They are used to help people visualize a situation in time, like an erupting volcano, new animals or plants, or even things that we may already know something about, like the California sea otter. The females are smaller, with an approximate length of four feet long, and weight of 60 pounds. Southern sea otters can dive for about four minutes to depths of around 300 feet, but most commonly they dive to around 60 feet. Because they spend most of their time in the water, feeding, playing, giving birth, or resting wrapped up in the kelp. Sea otters are also the most recently evolved marine mammal, and are usually found associated with kelp forests and rocky shores, but may also be found near sandy beaches or mudflats.
River otters are one of their closest relatives, and are easily confused with sea otters.
Northern river otters are smaller with long tails and slightly silvery fur on their undersides. River otters also live mainly in fresh water areas. Previous estimates of the worldwide sea otter population totaled between 150,000 to 300,000. The Coastal North American Indians, northern Aleuts, Russians and the Japanese hunted the sea otter for its warm fur. Approximately 50 otters were discovered along the Big Sur coast in 1915.