A beluga whale in Fall River, Mass., and a pod of killer whales off the coast of Nantucket, Mass., have piqued the interest of researchers from Mystic Aquarium studying the impact of weather and climate change on marine mammals.

A group of researchers from the aquarium traveled to the Taunton River in Fall River on Thursday in an attempt to get a first-hand look at the beluga whale. The lone whale was first spotted in the river on June 15 and confirmed by aerial survey on June 18 by the International Fund for Animal Welfare.

The Mystic Aquarium is home to three such whales, whose normal habitat is the arctic or subarctic regions, according to Dr. Tracy Romano, Mystic Aquarium’s executive vice president of research and zoological operations.

Romano, who is leading the team searching for the whale, said not only is it usual to see a beluga this far south, but being social animals, they don’t typically travel alone. The group had yet to spot the whale as of Thursday afternoon.

“The bigger picture here is that in addition to this beluga coming this far south, for perhaps the first time ever we’re seeing orcas this far south,” she said. “This relates to the bigger picture of climate change, melting ice in the arctic and how that is impacting animals.”

Romano said a beluga this far south is rare, but not unheard of. She recalls beluga whale sightings over the past decade in Boston Harbor and the Philadelphia River.

Observing the beluga whale will help in the aquarium’s current research into how weather patterns and climate change affect the animals’ health and behavior, Romano said. The hands-on work with belugas typically takes place in places like Alaska, she said.

“I just think it’s exciting and interesting. The observation speaks to what we’re seeing up in the arctic,” Romano said.

The killer whales were spotted and photographed Wednesday by personnel aboard the U.S. Coast Guard Cutter Campbell about 150 miles off the coast of Nantucket, Romano said.

Romano said it’s unclear what brought the beluga so far south, but said during the summer months it is not uncommon for the whales to swim up rivers in search of food in warmer waters.

“We really don’t know what brought it here,” she said.

The International Fund for Animal Welfare is asking the public to report any further sightings to the IFAW Marine Mammal Rescue Hotline at (508) 743-9548, and to provide the location and description of the whale’s behavior. The public is also asked to resist the urge to interact with the whale and keep a safe distance from the whale of at least 150 feet.

g.smith@theday.com