Wrong-way whales draw a crowd

Two lost humpback whales continued their four-day odyssey up a busy delta river channel Wednesday as hundreds looked on with amusement and concern.

The mother and calf apparently suffered wounds inflicted by a boat propeller, scientists said at a packed news conference. They said the injuries occurred after the pair entered the Sacramento River Delta on Sunday and do not explain why the whales veered into inland waters.

Rescue workers also announced an ambitious plan to coax the rare whales back toward the ocean, beginning today. The strategy will use pipe-banging noises to prod the whales from behind and recordings of feeding humpbacks in front to lure them southward.

That worked in 1985 when rescuers saved an errant humpback whale nicknamed Humphrey, ending the creature’s much-publicized 26-day wanderings up and down the delta.

“We want to get these two whales back to San Francisco Bay so they can exit beneath the Golden Gate Bridge back to the ocean,” said Frances Gulland, a marine mammal veterinarian with the Sausalito-based Marine Mammal Center, which is assisting federal officials in the rescue.

The two whales haven’t drawn the overflow crowds that gathered across the delta to get a glimpse of Humphrey, the last humpback spotted in these waters, or to glimpse a bottlenosed whale that last year made its way to the Thames River in London but died as rescuers moved it to deeper waters.

Still, hundreds showed up at a dirt levee near the Port of Sacramento south of downtown for the new sport around the inland state capital: whale watching.

Using binoculars and telephoto camera lenses, spectators scouted for signs of the humpbacks, which were tailed by a flotilla of boats carrying scientists while TV helicopters hovered overhead.

Experts believe there are fewer than 6,000 humpback whales in existence. The mammals, which can exceed 50 feet in length and weigh 50 tons, are protected under both the U.S. Endangered Species and Marine Mammal Protection acts.

“Whales are cool things,” said Jerry Glasco, 54, an unemployed bridge tender as he stood along a dirt levee near the Port of Sacramento. “They’re big, they’re slow, they don’t eat people. They’re the kind of creatures everyone can relate to. To see them this far inshore is pretty special.”

Humpback whales traditionally migrate twice a year between feeding grounds in colder waters off Washington state, Oregon and Canada and the warmer breeding waters off Central America and Mexico. The mother and calf were apparently headed north when their navigation went amiss.

Since Sunday, they have swum 90 miles up the Sacramento River from San Pablo Bay. By Wednesday, they had reached a deep-water channel used by ocean-going ships that dead-ends at the Port of Sacramento.

Gulland said the 45-foot-long mother whale, which weighs about 45 tons, suffered a 2-foot-long gash across her back that was not life-threatening. She said what had been mistaken as fishing line dangling from the whale was a flap of skin hanging from the 6-inch-deep gouge.

The calf, however, had a possibly more serious wound beneath its right flank. Gulland said the injury was only visible after the whale surfaced from a deep dive, and that marine biologists had glimpsed the gash twice during a three-hour observation period. Gulland said there was no need to treat the creatures right away and that the mother’s wound would likely heal when exposed to cleansing ocean waters. She said there was no way to determine yet the long-term health of the calf, which she said was about 20 feet long and weighed about 20 tons.

The biologist said the mother and calf had not been feeding in the delta and that they were swimming together near the surface, probably casing their new environment and looking for a way out. She said that fresh water, in time, might cause lesions on the whales’ skin but that it would not otherwise harm them.

The late-afternoon news conference near the port drew 13 television stations and countless reporters. One asked Gulland whether the mother whale had veered off course because she was nursing.

The British-born scientist winced, saying the whale’s sex had little to do with its predicament. She pointed out that Humphrey, a male, also got lost.

Sarah Wilkin, a marine biologist with the National Marine Fisheries Service, said the agency rescues at least one off-course whale, dolphin or porpoise each year. Still, little is known about what triggers the aberrant behavior. “We haven’t really ever done studies as to why certain animals go off path,” she said.

“Most survive; that’s the good news,” she said, but added, “We can only investigate them completely if they died and their bodies are recovered.”

When a beluga whale nicknamed Poco died after veering off course in Maine in 2004, a necropsy found underlying health problems. “That’s the concern with these wayward animals -- that something triggered the behavior, such as stress or disease,” Wilkin said.

In recent years, scientists have differed over the role humans should play in helping whales that stray far from their natural habitat. Some say such behavior is part of natural selection and should be allowed to occur without human interruption. In England, the bottlenosed whale died after lapsing into convulsions as rescuers loaded it onto a barge.

In Sacramento, spectators applauded rescue efforts.

“These whales don’t have their natural food,” said Alane Smith, who hurried to the port after dropping off her child at preschool. “I’ve heard that there’s something stuck around the mother’s head and that she can’t even get her mouth open to feed. She must be tired and hungry. I just want to see these two creatures turn around and go back home.”

Two decades ago, tens of thousands worried over Humphrey’s plight as scientists tried various methods to rescue him. Humphrey eventually returned to the ocean -- only to show up again five years later, briefly beaching himself on a muddy tidal flat near San Francisco’s Candlestick Park. The whale was towed back to deep water.

As she gazed across the delta for signs of the mother and calf Wednesday, schoolteacher Nan Williams, who wore green socks embroidered with tiny whales, recalled the frenzy to save Humphrey. “Whales bring out our mothering instincts. We don’t want anything bad to happen to them,” she said.

Williams said she still worried about Humphrey all these years later: “I hope he’s happy wherever he is.”

*

john.glionna@latimes.com