Science

NOAA Fisheries scientists are leading the effort to answer key questions about beluga whales, with a special focus on the Cook Inlet population. Current research includes studies of beluga whale behavior, ecology, health, distribution, and population trends.

Satellite Tagging

NOAA Fisheries scientists and their collaborators track location data from satellite tags deployed on whales to determine their movements, distribution, diving behavior, and range. In Alaska, scientists and Native subsistence hunters have worked together to place satellite tags on belugas.

From 1999 to 2002, we attached satellite tags to belugas in Cook Inlet and observed their year-round distribution for the first time. Tag data showed changes in beluga behavior. During the ice-covered period (December to May), tagged whales did not leave the upper Cook Inlet and remained within the ice floes. Whales with dive-monitoring tags also began to dive deeper and for longer periods. These long-term survey studies show that the seasonal range of the beluga whales in Cook Inlet has contracted since the early 1990s as the size of the population has decreased.

Learn more about the movement and dive behavior of beluga whales in Cook Inlet (PDF, 48 pages) 

From 2007 to 2009, scientists from the United States, Canada, Greenland, Norway, and Russia worked together to track beluga movements and habits throughout arctic and subarctic waters using satellite tags. This international project helped us learn more about the behavior and life history of belugas.

Learn more about beluga whale tagging studies

Observational Studies

NOAA Fisheries conducts observational studies using photo-identification and other techniques to understand the behavior and population dynamics of beluga whales, as well as threats against them.

Between 2005 and 2014, we worked with our partners to develop a photo-identification catalog and associated surveys of Cook Inlet belugas. The data we collected helped us learn more about individual movement patterns, preferred habitat, social structure, how often individual mothers give birth, and how long calves remain with their mothers.

Learn more about the Cook Inlet beluga whale photo-identification project

In 2017, scientists began using hexacopters (aerial drones) to collect photographs of the endangered Cook Inlet beluga whale to estimate the length of individual animals and learn more about why they have been slow to recover despite many efforts to help them. Knowing the length of the whales helps scientists determine whether they are adults, juveniles, or calves. Beluga whales give birth from late July to September. By doing hexacopter photography surveys each year in late August or early September, we hope to monitor calf production and compare that to environmental factors, such as the strength of salmon runs in a given year—an important food source for belugas. 

Learn more about how we measure whales from the air using hexacopters

Beluga whale at water's surface.

Beluga whale photographed during the 2017 hexacopter photogrammetry study of the Cook Inlet population. Photo: NOAA Fisheries/Paul Wade.

Measuring Pollutants and Spills

NOAA Fisheries scientists and their collaborators collect tissue samples to study the chemicals that belugas are exposed to in Cook Inlet. Our scientists also test whether pollutants and oil spills affect the fish that belugas eat. This research helps us understand the threats that belugas and their prey face when harmful substances are spilled in Cook Inlet.

Acoustic Science

Other research focuses on the acoustic environment of cetaceans, including beluga whales. Acoustics is the science of how sound is transmitted. This research involves increasing our understanding of the basic acoustic behavior of whales, dolphins, and fish; mapping the acoustic environment; and developing better methods to locate cetaceans using autonomous gliders and passive acoustic arrays.

We use acoustic science to monitor beluga hearing levels and feeding behavior. We also study how underwater noise in Cook Inlet affects the way belugas behave, eat, interact, and move within their habitat.

Learn more about acoustic science

Aerial Surveys

Scientists use small aircraft to observe beluga whales in Cook Inlet and other regions in Alaska to record their numbers and distribution. Surveys typically occur during the summer months when whales are concentrated in bays and estuaries within their respective stock areas. By comparing numbers collected over multiple years, scientists can look for trends—i.e., whether the population is increasing, decreasing, or remaining stable during a given period.

Aerial surveys, along with satellite tagging studies, have documented thatCook Inlet beluga whales have contracted their distribution into a much smaller area in the upper inlet during summer months than had been previously observed in the late 1970s—important information for wildlife managers.

Learn more about aerial surveys in Cook Inlet

Stock Assessments

Determining the number of beluga whales in each population—and whether a stock is increasing or decreasing over time—helps resource managers assess the success of enacted conservation measures. Our scientists collect information and present these data in an annual stock assessment report.

Find beluga whale stock assessment reports