Description: This group layer depicts the relative intensity and proportion of fishing effort for commercial bottom trawling off the U.S. West Coast from 1 Jan 2002 to11 Jun 2006.
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: NOAA Fisheries, Northwest Fisheries Science Center, Fishery Resource Analysis and Monitoring Division
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This data layer depicts the relative intensity of fishing effort for commercial bottom trawling off the U.S. West Coast from 1 Jan 2002 to</SPAN><SPAN><SPAN>11 Jun 2006. Each of the three coastal states administers a commercial logbook program, for which records are uploaded to the Pacific Fisheries Information Network (PacFIN) regional database. Database records were utilized for commercial trips using limited entry </SPAN></SPAN><SPAN>bottom trawl gear types (e.g., "small" footrope, "large" </SPAN><SPAN><SPAN>footrope, flatfish, selective flatfish, and roller trawl) regardless of fishery sector. Records from the majority of state-managed trawl fisheries (e.g., pink shrimp, ridgeback prawn, sea urchin) are not included in PacFIN and thus are not represented. However, tows targeting California halibut while also participating in the federal trawl fishery are submitted to PacFIN and included in this data layer</SPAN></SPAN><SPAN><SPAN>.</SPAN></SPAN></P><P><SPAN>The intensity layer is a raster layer with cell values representing the total length of all lines intersecting a standardized area. To calculate this metric, we applied a line density algorithm in ArcGIS geographical information system software (Environmental System Research Institute, Incorporated, Redlands, California). The line density algorithm calculates density within a circular search area (radius = 3 km) centered at a grid cell (size 500 m x 500 m). The value (units: km/km</SPAN><SPAN><SPAN>2</SPAN></SPAN><SPAN>) for each raster cell is the quotient of total line portions intersecting the circular area per cell area. Since density outputs are highly sensitive to the specified radius and cell size, the absolute values are less important than the relative nature of them. The benefit of this output over depicting lines themselves is that the density output better identifies areas where fishing effort is concentrated, while still ensuring confidentiality of individual fishing locations. The initial density output was more spatially extensive than the one shown in the figures, because it included cells with density values calculated from tows made by less than three vessels. Those "confidential" cells were removed for the final published data layer. Density parameters were chosen in order to minimize data exclusion (due to confidentiality mandates) while still providing a fairly high spatial resolution (500 x 500 m).</SPAN></P><P><SPAN><SPAN>This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. It is recognized that fishing events, particularly for mobile gears, rarely follow straight-line paths; however, this was the most readily available information. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats.</SPAN></SPAN></P></DIV></DIV></DIV>
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration
Pacific States Marine Fisheries Commission
Description: Abstract: This data layer depicts the proportion of fishing effort for commercial bottom trawling off the U.S. West Coast from 1 Jan 2002 to 11 Jun 2006. Each of the three coastal states administers a commercial logbook program, for which records are uploaded to the Pacific Fisheries Information Network (PacFIN) regional database. Database records were utilized for commercial trips using limited entry bottom trawl gear types (e.g., "small" footrope, "large" footrope, flatfish, selective flatfish, and roller trawl) regardless of fishery sector. Records from the majority of state-managed trawl fisheries (e.g., pink shrimp, ridgeback prawn, sea urchin) are not included in PacFIN and thus are not represented. However, tows targeting California halibut while also participating in the federal trawl fishery are submitted to PacFIN and included in this data layer.The polygon layer is a vector layer with values representing the proportion of all lines coastwide intersecting each 10 x 10 min cell. The benefit of this output over depicting lines themselves is that all data can be represented, while still ensuring confidentiality of individual fishing locations.This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. It is recognized that fishing events, particularly for mobile gears, rarely follow straight-line paths; however, this was the most readily available information. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats. Purpose: The main purpose of this data layer is to help inform the National Marine Fisheries Service Biological Opinion on Continuing Operation of the Pacific Coast Groundfish Fishery (NMFS 2012). In 2011, new regulations governing the limited entry bottom trawl and midwater trawl fisheries led to the induction of individual fishing quotas (IFQs). Primary goals of IFQ management included decreased bycatch and increased catch accountability, profitability, and efficiency. In the shoreside bottom trawl fishery, permit holders with IFQ and a trawl endorsement can use multiple gear types (although not within the same trip), including bottom trawl, midwater trawl, hook-and-line gear, and pot gear. These management changes could impact fishing effort in trawl sectors, as well as alter fixed gear fishing effort by providing a new opportunity for fixed gear fishing activity and potential competition between IFQ and other fixed gear sectors. This data layer displays fishing effort to assess these potential changes. NMFS (National Marine Fisheries Service). 2012. Continuing Operation of the Pacific Coast Groundfish Fishery - Endangered Species Act (ESA) Section 7(a)(2) Biological Opinion and Section 7(a)(2) "Not Likely to Adversely Affect" Determination. PCTS Number: NWR-2012-876. 194 p. Credit: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration Pacific States Marine Fisheries Commission
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration Pacific States Marine Fisheries Commission
Description: This group layer depicts the relative intensity and proportion of fishing effort for commercial bottom trawling off the U.S. West Coast from 12 Jun 2006 to 31 Dec 2010.
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: NOAA Fisheries, Northwest Fisheries Science Center, Fishery Resource Analysis and Monitoring Division
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This data layer depicts the relative intensity of fishing effort for commercial bottom trawling off the U.S. West Coast from 12 Jun 2006 to </SPAN><SPAN><SPAN>31 Dec 2010. Each of the three coastal states administers a commercial logbook program, for which records are uploaded to the Pacific Fisheries Information Network (PacFIN) regional database. </SPAN></SPAN><SPAN>Database records were utilized for commercial trips using limited entry bottom trawl gear types (e.g., "small" footrope, "large" </SPAN><SPAN><SPAN>footrope, flatfish, selective flatfish, and roller trawl) regardless of fishery sector. Records from the majority of state-managed trawl fisheries (e.g., pink shrimp, ridgeback prawn, sea urchin) are not included in PacFIN and thus are not represented. However, tows targeting California halibut while also participating in the federal trawl fishery are submitted to PacFIN and included in this data layer</SPAN></SPAN><SPAN><SPAN>.</SPAN></SPAN></P><P><SPAN>The intensity layer is a raster layer with cell values representing the total length of all lines intersecting a standardized area. To calculate this metric, we applied a line density algorithm in ArcGIS geographical information system software (Environmental System Research Institute, Incorporated, Redlands, California). The line density algorithm calculates density within a circular search area (radius = 3 km) centered at a grid cell (size 500 m x 500 m). The value (units: km/km</SPAN><SPAN><SPAN>2</SPAN></SPAN><SPAN>) for each raster cell is the quotient of total line portions intersecting the circular area per cell area. Since density outputs are highly sensitive to the specified radius and cell size, the absolute values are less important than the relative nature of them. The benefit of this output over depicting lines themselves is that the density output better identifies areas where fishing effort is concentrated, while still ensuring confidentiality of individual fishing locations. The initial density output was more spatially extensive than the one shown in the figures, because it included cells with density values calculated from tows made by less than three vessels. Those "confidential" cells were removed for the final published data layer. Density parameters were chosen in order to minimize data exclusion (due to confidentiality mandates) while still providing a fairly high spatial resolution (500 x 500 m).</SPAN></P><P><SPAN><SPAN>This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. It is recognized that fishing events, particularly for mobile gears, rarely follow straight-line paths; however, this was the most readily available information. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats.</SPAN></SPAN></P></DIV></DIV></DIV>
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration
Pacific States Marine Fisheries Commission
Description: Abstract: This data layer depicts the proportion of fishing effort for commercial bottom trawling off the U.S. West Coast from 12 Jun 2006 to 31 Dec 2010. Each of the three coastal states administers a commercial logbook program, for which records are uploaded to the Pacific Fisheries Information Network (PacFIN) regional database. Database records were utilized for commercial trips using limited entry bottom trawl gear types (e.g., "small" footrope, "large" footrope, flatfish, selective flatfish, and roller trawl) regardless of fishery sector. Records from the majority of state-managed trawl fisheries (e.g., pink shrimp, ridgeback prawn, sea urchin) are not included in PacFIN and thus are not represented. However, tows targeting California halibut while also participating in the federal trawl fishery are submitted to PacFIN and included in this data layer.The polygon layer is a vector layer with values representing the proportion of all lines coastwide intersecting each 10 x 10 min cell. The benefit of this output over depicting lines themselves is that all data can be represented, while still ensuring confidentiality of individual fishing locations.This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. It is recognized that fishing events, particularly for mobile gears, rarely follow straight-line paths; however, this was the most readily available information. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats. Purpose: The main purpose of this data layer is to help inform the National Marine Fisheries Service Biological Opinion on Continuing Operation of the Pacific Coast Groundfish Fishery (NMFS 2012). In 2011, new regulations governing the limited entry bottom trawl and midwater trawl fisheries led to the induction of individual fishing quotas (IFQs). Primary goals of IFQ management included decreased bycatch and increased catch accountability, profitability, and efficiency. In the shoreside bottom trawl fishery, permit holders with IFQ and a trawl endorsement can use multiple gear types (although not within the same trip), including bottom trawl, midwater trawl, hook-and-line gear, and pot gear. These management changes could impact fishing effort in trawl sectors, as well as alter fixed gear fishing effort by providing a new opportunity for fixed gear fishing activity and potential competition between IFQ and other fixed gear sectors. This data layer displays fishing effort to assess these potential changes. NMFS (National Marine Fisheries Service). 2012. Continuing Operation of the Pacific Coast Groundfish Fishery - Endangered Species Act (ESA) Section 7(a)(2) Biological Opinion and Section 7(a)(2) "Not Likely to Adversely Affect" Determination. PCTS Number: NWR-2012-876. 194 p. Credit: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration Pacific States Marine Fisheries Commission
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration Pacific States Marine Fisheries Commission
Description: This group layer depicts the relative intensity adn proportion of fishing effort for at-sea processed commercial midwater catcher-processors off the U.S. West Coast from 1 Jan 2002 to 31 Dec 2005.
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: NOAA Fisheries, Northwest Fisheries Science Center, Fishery Resource Analysis and Monitoring Division
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This data layer depicts the relative intensity of fishing effort for at-sea processed commercial midwater catcher-processors off the U.S. West Coast from 1 Jan 2002 to 31 Dec 2005. Records of at-sea processed midwater trawl tows were compiled from observer records from the At-Sea Hake Observer Program (A-SHOP).</SPAN></P><P><SPAN>The intensity layer is a raster layer with cell values representing the total length of all lines intersecting a standardized area. To calculate this metric, we applied a line density algorithm in ArcGIS geographical information system software (Environmental System Research Institute, Incorporated, Redlands, California). The line density algorithm calculates density within a circular search area (radius = 3 km) centered at a grid cell (size 500 m x 500 m). The value (units: km/km</SPAN><SPAN><SPAN>2</SPAN></SPAN><SPAN>) for each raster cell is the quotient of total line portions intersecting the circular area per cell area. Since density outputs are highly sensitive to the specified radius and cell size, the absolute values are less important than the relative nature of them. The benefit of this output over depicting lines themselves is that the density output better identifies areas where fishing effort is concentrated, while still ensuring confidentiality of individual fishing locations. The initial density output was more spatially extensive than the one shown in the figures, because it included cells with density values calculated from tows made by less than three vessels. Those "confidential" cells were removed for the final published data layer. Density parameters were chosen in order to minimize data exclusion (due to confidentiality mandates) while still providing a fairly high spatial resolution (500 x 500 m).</SPAN></P><P><SPAN>This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. It is recognized that fishing events, particularly for mobile gears, rarely follow straight-line paths; however, this was the most readily available information. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats.</SPAN></P></DIV></DIV></DIV>
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration
Description: This group layer depicts the relative intensity and proportion of fishing effort for at-sea processed commercial midwater catcher-processors off the U.S. West Coast from 1 Jan 2006 to 31 Dec 2010.
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: NOAA Fisheries, Northwest Fisheries Science Center, Fishery Resource Analysis and Monitoring Division
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This data layer depicts the relative intensity of fishing effort for at-sea processed commercial midwater catcher-processors off the U.S. West Coast from 1 Jan 2006 to 31 Dec 2010. Records of at-sea processed midwater trawl tows were compiled from observer records from the At-Sea Hake Observer Program (A-SHOP).</SPAN></P><P><SPAN>The intensity layer is a raster layer with cell values representing the total length of all lines intersecting a standardized area. To calculate this metric, we applied a line density algorithm in ArcGIS geographical information system software (Environmental System Research Institute, Incorporated, Redlands, California). The line density algorithm calculates density within a circular search area (radius = 3 km) centered at a grid cell (size 500 m x 500 m). The value (units: km/km</SPAN><SPAN><SPAN>2</SPAN></SPAN><SPAN>) for each raster cell is the quotient of total line portions intersecting the circular area per cell area. Since density outputs are highly sensitive to the specified radius and cell size, the absolute values are less important than the relative nature of them. The benefit of this output over depicting lines themselves is that the density output better identifies areas where fishing effort is concentrated, while still ensuring confidentiality of individual fishing locations. The initial density output was more spatially extensive than the one shown in the figures, because it included cells with density values calculated from tows made by less than three vessels. Those "confidential" cells were removed for the final published data layer. Density parameters were chosen in order to minimize data exclusion (due to confidentiality mandates) while still providing a fairly high spatial resolution (500 x 500 m).</SPAN></P><P><SPAN>This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. It is recognized that fishing events, particularly for mobile gears, rarely follow straight-line paths; however, this was the most readily available information. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats.</SPAN></P></DIV></DIV></DIV>
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration
Description: This group layer depicts the relative intensity and proportion of fishing effort for at-sea processed commercial midwater mothership catcher vessels off the U.S. West Coast from 1 Jan 2002 to 31 Dec 2005.
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: NOAA Fisheries, Northwest Fisheries Science Center, Fishery Resource Analysis and Monitoring Division
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This data layer depicts the relative intensity of fishing effort for at-sea processed commercial midwater mothership catcher vessels off the U.S. West Coast from 1 Jan 2002 to </SPAN><SPAN><SPAN>31 Dec 2005. Records of at-sea processed midwater trawl tows were compiled from observer records from the At-Sea Hake Observer Program (A-SHOP). </SPAN></SPAN></P><P><SPAN>The intensity layer is a raster layer with cell values representing the total length of all lines intersecting a standardized area. To calculate this metric, we applied a line density algorithm in ArcGIS geographical information system software (Environmental System Research Institute, Incorporated, Redlands, California). The line density algorithm calculates density within a circular search area (radius = 3 km) centered at a grid cell (size 500 m x 500 m). The value (units: km/km</SPAN><SPAN><SPAN>2</SPAN></SPAN><SPAN>) for each raster cell is the quotient of total line portions intersecting the circular area per cell area. Since density outputs are highly sensitive to the specified radius and cell size, the absolute values are less important than the relative nature of them. The benefit of this output over depicting lines themselves is that the density output better identifies areas where fishing effort is concentrated, while still ensuring confidentiality of individual fishing locations. The initial density output was more spatially extensive than the one shown in the figures, because it included cells with density values calculated from tows made by less than three vessels. Those "confidential" cells were removed for the final published data layer. Density parameters were chosen in order to minimize data exclusion (due to confidentiality mandates) while still providing a fairly high spatial resolution (500 x 500 m).</SPAN></P><P><SPAN><SPAN>This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. It is recognized that fishing events, particularly for mobile gears, rarely follow straight-line paths; however, this was the most readily available information. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats.</SPAN></SPAN></P></DIV></DIV></DIV>
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration
Description: This group layer depicts the relative intensity and proportion of fishing effort for at-sea processed commercial midwater mothership catcher vessels off the U.S. West Coast from 1 Jan 2006 to 31 Dec 2010.
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: NOAA Fisheries, Northwest Fisheries Science Center, Fishery Resource Analysis and Monitoring Division
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This data layer depicts the relative intensity of fishing effort for at-sea processed commercial midwater mothership catcher vessels off the U.S. West Coast from 1 Jan 2006 to </SPAN><SPAN><SPAN>31 Dec 2010. Records of at-sea processed midwater trawl tows were compiled from observer records from the At-Sea Hake Observer Program (A-SHOP). </SPAN></SPAN></P><P><SPAN>The intensity layer is a raster layer with cell values representing the total length of all lines intersecting a standardized area. To calculate this metric, we applied a line density algorithm in ArcGIS geographical information system software (Environmental System Research Institute, Incorporated, Redlands, California). The line density algorithm calculates density within a circular search area (radius = 3 km) centered at a grid cell (size 500 m x 500 m). The value (units: km/km</SPAN><SPAN><SPAN>2</SPAN></SPAN><SPAN>) for each raster cell is the quotient of total line portions intersecting the circular area per cell area. Since density outputs are highly sensitive to the specified radius and cell size, the absolute values are less important than the relative nature of them. The benefit of this output over depicting lines themselves is that the density output better identifies areas where fishing effort is concentrated, while still ensuring confidentiality of individual fishing locations. The initial density output was more spatially extensive than the one shown in the figures, because it included cells with density values calculated from tows made by less than three vessels. Those "confidential" cells were removed for the final published data layer. Density parameters were chosen in order to minimize data exclusion (due to confidentiality mandates) while still providing a fairly high spatial resolution (500 x 500 m).</SPAN></P><P><SPAN><SPAN>This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. It is recognized that fishing events, particularly for mobile gears, rarely follow straight-line paths; however, this was the most readily available information. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats.</SPAN></SPAN></P></DIV></DIV></DIV>
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration
Description: This group layer depicts the relative intensity and proportion of fishing effort for commercial non-catch shares hook-and-line gear off the U.S. West Coast from 1 Jan 2002 to 31 Dec 2010.
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: NOAA Fisheries, Northwest Fisheries Science Center, Fishery Resource Analysis and Monitoring Division
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This data layer depicts the relative intensity of fishing effort for commercial non-catch shares hook-and-line gear off the U.S. West Coast from 1 Jan 2002 to </SPAN><SPAN><SPAN>31 Dec 2010. Records of hook-and-line gear fishing locations were compiled from one source: observer records from the West Coast Groundfish Observer Program (WCGOP) database. The WCGOP database includes records of trips for vessels participating in the following sectors: limited entry sablefish-endorsed primary season, limited entry non-sablefish endorsed, and open access fixed gear</SPAN></SPAN><SPAN><SPAN>. </SPAN></SPAN><SPAN><SPAN>Annual WCGOP coverage of fixed gear sectors can be found online at: </SPAN></SPAN><SPAN><SPAN>https://www.nwfsc.noaa.gov/research/divisions/fram/observation/index.cfm. </SPAN></SPAN><SPAN><SPAN>Because all fishing operations are not observed, neither the maps nor the data can be used to characterize the fishery completely. We urge caution when utilizing these data due to the complexity of groundfish management and fleet harvest dynamics.</SPAN></SPAN></P><P><SPAN>The intensity layer is a raster layer with cell values representing the total length of all lines intersecting a standardized area. To calculate this metric, we applied a line density algorithm in ArcGIS geographical information system software (Environmental System Research Institute, Incorporated, Redlands, California). The line density algorithm calculates density within a circular search area (radius = 5 km) centered at a grid cell (size 500 m x 500 m). The value (units: km/km</SPAN><SPAN><SPAN>2</SPAN></SPAN><SPAN>) for each raster cell is the quotient of total line portions intersecting the circular area per cell area. Since density outputs are highly sensitive to the specified radius and cell size, the absolute values are less important than the relative nature of them. The benefit of this output over depicting lines themselves is that the density output better identifies areas where fishing effort is concentrated, while still ensuring confidentiality of individual fishing locations. The initial density output was more spatially extensive than the one shown in the figures, because it included cells with density values calculated from tows made by less than three vessels. Those "confidential" cells were removed for the final published data layer. Density parameters were chosen in order to minimize data exclusion (due to confidentiality mandates) while still providing a fairly high spatial resolution (500 x 500 m).</SPAN></P><P><SPAN><SPAN>This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. Although fishing does not occur continuously along a fixed gear set (e.g., longline, pots), some amount of fishing does occur between set and retrieval points. For that reason, we treated fixed gear sets similarly to trawl tows. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats.</SPAN></SPAN></P></DIV></DIV></DIV>
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration
Description: This group layer depicts the relative intensity and proportion of fishing effort for commercial non-catch shares pot gear off the U.S. West Coast from 1 Jan 2002 to 31 Dec 2010.
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: NOAA Fisheries, Northwest Fisheries Science Center, Fishery Resource Analysis and Monitoring Division
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This data layer depicts the relative intensity of fishing effort for commercial non-catch shares pot gear off the U.S. West Coast from 1 Jan 2002 to </SPAN><SPAN><SPAN>31 Dec 2010. Records of pot gear fishing locations were compiled from one source: observer records from the West Coast Groundfish Observer Program (WCGOP) database. The WCGOP database includes records of trips for vessels participating in the following sectors: limited entry sablefish-endorsed primary season, limited entry non-sablefish endorsed, and open access fixed gear</SPAN></SPAN><SPAN><SPAN>.</SPAN></SPAN><SPAN><SPAN>Annual WCGOP coverage of fixed gear sectors can be found online at: </SPAN></SPAN><SPAN><SPAN>https://www.nwfsc.noaa.gov/research/divisions/fram/observation/index.cfm. </SPAN></SPAN><SPAN><SPAN>Because all fishing operations are not observed, neither the maps nor the data can be used to characterize the fishery completely. We urge caution when utilizing these data due to the complexity of groundfish management and fleet harvest dynamics.</SPAN></SPAN></P><P><SPAN>The intensity layer is a raster layer with cell values representing the total length of all lines intersecting a standardized area. To calculate this metric, we applied a line density algorithm in ArcGIS geographical information system software (Environmental System Research Institute, Incorporated, Redlands, California). The line density algorithm calculates density within a circular search area (radius = 5 km) centered at a grid cell (size 500 m x 500 m). The value (units: km/km</SPAN><SPAN><SPAN>2</SPAN></SPAN><SPAN>) for each raster cell is the quotient of total line portions intersecting the circular area per cell area. Since density outputs are highly sensitive to the specified radius and cell size, the absolute values are less important than the relative nature of them. The benefit of this output over depicting lines themselves is that the density output better identifies areas where fishing effort is concentrated, while still ensuring confidentiality of individual fishing locations. The initial density output was more spatially extensive than the one shown in the figures, because it included cells with density values calculated from tows made by less than three vessels. Those "confidential" cells were removed for the final published data layer. Density parameters were chosen in order to minimize data exclusion (due to confidentiality mandates) while still providing a fairly high spatial resolution (500 x 500 m).</SPAN></P><P><SPAN><SPAN>This spatial summary of fishing effort was developed from lines connecting gear set and retrieval points. Although fishing does not occur continuously along a fixed gear set (e.g., longline, pots), some amount of fishing does occur between set and retrieval points. For that reason, we treated fixed gear sets similarly to trawl tows. This summary is not intended to quantify total impact of fishing on either benthic or pelagic habitats.</SPAN></SPAN></P></DIV></DIV></DIV>
Service Item Id: 3a394bd91ce44a519b43069a14e940cf
Copyright Text: Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration