The beluga whale (Delphinapterus leucas) is a medium-sized toothed whale of Arctic and subarctic waters. The Cook Inlet stock near Anchorage is the smallest and most genetically distinct of Alaska’s belugas and is designated depleted.[1]
| Scientific name | Delphinapterus leucas |
|---|---|
| Adult male | 11–15 ft; 1,000–2,000 lb |
| Blubber | Up to 5 in thick |
| Gestation | About 14.5 months |
| Cook Inlet low count | About 347 by 1998 |
| Lifespan | Up to about 80 years |
Description
The beluga is a toothed whale whose closest relative is the narwhal. It has a blubber layer up to five inches thick and a dorsal fin reduced to a low ridge, and it is the only whale known to bend its neck. Newborns are about five feet long and dark blue-gray, adults usually turn white by age 8 to 10, males reach 11 to 15 feet and females are seldom over 12 feet.[1]
Cook Inlet population
The Cook Inlet stock is the smallest and most genetically distinct Alaskan stock. It was believed to have exceeded 1,000 whales at one time and fell to about 347 by 1998, largely through overharvest. A harvest moratorium was imposed in 1999 and the stock was designated depleted in 2000. The most recent survey in the source counted about 375 whales, and listing petitions under the Endangered Species Act were filed in 1999, which was rejected, and 2007. These figures are from the source and may have changed.[1]
Diet
Summer diet centres on schooling and anadromous fish, including herring, capelin, smelt, Arctic and saffron cods, salmon, flatfishes and sculpins, with occasional octopus, squid, shrimp, crabs and clams. Typical feeding dives in Alaska are 20 to 100 feet and last two to five minutes.[1]
Reproduction and other stocks
Females mature at 8 to 10 years and breeding occurs in March or April. Gestation lasts about 14.5 months, calves are born from May to July, most females have one calf every three years and nursing lasts about two years. Other Alaskan stocks are co-managed with Alaska Native hunters through the Alaska Beluga Whale Committee, and the source gave about 18,000 belugas in the Bering Sea and close to 40,000 in the Beaufort Sea.[1]
FAQs
How many Cook Inlet belugas are there? About 375 in the source survey.
How long do belugas live? Up to about 80 years.
Why did the Cook Inlet stock decline? Largely overharvest.
Sources
Key facts
- About 375 whales in source survey
- Harvest moratorium 1999
Quick checkWhich beluga stock near Anchorage is depleted?Show answer
The Cook Inlet stock
Sources
- Alaska Department of Fish and Game. Beluga Whale, Wildlife Notebook Series. 2026 (accessed 2026-11-14)
Editorially reviewed by Specialty Digest Editorial TeamLast reviewed November 14, 2026Researched and drafted with AI assistanceReport an issue