Sighting of sperm whales in Arctic a sign of changing ecosystem, say scientists

Rare sighting in the Canadian Arctic as a growing number of species expand their range into warming waters
Leyland Cecco The Guardian 5 Nov 18;

A rare sighting of sperm whales in the Canadian Arctic is the latest sign of a quickly changing ecosystem, say scientists, as a growing number of species expand their range into warming Arctic waters.

Brandon Laforest, a marine biologist with the World Wildlife Fund, and guide Titus Allooloo were working on a project monitoring the effect of marine traffic on the region’s narwhal population when they spotted the pair of large whales just outside Pond Inlet, a community at the northern tip of Baffin Island in September.

Video of the incident, released at the end of October, captures the second known sighting of sperm whales in the region. In 2014, hunters from Pond Inlet spotted them in the area.

At first, Allooloo and Laforest thought the dark shapes in the water were killer whales – another species that has become a frequent visitor to the waters as temperatures creep up. But the distinct shape of the dorsal fin surprised Allooloo – a veteran hunter.

“They’re not known by us, we don’t know too much about them,” Allooloo told the CBC.

While a number of whales species thrive year-round in the Arctic, including beluga, bowhead and narwhal, the physiology of a sperm whale makes it difficult for them to navigate colder waters.

Their heads and upper parts of the body are soft and contain an oily fat – long prized by whalers – that turns waxy in cold waters. Their bodies – which can weigh as much as 125,000lb (56,700kg) – are also ineffective at breaking through ice.

While they don’t represent a threat to the ecosystem, there are worries sperm whale could become trapped as winter approaches.

“Inexperienced whales exploiting a northern habitat may not know to leave early enough before the sea ice forms,” Laforest told the CBC.

The vast area of the Arctic waters – estimated by Canadian researchers to measure 5.5m sq miles - makes it difficult for scientists to effectively track changes in the ecosystem, including the arrival of previously unreported species.

Baseline datasets are also rare, making trend gathering difficult. Increasingly, researchers are working with Inuit communities, which have a long oral history of species in the region.

In recent years, killer whales, or orcas, have also become more frequent in a number, taking advantage of longer ice-free seasons. The whales, which feast on resident narwhal, have even started changing narwhal behaviour, according to a 2017 report by the Department of Fisheries and Oceans.

“I think the narwhal are scared to death,” report co-author Steve Ferguson told the Canadian Press. “Watching your brother or sister or mother get killed and eaten by a killer whale would cause a little post-traumatic stress in most of us.”

A recent presentation by the department also highlighted a spike in chum salmon populations the western Arctic – in numbers far greater than previously recorded.

Warming temperatures have also prompted interest in the potential for expanded commercial fishing in the Arctic. In response, nine countries have agreed to ban fishing in the region until a more thorough study of the ecosystem can be completed.