Stinky Sea Lions Inspire Wacky Deterrents—Like Fake Orcas

The pungent pinnipeds are sparking frustration from California to Canada. When will we learn to live with this marine mammal?

Along North America's West Coast, human beings are wrestling with the triumphant return of the slippery California sea lion.

The thick-bodied creatures in La Jolla, California, muscle their way into lifeguard chairs, block access to public steps, and laze about on dry rocks, where the sun bakes their feces into a stench that clears out nearby restaurants.

Up north in Oregon, these sleek swimmers so completely take over docks and marinas that port officials repel them with paint guns, electric mats, and the same Gumby-like wiggling inflatable air dancers that usually advertise clearance sales at car lots. Still, the animals keep coming.

And 145 miles (235 kilometers) up the mighty Columbia River, sea lions now feast on so many endangered fish that the federal government last week renewed authority for states to remove or euthanize the most gluttonous of the predators.

Forty-four years after passage of the Marine Mammal Protection Act (MMPA), the population of smart, muscle-bound sea lions has climbed to almost 300,000. That’s a far cry from the 1930s and 1940s, when these animals dipped to less than 20,000 and may have numbered as few as 10,000. For a fish-eating critter once slaughtered for dog food, its blubber sold for oil and its whiskers used as tobacco pipe cleaners, that is a stunning comeback.

"It's one of the greatest success stories we can talk about in terms of marine mammals," says Garth Griffin, with the National Oceanic and Atmospheric Administration in Oregon. "The MMPA flat out did its job."

But how well are we learning to live with that success?

During the last few years, thousands of baby sea lions were stranded in southern California as ocean changes redistributed their mothers’ prey. The images of these starving young mammals may have overshadowed another phenomenon: Even as juveniles were dying, adult males were congregating in record numbers in a few unfortunate places, destroying docks, sinking boats, and munching scarce stocks of salmon.

One Oregon port last year even deployed a boat painted like a sea lion-eating orca. It was supposed to emit whale noises in an attempt to scare the whiskered critters off. It capsized.

These beautiful barking animals keep finding new ways to bamboozle us.

"Overall, California sea lions are doing quite well, and that's a good thing," says Chris Yates, assistant regional administrator for NOAA Fisheries. "However, it hasn't come without consequences. Once these animals settle in a place, they can be very hard to deter." 

A Marine Mammal Fracas

Few people are coming to understand that better than Steve Haskins. While serving as president of the La Jolla Town Council, a community within the city of San Diego, the local real estate attorney landed in the middle of a small marine mammal fracas.

For more than a decade, some in his community had been embroiled in a surprisingly bitter spat over a group of harbor seals that commandeered a tranquil beach where residents taught their kids to swim. Those seeking protection for this fresh habitat and those itching for continued beach access faced off in lawsuits and public screaming matches. There were death threats, arrests, even a fist fight with a stun gun.

In the midst of this melee, a handful of sea lions arrived and began hauling out on rocky bluffs above popular La Jolla Cove, less than a quarter mile from outdoor restaurants and fancy hotels. The fetid mess left behind, along with the waste from cormorants and other seabirds, sometimes proved overwhelming in a community where tourists pay to eat outside.

The city sprayed a special microbial foam to counteract the stink. That eliminated the wafting odor of bird poop, but did little to knock down the sea lion's musky funk.

"We're pretty temperate, so the sea lion droppings would stay there and the sun would hit and it would get very, very smelly," Haskins says. "It would go up into the restaurant district and drive people crazy."

The same attorneys who sued to protect the seals went to court to try and force the city of San Diego to clean the waste. They argued the smell of sea lion-digested anchovies was costing businesses too much money.

"The professional boxer Floyd Mayweather, for example, recently booked two villas and six rooms for his entourage at the historic waterfront hotel La Valencia, but checked out 15 minutes after arriving because of the noxious odors emanating from La Jolla Cove," the suit claimed.

A judge dismissed the case. A rise in bacteria in the water this year even spiked a popular open-ocean swimming race.

So Haskins and others kicked around solutions, ranging from spraying animals with hoses to mounting a set of rollers on the rocks that would make it hard for sea lions to haul out in the first place. But then this year, the animals shifted gears; they began congregating on a popular protected beach.

"The only way in or out is to swim, or there are two sets of stairs going down to the beach," Haskins says. "What the sea lions would do is get on the stairway and sit there. They'd block it. People on the beach couldn't get out. Then they'd climb into the lifeguard stations. Lifeguards were dealing with sea lions and not watching for people drowning."

Haskins isn't sure what comes next.

"No one wants to do anything that might harm marine life," he says. "It may be one of those things for which there is no good answer." 

Some communities have simply embraced their uninvited guests.

"When you think about it, it's absolutely spectacular that people can observe these big predatory animals that closely, and have the opportunity to see them while eating lunch," says Bob DeLong, with NOAA's Alaska Fisheries Science Center, who has worked with sea lions since 1969.

European hunters centuries ago began driving sea lion numbers down, harvesting them for hides and blubber, and because they were rivals for fish. Today, these sea lions breed on offshore islands in southern California, but some also mate in the Farallones, off San Francisco, and on islands in Mexico. While females may nurse their young for much of the year, adult males tend to roam.

"It's that sexual separation that really sets things up for a lot of the conflicts that we see," DeLong says. "It's not the females; they're too busy making milk to feed junior to come up north and eat salmon or haul out on people's docks."

But males, after four or five years, travel far and wide, hightailing it to wherever they find food, sometimes as far north as Alaska. That appetite and wanderlust can bring a spot of trouble.

In 1989, after the Loma Prieta earthquake, a few sea lions chasing herring found their way to a new dock at San Francisco's Pier 39. Within a year, the number of sea lions topped several hundred, rendering the pier almost useless as a marina. Frustrated, boat users abandoned the yacht mooring spot to the lounging pinnipeds. Now Pier 39 sometimes attracts 1,700 or more sea lions and is "one of the most visited attractions following Disneyland," DeLong says.

"LaJolla just hasn't gotten used to what they have," he says. "There's lemonade to be made there."

That lemonade doesn't always come cheap. When sea lions amassed at Moss Landing Marina in California's Monterey Bay, "they sunk boats, they broke rails, smashed in doors; there was feces everywhere," says NOAA's Yates. After years of effort and thousands of dollars in damage, the harbormaster began installing special equipment to protect the structures. "It's expensive and hard, and it's a long painful process with angst on all sides."

And not all conflicts are with people.

Mysterious Hershel and Hondo Return

In the early 2000s, during one of the Columbia River's best salmon runs in decades, the Army Corps of Engineers noticed a few sea lions making their way to Bonneville Dam, where they ate salmon, including chinook and steelhead, which are protected under the Endangered Species Act.

"There's no archaeological evidence that sea lions historically occurred in the Columbia," says Robin Brown, with Oregon Department of Fish and Wildlife.

At first it was an amusing head-slapper. The mammals usually appeared at the Columbia's mouth to snatch smelt. But with smelt numbers down and salmon up, the sea lions traveled upriver to the dam. Soon they were arriving by the hundreds, helping drive down fish populations. "The impact varies year to year, but it's potentially significant," Yates says.

Now, each spring, marksmen patrol the river, shooting sea lions with bean bags, rubber bullets, noisemakers, and firecrackers, trying to prevent one protected species from making a smorgasbord of the other. In extreme cases, the animals can be removed or killed.

Some animal-rights groups oppose this treatment, and many environmentalists suggest the focus on sea lions detracts from larger threats to the Columbia, namely habitat destruction upstream and dams that warm the water and complicate fish passage. But river and wildlife managers point to sea lions' history of doing damage when not kept in check.

In the 1970s, a pair of the pinnipeds, Herschel and Hondo, began gorging on endangered steelhead at a set of locks on Washington's Puget Sound. Within a decade, the problem was so severe that federal managers turned to crossbows and slingshots and specially prepared fish pumped full of nausea-inducing drugs in an attempt to turn the mammals off steelhead for good.

When that didn't work, they drove the sea lions away—literally—by capturing and trucking them out to the coast. The animals returned two weeks later. Later, the sea lions were dumped thousands of miles south in California's Channel Islands, but still found their way back. By the time the problem was controlled in the early 1990s, fewer than 100 of the winter steelhead run remained. Today those fish are all gone.

Scientists suspect the strandings of young sea lions in recent years ultimately will drive that marine mammal population down a bit in coming years. In addition, the return of white sharks and shortfin makos that prey on sea lions may also bring down sea lion populations. But scientists don’t believe that will ultimately help the endangered fish.

And recent winters have given researchers pause.

Unusually large populations of smelt have drawn record numbers of sea lions to an area near the mouth of the river. While hundreds swarmed the docks near the estuary in 2012, that number hit nearly 4,000 by 2016. But when the years of those bountiful smaller fish peter out, some experts fear they know what comes next.

"The sea lions will show up, expecting their smelt, but then see those large salmon swimming by and simply follow them up the river," Griffin says. "I believe that this problem will either stay the same or get worse."

Discuss this article

Newsletter

Never miss a Nat Geo moment

Your email address
Submit