AFSC/RACE/GAP/Prescott: Norton Sound Shoreline
공공데이터포털
We assembled approximately 230,000 National Ocean Service (NOS) bathymetric soundings from 39 lead-line and single-beam echosounder hydrographic surveys conducted from 1896 to 2005 in Norton Sound, 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 Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum. We incorporated 3 multibeam surveys, and added an additional 6,992 single-beam soundings from the 2010 Northern Bering Sea bottom trawl survey to fill in where smooth sheet data was lacking. We proofed and digitized 312 cartographic features, comprised mostly of rocks and islets and also digitized 4,305 verbal sediment descriptors, and digitized or adapted 2,142 km of mainland and 837 km of island shoreline.
AFSC/RACE/GAP/Prescott: Norton Sound Features
공공데이터포털
We assembled approximately 230,000 National Ocean Service (NOS) bathymetric soundings from 39 lead-line and single-beam echosounder hydrographic surveys conducted from 1896 to 2005 in Norton Sound, 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 Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum. We incorporated 3 multibeam surveys, and added an additional 6,992 single-beam soundings from the 2010 Northern Bering Sea bottom trawl survey to fill in where smooth sheet data was lacking. We proofed and digitized 312 cartographic features, comprised mostly of rocks and islets and also digitized 4,305 verbal sediment descriptors, and digitized or adapted 2,142 km of mainland and 837 km of island shoreline.
AFSC/RACE/GAP/Prescott: Norton Sound Bathymetry
공공데이터포털
We assembled approximately 230,000 National Ocean Service (NOS) bathymetric soundings from 39 lead-line and single-beam echosounder hydrographic surveys conducted from 1896 to 2005 in Norton Sound, 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. We incorporated 3 multibeam surveys, and added an additional 6,992 single-beam soundings from the 2010 Northern Bering Sea bottom trawl survey to fill in where smooth sheet data was lacking. We proofed and digitized 312 cartographic features, comprised mostly of rocks and islets and also digitized 4,305 verbal sediment descriptors, and digitized or adapted 2,142 km of mainland and 837 km of island shoreline.
AFSC/RACE/GAP/Zimmermann: Cook Inlet Sediments
공공데이터포털
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.
AFSC/RACE/MACE: Results of 2011 acoustic trawl survey Gulf of Alaska DY1103
공공데이터포털
Scientists from the Midwater Assessment and Conservation Engineering (MACE) Program of the Alaska Fisheries Science Center (AFSC) Resource Assessment and Conservation Engineering (RACE) Division routinely conduct acoustic-trawl (AT) stock assessment surveys to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus).The survey (cruise DY2011-03) was conducted between 14 June and 12 August on the Gulf of Alaska shelf from 50-500 m depth extending from the Islands of Four Mountains to the Chiniak Trough east of Kodiak Island. The area referred to as the shelf includes transects that are roughly perpendicular to the continental shelf depth contours and extend in a general north-south direction from inshore bottom depths of <=50 m to upper continental slope bottom depths of >500 m. Smaller surveys were conducted in several bays and around islands including: Morzhovoi Bay, Sanak Trough, Pavlof Bay, the Shumagin Islands areas of Renshaw Point, Unga Strait, and West Nagai Strait, Mitrofania Island, Nakchamik Island, Shelikof Strait, Chiniak Trough, Barnabas Trough, and Alitak Bay. All activities were conducted aboard the NOAA ship Oscar Dyson, a 64-m stern trawler equipped for fisheries and oceanographic research. The survey followed established AT methods as specified in NOAA protocols for fisheries acoustics surveys and related sampling.
AFSC/RACE/GAP/Zimmermann: Cook Inlet Shoreline
공공데이터포털
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.
AFSC/RACE/MACE: Results of 2013 acoustic trawl survey Gulf of Alaska DY1307
공공데이터포털
Scientists from the Midwater Assessment and Conservation Engineering (MACE) Program of the Alaska Fisheries Science Center (AFSC) Resource Assessment and Conservation Engineering (RACE) Division conducted an acoustic-trawl (AT) stock assessment survey of portions of the Gulf of Alaska (GOA) shelf to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus) during summer of 2013. The survey (cruise DY2013-07) was conducted between 8 June and 9 August on the Gulf of Alaska shelf from 50-1,000 m depth extending from the Islands of Four Mountains to Yakutat Bay. The area referred to as the shelf includes transects that are roughly perpendicular to the continental shelf depth contours and extend in a general north-south direction from inshore bottom depths of =50 m to upper continental slope bottom depths of > 1,000 m. Smaller surveys were conducted in several bays and around islands including: Sanak Trough, Morzhovoi Bay, Pavlof Bay, the Shumagin Islands area (including Renshaw Point, Unga Strait, and West Nagai Strait), Mitrofania Island, Nakchamik Island, Shelikof Strait, Alitak Bay,Barnabas Trough, Chiniak Trough, Marmot Bay, Prince William Sound, Kayak Island Trough, and Yakutat Trough. All activities were conducted aboard the NOAA ship Oscar Dyson, a 64-m stern trawler equipped for fisheries and oceanographic research. The survey followed established AT survey methods as specified in NOAA protocols for fisheries acoustics surveys and related sampling.
AFSC/RACE/MACE: Results of 2017 acoustic trawl survey Gulf of Alaska DY1706
공공데이터포털
Scientists from the Midwater Assessment and Conservation Engineering (MACE) Program of the Alaska Fisheries Science Center's (AFSC) Resource Assessment and Conservation Engineering (RACE) Division conducted an acoustic-trawl (AT) survey of the Gulf of Alaska (GOA) shelf to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus) in summer 2017. Previous surveys of the GOA have also been conducted by the MACE program during the summers of 2003, 2005, 2011, 2013, and 2015. The 2017 survey covered the shelf from the Islands of Four Mountains to Yakutat Trough including many bays and troughs. Surface water temperatures across the GOA shelf averaged 11.6° C, overall, approximately 0.6° C cooler than in 2015 (mean 12.2° C) and 1.0° C warmer than in 2013 (mean 10.6° C), which were the only other surveys with comparable coverage. Large aggregations of age-0 pollock were observed throughout the survey but especially in the Shumagin Islands and Shelikof Strait areas. The estimated amounts of age-1+ pollock for the entire surveyed area were 2.64 billion fish weighing 1,341,973 metric tons (t). The majority of the pollock biomass was observed on the continental shelf (84%), Shelikof Strait (5%), near Mitrofania Island (3%), and east of Kodiak Island in Chiniak (2%) and Barnabas Troughs (4%). The majority (86%) of the biomass in the survey area consisted of age-5 fish from the 2012 year class. Compared to previous summer GOA surveys, fish weight at length was similar, but length at age was slightly smaller. Backscatter was attributed to species other than pollock when trawl verification, differentiation based on backscatter frequency response, or other methods allowed. Abundance and biomass estimates were calculated for Pacific ocean perch (Sebastes alutus; 305.9 million fish weighing 172,388 t), and backscatter distribution and abundance relative to previous surveys was estimated for euphausiids (primarily consisting of Thysanoessa inermis, but also including T. spinifera, T. raschii, and Euphausia pacifica).