Bluefin Tuna Are Showing Up in the Arctic-and That's Not Good News

[Omaha Steve]

Warming oceans mean fish are migrating north, sparking new conflicts over fisheries.

September 15, 2014 By Hannah Hoag

Hannah Hoag reports on the environment, global health, science, and science policy for Nature, Discover, Wired, and others.

When you throw a net into the ocean, you never know what you’ll pull out.

That was the case for researchers cruising the freezing Arctic waters off Greenland in August 2012 in search of mackerel to see if there were enough of the fish to support a commercial fishery. In one haul, three endangered Atlantic bluefin tuna, each weighing roughly 220 pounds, were pulled onto the ship’s deck amid six metric tons of mackerel.

“It was a bit surprising,” said Brian MacKenzie, a marine ecologist at the National Institute for Aquatic Resources at the Technical University of Denmark. The research ship was sailing in the Denmark Strait, between Greenland and Iceland, where water temperatures have historically been too cold for bluefin tuna.

More bluefin tuna have been caught off eastern Greenland since then. From June to the end of August of this year, Greenland fishing vessels caught 21 tuna—in addition to 65,000 metric tons of mackerel, according to Greenland Today.

The ever warmer Arctic waters could have profound impacts on how fisheries and food webs are managed and conserved in the future as tropical and Mediterranean species migrate into what were once colder waters.

FULL story at link.