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.

The Resource Assessment and Conservation Engineering Division (RACE) of the Alaska Fisheries Science Center (AFSC) conducts bottom trawl surveys to monitor the condition of the demersal fish and crab stocks of Alaska. These data include catch per unit effort for each commercially important crab species at a standard set of stations in the eastern Bering Sea. This is a subset of the main database. Excluded are certain non standard tows and other types of data collected other than species id, species size category, species catch per unit effort (number per square nautical mile), water temperature and depth.

In December of 2009, a total of 135 adult male red king crab (Paralithodes camtschaticus) were tagged with depth and temperature recording archival tags and released in eastern Bering Sea for the purpose of tracking their seasonal migrations. A total of 2 crab were recaptured by the commercial fishery after being at liberty for 315 and 330 days

This database contains information about shrimp surveys conducted by the National Marine Fisheries Service and the Alaska Department of Fish and Game in the Gulf of Alaska, Bering Sea and Aleutian Islands dating back to 1953. The main tables used for analysis are the shrimp.catch, shrimp.length, shrimp.cruise, and shrimp.haul tables. Join columns provide linkages between the tables.The shrimp.catch table contains catch weights and counts by haul. Not all catch weights have associated counts and in the earlier years of the time series the catch of all species was not recorded so care must be taken that a non-recorded catch is not interpretated as a zero catch. The shrimp.length table contains the length measurements of the shrimp and other taxa taken during the smallmesh survey.The Shrimp.cruise table contains information on each of the individual surveys called cruises included in the smallmesh database from the Bering Sea, Gulf of Alaska, and Aleutian Islands. The definition of a cruise has not been consistent over the years. Generally, a cruise is conducted by a single vessel in a single geographic area. For certain cruises however, multiple vessels participated in hauls ranging from the Bering Sea to the Gulf of Alaska. The records from some cruises contain as few as one haul while several consist of over 500 hauls. The Shrimp.haul table contains the basic information gathered for each haul including location, date and time, and gear information. Some of the hauls in the data set are from surveys not necessarily targeting shrimp, mainly the hauls in the Bering Sea and Aleutian Islands.

The Northern Shrimp Survey was initiated in 1983 by the Atlantic States Marine Fisheries Commission (ASMFC) and monitors the relative abundance (number of shrimp), biomass (weight of shrimp), and composition of the northern shrimp stock throughout the Gulf of Maine. The data give an understanding of year class strength and sex stage and maturity of shrimp in the population. The survey focuses its efforts in offshore waters (in depths greater than 50 meters) and is timed to sample both males and females during the summer when they are expected to be offshore. The data it collects forms the basis of the annual northern shrimp assessment, which in turn, is used by fishery managers from Maine, New Hampshire and Massachusetts to set each year’s fishing regulations.

We assembled 1.4 million National Ocean Service (NOS) bathymetric soundings from 98 lead-line and single-beam echosounder hydrographic surveys conducted from 1910 to 1999 in Cook Inlet, Alaska. These bathymetry data are available from the National Geophysical Data Center (NGDC: http://www.ngdc.noaa.gov), which archives and distributes data that were originally collected by the NOS and others. While various bathymetry data have been downloaded previously from NGDC, compiled, and used for a variety of projects, our effort differed in that we compared and corrected the digital bathymetry by studying the original analog source documents - digital versions of the original survey maps, called smooth sheets. Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum. There were six areas where these older surveys were superseded by compilations of reduced-resolution multibeam surveys. We digitized 12,000 features, such as rocky reefs, kelp beds, rocks and islets, adding them to what was originally available, and creating the most thorough source (n = 18,000) of these typically shallow, inshore features. We also digitized 2,418 km of the mainland and 529 km of island shoreline, generally at a resolution of 1:20,000, and digitized 9,271 verbal surficial sediment descriptions from the smooth sheets. The depth surface, shoreline, inshore features, and sediment data sets are mostly produced at a scale of 1:20,000.

We assembled 1.4 million National Ocean Service (NOS) bathymetric soundings from 98 lead-line and single-beam echosounder hydrographic surveys conducted from 1910 to 1999 in Cook Inlet, Alaska. These bathymetry data are available from the National Geophysical Data Center (NGDC: http://www.ngdc.noaa.gov), which archives and distributes data that were originally collected by the NOS and others. While various bathymetry data have been downloaded previously from NGDC, compiled, and used for a variety of projects, our effort differed in that we compared and corrected the digital bathymetry by studying the original analog source documents - digital versions of the original survey maps, called smooth sheets. Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum. There were six areas where these older surveys were superseded by compilations of reduced-resolution multibeam surveys. We digitized 12,000 features, such as rocky reefs, kelp beds, rocks and islets, adding them to what was originally available, and creating the most thorough source (n = 18,000) of these typically shallow, inshore features. We also digitized 2,418 km of the mainland and 529 km of island shoreline, generally at a resolution of 1:20,000, and digitized 9,271 verbal surficial sediment descriptions from the smooth sheets. The depth surface, shoreline, inshore features, and sediment data sets are mostly produced at a scale of 1:20,000.

As part of a series of ongoing research projects, the AFSC has been mapping and modeling the distribution of deep-sea coral and sponge communities throughout Alaska. A comprehensive stereo video camera survey has been undertaken as part of this project to verify model predictions of the locations of corals and sponges. Additionally, density and height information as well as species associations have been documented in the underwater camera survey.

The GOA/AI Bottom Trawl Estimate database contains abundance estimates for the Alaska Biennial Bottom Trawl Surveys conducted in the Gulf of Alaska and the Aleutian Islands in alternate years. The estimates build upon raw and summary data available from the RACEBASE database and include calculated catch-per-unit-effort (cpue)s for principal species of groundfish and key invertebrates for each survey region. The cpues are averaged by survey strata, and then average cpues are multiplied by stratum areas which results in estimates of biomass and numerical abundance. Length and age data are combined with abundance to estimate the population at length and sex and population at age and sex.

Seasonal migration of commercial-size (=102 mm carapace width [CW]), morphometrically mature (MM) snow crabs (Chionoecetes opilio) from the eastern Bering Sea was examined in relation to the summer distribution of mature females to identify spatiotemporal overlap of males and females and determine the likelihood of mating associations for specific reproductive stages. Depth variation associated with this migration was examined to determine whether seasonal migrations contribute to previously recognized spatial differences in distributions of commercial-size males caught in the winter fishery and in the National Marine Fisheries Service summer bottom trawl survey. Depth data from 33 data storage tags attached to commercial-size MM males during 2010 and 2011 indicated that most males moved inshore during spring—a movement that would allow them to mate with multiparous females but not with pubescent-primiparous females. Smaller tagged males (100–102 mm CW) underwent more extensive inshore migrations, and several of them traveled more than 100 km in one direction. Both tagging and distribution data indicated that most commercial-size MM males remained predominantly on the outer shelf throughout the year (despite some inshore movements during spring) and, therefore, these males did not contribute greatly to the spatial differences observed between winter and summer.