What is a Sea Otter?
A sea otter is a marine mammal that lives in coastal waters in the central and north Pacific Ocean. It is the smallest marine mammal in North America and is about 4 feet long. Female otters weigh an average of 45 pounds and male otters weigh an average of 65 pounds. Sea otters live an average of 10-11 years.
What do sea otters eat?
Sea otters eat clams, crabs, snails, starfish, abalone, and 40 other marine animals. Sea otters dive up to 120 feet to find food. Their average dive lasts about a minute; the longest dive recorded, however, lasted 4 minutes. When sea otters come to the surface they lie on their backs and use their stomachs as a table. Sometimes they use a tool, such as a rock, to help them open the hard shells of their prey. They bang the hard shell on the rock until it breaks open. Sea otters must eat 25 percent of their body weight each day in order to stay alive. That means a 40-pound sea otter must eat 10 pounds of food each day! How do sea otters swim?
Sea otters usually swim on their backs at the water's surface. They use their rear flippers to move and their tails to steer. They don't swim very fast (about 1 1/2 miles an hour). If otters are frightened they will flip over on their stomachs and swim away. Sometimes they will dive under water to get away. How do sea otters stay warm?
The water that southern sea otters live in is a chilly 30 to 50 degrees Fahrenheit - much too cold for humans. Otters don't have blubber to keep them warm like other marine mammals. Instead, they rely on their thick fur coat. Sea otter fur is the thickest fur of any animal. It has 600,000 to 1 million hairs per square inch - humans only have 20,000 hairs on their whole head! It is important for otters to keep each individual hair clean. If the fur isn't clean then it gets matted and otters can die from hypothermia. Why aren't there more sea otters?
Two hundred years ago, a million otters may have ranged along the 6,000 miles of Pacific coastline from northern Japan, through the Aleutian Islands of Alaska, down the coast of California to Baja Mexico. Because the pelts of sea otters are thick, warm and beautiful, fur hunters killed hundreds of thousands of them - until not a single otters was visible along the entire California coastline. The southern sea otter was thought to be extinct. Then, in 1938, a raft of about 300 otters was discovered off the coast of Big Sur, California. This group has spread along the 200 miles of California coastline, but its population is still small - only about 2,300. Southern sea otters are now protected by the Endangered Species Act and the Marine Mammal Protection Act, so they cannot be hunted. Where do southern sea otters live?
Southern sea otters are found in the Pacific Ocean off the coast of central California. They range from Año Nuevo (9 miles north of Santa Cruz) to Purisima Point (just north of Point Conception). Additionally, there is a small colony off San Nicolas Island near Santa Barbara. Usually sea otters stay close to shore, but sometimes they are found out as far as 3 miles from shore. Otters rest in kelp forests, in groups called rafts. Often they will drape the kelp over their bodies to keep from drifting away. What are some threats to the sea otter?
Now there are other threats to otters. Oil spills can be fatal to the sea otter and could cause this species to become extinct. Oil coats the fur, destroying the blanket of air that keeps the animal warm. This causes chilling and death (hypothermia). Increased pollution in our oceans is also a threat to sea otters. Fishing nets are another cause of sea otter deaths. Sea otters become caught in the nets and drown. Laws have been passed to limit the use of fishing nets along the coastline. This has helped sea otter populations. |
