gov.noaa.nmfs.inport:28206 eng UTF8 dataset Alaska Fisheries Science Center 7600 Sand Point Way N.E., Building 4 Seattle WA 98115 USA https://www.afsc.noaa.gov WWW:LINK-1.0-http--link Website Website for this organization information 0700-1700 Pacific Time resourceProvider Intelmann, Steve (206) 526-4157 (206) 526-6723 7600 Sand Point Way N.E., Building 4 Seattle WA 98115 USA steve.intelmann@noaa.gov pointOfContact 2026-03-04T19:17:17 ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data ISO 19115-2:2009(E) AFSC/RACE/GAP/McConnaughey: Trawlex Chronic Effects: Side Scan Sonar Mosaic - Experimental tow in the mid-east region of CHPZ1. AFSC/RACE/GAP/McConnaughey: Trawlex Chronic Effects: Side Scan Sonar Mosaic - Experimental tow in the mid-east region of CHPZ1. publication NOAA/NMFS/EDM 28206 https://www.fisheries.noaa.gov/inport/item/28206 WWW:LINK-1.0-http--link Full Metadata Record View the complete metadata record on InPort for more information about this dataset. information mapDigital Side-scan sonar images were collected using a Klein 2000 system and a 100/500-kHz towed ?sh that also contained a 3.5-kHz pro?ler source. A shipboard fathometer re- cording system was inoperable during the survey. The side-scan data were recorded digitally at a 10-kHz sample rate over a swath width of 100 m. Six swaths of 100-kHz data were anamorphosed, filtered, overlaid and projected to produce a spatially correct, georeferenced image of the seafloor with pixel resolution of 40 cm. Benthic communities are structured by dynamically interacting factors that determine habitat quality. Since benthic macrofauna demonstrate strong and often narrowly defined affinities, forces altering (or disturbing) the environment will be of considerable importance to their distribution and abundance. Commercial fishing with mobile gear, such as bottom trawls and dredges, and the physical disturbance that results, is widespread in continental shelf areas. Because of its prevalence and the potential for adverse effects, there have been numerous attempts to quantify sea-floor exposure at various spatial scales. The well documented development of commerical fisheries in the eastern Bering Sea (EBS) since 1954 presents a unique opportunity for studying trawling impacts. The Crab and Halibut Protection Zone 1 (CHPZ1; also known as management area 512), located north of the Alaska Peninsula in Bristol Bay, has a long and complex history of trawl prohibitions that extend from 1959 to the present. Using detailed accounts of closures and fishing activity, it is possible to reconstruct historical effort and identify essentially pristine areas immediately adjacent to areas that have been heavily fished with bottom trawls. This physical arrangement permits an examination of chronic disturbance by bottom trawls, without confounding environmental effects that result from geographic separation. Sampling locations were preselected on the basis of historical fish effort. Intelmann, Steve (206) 526-4157 (206) 526-6723 7600 Sand Point Way N.E., Building 4 Seattle WA 98115 USA steve.intelmann@noaa.gov pointOfContact McConnaughey, Bob bob.mcconnaughey@noaa.gov custodian notPlanned Geomorphology Side Scan Sonar theme Bering Sea place DOC/NOAA/NMFS/AFSC > Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Department of Commerce dataCentre Global Change Master Directory (GCMD) Data Center Keywords 2017-04-24 publication 8.5 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian AFSC/RACE/GAP/McConnaughey:Trawlex chronic effects-1997-USGS Sidescan project InPort otherRestrictions Cite As: Alaska Fisheries Science Center, [Date of Access]: AFSC/RACE/GAP/McConnaughey: Trawlex Chronic Effects: Side Scan Sonar Mosaic - Experimental tow in the mid-east region of CHPZ1. [Data Date Range], https://www.fisheries.noaa.gov/inport/item/28206. NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose. otherRestrictions Access Constraints: None otherRestrictions Use Constraints: The United States Government shall not be held liable for improper or incorrect use of data described and/or contained herein. These data and related graphics are not legal documents and are not intended to be used as such. The Alaska Fisheries Science Center gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. Spatial information may not meet National Map Accuracy Standards. The information contained in these data is dynamic and may change over time. Original data were compiled from various sources. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. It is strongly recommended that these data are directly acquired from an Alaska Fisheries Science Center server and not indirectly through other sources which may have changed the data in some way. Although these data have been used (processed) successfully on a computer system at the Alaska Fisheries Science Center, no warranty expressed or implied is made regarding the utility of the data on another system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. unclassified NOAA Data Management Plan (DMP) NOAA/NMFS/EDM 28206 https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/afsc/dmp/pdf/28206.pdf WWW:LINK-1.0-http--link NOAA Data Management Plan (DMP) NOAA Data Management Plan for this record on InPort. information crossReference eng; US geoscientificInformation Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.3.0.4322 -160.729892 -160.386336 57.078774 57.092484 1996 1997 Tidally generated sea-floor lineations in Bristol Bay, Alaska, USA. M. S. Marlow, A. J. Stevenson, H. Chezar and R. A. McConnaughey. Geo-Marine Letters (1999) 19: 219-226. dataset Side-scan sonar images were collected using a Klein 2000 system and a 100/500-kHz towed ?sh that also contained a 3.5-kHz pro?ler source. The side-scan data were recorded digitally at a 10-kHz sample rate over a swath width of 100 m. A single line of 100-kHz data was anamorphosed, filtered, overlaid and projected to produce a spatially correct, georeferenced image of the seafloor with pixel resolution of 40 cm. Grey scale stretch was applied to the data for visual aesthetics. Data were processed using USGS MIPS, where an img and lbl and file was created. The img and lbl file were then converted to bil and hdr format. The bil and hdr file were imported into a raster file geodatabase in ArcGIS and assigned a projection