Science & Technology

Killer whales come in as the Arctic ice melts

One of the most dreaded predators in the ocean is invading new parts of the icy Arctic Ocean.

Orca, also known as the killer whale, appears in places never before discovered. Scientists believe that the cause is the melting of sea ice.

“”[Killer whales] “Usually avoid ice to avoid confinement and choking,” said Brin Kimber, a research scientist at the Institute for Climate, Marine and Ecosystems, at a press conference hosted by the American Acoustic Society on Wednesday. .. “But with less ice, of course, less risk to them, they can step further into the Arctic Circle.”

Kimber has used an underwater recorder to track the movement of killer whales through the Arctic Circle of Alaska. The underwater recorder picks up the sound of marine animals swimming. Orcas has a very distinctive call that can be easily recognized in the recording.

Kimber presented her findings at the American Acoustical Society yesterday. Annual meeting In Seattle. This study utilizes eight years of acoustic data from 2012 to 2019 collected by recorders operated by NOAA’s Institute for Marine Mammals.

Conclusion: As the ice moves, Orcas moves.

Data from the Bering Strait, which runs between Alaska and Russia, suggest that killer whales are migrating to the region earlier in the year. Killer whales are usually seasonal visitors to the region, moving during the summer when sea ice melts and returning when the water begins to freeze.

The sea ice was melting in June 2012, when the recording started. By the end of the dataset, in 2019, it had disappeared a month ago. Meanwhile, orca began to appear early.

The recording bureau further north has collected even more amazing information.

Stations in the northern Chukchi Sea recorded orca in 2018 and 2019 in previously undetected locations. The ice there is usually too thick.

“I was watching killer whales in places I didn’t expect to see them,” Kimber said in an interview with E & E News.

It is unknown why the killer whale is invading. But Kimber suspects they are probably chasing their prey.

Killer whales often feed on gray whales, bowhead whales, and various types of seals, all of which are common in the Arctic Ocean. These animals are adapted to cold climates and can easily move through the icy seas. Killer whales, on the other hand, find it difficult to swim in ice-covered waters. The high dorsal fin on the back makes it difficult to crumple the ice.

When the sea ice disappears, killer whales may find it easier to chase their prey further into the Arctic Ocean.

Kimber pointed out that their presence in these northern waters could be a source of concern. At least it’s worth the attention. Killer whales are skilled hunters and can have a chain effect on the delicate Arctic food web.

She added that it may also affect the nearby human community. Bowhead whales, for example, are also a major source of survival for some indigenous communities such as Alaska and Siberia.

This is not the first study to suggest that killer whales are moving to the Arctic Circle. Others have also found that orca sightings are increasing over time, primarily in the Arctic Circle of Canada.

Other studies have also warned of the potential impact of orca on Arctic ecosystems.one Recent researchWas published in the journal last year Global change biologyA killer whale found in the Canadian Arctic (probably a seasonal population of about 160 orca) can consume more than 1,000 narwhal each year.

Bowhead whale-like narwhals are an important traditional food source for some communities in the Canadian Arctic.

More monitoring is needed to fully understand the consequences of changes in the Arctic ecosystem. Studies that specifically focus on orca and climate change are still relatively limited.

But “Killer whales are very good at hunting things … I think it’s very important to keep an eye on them,” Kimber said.

Reprinted from E & E News With the permission of POLITICO and LLC. Copyright 2021. E & E News provides essential news for energy and environmental professionals.

Killer whales come in as the Arctic ice melts

https://www.scientificamerican.com/article/as-arctic-sea-ice-melts-killer-whales-are-moving-in/ Killer whales come in as the Arctic ice melts

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