AFSC/RACE/MACE: Results of 2013 acoustic trawl survey Gulf of Alaska DY1307

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.

Pollock Stock assessment

Enter notes if applicable.

Enter other citation details.

Enter supplemental information if applicable.

Enter a general description of the extent, if any.

Go to https://www.ngdc.noaa.gov/mgg/wcd/ or email Anderson, Charles (charles.anderson@noaa.gov)

The data set is still being analyzed and will not be available for distribution until it has been finalized and all QA/QC practices have been performed. Contact the Data Point Of Contact for estimated time of release.

User must read and fully comprehend the metadata prior to use. User must acknowledge the Originator when using the data set as a source. User must share data products developed using the source data set with the Originator. Data should not be used beyond the limits of the source scale.

These data were collected in accordance NOAA protocols for fisheries acoustics surveys and related sampling (Alaska Fisheries Science Center), 23 p. Prepared by Midwater Assessment and Conservation Engineering Program, Alaska Fish. Sci. Center, Natl. Mar. Fish. Serv., NOAA. Available online: http://www.afsc.noaa.gov/RACE/midwater/AFSC%20AT%20Survey%20Protocols_Feb%202013.pdf

If the delay between data collection and dissemination is longer than the latency of automated processing, explain under what authority data access is delayed. This field should only be included if the delay is longer than the latency of automated processing.

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.

Acoustic data were recorded at the five split-beam frequencies using ER60 software and, as a backup, acoustic telegram data were logged with Myriax EchoLog 500 software. Acoustic measurements were collected from 16 m below the sea surface to within 0.5 m of the sounder-detected bottom or a maximum of 1,000 m in deep water. Data were analyzed using Myriax Echoview post-processing software. See National Marine Fisheries Service (NMFS) 2013. NOAA protocols for fisheries acoustics surveys and related sampling (Alaska Fisheries Science Center), 23 p. Prepared by Midwater Assessment and Conservation Engineering Program, Alaska Fish. Sci. Center, Natl. Mar. Fish. Serv., NOAA. Available online: http://www.afsc.noaa.gov/RACE/midwater/AFSC%20AT%20Survey%20Protocols_Feb%202013.pdf