Cook Inlet Beluga Whale Aerial Survey Counts

Aerial surveys of Cook Inlet beluga whales (Delphinapterus leucas) were conducted from 1993 to 2022, excluding 2013. The data includes environmental conditions, time, location, species, and inclinometer angle for each sighting, supporting inter-annual trend analyses. Beginning in 2005, August surveys were added to document calving groups in the upper Inlet.

Use Cases

• Calculating population abundance estimates based on aerial observer counts and video-corrected group sizes.
• Analyzing long-term population trends from 1993 to 2022 using consistent June survey protocols.
• Studying calving group distribution and demographics using August survey data added in 2005.
• Correcting for perception bias in counts by comparing observer tallies with video footage.
• Examining age class color ratios (white adults vs. darker juveniles/calves) from zoomed video.

Strengths

• Long-term data collection spanning nearly 30 years (1993-2022), enabling robust trend analysis.
• Methodological rigor includes paired independent observers and video validation to correct for missed animals.
• Cross-platform presence on Data.gov and NASA Earthdata signals its importance and curation.

Limitations

• Column names and dataset size (row count) are not provided in any source, limiting assessment of structure.
• Sources conflict on the end date of data collection (2014 vs. 2022), creating uncertainty about temporal coverage.
• License information is not provided, restricting clarity on permissible use.

Provenance

Source

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

Collection Method

Aerial surveys with paired observers and simultaneous video recording.

Time Range

1993 to 2022 (excluding 2013).

Freshness

Last updated on Data.gov: 2026-04-01.

Geography

Cook Inlet, Alaska, USA.