AFSC/RACE/SAP: Detailed Crab Data From NOAA Fisheries Service 2012 Chukchi Sea Bottom Trawl Surveys

Metadata Updated: February 8, 2018

This dataset contains detailed crab data collected from the 2012 NOAA/NMFS/AFSC/RACE crab-groundfish bottom trawl survey of the Chukchi Sea. 71 survey stations were successfully completed during the bottom trawl survey. The survey area extended north and east from the Bering Strait to Barrow Canyon, bounded to the west by the U.S.-Russia Maritime Boundary and east to the 10-m bathymetry limit along the Alaska coastline. Demersal populations were sampled by trawling at stations centered within 55.56 x 55.56 km (30 x 30 nautical miles) grid cells covering the survey area. 100% of the catch is sorted for commercially important crab species. Crabs are sorted by species and sex, and a sample is measured to the nearest millimeter to provide a size-frequency distribution (see note under use constraints for analyzing catches where crab were subsampled for measurement). Carapace width is measured for Tanner crabs, and carapace length is measured for king and hair crabs.

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Metadata Date March 1, 2017
Metadata Created Date May 31, 2016
Metadata Updated Date February 8, 2018
Reference Date(s) (publication)
Frequency Of Update annually

Metadata Source

Harvested from NOAA CSW Harvest Source

Additional Metadata

Resource Type Dataset
Metadata Date March 1, 2017
Metadata Created Date May 31, 2016
Metadata Updated Date February 8, 2018
Reference Date(s) (publication)
Responsible Party (Point of Contact, ); Alaska Fisheries Science Center (Custodian)
Contact Email
Access Constraints Access Constraints: There are no legal restrictions on access to the data. They reside in public domain and can be freely distributed. | Use Constraints: Population size estimates make the assumption that 100% of the species within the path of the trawl are captured. In fact, the situation is more complex. As with any fishing gear, the survey trawl exhibits some size selectivity. Some crab may escape under the footrope of the net. Survey abundance estimates are probably best seen as relative measures of abundance. This survey was designed as a systematic survey based on a 55.6 km (30 nautical mile (nmi)) square grid pattern with the planned trawl stations located at the approximate center of each grid cell. Any data analysis must take into consideration the survey design for the results to be valid. This dataset includes data obtained from non-standard (special project, beam trawl,opportunistic collections, etc.) tows, and data that may have been collected from poor performance tows. Note that, while 100% of the total catch is sorted for all commercially important crab species, it may not be possible to measure all crabs. This is noted in the SAMPLING_FACTOR data field: a sampling factor of 1 indicates that all crab were measured; a sampling factor > 1 indicates that crabs were subsampled for measurement. To calculate the total number of crab caught by haul, sum the sampling_factor. This database should not be copied or distributed without its associated metadata file. User must read and fully comprehend the metadata prior to use. Use of these data is not restricted; however, organizations, agencies, units of government, or other users are responsible for the appropriate application of these data. Acknowledgement of NOAA/NMFS/AFSC ,as the source from which these data were obtained, in any publications and/or other representations of these data is suggested. | Distribution Liability: The user is responsible for the results of any application of this data for other than its intended purpose.NOAA denies liability if the data are misused.
Bbox East Long -157.17
Bbox North Lat 73.05
Bbox South Lat 66
Bbox West Long -168.58
Coupled Resource
Frequency Of Update annually
Guid gov.noaa.nmfs.inport:23470
Harvest Object Id 6507d99e-32ac-45da-b34d-652c76f8270f
Harvest Source Id 2aed8e29-fc5b-4cde-aa66-fb1118fd705e
Harvest Source Title NOAA CSW Harvest Source
Metadata Language eng
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True
Temporal Extent Begin 2012-08
Temporal Extent End 2012-09

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