Whales make comeback off Sonoma Coast
This year’s parade of gray whales along the California coast is one of the best in decades, continuing a remarkable comeback story for a species that was hunted to the brink of extinction and in more recent years experienced high death rates due to food scarcity.
Marine biologists say that at the moment, a population estimated at more than 20,000 gray whales appears to be healthy and reproducing well, as compared to the hundreds that washed up dead and the emaciated individuals that were observed 15 years ago as changing oceanographic conditions eliminated or modified their food supply.
“Right now, it’s a good story - a population that recovered and is doing well,” said Wayne Perryman, a federal marine biologist who has been studying gray whales for 22 years. “The animals look robust and healthy.”
Whale tour boat operators are reporting a banner year for sightings.
“This was the most impressive gray whale season that I’ve had in all my years,” said Capt. Rick Powers, a Bodega Bay skipper who has been conducting tours for 31 years.
“We saw gray whales every single trip this season. It’s very unusual to go out every trip and bat a thousand,” he said of the trips he’s led so far this spring.
Despite the rosy picture, scientists are concerned the whales face continued peril from the unfolding effects of climate change. And advocates for the leviathans, such as the California Gray Whale Coalition, worry that a Washington state Indian tribe’s current proposal to resume traditional gray whale hunting could open the door for more widespread killing of grays, as well as humpbacks.
The gray whales, which spotters say make up 95 percent of the whales seen off the Sonoma Coast, face a host of challenges, from both man-made obstacles and natural predators, as they head toward their Arctic feeding grounds, where they gorge during the summer on tons of minuscule, shrimplike bottom-dwelling amphipods.
The round-trip migration, which averages approximately 12,000 miles, is considered one of the longest among mammals. The northbound migration off the California Coast is expected to run through May.
Bodega Head provides one of the best places on the Sonoma Coast to spot the whales as they come past Doran Beach, and around the mouth of the bay, just outside the surf line.
“The cows and the calves come by very close to the shore - within 100 yards,” said Larry Tiller, a naturalist who is at Bodega Head almost daily to help people spot the whales, which can measure up to 50 feet in length, and educate them about the mammals.
Conditions were windy with 20- to 25-mph gusts on Wednesday as Tiller spotted the telltale spouts and backs of whales.
“Right on cue,” he said as a couple pairs of mothers and calves appeared. “They’re going north to Alaska,” he announced to curious observers, including one middle-aged woman seeing a whale for the first time.
“It about made me cry. I saw the fluke, two little spouts. I’m no longer a whale virgin!” exclaimed Gusti Boiani, an energy medicine practitioner from Colorado.
As the calves, most of which are born in the warm waters of Mexican lagoons, swim north for the first time under the protective presence of their mothers, they have to contend with avoiding boats and freighters in major shipping lanes, as well as fishing gear - nets, lines and floats - that can entangle them. There is also underwater noise from seismic surveys that advocates see as a serious threat to the whales.
One of the biggest hazards is killer orca whales eager to pounce on the relatively defenseless baby gray whales if they stray, for example, into the deeper waters of Monterey Bay.
Mother whales try to fend off attacks by having the babies roll onto the mothers’ backs. But thousands of miles ahead is another formidable challenge - Unimak Pass - a choke point at the Alaskan Peninsula where orcas congregate.
“There are probably 200 killer whales waiting to make calf sandwiches. They lose quite a few,” said Perryman, a scientist with National Marine Fisheries Service.
He said that by the time the mother gray whales arrive there with their calves, “They are out of gas after lactating four months. There’s not much strength left.”
By some estimates as many as 30 percent of the newly born whales don’t survive their first year. But once past that critical first year, gray whales can live 40 to 60 years, with some making it perhaps to 80 years of age.
Biologists say the past four years have been good for calf production following high overall mortality rates for both adults and calves in 1999 and 2000.
“In the last four or five years, the numbers have picked up,” said Steven Swartz, a marine biologist who has studied gray whales for almost 40 years. “It suggests they found enough food and the population is healthy enough that they’re starting to reproduce like they used to.”