Aggressive Elephant Seal in Sonoma

Aggressive Elephant Seal in Sonoma

I know this elephant seal and he has been coming to Goat rock for years. It's pretty obvious (to anyone who has volunteered at the Marine Mammal Center) that he has Domoic acid poisioning (a condition that causes seals to go basically nuts). The results of the poisoning (which is treatable) is agressive behavior, seizure, and eventually death. No one really knows what causes it, but there are theories that it is due to the lowering PH (acidity) of the oceans due to rising CO2 levels... another sign that the oceans are in serious trouble. Last fall there was a famous incident of a seal attacking a swimmer in SF bay repeatedly. We will see more and more of this type of behavior in seals and sea lions as the oceans begin to collapse.
-sabrina

AGGRESSIVE ELEPHANT SEAL MENACES SONOMA BEACHES
2,500-pound 'Nibbles' bit a surfer and a dog and has killed at least a dozen harbor seals

Paul McHugh, Chronicle Outdoors Writer

A rogue elephant seal nicknamed Nibbles has run rampant near the mouth of the Russian River in recent weeks, killing a dozen harbor seals, biting a surfer and jumping out of the water to attack a pit bull terrier on Easter.

One witness said the 2,500-pound male, who often lunges at his victims, is the most aggressive elephant seal he's ever seen.

"This bull does straight-out murder," said Keary Sorenson of Sebastopol, a former surfer who volunteers for government and nonprofit agencies in Sonoma County. "A week ago, I saw him chase down a female harbor seal, use chest blows to crush her, then bare his upper canine teeth and drive them down onto her head and back."

Warning signs have gone up on beaches near Jenner, and officials cautioned the public Monday not to swim or wade in the estuary waters around Goat Rock Beach or approach the big seal should they see him basking in the sun. Kayakers also have grown wary, scouting the estuary from overlooking bluffs before going for a paddle.

"Just because elephant seals are big doesn't mean they won't move quickly," said Sarah Allen, a National Park Service biologist at Point Reyes National Seashore. "On beach sand, a bull can charge faster than I can run. They may appear docile. But they're very unpredictable. Everyone who works with them has to undergo intensive safety training."

Allen, an expert on elephant seals, put a pink tag on the bull's hind flippers when he first showed up at the river estuary as an adolescent five years ago. While males often become aggressive, this one's behavior is extreme.

Last month, the seal bit the leg of a surfer in the ocean after the surfer fell on the animal. The bite caused no serious injury.

Then, on Easter, he attacked a pit bull, a 10-year-old female named Sativa, while the dog was being walked on a beach below River's End Restaurant & Inn in Jenner. Angel Garcia, exercising the dog for a friend, was tossing a stick in the water for it to retrieve.

Kathie Lowrey, who lives nearby and was outside washing her car before going to church, saw the dog emerge from the water, drop the stick and begin to shake off droplets of water.

"I saw the elephant seal come out of the water like a torpedo, angle down on the dog and land on him," said Lowrey. "Somehow the dog wriggled out and turned and squared off with the seal."

Erinn Flaherty, the dog's owner, said Garcia told her Sativa barked defiantly at the seal while Garcia hurled the stick at him. Garcia then escaped with the dog, which suffered a puncture wound the diameter of a quarter in one thigh.

"It's the third time I know of that something like this has happened with elephant seal bulls in the last 10 years," said Joe Cordaro, a wildlife biologist with the National Marine Fisheries Service in Long Beach. "It sometimes happens, with a young displaced bull with high testosterone levels, that they try to establish new territory and mate with whatever they come across. This does fit a certain pattern. There is no evidence yet that it is sick in any way."

Sorenson says that soon after the bull first appeared, he tried unsuccessfully to mate with the (much smaller) female harbor seals. Then, last year, after trying again to mate, he turned violent and began to kill. This year, he is staying around well past his usual departure date at the end of March, and now has started to consume his kills.

"Juveniles tend to travel about -- that's how new colonies get established," Allen said. "But I think this guy is confused; he doesn't know where his colony is. He's out of time, out of sequence. Right now, he should be traveling up to forage in Alaska.

"He's not getting his desired response from the harbor seal females. They are running away from him. So he's not getting any social development. And elephant seals do combat play on land, whereas water zones are where harbor seals do it. So that's not working out for him, either."

Wildlife officials have several intervention options should the elephant seal -- nicknamed two years ago after he bit a kayaker -- linger much longer on his own.

They could try to harass him into leaving. Allen says daily exposure to a flapping blue tarp can sometimes do the trick. Sorenson says he is talking with the California Department of Fish and Game about using a bottle-rocket-like device with a whistle, flash and boom to make the estuary an unpleasant place for the seal to stay.

And should that fail and should the bull continue to threaten other wildlife and possibly attack some unwary person, wildlife officials could shoot him with tranquilizing darts and move the mammal -- or shoot and kill him.

"The Marine Mammal Protection Act of 1972 does protect this animal," said Cordaro. "But if we determine it's an anomalous threat to the public, the state park and state Fish & Game can take whatever measure they deem necessary. You hope it doesn't reach that level. But it could."

The colonization of the Pacific Coast shoreline by northern elephant seals is a result of the demise of one its predators.

"Before the time of European colonization, grizzly bears would have kept all the elephant seals in check," Allen said. "Only harbor seals would have been there. They have the instincts to take off into the water if they see a land animal appear, then come back when that animal's gone. Elephant seals don't. They confront what shows up. They are used to inhabiting islands. So it's an interesting example of what happens when an ecosystem is disrupted. Take grizzlies out of the picture, and elephant seals aren't scared off of the mainland beaches anymore."

Now the aggressor in the Russian River is an elephant seal who will stand up to other animals and even humans.

"Bottom line is, he's very dangerous," said Allen. "You wouldn't want to get bitten by one. They have huge incisors, and even a warning nip can break a human bone."
Elephant seals

(Mirounga angustirostris)

-- Range and population

Northern elephant seals are found in the North Pacific, from Baja California to the Aleutian Islands. During breeding season, they live on beaches on offshore islands and remote spots on the mainland. Hunted for their blubber to only a few hundred in the early 20th century, they are estimated to number about 180,000 today.

-- Physical agility

They seldom move rapidly on land, but they can move faster than most humans on sand. They swim at speeds of 10 to 15 mph and dive to incredible depths -- the maximum recorded depth is 5,015 feet by a male in 1991 -- in search of food at sea.

-- Food and predators

Male and female elephant seals are believed to feed on different prey. Females primarily eat squid and the male diet includes small sharks and bottom-dwelling fish. Great white sharks and killer whales prey on them.

Sources: The Marine Mammal Center; Friends of the Elephant Seal; California State Parks

E-mail Paul McHugh at pmchugh@sfchronicle.com.