Thursday, May 17, 2007

Wayward Whales to Be Lured Back to Sea by whale songs

Wayward Whales to Be Lured Back to Sea by whale songs
AP
WEST SACRAMENTO, Calif. (May 17) - Biologists were counting on an underwater recording of humpback whale songs Thursday to lure two injured whales back down the Sacramento River and toward the ocean.
 
The biologists hope the salty water and ample food of the Pacific will speed the recovery of the two whales, believed to a mother and calf. Both were wounded during their 90-mile inland detour.

To get the wayward whales headed in the right direction, researchers with the Sausalito-based Marine Mammal Center planned to play recorded humpback sounds from a boat Thursday as the tide goes out, then use more boats lining the channel to try to prevent the two from turning around.

"Plan B is herding the animals out using a platoon of boats," said Frances Gulland, director of veterinary science at the center.

The whales, first spotted Sunday in the lower Sacramento River, likely were on their northward migration from Mexico up the California coast when they were sidetracked, biologists said. Because they are at the end of their hibernation season, they have less blubber to rely on for fuel than they would later in the summer or fall.

The pair spent Wednesday exploring the muddy waters of the Sacramento River basin as hundreds of people flocked to the banks to see them.

Photos revealed that they had been wounded, likely by a ship's propeller, Gulland said. If they can be returned to their natural sea water habitat, which is cleaner than the fresh water in the port, they likely won't need treatment, researchers said.

Shipping and small boat traffic were halted in the basin, which is 30 feet deep and 200 feet wide. The next ship was not expected to dock for another week, giving authorities time to try to escort the whales out of the channel and back to the Pacific, said Teresa Bledsoe, administrative clerk at the Port of Sacramento.

It's unusual for whales to reach so far into the Sacramento-San Joaquin Delta, but it has happened before. In 1985, a humpback nicknamed Humphrey was escorted back to sea after swimming in the delta for nearly a month.

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