The call came in on a Thursday afternoon in August: a Cook Inlet beluga whale had been spotted, stranded on the mudflats south of Anchorage, Alaska.
Once a stranded beluga is reported to NOAA Fisheries, biologists spring into action to coordinate a response. When the animal is in a remote location or out on dangerous tidal flats, as in this case, part of the response typically involves chartering a helicopter or airplane to fly over the stranded animal to assess the situation before determining a course of action. This time, however, NOAA Fisheries biologists were ready to try a new tool: an unmanned aircraft system (UAS) with high-definition video capabilities.
Live strandings of beluga whales are not uncommon in upper Cook Inlet. Each year during the past 10 years, an average of two to three mass stranding events (mass strandings involve at least two whales) of Cook Inlet belugas have been reported to NOAA Fisheries. These mass strandings often coincide with extreme tides. Stranded whales are usually spotted opportunistically from the Seward Highway along Turnagain Arm, or from small aircraft flying over Cook Inlet. A rapid response to marine mammal strandings is critical, not only to help the animals but also to obtain biological samples that can help assess threats facing this population.
NOAA Fisheries listed Cook Inlet belugas as endangered under the Endangered Species Act (ESA) in 2008. The Cook Inlet beluga population has decreased by nearly 75 percent since 1979, when the population was estimated at approximately 1,300 whales, to an estimated 340 whales in 2014. Of the five Alaska beluga whale stocks, Cook Inlet belugas are the smallest and most isolated. Because of their precarious existence, they were designated as one of eight NOAA Fisheries Species in the Spotlight, a concerted agency-wide effort to spotlight and save highly at-risk species.
As part of the Species in the Spotlight campaign, NOAA Fisheries will enhance its stranding response program for Cook Inlet beluga whales. Incorporating the use of new technology, such as small UAS with high-definition video imagery capabilities, is part of that effort.
“Fortunately, when the beluga was reported stranded in the mudflats along the Seward Highway, we had recently contracted Alaska Aerial Media to operate their UAS specifically to collect video imagery of stranded belugas,” said NOAA Fisheries biologist Mandy Migura.
This beluga stranding event was the first test of the new technology for the stranding program. Migura indicated that, using the UAS imagery, marine mammal stranding responders were able to determine that the report of a single stranded beluga was, in fact, two stranded belugas, a mother-calf pair. Only the adult could be seen from the highway.
Using the UAS footage, NOAA Fisheries biologists could observe and document the belugas’ behaviors during the stranding event, while both the mother and calf were stuck in a small tide pool out in the mudflats. The UAS technology also provided a bird’s-eye view of the whales swimming freely when the tide came back.
The UAS technology has proven a valuable tool for stranding responses. The information collected not only allows for a more accurate count of stranded belugas, but also provides a closer look at their behavior during and immediately after a stranding event. With enough data, UAS imagery may provide insights as to why some belugas survive a live stranding event and others do not—insights that could help prevent extinction of this at-risk species.