As Arctic ice melts whales move into the area, expanding their territory.
In order to watch this progression researchers set up underwater microphones in the narrow Bering Strait to pick up whale sounds, a University of Washington news release reported.
The research team observed Arctic beluga and bowhead whales migrating through the region as well as "sub-Arctic humpback, fin and killer whales" moving north through the Strait.
"It's not particularly surprising to those of us who work up in the Arctic," Kate Stafford, an oceanographer with the University of Washington's Applied Physics Laboratory, said in the news release. "The Arctic seas are changing. We are seeing and hearing more species, farther north, more often. And that's a trend that is going to continue."
The team also observed ships using the ice-free area as shipping lanes, putting the whales at risk of collision; the noise pollution could also pose a problem.
"Marine mammals rely primarily on sound to navigate, to find food and to find mates. Sound is their modality," Stafford said. "If we increase the ambient sound level, it has the potential to reduce the communication range of cetaceans and all marine mammals."
The Bering Strait is about 58 miles wide and at about 160 feet deep at most; it spans Russia and the U.S. The researchers recommended "international collaboration" in protecting the region and its creatures.
"The Arctic areas are changing," Stafford said. "They are becoming more friendly to sub-Arctic species, and we don't know how that will impact Arctic whales. Will they be competitors for food? Will they be competitors for habitat? Will they be competitors for acoustic space, for instance these humpbacks yapping all the time in the same frequency band that bowheads use to communicate? We just don't know."
Slowing ship speeds through the region and reducing engine noise could be the first steps towards preventing harm to the migrating whales. Research has shown "bowhead whales tend to travel up the U.S. side on the way north in the spring and on the Russian side on their way back in the fall," the news release reported. Harm could be reduced if ships did the opposite in an effort to avoid collisions.
"The question is, are these whale populations recovering and so they're reoccupying former habitat, or are they actually invading the Arctic because they can, because there is less seasonal sea ice?" Stafford said.
