23470 AFSC/RACE/SAP: Detailed Crab Data From NOAA Fisheries Service 2012 Chukchi Sea Bottom Trawl Surveys Data Set Published / External 22354 Shellfish Assessment Program Project Completed 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. Provide crab data from the 2012 bottom trawl survey of the Chukchi Sea. Loaded by FGDC Metadata Uploader, batch 5413, 02-26-2015 12:44 The following FGDC sections are not currently supported in InPort, but were preserved and will be included in the FGDC export: - Taxonomy (FGDC:taxonomy) - Lineage (FGDC:lineage) Funding for this survey was provided in part by the Bureau of Ocean Energy Management (BOEM) Arctic Ecosystem Integrated Survey (Arctic Eis) contract agreement number M12PG00018. Survey efforts were conducted aboard the 43.5 m FV Alaska Knight, a twin-engine, houseforward, commercial stern trawler with Kort nozzles allowing for suitable control of the vessel at slow trawling speeds (3.0 knots). The bottom trawl used for sampling was an 83-112 Eastern trawl, which has a 25.3 m (83 ft) headrope and a 34.1 m (112 ft) footrope. Survey trawls were towed behind 816 kg, 1.8 x 2.7 m, steel V-doors and 54.9 m (30 fathoms) paired bridles. Each lower bridle had a 61 cm chain extension connected to the lower wing edge to improve bottom-tending characteristics. The footrope was fished without roller gear and consisted of a wrapped 0.8 cm (5/16 in.) chain to maximize bottom contact. The body of the net was constructed from nylon with stretched mesh sizes 10.2 cm (4 in.) in the wings and body and 8.9 cm (3.5 in.) in the intermediate and codend. The codend also had a liner of 3.2 cm (1.25 in.) mesh. Samples were collected by bottom trawling at each station for a target fishing time of 15 minutes at a speed of 1.54 msec-1 (3 knots). When possible, the tow was conducted near the center of a 55.6 x 55.6 km grid cell, and the vessel maintained a constant heading during the tow. 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 greater than 1 indicates that crabs were subsampled for measurement. To calculate the total number of crab caught by haul, sum the sampling_factor. Theme ISO 19115 Topic Category biota Theme ISO 19115 Topic Category oceans Temporal fall Temporal summer Spatial Alaska Spatial Chukchi Sea Alaska Fisheries Science Center Seattle WA USA Oracle database Data Set CSV Files Annually Table (digital) RACE Shellfish Assessment Program eastern Bering Sea shelf crab database EBSCRAB Refer to the pdf document Crab Code Instructions" provided with this dataset for a detailed descript 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. Not Applicable Not Applicable Not Applicable 23471 EBSCRAB Published / External Completed NA Loaded by FGDC Metadata Uploader, batch 5413, 02-26-2015 12:44 NA CRAB_ID NUMBER No No Active Unique number generated by Oracle that identifies each record in the CRAB.EBSCRAB table NA - NA HAULJOIN NUMBER No No Active NA NA - NA CRUISE NUMBER No No Active 6-digit number assigned to each RACE survey cruise; first 4 digits identify cruise year NA - NA VESSEL NUMBER No No Active Numeric code assigned to each vessel participating in a RACE cruise (source: RACE ADP codebook) NA - NA HAUL NUMBER No No Active Number identifying a specific tow NA - NA STATION Unknown No No Active NA unknown SPECIES_CODE NUMBER No No Active 5-digit number assigned to a species (source: RACE ADP codebook) NA - NA SPECIES_KFRC NUMBER No No Active Numeric code assigned to a species (source: NMFS Kodiak Shellfish Assessment Program) NA - NA SEX VARCHAR2 No No Active 1-digit numeric code assigned to a particular sex of crab 1, 2, 3, 4 LENGTH NUMBER No No Active Carapace measurement, in millimeters, of king and hair crabs NA - NA WIDTH NUMBER No No Active Carapace measurement, in millimeters, of Chionoecetes and Dungeness crabs NA - NA SHELL_CONDITION VARCHAR2 No No Active 1-digit numeric code describing carapace condition of crab 0, 1, 2, 3, 4, 5, 9 EGG_COLOR VARCHAR2 No No Active 1-digit numeric code describing color of eggs in female crab 0, 2, 3, 4, 5, 6, 7, 9 EGG_CONDITION VARCHAR2 No No Active 1-digit numeric code describing condition of eggs in female crab 0, 1, 2, 3, 4, 9 CLUTCH_SIZE VARCHAR2 No No Active 1-digit numeric code describing fullness of clutch in female crab 0, 1, 2, 3, 4, 5, 6, 9 WEIGHT NUMBER No No Active Weight, in grams, of individual crab NA - NA DISEASE_CODE NUMBER No No Active 1-digit numeric code indicating presence of certain diseases in crab NA - NA DISEASE_DORSAL NUMBER No No Active If black mat disease is present, this 1-digit number describes percent of dorsal body surface covered by disease NA - NA DISEASE_VENTRAL NUMBER No No Active If black mat disease is present, this 1-digit number describes percent of ventral body surface covered by disease NA - NA DISEASE_LEGS NUMBER No No Active If black mat disease is present, this 1-digit number describes percent of leg surface covered by disease NA - NA SAMPLING_FACTOR NUMBER No No Active NA NA - NA CHELA_HEIGHT NUMBER No No Active Measurement, in millimeters, of height of right chela of crab NA - NA GIS_STATION Unknown No No Active NA unknown COMMENTS Unknown No No Active Any comments particular to that crab record or haul unknown Data Steward 2015 Person Armistead, Claire claire.armistead@noaa.gov 907 481 1730 claire.armistead@noaa.gov Distributor 2015-02-26 Person Foy, Robert robert.foy@noaa.gov robert.foy@noaa.gov Metadata Contact 2015-02-26 Person Armistead, Claire claire.armistead@noaa.gov 907 481 1730 claire.armistead@noaa.gov Originator 2015-02-26 Organization Alaska Fisheries Science Center AFSC afsc.webmaster@noaa.gov https://ror.org/01h7fye62 7600 Sand Point Way N.E., Building 4 Seattle WA 98115 USA (206) 526-4000 (206) 526-4004 https://www.fisheries.noaa.gov/about/alaska-fisheries-science-center AKFSC Home Page Online Resource 0700-1700 Pacific Time Point of Contact 2015-02-26 Person Foy, Robert robert.foy@noaa.gov Ground Condition -168.58 -157.17 73.05 66 More elaborate than a keyword. Range 2012-08 2012-09 Unclassified unknown There are no legal restrictions on access to the data. They reside in public domain and can be freely distributed. 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. https://www.afsc.noaa.gov/Publications/AFSC-TM/NOAA-TM-AFSC-278.pdf Online Resource pdf AFSC Technical Memorandum summarizing results of the 2012 Chukchi Sea bottom trawl survey of bottomfishes, crabs, and other demersal macrofauna https://www.afsc.noaa.gov/RACE/groundfish/species_codebook.pdf Online Resource pdf Listing of codes used for fish and invertebrates identified in RACE Division surveys Oracle 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. Data set includes data collected from standard and non-standard hauls (special projects, opportunistic collections, etc.). Users of this dataset should be familiar with the haul type codes used in RACEBASE.HAUL (linked to CRAB.EBSCRAB via hauljoin field) before performing analyses Data is checked for values outside range All data is submitted through a thorough QA/QC process. Data is checked for outliers, impossible values, and invalid values. No Unknown Yes No yes unknown No delay NCEI-MD Unknown IT Security and Contingency Plan for the system establishes procedures and applies to the functions, operations, and resources necessary to recover and restore data as hosted in the Western Regional Support Center in Seattle, Washington, following a disruption. unknown 1 All crab were removed from the catch, sorted by species and sex, and a total catch weight was obtained for each species. Tanner and snow crab hybrids are identified by a combination of characteristics including curve of the epistome margin, eye color, carapace shape, and space between or shape of the rostrum horns. A random subsample of the total catch occurred when an exceptionally large number (> 300) of a species was caught in a tow. The subsample varies in size and composition depending on the particular tow. The subsample may have occurred at the level of the entire catch or at the level of a particular size and sex category once the catch was sorted. The total weights of the sampled crab and non-sampled crab were recorded and an expansion factor was calculated to determine the final number of each species in the catch. Individual crab carapaces were measured (± 1 mm) to provide a size-frequency distribution of each sample. Crab sizes are reported as carapace width (CW) excluding spines for Tanner and snow crab, and carapace length (CL) for all king crab and hair crab. In the absence of specific age data, shell condition classification by length and sex is necessary for apportioning stock abundance and biomass for determination of stock status, analytical stock assessment, and for establishing annual management controls. Shell condition class serves as a semi-quantitative index of molt status and time in shell post-molt. For all EBS crab stocks, and particularly those which exhibit a terminal molt at maturity (i.e., Chionoecetes spp.), shell condition is a requisite for setting overfishing limits and harvest quotas. Carapace shell condition was assessed for each crab sampled and assigned to one of six classes according to specific criteria (0 = premolt or molting, 1 = soft and pliable, 2 = new hardshell both firm and clean, 3 = oldshell slightly worn, 4 = oldshell worn, 5 = very oldshell). Clutch assessment is used to estimate spawning stock biomass and overall reproductive health and to monitor demographic changes in the mating population. All female crab abdomens were evaluated to determine reproductive condition based on the color of the eggs (0 = no eggs, 2 = purple, 3 = brown, 4 = orange, 5 = purple-brown, 6 = pink), the condition of the eggs (0 = no eggs, 1 = uneyed, 2 = eyed, 3 = dead, 4 = empty egg cases), and the size of the egg clutch (0 = immature, 1 = mature female no eggs, 2 = trace to 1/8, 3 = 1/4, 4 = 1/2, 5 = 3/4, 6 = full). For mature females, egg clutch and egg condition codes were used to identify the stage in the molt-mate cycle, where the presence of eyed embryos, empty egg cases, or absence of eggs (barren, hereafter) in mature-sized females were indications of an incomplete cycle while mature females brooding uneyed embryos indicated completion of the cycle. 2 Catch-per-unit-effort CPUE), abundance, and biomass estimates are calculated by species and by stock. Area swept is calculated as the product of the distance trawled while the net had bottom contact by the mean net width over the duration of the tow. CPUE is expressed in terms of number (or weight) of crab per square nautical mile. Biomass estimates are calculated for the number of individual male and female crab species at each 1 mm size category using the weight-size relationships developed by the AFSC’s Kodiak Laboratory. The size-weight relationships are described by the expression: W = a Lb, where W is the total weight in grams, L is either CL or CW in millimeters, a is the intercept in log scale and b is the slope. Parameters a and b for the size-weight relationships are estimated from a linear regression fitted to log-transformed size-weight data. The weights calculated at each 1 mm size category are summed within the legal male, sublegal male, mature and immature size categories for each species and sex caught at a station. The crab biomass within a district or section stratum was estimated by averaging crab densities from all stations within the defined district or section stratum and multiplied by the total area of the district or section stratum specific to that stock. Total biomass was calculated using a stratified design based on management units (standard density, high density, Alaska Department of Fish&Game-defined districts, or section stratum). Population biomass estimates were calculated in each stratum and then summed among strata. Variance of the total biomass estimate for each size class was calculated by summing the variance of each stratum. The 95% confidence intervals were calculated using the standard error of the total population multiplied by 1.96. 23471 Entity gov.noaa.nmfs.inport:23470 Nancy Roberson 2015-02-26T12:44:05 SysAdmin InPortAdmin 2026-03-04T19:17:17 2016-05-16 Alaska Fisheries Science Center AFSC 7600 Sand Point Way N.E., Building 4 Seattle WA 98115 USA https://www.afsc.noaa.gov 0700-1700 Pacific Time 1001 Public No No 2016-05-16 1 Year 2017-05-16 none crab Kingdom Animalia Genus Chionoecetes Species opilio snow crab Genus Paralithodes Species camtschaticus red king crab Genus Paralithodes Species platypus blue king crab EBSCRAB NA AFSC CRAB_ID Unique number generated by Oracle that identifies each record in the CRAB.EBSCRAB table AFSC NA NA HAULJOIN NA AFSC NA NA CRUISE 6-digit number assigned to each RACE survey cruise; first 4 digits identify cruise year AFSC NA NA VESSEL Numeric code assigned to each vessel participating in a RACE cruise (source: RACE ADP codebook) AFSC NA NA HAUL Number identifying a specific tow AFSC NA NA STATION NA AFSC unknown SPECIES_CODE 5-digit number assigned to a species (source: RACE ADP codebook) AFSC NA NA SPECIES_KFRC Numeric code assigned to a species (source: NMFS Kodiak Shellfish Assessment Program) AFSC NA NA SEX 1-digit numeric code assigned to a particular sex of crab AFSC 1 male AFSC 2 female AFSC 3 unidentifiable AFSC 4 hermaphrodite AFSC LENGTH Carapace measurement, in millimeters, of king and hair crabs AFSC NA NA WIDTH Carapace measurement, in millimeters, of Chionoecetes and Dungeness crabs AFSC NA NA SHELL_CONDITION 1-digit numeric code describing carapace condition of crab AFSC 0 pre_molt and molting crab AFSC 1 soft AFSC 2 new; firm to hard AFSC 3 old AFSC 4 very old AFSC 5 ancient AFSC 9 missing data AFSC EGG_COLOR 1-digit numeric code describing color of eggs in female crab AFSC 0 no eggs AFSC 2 purple AFSC 3 brown AFSC 4 orange AFSC 5 purple-brown AFSC 6 pink AFSC 7 cream/yellow AFSC 9 missing data AFSC EGG_CONDITION 1-digit numeric code describing condition of eggs in female crab AFSC 0 no eggs AFSC 1 uneyed eggs AFSC 2 eyed eggs AFSC 3 dead eggs AFSC 4 empty egg cases AFSC 9 missing data AFSC CLUTCH_SIZE 1-digit numeric code describing fullness of clutch in female crab AFSC 0 immature AFSC 1 mature female with no eggs AFSC 2 trace to 1/8 full AFSC 3 1/4 full AFSC 4 1/2 full AFSC 5 3/4 full AFSC 6 full AFSC 9 missing data AFSC WEIGHT Weight, in grams, of individual crab AFSC NA NA SPECIAL_SAMPLE 1-digit numeric code indicating presence of certain diseases in crab AFSC NA NA SPECIAL1 If black mat disease is present, this 1-digit number describes percent of dorsal body surface covered by disease AFSC NA NA SPECIAL2 If black mat disease is present, this 1-digit number describes percent of ventral body surface covered by disease AFSC NA NA SPECIAL3 If black mat disease is present, this 1-digit number describes percent of leg surface covered by disease AFSC NA NA SAMPLING_FACTOR NA AFSC NA NA CHELA_HEIGHT Measurement, in millimeters, of height of right chela of crab AFSC NA NA GIS_STATION NA AFSC unknown COMMENTS Any comments particular to that crab record or haul AFSC unknown RACE Shellfish Assessment Program eastern Bering Sea shelf crab database EBSCRAB Refer to the pdf document Crab Code Instructions" provided with this dataset for a detailed description of the codes