Global Warming Alters Arctic Food Chain

Global Warming Alters Arctic Food Chain

The Arctic Ocean may seem remote and forbidding, but to birds, whales and other animals, it’s a top-notch dining destination.

“It’s a great place to get food in the summertime, so animals are flying or swimming thousands of miles to get there,” said Kevin R. Arrigo, a biological oceanographer at Stanford University.

But the menu is changing. Confirming earlier research, scientists reported Wednesday that global warming is altering the ecology of the Arctic Ocean on a huge scale.

Since the mid-2000s, researchers like Dr. Arrigo have been trying to assess the effects of retreating ice on the Arctic ecosystem.

The sun returns to the Arctic each spring and melts some of the ice that formed in winter. Algae in the open water quickly spring to life and start growing.

These algae are the base of the food chain in the Arctic Ocean, grazed by krill and other invertebrates that in turn support bigger fish, mammals and birds.

Dr. Arrigo and his colleagues visited the Arctic in research ships to examine algae in the water and to determine how it affected the water’s color. They then reviewed satellite images of the Arctic Ocean, relying on the color of the water to estimate how much algae was growing — what scientists call the ocean’s productivity.

The sea’s productivity was rapidly increasing, Dr. Arrigo found. Last year he and his colleagues published their latest update, estimating that the productivity of the Arctic rose 30 percent between 1998 and 2012

Full Articles From NYTimes.