36841 Data Set Published / External 31076 AMLR Krill Models Project Completed 1981 2014 An integrated, age-structured model was fitted to different combinations of survey data using two forms of selectivity (logistic or double-logistic) with time-constant or annually varying selectivity to investigate the population dynamics of Antarctic krill (Euphausia superba) near the Antarctic Peninsula. The data were from surveys conducted by the U.S. Antarctic Marine Living Resources Program around the South Shetland Islands from 1992 to 2011. Two indices of krill biomass based on (1) trawl-net samples and (2) hydroacoustic sampling were combined with length-compositions from the nets. Sixteen model configurations using different combinations of the two biomass surveys with the various options for modeling selectivities were examined. An integrated, age-structured model was fitted to different combinations of survey data using two forms of selectivity (logistic or double-logistic) with time-constant or annually varying selectivity to investigate the population dynamics of Antarctic krill (Euphausia superba) near the Antarctic Peninsula. The data were from surveys conducted by the U.S. Antarctic Marine Living Resources Program around the South Shetland Islands from 1992 to 2011. Two indices of krill biomass based on (1) trawl-net samples and (2) hydroacoustic sampling were combined with length-compositions from the nets. Sixteen model configurations using different combinations of the two biomass surveys with the various options for modeling selectivities were examined. This analyses conducted are described in Kinzey, D., G. M. Watters, C. S. Reiss. 2015. Selectivity and two biomass measures in an age-based assessment of Antarctic krill (Euphausia superba). FishRes 168:72-84. This paper is made available as part of the dataset and fully describes the methods, data and results. Theme ADMB Theme AMLR Theme CCAMLR Theme IKMT Theme MOCNESS Theme RMT8 Theme acoustics Theme bathymetry Theme benthic Theme bioacoustic Theme biomass Theme ecosystem Theme hydroacoustic Theme krill Theme marine Theme population Theme surveys Theme trawl Theme weather Spatial Admiralty Bay Spatial Antarctic Spatial Antarctica Spatial Bransfield Strait Spatial Cape Shirreff Spatial Chile Spatial Clarence Island Spatial Copacabana Spatial Deception Island Spatial Drake Passage Spatial Elephant Island Spatial King George Island Spatial Livingston Island Spatial Peninsula Spatial San Telmo Islands Spatial Seal Island Spatial South Shetlands Southwest Fisheries Science Center La Jolla CA USA Data Set Mixed models, code, data Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the National Marine Fisheries Service, US AMLR or its partners. US Antarctic Marine Living Resources Program, NOAA multi-frequency and multi-beam echosounders (Simrad) various fishing and research vessels MOCNESS, IKMT, RMT8 Data Steward 2019 Person Woodman, Sam sam.woodman@noaa.gov 8901 La Jolla Shores Dr La Jolla CA 92037 USA 858-546-7138 Distributor 2019 Organization Southwest Fisheries Science Center SWFSC https://ror.org/022d75229 8901 La Jolla Shores Dr. La Jolla CA 92037 USA (858)546-7000 https://swfsc.noaa.gov/ 8:00-16:30 Metadata Contact 2019 Person Kinzey, Doug doug.kinzey@noaa.gov 8901 La Jolla Shores Dr La Jolla CA 92037 USA 858-546-5601 Point of Contact 2019 Person Kinzey, Doug doug.kinzey@noaa.gov 8901 La Jolla Shores Dr La Jolla CA 92037 USA 858-546-5601 -64 -43 -58 -65 FAO Area 48.1, CCAMLR Area 48.1, Antarctic Peninsula, South Shetland Islands, South Orkney Islands Range 1981 2014 Unclassified Available upon request; response time varies based on data management resources available at the time of the request. Contact AMLR Point of Contact if further guidance is needed. None None None None 2019 Organization Southwest Fisheries Science Center https://ror.org/022d75229 Integrated Age-based Krill Model Fish Res 2015 Zip Zip https://www.fisheries.noaa.gov/about/antarctic-ecosystem-research-division-southwest-fisheries-science-center US AMLR Stock Assessments Online Resource Stock assessments to estimate the status and productivity of biological populations are a central tool in the management of the harvesting of living resources. These methods are used to determine sustainable catch levels that can be demonstrated to meet long-term management criteria. Echosounders are calibrated to industry standards. Industry standards are applied. No Unknown No No Two years NCEI-CO Two years Data are stored on a server at the Southwest Fisheries Science Center which has all appropriate access controls. Raw acoustic data are collected from calibrated echosounders and archived on the vessel and later on shore-based servers. Samples from nets are processed on board the vessel, and descriptive information is entered into data logs and/or databases. All datasets are ultimately returned to the SWFSC for QA/QC, archiving and review. Simrad EM3000 ac77b0a7-7efd-4f26-9a25-d2aaca06c9ba instrument Multibeam Echosounder The EM 3000 multibeam echo sounder is a very high resolution seabed mapping and inspection system with respect to high accuracy and resolution. The minimum operating depth is from less than 1 m below its transducers, and in typical sea water conditions the system operates to more than 150 m depth (less in warm water and more in fresh water). Small dimensions and low weight makes the system portable and easy to install. This allows use on survey launches and subsea vehicles to 1500 m water depth. The EM 3000 system has a very high ping rate of up to 40 Hz, a large number of measurements per ping (typically about 120), 1.5 degrees beamwidth, and electronic pitch stabilization of the transmit beam. 100% coverage of the bottom is achievable at vessel speeds of about 10 knots in shallow waters with acrosstrack coverage of up to four times depth beneath the transducers with a basic system. At longer range the achievable coverage may be up to 200 m, and 100% coverage is achievable with vessel speeds up to 20 knots. The EM 3000 may be configured to use two sets of transducers (Sonar Heads). This increases the shallow water coverage to up to ten times the depth, and the number of measurements per ping to typically 220. With an angular coverage sector of nominally 200 degrees the dual system also allows surveying to the water surface along shorelines, river banks and man-made structures. The system sonar frequency is 300 kHz allowing small dimensions, good range capability and high tolerance to turbid waters. Integrated seabed acoustical imaging capability (like a sidescan sonar) is included as standard. A nearfield mode is available for increased resolution at very short ranges (less than 4 m). A combination of phase and amplitude bottom detection algorithm is used, resulting in a measurement accuracy of 5 cm RMS being achievable practically independent of beam pointing angle. The EM 3000 multibeam system was in production from 1996 to 2004 and was replaced with the EM 3002. MOCNESS gear Plankton Nets The Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS) uses a stepping motor to sequentially control the opening and closing of individual nets to obtain discrete depth tow data. The MOCNESS uses underwater and shipboard electronics for controlling the device. The electronics system continuously monitors the functioning of the nets, frame angle, horizontal velocity, vertical velocity, volume filtered, and selected environmental parameters such as salinity and temperature. Isaac-Kidd Midwater Trawl (IKMT) gear Trawl Nets The Isaacs-Kidd Midwater Trawl (IKMT) is used to collect deep water biological specimens larger than those taken by standard plankton nets. The mouth of the net is attached to a wide, V-shaped, rigid diving vane that keeps the mouth of the net open and maintains the net at depth for extended periods Charter vessels-small boats various vessels ranging in size (20-40 ft length) chartered for cetacean surveys when a NOAA small boat is not available. Simrad EM3000 ac77b0a7-7efd-4f26-9a25-d2aaca06c9ba instrument Multibeam Echosounder The EM 3000 multibeam echo sounder is a very high resolution seabed mapping and inspection system with respect to high accuracy and resolution. The minimum operating depth is from less than 1 m below its transducers, and in typical sea water conditions the system operates to more than 150 m depth (less in warm water and more in fresh water). Small dimensions and low weight makes the system portable and easy to install. This allows use on survey launches and subsea vehicles to 1500 m water depth. The EM 3000 system has a very high ping rate of up to 40 Hz, a large number of measurements per ping (typically about 120), 1.5 degrees beamwidth, and electronic pitch stabilization of the transmit beam. 100% coverage of the bottom is achievable at vessel speeds of about 10 knots in shallow waters with acrosstrack coverage of up to four times depth beneath the transducers with a basic system. At longer range the achievable coverage may be up to 200 m, and 100% coverage is achievable with vessel speeds up to 20 knots. The EM 3000 may be configured to use two sets of transducers (Sonar Heads). This increases the shallow water coverage to up to ten times the depth, and the number of measurements per ping to typically 220. With an angular coverage sector of nominally 200 degrees the dual system also allows surveying to the water surface along shorelines, river banks and man-made structures. The system sonar frequency is 300 kHz allowing small dimensions, good range capability and high tolerance to turbid waters. Integrated seabed acoustical imaging capability (like a sidescan sonar) is included as standard. A nearfield mode is available for increased resolution at very short ranges (less than 4 m). A combination of phase and amplitude bottom detection algorithm is used, resulting in a measurement accuracy of 5 cm RMS being achievable practically independent of beam pointing angle. The EM 3000 multibeam system was in production from 1996 to 2004 and was replaced with the EM 3002. MOCNESS gear Plankton Nets The Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS) uses a stepping motor to sequentially control the opening and closing of individual nets to obtain discrete depth tow data. The MOCNESS uses underwater and shipboard electronics for controlling the device. The electronics system continuously monitors the functioning of the nets, frame angle, horizontal velocity, vertical velocity, volume filtered, and selected environmental parameters such as salinity and temperature. Isaac-Kidd Midwater Trawl (IKMT) gear Trawl Nets The Isaacs-Kidd Midwater Trawl (IKMT) is used to collect deep water biological specimens larger than those taken by standard plankton nets. The mouth of the net is attached to a wide, V-shaped, rigid diving vane that keeps the mouth of the net open and maintains the net at depth for extended periods gov.noaa.nmfs.inport:36841 Stephanie Sexton 2017-02-21T19:07:45 SysAdmin InPortAdmin 2026-03-04T19:17:18 2017-03-09 Southwest Fisheries Science Center SWFSC 8901 La Jolla Shores Dr. La Jolla CA 92037 USA (858)546-7000 https://swfsc.noaa.gov/ 8:00-16:30 1001 Public No No 2017-03-09 1 Year 2018-03-09