California Sea Otters Amaze Observer


 

California Sea Otter

California Sea Otter

Editor’s Note:  I have taken the liberty of reposting a piece posted on Facebook by Ron Eby who studies and observes the otters at and near Elkhorn Slough near Monterey, California.  Eby’s words are followed by a report on California Sea Otters by The Mercury News.

 

Today I saw something that may be of interest to those of you that follow me because of your interest in otters. I was at Moss Landing State Beach Park doing my normal morning otter resights when the leader of a group of students from Portland, Oregon came over and told me there was a dead otter on the beach. I told him it was most likely just resting and but I would check it as soon as I finished entering the data.

What I saw next really surprised me. There was indeed a dead otter on the beach but there was another otter touching it with its nose and paws almost as if it was trying to revive the deceased otter. This continued for several minutes. The students told me that they had seen the otter take its last breath.

I quickly put on my waders and went to the beach to pick up the carcass. As I approached I saw two otters on the beach by the dead otter both touching it with their paws and sniffing it especially at the mouth. I had to wait several minutes for those two otters to leave the deceased otter on the beach so I could recover the carcass.

The otter appeared to be rather old and likely died from natural causes. That’s life, but seeing the other otters reaction was something I’ve never seen before. I’ve seen female otters hang onto their dead pumps for days but I’ve never seen otters reacting this way to another dead otter.

I just had to share. Nature continues to amaze me. We are not the only intelligent or emotional species. I’ve heard of other mammal species showing what appears to be remorse at the death of one of their species. But I’ve never seen this in otters.

Otter Mother and Pup

California sea otter pup rests with its mother.

From The Mercury News:

In a historic rebound, California sea otters, the frolicking ocean ambassadors of Monterey Bay and Big Sur, have reached their highest population level since 1982, when federal and state officials first began keeping track.

A growth in the amount of sea urchins, one of the otters’ favorite foods, seems to be the leading reason why otter numbers along the California coast have grown to 3,272 this year, up 11 percent since 2013, experts said as they released the latest survey Monday.

“The population is slowly but steadily recovering,” said Tim Tinker, a research biologist in Santa Cruz who leads the U.S. Geological Survey’s otter program. “And that’s good news because sea otters bring ecological benefits.”

In fact, the otter population is likely at its highest level in at least 100 years, Tinker said. And for the first time, the otter numbers have exceeded 3,090, the total that the U.S. Fish and Wildlife Service says is needed to be met for three years in a row before they can be considered for removal from the endangered species list.

Chief among them is that the otter population is booming between Monterey and Morro Bay. But the fuzzy marine mammals have not been able to expand their range north, past Año Nuevo State Park in San Mateo County, or farther south, past Santa Barbara, because they are being killed by great white sharks.

California sea otters at Morro Bay, Spring 2017.

No one knows for sure why shark bites have become the chief source of mortality for California sea otters. But one theory is that the Marine Mammal Protection Act of 1972 banned the killing of elephant seals and sea lions, both of which are food sources for white sharks. The populations of those animals soared, particularly off Año Nuevo and Piedras Blancas near Hearst Castle. With more food, the sharks may have expanded in number also, or they may have changed their range.

“We don’t think sharks eat otters; they just bite them and spit them out because sea otters don’t have blubber,” said Lilian Carswell, southern sea otter recovery and marine conservation coordinator for the U.S. Fish and Wildlife Service. “There’s not much there, just fur and bones. So they may be really targeting juvenile elephant seals and sea lions and biting otters instead.”

The annual survey, conducted by the USGS, U.S. Fish and Wildlife Service, Monterey Bay Aquarium, California Department of Fish and Game, and others, is done in the spring by airplane and by people counting from shore. To improve accuracy, each year’s total is a three-year average.

Historically there were about 16,000 southern sea otters, commonly known as California sea otters, that lived from Oregon to Baja, Mexico. But they were hunted relentlessly in the late 1700s and early 1800s by Russian, British and American fur traders for their pelts, which are denser and softer than mink fur.

California sea otters were feared to be extinct until a small number, about 50, were discovered in remote coves off Big Sur in the 1930s. They were protected by the Endangered Species Act in 1977 and began a slow comeback.

Having more sea urchins to eat has likely helped young otters survive because the urchins are nutritious and abundant. One reason there may have been so many more sea urchins in recent years, scientists say, is because of a disease that killed huge numbers of sea stars, or starfish, along the West Coast. Sea stars eat sea urchins, and although the sea stars have slowly started to recover, the urchin population has grown dramatically.

“It’s sort of like a perfect storm where we just had a blast of food,” said Carswell. “How long is that going to last? It’s not a long-term solution. The long-term solution is range expansion.”

Tinker said no scientists are calling for white sharks to be killed to protect the otters because that would cause other environmental problems. At some point, there may be efforts to move some otters to new locations, like San Francisco Bay or farther up the California coast toward Oregon, he said.

Other attempts to move otters have met with mixed results. A project in the 1970s to transfer some from the Aleutian Islands to southeastern Alaska succeeded. But an effort in the 1980s to move them to San Nicolas Island off the Southern California coast was considered a failure because many swam back to the mainland or died. However, their numbers at San Nicolas are finally growing and now near 100.

Moving otters would likely be controversial, particularly among fishermen, since they eat abalone, crabs and urchins, all of which are fished commercially.

Otters are a keystone species, and they affect all levels of the food chain. They help boost kelp beds, which provide a home to fish and other species, for example, because they eat urchins, which eat kelp. And recent research in Elkhorn Slough in Monterey County has found otters help boost sea grass, also a key home for fish, because they eat crabs. With fewer crabs, the population of sea slugs grows. Sea slugs eat the algae that builds up on sea grass from human runoff of fertilizer and other nutrients. With less algae, the sea grass prospers, providing a nursery for young fish.

“Over the longer term, it’s not just sea otter numbers we’re after, but the restoration of ecological relationships,” said Carswell.

 



Categories: California Sea Otters, Marine Mammals, Sea Otters, Uncategorized

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