB 1117 Cooperative research to develop new trawl footrope designs to reduce mortality of southern Tanner and snow crabs (Chionoecetes bairdi and C. opilio) incidental to Bering Sea bottom trawl fisheries [Data Date Range], https://www.fisheries.noaa.gov/inport/item/28425. NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose. otherRestrictions Access Constraints: "FISMA Controls are in place to protect stored data from unauthorized access and/or disclosure" unclassified NOAA Data Management Plan (DMP) NOAA/NMFS/EDM 28425 https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/afsc/dmp/pdf/28425.pdf WWW:LINK-1.0-http--link NOAA Data Management Plan (DMP) NOAA Data Management Plan for this record on InPort. information crossReference eng; US oceans Bering Sea: http://www.marineregions.org/gazetteer.php?p=details&id=4310 | Currentness: Ground Condition 2011 2014 Alaska Fisheries Science Center (206) 526-4000 (206) 526-4004 7600 Sand Point Way N.E., Building 4 Seattle WA 98115 USA afsc.webmaster@noaa.gov https://www.fisheries.noaa.gov/about/alaska-fisheries-science-center WWW:LINK-1.0-http--link Alaska Fisheries Science Center Website AKFSC Home Page information 0700-1700 Pacific Time distributor http://projects.nprb.org/#metadata/d3d4915c-786d-42d0-9fcf-ffef4a24c708/project WWW:LINK-1.0-http--link http://projects.nprb.org/#metadata/d3d4915c-786d-42d0-9fcf-ffef4a24c708/project download dataset Video and physical samples were viewed and assessed for degree of trawl interactions with benthos.