Was that a sea otter or a river otter you just saw swimming offshore? People often think they see sea otters foraging on our beaches, swimming by, or playing in a boat at the marina. Sea otters are actually rarely spotted near Port Townsend, but river otters are thriving local residents. Sea otters have been documented near Protection Island and by Point Wilson, but most spotting in the Strait of Juan de Fuca occurs closer to Port Angeles.

Juvenile River Otter

How to tell the difference? Sea otters can weigh 50-100 pounds; river otters are much smaller, with females weighing 11-20 pounds, and male river otters reaching at most 31 pounds. Sea otters have the densest fur of all animals. River otters also have lovely, short, coarse fur, with two layers— one is for warmth, and the other is water-repellent. Unlike sea otters, river otters have a layer of fat on their bodies. Here’s a juvenile river otter in the middle of eating a large fish on a boulder by Cape George.

River Otter Emerges from Lagoon

River otters have long, thick whiskers that enhance their sensory perception underwater and on land. They have a sharp sense of smell and hearing. However, out of the water they are near-sighted, since they’ve adapted to seeing well underwater. This otter seemed to wonder what I was when we encountered each other by a pocket of Chinese Gardens lagoon in Ft. Worden.

River Otter Swimming

River otters have a streamlined profile in water, swimming expertly mostly submerged with their belly down, using all four webbed feet. They use their tail, which is about 1/3 their body length, to propel themselves and for stability when swimming. They can stay underwater for almost four minutes, swim almost 7 mph, and dive over 60 feet deep. They are beautiful to watch swimming in our Salish Sea.

River Otter with Starry Flounder

Unlike sea otters who float on their backs to eat, river otters eat small fish while swimming, and they eat large fish on shore, on an offshore boulder, or on a dock. They often prefer to eat fish head first, like this otter eating a Starry Flounder. Notice its sharp teeth and claws, and its huge paws.

River Otter with a Red Rock Crab

The North American River Otter (Lontra canadensis), as a mustelid, or member of the weasel family, has specialized, sharp canine and carnassial teeth to bite and shear fish, and large molars to crush hard prey, like crabs. This otter swam, carrying the Red Rock Crab all the way from Pt. Wilson, before hauling it onto the former dock at the Port Townsend Marine Science Center to eat.

River Otters Resting

River otters are very playful, especially immature otters, who wrestle, chase each other, and play to learn survival skills, like fighting and hunting. The Leader recently ran a story about the successful rehabilitation of two juvenile river otters at the Center Valley Animal Rescue. The Center’s director, Sara Penhallegon, noted that they were very intelligent and unruly, as well as natural escape artists. Young otters need to be with other otters to thrive. I’ve seen them a few times cuddling up together in the sun, like these on a local dock.

River Otter Family

You’ll often see river otters in groups, as they are a very social species. A family often includes an adult female and her children. Adult males can also create lasting social groups, with up to 17 otters. Here a family of nine otters swam by Fort Worden.

River Otter Paw Prints

River otters have distinctive paw prints with five pads facing forward. David Moskowitz, author of Wildlife of the Pacific Northwest, writes “A (river) otter’s feet are highly adapted to its aquatic lifestyle but still retain similarities to those of other mustelids. Webbing on both front and hind feet connects toes at about the middle of each toe pad…” Look for river otter prints in the sand under and beside the Port Townsend Marine Science Center pier.

River Otters Mating

River otters reach sexual maturity between age two and three, earlier than sea otters. Their prolonged copulation can be quite noisy and appear quite violent to beach walkers, as it did one summer day at North Beach when a male otter grabbed a female on the neck with his teeth. Females have the unusual ability of delaying implantation up to eight months, and the babies are born in early spring. Sea otters give birth to only one pup, whereas river otters usually have a litter of two or three but can even have up to five pups.

All photos by Wendy Feltham


  1. Fascinating, very informative, and great photos. Thanks. Looking forward to your piece on sea otters (it’s coming, right?), but at least I could probably tell the difference now.

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