Imagine that you are fishing on the coast of the United States or Canada. You see a large brown and tan spot in the Pacific Ocean. It is coming closer and closer. You’re scared about what it could be. You’ve never seen anything like it. You snap a picture of it so you can ask someone to identify what it is. Someone tells you it is a sea otter. Next, you decide to look up information on sea otters.
Life Cycle of a Sea Otter
The majority of sea otter pups are born in early spring. Newborn sea otters range in weight from 3 to 5 lbs. Sea otter pups are typically born in the water. After a few weeks, young sea otters can be found swimming, diving, grooming themselves, and also beginning to eat solid foods. Young sea otters are very curious and play in a rough way. Between five and eight months of age, sea otters leave their mother to make it on their own.
Sea otters have a small, round head, closeable nostrils, ears with flaps, and small eyes that are good for seeing in and out of the water. The nostrils and the ears close while underwater so that no water gets into them.
Southern sea otters are about 4 feet long including their 12-inch tails. Northern sea otters tend to be a little larger. Male sea otters are usually about 65 lbs. and females are about 20 lbs. less than males.
Sea otters have the thickest fur of all mammals. Sea otter fur contains two layers, an undercoat and long guard hairs on top. These two layers have air trapped between them to keep in warmth. Sea otter fur is usually a brown to a black color. Sometimes the guard hairs can be a light tan color.
Sea otters have front paws shaped like mittens. Although their front paws are covered with fur, they have rough pads and claws to hold their prey better. Like cat claws, sea otters’ claws can be pulled back into their paws. The front paws of a sea otter are very different from the paws on the hind legs. The paws on a sea otter’s hind feet are webbed. This helps the sea otter swim faster.
Otters make several different sounds to communicate. A baby sea otter will cry when it is left alone. It makes a shrill "wee" sound like a sea gull. Otters will whistle or whine when upset or frustrated. Hissing or growling warns predators to back off. The mother sea otters will "coo" when they are grooming their baby’s fur with their teeth or claws. They will make a grunting sound when they are happy, such as enjoying a tasty snack.
Sea otters also communicate by body language. Moving their heads from side to side is like saying hello. The babies cling to their mothers or other sea otters when they are afraid.
Sea Otter Family
Sea otters are mammals like you and me. Like all mammals, they are warm blooded. Their babies are born alive and the babies feed from their mothers’ milk. The group of mammals that the sea otter are included in is called the Mustelidea family. This group includes badgers, weasels, minks, pine martens, and skunks.
Sea otters have a unique way of eating. They use their stomachs as a table by placing all their food on it. When sea otters bring up hard shells with prey inside, they also bring up a big piece of rock. They then bang the hard shell on the rock until it opens enough so they can eat what is inside.
Sea otters eat clams, snails, abalone, crabs, starfish, mussels, scallops, squid, chitons, small octopuses, sea urchins, prawns, sea cucumbers, limpets, marine worms, several types of fish, and a variety of other things. Sea otters eat about 160 different types of food.
Most of the time sea otters eat at the surface. When they come across a fast moving fish, they will swallow the fish underwater. Sea otters use loose folds of skin as shopping bags. For example, a sea otter could tuck scallops, sea urchins, crabs, or other edibles under its arm. Scallops are two shells put together with an animal inside. When sea otters eat starfish, they bite off the tips of their legs, so they can then suck out the soft parts.
Sea otters live in cold water, which makes it hard for them to keep warm. Sea otters have to eat at least 25% of their body weight each day. This is to keep a stable body temperature because they do not have a layer of blubber. For example, if an otter weighed 55 pounds it would have to eat 13.75 pounds a day. Each day, sea otters need to eat every three hours.
Where Sea Otters Live
Sea otters today live in these places: the Kuril Islands, Kamchatka, the Commander Islands, the Aleutian Islands, British Colombia, Vancouver Island, and Point Sur, California. Sea otters no longer live off the coast of Mexico, the Pribilof Islands, and Hokkaido. This is because a long time ago too many people killed the sea otters and used the valuable thick sea otter fur for trading.
The population of sea otters in British Colombia is increasing by 17% - 20% each year. This is due to environmentalists moving some of the population from the Aleutian Islands to British Columbia. This was decided because the population in the Aleutian Islands is decreasing rapidly. The reason for this may be because of a decline in pinnipeds. Killer whales usually prey on pinnipeds. The pinniped population is decreasing, because of lack of food and global warming, so the killer whales now seem to be eating sea otters instead of pinnipeds.
Sea otter fur can become covered with oil when tanker spills occur. This makes grooming for the sea otter extremely difficult. This can kill the sea otter because if they cannot groom themselves, the air trapped between the two layers of skin will not be pushed next to their undercoat. This will result in the air not holding in heat for the otter’s body.
Another problem with oil getting trapped in their fur is the sea otter could swallow the oil, which is poisonous, while they are grooming. Also eating an animal that has touched oil could cause damage to the sea otters’ kidneys, eyes, lungs, and liver.
Between 3,500 and 5,500 sea otters have died because of oil spills. All around the world 350 million gallons of oil gets dumped into storm drains, waterways and soil each year. This is 30 times greater than the largest oil tanker spill. Some ways we can help this problem are:
When you are finished researching sea otters, you take your boat out to the same spot you first saw the sea otter. This time there isn’t a sea otter. Instead, there is a strange looking creature. You take a picture of it. What is it? (Find out in my next report!)
Aqua Facts: Sea Otters. Vancouver Aquarium Marine Science Centre, 1997-2001. http://www.vanaqua.org/visitors/faq/AquaFact/seaotter.htm. Last Visited: December 20, 2001.
Paine, Stephan. The World of the Sea Otter. Vancouver British Colombia: Greystone Publishers, 1993.
Silverstein, Virginia, Silverstein, Robert, and Silverstein, Alvin. The Sea Otter. Brookfield, Connecticut: Millbrook Press, 1995.
Friends of the Sea Otter Information. Sunstar Media, 1997-2002. http://www.sea_otters.org Last Visited: December 27, 2002.