Cook Inlet Beluga UAS Photogrammetry and Photo-Identification Survey Brief - 2025

Who is conducting the research?

This project is supported by NOAA Fisheries. Field participants include scientists and UAS pilots from the Alaska Fisheries Science Center's (AFSC) Marine Mammal Laboratory (MML). Data will be analyzed by MML staff.

What is the research objective?

The overall objective is to apply photogrammetry and photo-identification methods to overhead photographs collected from a small UAS (drone), in order to estimate an annual calf production index and to estimate the abundance of the population. In previous surveys we have shown we can collect a large number of high-resolution photographs of beluga whales with little or no disturbance to the whales. Photogrammetry will be used to estimate the relative length of whales by measuring the distance from the blowhole to the dorsal ridge, which will be scaled up to total length. Length measurements will be used to identify newborn calves and estimate an annual calf production index.

Photographs of whales will be matched to each other to identify re-sightings of the same individual whales across different days, using scratches and other natural markings on the whales. The sighting histories of each identified whale will be used to estimate the abundance of the population through closed-model mark-recapture methods.

Where is the research being conducted?

Daily surveys will begin and end each day at the Ship Creek boat ramp, in Anchorage, AK. Surveys will rotate between Chickaloon Bay, Susitna River delta, and Knik Arm, depending upon weather.

Why are the data important?

Biennial airplane surveys have estimated the Cook Inlet beluga population is currently declining, for unknown reasons. These UAS data will provide an alternative way of monitoring the population on an annual basis, and the calf production estimate will determine if the population is producing enough calves to recover.

Last updated by Alaska Fisheries Science Center on 06/04/2025

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