Sea Otters: Time to Look for the Babies!

A sea otter mom and her newly born pup. Photo by Steve Choy, courtesy NOAA MBNMS,
A sea otter mom and her newly born pup. Photo by Steve Choy, courtesy NOAA MBNMS,

As land dwellers we think of springtime as the time of year when animals mate and have babies. In the sea, many mammals birth their young in the thick of winter. Elephant seals arrive at breeding grounds up and down the west coast in January and give birth within a week. Sea otters (Enhydra lutris) can give birth year-round but most are born between November and March with January and February the best months to see females floating in kelp beds with babies on their tummies.

During winter, the kelp forests, home to the sea otter, are severely beat up and reduced by storms. With reduced habitat, storm swells and large breaking winter waves, it seems a strange time to give birth. Nevertheless they do! Perhaps its because the pup fur is so buoyant they cannot dive for 3-4 months until their regular fur comes in. So if they are born in winter, come spring when the kelp forests have recovered, and food is fairly abundant, they are set to dive and get solid food for themselves.

A near-shore kelp forest in Monterey Bay. Photo by Dr. Steve Lonhart, courtesy NOAA MBNMS,
A near-shore kelp forest in Monterey Bay. Photo by Dr. Steve Lonhart, courtesy NOAA MBNMS,

Living In Bone-Chilling Water

A member of the weasel family, this sea otter is the only marine mammal that doesn’t have a layer of blubber for protection against the cold water. Instead it has the thickest fur of all marine mammals: up to one million hairs per square inch. It can pack so much air into its fur that its skin is perfectly dry. You can often see them rolling in the water, grooming and filling their fur with air before starting a forage session.

To survive, otters must eat a huge amount of food, 15 to 20 pounds or more a day (about 20% of its body weight), to keep up a high metabolism. Female sea otters are no exception and cannot, like many marine mammals, give up eating while nursing their babies. Before diving for food—almost anything on the sea floor made of meat— a female otter will wrap her pup in the kelp. Young pups may let out a squeaky, high-pitched cry if mom is away too long. Pups nurse from nipples on the lower part of the mothers body for up to ten months though they start eating solid food when they are 3-4 months old.

Sea Otter mother with nursing pup in the Morro Bay harbor, Morro Bay, CA. Oct. 2008. Photo by Michael "Mike" L. Baird.
Sea otter mother with nursing pup in the Morro Bay harbor, Morro Bay, CA. Oct. 2008. Photo by Michael “Mike” L. Baird.

Where To See Them

The kelp forests seen off the Santa Cruz Wharf and along West Cliff Drive are home to the California sea otter. They are often seen swimming, diving for food, grooming, or wrapped up in kelp fronds sleeping. Perfectly adapted to live in the cold, arctic California Current that flows into Monterey Bay, they rarely leave the water. Another good place in Santa Cruz county to see otters is the northern part of Moss Landing Harbor close to Moss State Beach.
When looking for otters, listen for the tell-tale click-click-click of an otter lying on its back and pounding at a clam or snail with a rock. The sea otter is one of the few animals known to use a tool.

A California Sea Otter. Picture courtesy of and © Paul Babb 2013.
A California sea otter. Picture courtesy of and © Paul Babb 2013.

A Keystone Animal

The kelp forest is a major nursery to thousands of kinds of marine animals. Like any forest, it is itself an ecosystem and needs balance among the animals that live and breed there. If the sea otter is taken out of the kelp forest ecosystem, the kelp-eating animals like sea urchins and abalone, would grow unchecked and destroy the kelp forest. Thus the sea otter is called a “keystone animal.”

A Well Kept Secret

Prior to hunting in the 18th and 19th centuries there were as many as 300,000 sea otters worldwide and about 18,000 along the California coast. By the end of the fur trade in the early 1920s the California sea otter was thought to be extinct. In the 1930s, a few remaining animals, less than 100, were discovered hidden in coves along the Big Sur coastline. Their existence was kept a secret until they were finally given federal protection under the Endangered Species Act in 1977.
Sea otter numbers in California counted at 2,941 in 2013. In 2009 they were counted at 2,811 and dropped to 2,711 in 2010. Since being protected in 1977 the numbers have not rebounded as fast as was anticipated. They have struggled for years with diseases, parasites, and even the occasional collision with boats. Recently, they are increasingly facing another threat: shark attacks.
Twenty years ago, about 10% of sea otter deaths along California’s coast were from shark bites. In 2012 it was about 30% and growing. In fact, shark attacks are probably the main reason the otters are not close to being removed from the endangered species list. The mystery is that the sharks do not eat the otters but seem to just be tasting them. The phenomenon is being studied.

Take the Self-Guided Mobile Tour

This piece is part of the Marine Life Guide. Download the free app with many tours of the Santa Cruz area and beyond.


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  1. Sources Used

    • Otter numbers continue a renewed slow climb. Jason Hoppin. Santa Cruz Sentinel. September 12, 2013.
    • Personal Communication with Patrick Wilkinson. A Volunteer and Docent for Seymour Marine Discovery Center at Long Marine Lab and Bay Net, a volunteer organization under the auspices of the Monterey Bay National Marine Sanctuary.
    • Sea otters face a growing threat: shark attacks. Rogers Paul. San Jose Mercury News. February 16, 2012.
    • Seasons in the Sea. A month-to-month guide to Central California sea life. Kim Fulton-Bennet

About The Author

I really enjoy field trips. I love being in a cool place and having someone tell me about it. The problem is, you can’t always find a professor or park ranger-type to tell you all they know about the local rocks, plants, and history. So I decided to combine my love of things natural with mobile technology.

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