Sea otters take a bite out of invasive green crabs in Elkhorn Slough
It's a classic tale of nature finding a way. An invasive species of crab was threatening an entire ecosystem in Monterey County's Elkhorn Slough—until an unexpected hero stepped in. And, as it turns out, the solution is as cute as it was effective.
For years, Rikke Jeppesen has been setting traps in the slough's delicate ecosystem, trying to catch green crabs.
"Green crabs wreak havoc on native ecosystems. So once green crabs showed up on the U.S. West Coast, it was a major concern," she said.
Jeppesen, a scientist for the Elkhorn Slough National Estuarine Research Reserve, had been tracking the crustacean troublemakers who arrived here in the late 1980s, likely hitching a ride on a boat from Europe. They were outcompeting native species and throwing the entire ecosystem into chaos.
No matter how many traps, they set they always came back full. Until, out of nowhere, the crabs started disappearing with no clear explanation of where the crustaceans went.
"Now we pull out the traps and as you can see there are actually no crabs in here," Jeppesen said.
The team was stumped until one day, one of Jeppesen's colleagues was retrieving the traps and heard a loud chewing noise in the background.
The sneaky snackers? Sea otters.
Once nearly wiped out by the fur trade, these playful predators had made a sudden comeback—and with them, so had the entire habitat.
Today, about 100 otters call Elkorn Slough home, devouring tens of thousands of green crabs each year, doing for free what humans couldn't accomplish with millions of dollars.
Ron Eby, a local volunteer and otter whisperer, said otters didn't just save the environment, they also jumped started the local economy.
"The income here is several million dollars a week, so it's just incredible that tourism brings," he said.
Once confirmed, the discovery hit like thunder on a sunny day. With articles on major media outlets both in the U.S. and around the globe.
"Never before have I done anything that anyone cared that much about," Jeppesen said.
The California sea otter population now hovers around 3,000, a far cry from the tens of thousands that once roamed all the way to Mexico.
