Beluga whales are distributed throughout the Arctic waters of the northern hemisphere, with five stocks located in the waters surrounding Alaska.

Species Name:   Delphinapterus  leucas

Suborder: Toothed whales (Odontoceti)

Common Name:  Beluga (from the Russian word for “white”)

Size:   11.5-18 feet (3.5-5.5 meters) long, weigh up to 3,300 lbs (1,500 kg)

Color: Newborns are dark gray and lighten as they age.  Adults are typically white, although shade may depend on age, sex, and the individual.

Lifespan: 35-70 years.

Global Population: Approximately 80,000 worldwide, 279 Cook Inlet population (2019 estimate).

Dive time: 2-15 minutes.

Diet: opportunistic feeders, belugas eat invertebrates such as octopus, squid, crabs, shrimp, clams, mussels, snails, sandworms, and a variety of fishes including salmon, eulachon, cod, and, flounder.

Behavior: extremely social animals that typically migrate, hunt, and interact together in groups or single; known as the "canaries of the sea," because they produce a vast repertoire of sounds including whistles, squeals, moos, chirps, and clicks . Cook Inlet beluga whales do not migrate, instead they remain in Cook Inlet year-round.


Alaska’s Cook Inlet beluga whale (CIBW) population (Delphinapterus leucas) is considered a distinct population segment by the National Marine Fisheries Service (NMFS) due to geographic and genetic isolation from other beluga stocks (NMFS 2008).  A steep decline in the CIBW population occurred in the late 1990s, and the population was designated as depleted in 2000 under the Marine Mammal Protection Act (MMPA).  In 2008, NMFS listed the CIBW population as endangered under the Endangered Species Act (ESA, 73 FR 62919).  As a consequence of the ESA listing, NMFS was required to designate critical habitat (i.e., habitat deemed necessary for the survival and recovery of the population) and to develop a Recovery Plan for CIBWs.  In addition, the ESA mandates that all federal agencies consult with NMFS regarding any action that is federally authorized, funded, or implemented, to ensure that the action does not jeopardize the continued existence of the endangered species or result in the destruction or adverse modification of its designated critical habitat. 


The Cook Inlet beluga whale stock may once have numbered as many as 1,300 individuals but declined dramatically during the 1990's. Over the most recent 10-year time period (2008-2018), NMFS has estimated the trend in abundance is approximately -2.3%/year (estimated range between -4.1% to -0.6%), which is declining faster than the previous estimate of -0.5%/year (estimated range between -2.5% and +1.5%) (NMFS, 2020). NMFS abundance surveys from 2018 indicate that the current population estimate is 279 whales.