申論題

“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. The annual production of algae, the base of the food web, increased an estimated 47 percent between 1997 and 2015, and the ocean is greening up much earlier each year. These changes are likely to have a profound impact for animals further up the food chain, such as birds, seals, polar bears and whales. But scientists still don’t know enough about the biology of the Arctic Ocean to predict what the ecosystem will look like in decades to come. 

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.