SIMMERING SEAS

Warming water temperatures affect ocean animals in different ways, and animals that can adapt will be the ones to survive.

What's causing warmer seas? Carbon dioxide and other greenhouse gases are trapping heat near the Earth's surface warming the land and the seas. (Most of these gases come from burning fossil fuels like gas and coal for energy.) Even small temperature changes can have big effects. Scientists warn that the Arctic's summer sea ice could vanish much sooner than we think—as early as 2013.

Here in Monterey Bay, warmer seas are giving porcelain crabs heart attacks—water that's too warm stresses the crabs. But researchers at the Monterey Bay Aquarium Research Institute tell us that the change in temperature might be good news for some deep-sea jellies, whose populations have increased in the past 20 years.

Warmer ocean waters are also killing some corals, leaving only bleached-white coral skeletons. They can come back, but slowly. Bleached reefs are more common now—and more vulnerable to other ocean changes.

If we can slow the rate of temperature change in our seas, we might give ocean animals a chance to adapt.