A critically endangered population of Alaskan belugas has not recovered for the last 20 years due to unknown causes, and now Georgia Aquarium and Shedd Aquarium are partnering with several state and federal agencies, and universities to support new research on this at-risk population to identify the factors that are inhibiting its recovery. This will include expanding our understanding of how the whales currently use their habitat, how they forage and if noise pollution is impacting their natural behaviors.
The Cook Inlet belugas are a resident population that was once common throughout the inlet waters, historically numbering around 1,300 individuals. However, unmanaged subsistence hunting in the mid-1990s led to over-harvesting and a nearly 50 percent population decline. Today only an estimated 340 belugas remain.
The sub-population of Cook Inlet was listed as endangered under the Endangered Species Act in 2008, and critical habitat for the belugas was designated in 2011 – all in an effort to help reverse the precipitous decline. In spite of these efforts, Cook Inlet belugas have not recovered and the reasons why remain unknown.
“To understand what is keeping the Cook Inlet beluga population from recovering, we must first understand everything we can about how they behave, feed, mate, and interact with their surroundings,’ said Eric Gaglione, vice president of zoological operations for Georgia Aquarium. “Supporting this research means bringing us closer to potential solutions for a population that is in critical need of help.”
How do they compare to other belugas?
The goal of the new research is to better understand these rare whales so conservation initiatives can be implemented that would secure their survival. One of the new studies will utilize a data set collected from a more stable population of belugas living nearby in Bristol Bay, Alaska.
Because the populations are similar, some of the information gleaned from that effort can help inform kinship research on the endangered Cook Inlet belugas to better understand social structure and mating strategy, which is largely unknown for all beluga populations, including Cook Inlet. Knowing what makes other beluga populations healthy will help researchers know what the Cook Inlet belugas might be missing or additional challenges they are facing. Each year for nearly the last decade, Georgia Aquarium, Shedd Aquarium, state and federal agency and university partners have conducted the health assessments on the Bristol Bay belugas.
“Assistance and support from organizations like Georgia Aquarium and Shedd Aquarium are invaluable to our growing body of research for both the Bristol Bay and Cook Inlet beluga populations,” said Mandy Keogh, wildlife physiologist with the Alaska Department of Fish and Game.
Foraging and Habitat
Getting enough food to grow and reproduce is fundamental to survival for any species. One of the new research projects in Cook Inlet, led by Alaska Department Fish and Game, is to better understand how the belugas forage and use their habitat by analyzing annual growth layers on 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.
Is Noise a Problem?
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 where noise may displace belugas from feeding areas.
“Belugas make a certain buzzing sound when foraging for food,” said Tim Binder, executive vice president of animals at Shedd Aquarium. “While the tooth research will help us look into how the whales foraged in the past, the acoustic research will show us how the present population is using the habitat and if any anthropogenic noise is interfering.”
All Cook Inlet beluga whale research is led by NOAA Fisheries Alaska. This particular research on the Cook Inlet is being led by the Alaska Department of Fish and Game, and is supported with funds from NOAA Endangered Species Act Section 6 Program, Georgia Aquarium in Atlanta, and Shedd Aquarium in Chicago. Scientific collaborators include 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 LGL Alaska Research Associates, Inc.