No single non-lethal method is known to be universally or consistently effective in deterring sea lions from sunbathing on a dock or boat deck.
Not even a menacing plastic coyote.
Sea lion experts briefed the Newport Beach Harbor Commission on Wednesday on how to keep the massive animals at bay without harming them. The commission is considering updates to the local harbor code, including its provisions on sea lion interactions.
Sea lions are smelly, oily, occasionally noisy and cantankerous and always clever. They’re also federally protected, compounding the frustration of Newport Beach boat owners who want to keep them off their property.
“Taking” — killing, wounding or harassing sea lions — is forbidden under the Marine Mammal Protection Act, said Laura McCue, a biologist with the National Oceanic and Atmospheric Administration out of Long Beach.
That means no mats or barriers studded with nails or screws, no snare traps or razor wire, no striking the animals with boats or clubs and definitely no ammunition.
McCue acknowledged that sea lions can be “nuisance pinnipeds.”
Justin Viezbicke, NOAA’s marine mammal stranding coordinator for California, said sea lions are highly intelligent and need to be kept on their toes — or flipper tips — to keep them off private property, which the law allows people to protect, within limits.
Their intelligence means they’ll probably figure out that a plastic coyote isn’t a real threat, he said.
“These sea lions, they’re actually very smart and they’re very lazy,” he said. “If they can figure out a way to do things and get it for free, they’re going to do that.”
Viezbicke said he doesn’t think Newport Beach is doing anything extraordinary to attract the animals. But with its sprawling mooring fields — the harbor accommodates up to about 1,200 anchored vessels of all sizes — and ample supply of waterfront homes with private docks, sea lions have thousands of places to sun themselves.
NOAA suggests fences, noisemakers or relatively gentle methods such as paint balls or water jets as deterrents.
Devices like the locally manufactured SealStop also get the NOAA stamp of approval, and the experts brought some as visual aids. SealStops are plastic, nubby spinners that can be screwed onto swim steps, gunwales and decks and are pointy enough to jab a sea lion but not sharp enough to break its skin. The irritation is akin to stepping on a Lego barefoot, Viezbicke said.
The city requires boat owners to keep sea lions off their vessels and suggests several methods: blocking swim steps or decks with cloth covers, patio furniture, potted plants, large plastic buckets, snow fencing or kayaks. Those with an engineering inclination can build a solar-powered, motion-activated sprinkler to interrupt the animals’ basking.
Sea lions’ natural carrying capacity — the maximum population that can be sustained indefinitely in the environment — has probably been reached and their number is on a downward slope, Viezbicke said, pointing to increased pup strandings and mortality in the past few years.
Rescues of sick marine mammals have spiked this year in Orange County, the Pacific Marine Mammal Center in Laguna Beach said this month.
But the decline may not be obvious, Viezbicke said.