AFSC/FMA/North Pacific Observer Debriefed Data Presentation Layer (OBSINT)
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Observer data span more than two decades and multiple database development interations. To facilitate status of stocks authors and other users of these records, a data set separate from the OLAP was created which reformats and repackages vetted (debriefed) observer data from NORPAC into a common structure, format, and syntax. The granularity of current production data is compromised, however for the purposes of longitudinal research the data set is internally consistant, and spans the developmental boundaries.
AFSC/ABL: Gulf of Alaska Diel Trawl Survey, 2005-2006
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Diel epipelagic sampling for juvenile Pacific salmon (Oncorhynchus spp.), rockfish (Sebastes spp.), sablefish (Anoplopoma fimbria), and associated species was conducted in order to identify factors that may affect year-class success of these commercially important species. Sampling occurred in offshore marine habitats of the coastal northeast Pacific Ocean from 10-20 August 2005 and was conducted with a surface trawl fishing the upper 20 m of the water column along transects up to78 km offshore near 58 N. Three habitats were sampled along each transect over a 24-hr period: the continental shelf (<200 m depth), the continental slope (400-750 m depth), and the abyss (>2,000 m depth). A total of 38,747 fish and squid representing 24 species were sampled in 56 trawl hauls. Of the targeted juvenile fish species, a total of 587 salmon, 11 rockfish, and 70 sablefish were captured. Sampling during day (1500-1900) and night (2200-0200) periods indicated that biomass of fish and squid was 2-4 times higher at night at (each?)all habitat types pooled across transects. No distinct patterns between day or night occurrence were noted for juvenile pink salmon (O. gorbuscha), chum salmon (O. keta), sockeye salmon (O. nerka), or coho salmon (O. kisutch), however, juvenile Chinook salmon (O. tshawytscha) were encountered only at night. Catches of juvenile rockfish and juvenile sablefish were quite low in this study, and larger sample sizes of these fish are needed to adequately determine their diel distribution. Diel differences were apparent with forage species such as Pacific herring (Clupea pallasi), capelin (Mallotus villosus), and eulachon (Thaleichthys pacificus) that were almost exclusively sampled at night. The offshore distribution patterns of target species were distinctly different, with the most common occurrences of juvenile salmon over continental shelf habitats, juvenile sablefish over continental shelf and slope habitats, and juvenile rockfish over slope and abyss habitats. Pacific herring, capelin, eulachon, and Pacific sardines (Sardinops sagax) were found over continental shelf habitats, whereas small squid and myctophids occurred primarily at slope and abyssal habitats. The greatest overall catch biomass was of gelatinous species (jellyfish), which was consistently higher than that of all fish and squid combined, usually by an order of magnitude. Individual fish or squid species with highest average weight per haul were pomfret (Brama japonica), adult coho salmon, Humboldt squid (Dosidicus gigas), and blue sharks (Prionace glauca). The occurrence of the latter two warm-water species and Pacific sardines were of interest because this study occurred during an anomalously warm year and the capture of Pacific sardines and Humboldt squid represent northern range extensions for these species. Stomach content analysis of potential predator species of the target species showed that only adult coho salmon were predating on juvenile salmon and sablefish, and only pomfret were predating on juvenile rockfish. Further sampling of the target species is needed in these habitats during more normal environmental conditions to validate these observations.
AFSC/FMA/North Pacific Observer Foreign Fishing
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The National Marine Fisheries Service (NMFS) began placing observers on foreign fishing vessels operating off the northwest and Alaskan coasts of the United States in 1973, creating the North Pacific Foreign Fisheries Observer Program. Initially, observers were placed on vessels only upon invitation by host countries. In the early years of the program the primary purposes of observers were to determine incidental catch rates of Pacific halibut in groundfish catches and to verify catch statistics in the Japanese crab fishery. Later, observers collected data on the incidence of king crab, snow (Tanner) crab, and Pacific salmon, and obtained biological data on other important species. Following the implementation of the Magnuson Fishery Conservation and Management Act of 1976, which mandated that fishery observers be placed on foreign fishing vessels operating within the US 200-mile Exclusive Economic Zone (EEZ) off the Alaska coast of the Bering Sea and Gulf of Alaska, observer coverage rapidly expanded. By 1986, the foreign fisheries that were not joint-venture were halted.
AFSC/RACE/GAP/Zimmermann: Cook Inlet Shoreline
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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.