Gray whales' migrating a week later than in past

Source: Mercury News

Gray whales' migrating a week later than in past

By Mercury News
Posted: 02/16/2009 01:37:06 PM PST
Updated: 02/17/2009 07:02:17 AM PST

Out in the deep waters of Monterey Bay, gray whales will be swimming home later this month after a brief winter vacation in Baja California.

Wayne Perryman, a researcher at the Southwest Fisheries Science Center in La Jolla, said scientists at the center have observed the whales for more than 20 years as they pass through Monterey Bay. Compared with two decades ago, Perryman said, the animals are reaching the bay a week later.

"This isn't trivial," Perryman said. "It's a significant change."

Before leaving their arctic homes, the animals gorge on tiny crustaceans that live along the bottom of the ocean floor. Most gray whales won't eat during their swim south or when they finally reach Baja, so they must develop thick layers of blubber to help sustain them as they fast.

As warmer waters melt the oceans' ice, other animals move into the whales' habitat and start feeding on the crustaceans. Crowded out by the new competition, the gray whales have to travel farther north and feed longer to get their fill. These changes have disrupted the timing of the whales' yearly migration.

Read more: http://www.insidebayarea.com/news/ci_11721766

Considering the whales do not use a calender,allowing for our leap years this seems about right.