32  Seabird At-Sea Density

Description Seabird densities on the water during the breeding season can track marine environmental conditions and may reflect regional production and availability of forage. Data from this indicator type can establish habitat use and may be used to detect and track seabird population movements or increases/declines as they relate to ecosystem change. We monitor and report on at-sea densities of three focal seabird species in the Northern, Central, and Southern CCE.

Sooty shearwaters migrate to the CCE from the Southern Hemisphere in spring and summer to forage on the shelf and near the shelf break on small fish, including northern anchovy, as well as squid and zooplankton. Common murres and Cassin’s auklets are resident species in the CCE that feed primarily over the shelf. Common murres target a variety of pelagic fish, while Cassin’s auklets prey mainly on zooplankton and small fish.

Indicator Regions

Cape Flattery, WA to Newport, OR

• Species:
  • Cassins auklet, Summer
  • Common murre, Summer
  • Sooty shearwater, Summer
• Component Category: Seabirds
• Time Range: 2003 - 2024
• CCIEA Data Contact: tom.good@noaa.gov
• Institution: NOAA NWFSC
• Source Data: Data from Jen Zamon (jen.zamon@noaa.gov). Data are shipboard counts conducted during the NOAA Northwest Fisheries Science Center’s Juvenile Salmon & Ocean Ecosystem Survey (JSOES).
• Additional Calculations: Data are shipboard counts, transformed as ln(bird density/km-2 +1) and expressed as an anomaly of log density relative to the long-term mean.

N of Bodega Bay, CA to south of Monterey Bay, CA

• Species:
  • Cassins auklet, Summer
  • Common murre, Summer
  • Sooty shearwater, Summer
• Component Category: Seabirds
• Time Range: 1996 - 2024
• CCIEA Data Contact: tom.good@noaa.gov
• Institution: Farallon Institute
• Source Data: Data are from the SWFSC Rockfish Recruitment and Ecosystem Assessment Survey), courtesy of Dr. Bill Sydeman of the Farallon Institute (wsydeman@faralloninstitute.org)..
• Additional Calculations: Data are shipboard counts, transformed as ln(bird density/km-2 +1) and expressed as an anomaly of log density relative to the long-term mean.

CalCOFI lines 76 to 93

• Species:
  • Cassins auklet, Spring
  • Common murre, Spring
  • Sooty shearwater, Spring
  • Cassins auklet, Spring
  • Common murre, Spring
  • Sooty shearwater, Spring
• Component Category: Seabirds
• Time Range: 1987 - 2024
• CCIEA Data Contact: tom.good@noaa.gov
• Institution: Farallon Institute
• Source Data: Data are from CalCOFI surveys, courtesy of Dr. Bill Sydeman of the Farallon Institute (wsydeman@faralloninstitute.org).
• Additional Calculations: Data are shipboard counts, transformed as ln(bird density/km2 +1) and expressed as an anomaly of log density relative to the long-term mean.

Indicator Download

ERDDAP™ link:

https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_B_AS_DENS.html

References