Chapter 23
Nicole LaRoche, a sea otter researcher, talks about the state of sea otter populations on the Channel Islands today.
Sea otters are a very important species that, despite their small body size relative to other marine mammals, play a critical role in keeping California’s coastline habitat healthy. Because they eat, sleep, and raise their pups in the ocean, we can learn a lot about our coastal marine life community by studying them.
Sea otter research in California is conducted by many different agencies including the one I work for, the United States Geological Survey. My work as a sea otter researcher is mainly in the Santa Barbara Channel, studying what factors affect the sea otters that are re-colonizing their former range and how their return affects the habitat in exchange.
Sea otters were pushed to the brink of extinction in California due to overhunting for their luxurious fur hundreds of years ago. Now that law protects them, we are studying what they do and how other species respond as their population recovers and expands. We monitor tagged sea otters to see where they are going, what they are eating, how well they survive, and what causes their death.
I travel out on a boat and use binoculars, antennas and radio receivers to find sea otters that have been tagged with radio transmitters and color-coded flipper tags. Once we find them, we record information about their behavior, whether or not they have a pup, and many other things. Then we do it all again the next day.
Over the course of the three-year study we have learned that the sea otters expanding south into the Santa Barbara Channel do indeed have some different behaviors than the sea otters up north. Since they are the first otters to arrive, they have their pick of abundant food. A favorite food for sea otters is octopus. They seem to really enjoy eating the octopus in the channel!
The sea otters at San Nicolas Island are a special bunch. The otters that are there today are descendants of otters that were relocated there in the 1980s by US Fish and Wildlife as a part of a protection plan. Scientists were concerned that if there was a big oil spill off the coast of California, the entire local sea otter population could be decimated. With a smaller population on San Nicolas Island, 60 miles off the coast, there would be hope for saving this important species.
The relocation was not completely successful because a lot of the otters ended up swimming back to their original homes. However, some stayed and became the starting point for the current population off San Nicolas Island.
Twice a year, the sea otters at San Nicolas are counted. The population is rising steadily. In April 2016 there were 104 animals. Right now, San Nicolas Island is the only island in the California Channel Islands that has a continuous sea otter population.
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Last updated: November 16, 2017