AFSC/MML: Distribution and abundance of Southeast Alaska harbor porpoise, 2019

Description

As currently defined, the Southeast Alaska (SEAK) harbor porpoise (Phocoena phocoena) stock ranges from Dixon entrance to Cape Suckling, including inland waterways. Since the early 1990s, the Marine Mammal Laboratory (MML) has conducted ship and aerial surveys to assess abundance and status of harbor porpoise in this region (Dahlheim et al., 2009; Hobbs and Waite, 2010). In recent years, analysis of ship survey sighting data from inland waters has indicated the potential for substructure within this stock. Trends in abundance between 1991 and 2012 suggested that numbers of harbor porpoise in the northern portion of the study area (Glacier Bay/Icy Strait) were stable. However, in the southern portion of the range (Wrangell and Zarembo), numbers declined significantly in the mid-2000s and subsequently increased again in early 2010 (Dahlheim et al., 2015). The decline was observed only in a region where gillnet fisheries operate. Such contrasting trends in abundance between the northern and southern portions of the range suggest the possible existence of multiple populations within the currently recognized SEAK stock. There is evidence that incidental mortality of harbor porpoise in the salmon driftnet fishery in SEAK may exceed the maximum allowable level under the Marine Mammal Protection Act (MMPA) (Muto et al., 2018). The most recent estimate of abundance for the whole stock is more than 8 years old and cannot be used to estimate PBR. In addition, estimates of abundance from inland waters from 2011 are now outdated and are no longer applicable for management. Therefore, a new estimate was needed to update estimates of the maximum allowable bycatch levels.

Resources

Name Format Description Link
0 csv files with effort and sighting data. https://www.ncei.noaa.gov/access/metadata/landing-page/bin/iso?id=gov.noaa.nodc:0277244
0 View the complete metadata record on InPort for more information about this dataset. https://www.fisheries.noaa.gov/inport/item/69383
0 AKFSC Home Page https://www.fisheries.noaa.gov/about/alaska-fisheries-science-center
0 Publication on Southeast Alaska harbor porpoise demographically independent populations. https://repository.library.noaa.gov/view/noaa/46442
33 NOAA Data Management Plan for this record on InPort. https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/afsc/dmp/pdf/69383.pdf
0 csv files with effort and sighting data. https://www.ncei.noaa.gov/access/metadata/landing-page/bin/iso?id=gov.noaa.nodc:0277244
0 View the complete metadata record on InPort for more information about this dataset. https://www.fisheries.noaa.gov/inport/item/69383
0 Publication of abundance estimate from the 2019 harbor porpoise survey https://www.frontiersin.org/articles/10.3389/fmars.2022.966489/full
0 Publication on Southeast Alaska harbor porpoise demographically independent populations. https://repository.library.noaa.gov/view/noaa/46442
0 The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. https://www.earthdata.nasa.gov/learn/find-data/idn/gcmd-keywords
33 NOAA Data Management Plan for this record on InPort. https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/afsc/dmp/pdf/69383.pdf
0 Publication of abundance estimate from the 2019 harbor porpoise survey https://www.frontiersin.org/articles/10.3389/fmars.2022.966489/full
0 Global Change Master Directory (GCMD). 2024. GCMD Keywords, Version 19. 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 https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 AKFSC Home Page https://www.fisheries.noaa.gov/about/alaska-fisheries-science-center
0 View the complete metadata record on InPort for more information about this dataset. https://www.fisheries.noaa.gov/inport/item/69383
0 AKFSC Home Page https://www.fisheries.noaa.gov/about/alaska-fisheries-science-center
0 Publication on Southeast Alaska harbor porpoise demographically independent populations. https://repository.library.noaa.gov/view/noaa/46442
0 Global Change Master Directory (GCMD). 2024. GCMD Keywords, Version 19. 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 https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
33 NOAA Data Management Plan for this record on InPort. https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/afsc/dmp/pdf/69383.pdf
0 csv files with effort and sighting data. https://www.ncei.noaa.gov/access/metadata/landing-page/bin/iso?id=gov.noaa.nodc:0277244
0 Publication of abundance estimate from the 2019 harbor porpoise survey https://www.frontiersin.org/articles/10.3389/fmars.2022.966489/full

Tags

  • alaska fisheries science center
  • alaska
  • united states of america
  • continent
  • noaa
  • summer
  • north america
  • u.s. department of commerce
  • line transect
  • national marine fisheries service
  • doc/noaa/nmfs/afsc
  • abundance estimate
  • cetacean assessment and ecology program
  • distance sampling
  • phocoena phocoena

Topics

Categories