(Juneau) — Cook Inlet beluga whale reproduction, survival, foraging, and habitat use will be the focus of two new Alaska Department of Fish and Game-led research projects to identify factors impeding the species’ recovery from a decline that started 20 years ago. The research will be funded by grants received through the NOAA Endangered Species Act Section 6 Program.
Year-round Cook Inlet residents, the belugas were once common throughout inlet waters, historically numbering around 1,300. Unmanaged subsistence hunting in the mid-1990s led to a nearly 50 percent population decline and today an estimated 340 belugas remain, primarily in the upper inlet. A moratorium on the subsistence harvest of Cook Inlet belugas was established in 1999, they were listed as endangered under the Endangered Species Act in 2008, and critical habitat was designated in 2011. In spite of these efforts, Cook Inlet belugas have not recovered and the reasons why remain unknown.
One of the department’s new research projects will use existing data sets, including the Cook Inlet beluga photo-identification catalog and beach-cast carcass data, to build a population model to explore factors likely limiting recovery. A large genetic data set (from remote skin biopsies) of Bristol Bay belugas will be used to determine kinship of individuals observed in groups to study social structure and mating strategy, which is largely unknown for all belugas populations, including Cook Inlet. “These biopsies were collected to genetically identify individuals and estimate the size of the Bristol Bay beluga population,” said Wildlife Research Biologist Lori Quakenbush. “We also collected information on whales biopsied within the same group to learn about the social structure of belugas as a species, which we need to better understand why the number of belugas in Cook Inlet is not increasing.”
The second research project will focus on foraging and habitat use employing both field and laboratory methods. Getting enough food to grow and reproduce is fundamental to survival, so the department will use stable isotope analysis of annual growth layers in teeth from stranded belugas. These growth layers accumulate each year, providing a lifelong record of the general diet for individual whales. These data will be used to assess changes in diet and foraging areas, growth, and body condition over the last 50 years. Additionally, because belugas use sound to find prey, communicate, and navigate, high levels of human-generated noise may interfere with their ability to find and capture prey. Passive acoustic monitoring will be used to detect where belugas forage, classify noise sources, and determine whether noise may displace belugas from feeding areas.
“Understanding the foraging ecology and habitat use of the Cook Inlet beluga is important in determining whether changes in prey availability were a contributing factor in their decline and are currently impeding recovery,” said Wildlife Physiologist Mandy Keogh.
Both research projects start this fall and are designed to take three years, with funds provided annually by the NOAA Endangered Species Act Section 6 Program. Georgia Aquarium and John G. Shedd Aquarium have provided matching financial support and will develop education programs based on both projects. Department of Fish and Game marine mammal scientists will lead the research in collaboration with National Marine Fisheries Service’s Marine Mammal Laboratory, the University of Alaska Fairbanks, the University of Washington, Harbor Branch Oceanographic Institute at Florida Atlantic University, and the Cook Inlet Beluga Whale Photo-ID Project (at LGL Alaska Research Associates, Inc). Samples and data were also provided by the Marine Mammal Health and Stranding Response Program. For more information, visit the department’s Cook Inlet Beluga Whale Special Status webpage at
https://www.adfg.alaska.gov/index.cfm?adfg=specialstatus.fedsummary&species=cookinletbeluga
or contact Mandy Keogh at 907-459-7367 or Lori Quakenbush at 907-459-7214.[xyz-ihs snippet=”Adsense-responsive”]