It’s typical Sea Otter behavior. Lying on its back, an otter balances a fairly hefty rock on its chest while, in its front paws, it holds a clam or mussel. That it repeatedly—and aggressively—smacks against the rock until its shell breaks.
Though we do have photos of the pounding and breaking, the photo above shows you one of the sublime moments following the carnage: a piece of one shell lies precariously on the otter’s chest while she finishes off whatever remains in the remaining shell held upside down in her paws.
With the Monterey coast only about an hour away, it’s behavior we’ve witnessed numerous times. Fascinating creatures to watch, Sea Otter spend a lot of their time foraging and eating. They have to. Due to their high metabolic rate, otters have to consume about 25% of their body weight a day (20 pounds or more) just to survive. And, like cats, their diet consists entirely of protein: abalone, sea urchin, clams, mussels, crabs, octopus, and fish (among other marine delicacies).
In Moss Landing, we’ve also watched Sea Otter dine on what’s called “Fat Innkeeper Worms.” A marine worm native to the area, the Fat Innkeeper Worm—could we make up a name like that?—lives in burrows beneath the mud, and the otter uses its paws to find and dig them out. When the otter surfaces, it treads water while clutching the poor worm in its fist like a squishy sausage, and methodically wolfs the worm down. Finished, the otter, no time to waste, quickly dives back down to the muck to find another.
When a Sea Otter finishes eating, it preens. Otters have the densest fur of any animal on the planet, and they depend on that coat to keep them warm and dry. Unlike their distant cousins, the pinnipeds (seals and walruses), otters lack an insulating layer of fat, so they need to keep their fur clean, or they’ll succumb to hypothermia. That’s why oil spills can prove so deadly to otter: if their fur is fouled by oil or other petroleum products (as happened during the Exxon Valdez Oil Spill), the fur mats, losing all of its insulating and waterproofing properties.
Ironically, the otter’s fine fur nearly proved its downfall long before the era of oil spills. Beginning in the mid-eighteenth century, otters were hunted to near extinction by hunters employed by the fur trade. Though as many as a million sea otters once lived along Pacific coastlines—from the Siberian to the California coast—as few as 1,000 otters survived into the early 1900’s. And despite heroic conservation efforts, otters remain endangered to this day. Though protected through most of their range, otter numbers have not increased as rapidly as expected: only 100,000 Sea Otters live worldwide; only about 3,000 along the California coast.
Besides the threat of new oil spills, other dangers threaten otters. Industrial pollutants illegally released into the marine environment damage the otters’ nervous system. Algae blooms resulting from the release of agricultural runoff and human sewage can cause cardiac failure in both adult and juvenile otters. Deadly parasites (Toxoplasma gondii and Sarcocystis neurona) that cause brain damage have killed from 17% to 25% of the otters that have died from unnatural causes. The parasite, found in mice and birds, can be passed to feral and domesticated cats. Hardy, the parasites remain in the cats digestive system until evacuated. Runoff and sewage often transport the parasites to the ocean, where they infect the shellfish that Sea Otters consume. (That’s why we shouldn’t flush cat feces down the toilet.) And marine predators (the Great White Shark along the California coast and Orca off the Alaskan coast) have killed otters, especially when seal populations disperse or become reduced due to climate change or algae blooms.
You can read more about the California Sea Otter on the following websites: Defenders of Wildlife, the Marine Mammal Center, the Monterey Bay and Seattle aquariums, National Geographic, Ranger Rick, and Wikipedia.
We also invite you to take a look at a few more of our Sea Otter photos.