Whale rescuers get set to herd

SACRAMENTO, Calif. — A whale rescue team spent much of Friday experimenting with beckoning sounds — varying pitch, frequencies and types of calls — in an effort to coax a pair of whales away from the Port of Sacramento.

Barring any last minute successes, they intend to give the mother and calf humpbacks a break today, leaving them undisturbed, and move to Plan B next week.

But unless the animals begin heading out on their own or show other changes, Tuesday is the day now tentatively earmarked for Plan B, a more aggressive herding effort. Using a flotilla of up to 50 boats whose crews would bang on pipes suspended in the water, they would try to, in effect, herd the whales back toward the sea, 90 miles away.

Pieter Folkens, a research associate with the Alaska Whale Foundation, acknowledged that whale experts themselves are also in uncharted waters.

"We've never been in a situation with a cow-calf pair, both of whom are injured," said Folkens, and so far upriver. "What our scientists are attempting to do is basically an experiment."

Yet the experts aren't despairing. They're using sound relatively early in the whales' plight, and believe they have time to experiment with the little-understood ways that whales respond to each others' voices.

"The bottom line is, nobody really knows how whales communicate," said Jan Straley, a marine biologist at the University of Alaska at Sitka who studies humpback behavior.

Folkens compared the situation to the rescue of Humphrey from the Sacramento River in 1985. That was one of the first documented efforts to use recorded whale sound to manipulate a live whale, and it worked.

Officials didn't start using luring sounds with Humphrey until 20 days into his visit. Humphrey was already stressed and agitated by then, and the clock was ticking on his health.

This time, starting much sooner, the recorded whale sounds were first broadcast on Thursday from an underwater speaker aboard the Pike, an 87-foot Coast Guard cutter. They consisted of a variety of humpback vocalizations, including ones associated with feeding, socializing, leaving a feeding ground and schooling for prey.

Four other boats listened with underwater microphones to ensure the sounds reached the whales. The boats tried different volumes and sound patterns. When scientists thought the cutter may have been so noisy it muffled or distorted the whale sounds, they substituted a 25-foot Coast Guard vessel.