Alaskan Harbor Porpoise Aerial Survey Data 1997-1999

NOAA's Alaska Fisheries Science Center conducted aerial surveys to estimate harbor porpoise abundance across three Alaska stocks. Surveys used multiple observers in bubble and belly windows to collect sightings and calculate perception bias corrections. Data collection spanned from May 1997 to July 1999, covering the Southeast Alaska, Gulf of Alaska, and Bering Sea stocks.

Use Cases

• Estimating perception bias in aerial surveys by matching belly window sightings to side observer records.
• Modeling population abundance trends for the Southeast Alaska, Gulf of Alaska, and Bering Sea harbor porpoise stocks.
• Analyzing seasonal distribution patterns from summer survey data collected between 1997 and 1999.
• Providing baseline data for stock assessment reports required under the Marine Mammal Protection Act.

Strengths

• Surveys employed a specific three-observer method (two side, one belly) to estimate perception bias for harbor porpoise in Alaskan waters.
• Data collection covers three distinct geographic stocks over three consecutive summer seasons (1997-1999).
• Dataset is hosted on multiple authoritative platforms (Data.gov, NASA Earthdata), indicating institutional validation.

Limitations

• No column names, row counts, or file size information is provided by any source, limiting technical assessment.
• Conflicting last updated dates exist: Data.gov lists 2026-03 05, while NASA Earthdata lists 1999-07-04, creating uncertainty about metadata maintenance.
• License information is not specified, which may restrict certain types of reuse.

Provenance

Source

National Oceanic and Atmospheric Administration, Department of Commerce, Alaska Fisheries Science Center, National Marine Mammal Laboratory.

Collection Method

Aerial surveys with observers in bubble windows (left/right) and a belly window along the trackline.

Time Range

1997-05-08 to 1999-07-04

Freshness

2026 03-05 23:08:14.947745

Geography

Alaskan waters, covering Southeast Alaska, Gulf of Alaska, and Bering Sea stocks.