Nearshore Connections: Sea Otter Story
Students learn about the role of Sea Otters in their habitat through an interactive story.
Kelp forests are undersea forests made of seaweed instead of trees. Many types of fish live in kelp forests, finding shelter and relying on the kelp to lay their eggs. Crabs, snails, clams, and shrimp are also found in kelp forests. Sea otters play a very important role in keeping kelp forest ecosystems healthy. The sea otter is an example of an important keystone species (a species that, if removed, has a great effect on other species in its food web).
Sea otters find their food and sleep in kelp forests. They wrap kelp around themselves when they sleep, like fastening a seatbelt.
Even though sea otters live their whole lives in cold Pacific waters, they don't get cold. Other marine mammals have blubber to keep warm; instead of this fatty layer, sea otters have some of the thickest hair of any animal. There is up to one billion hairs in their fur coats, compared to the average person who has about 10,000 hairs on their head. In the 1700s and 1800s, sea otters were hunted for their thick fur coats until there were no more sea otters found on the BC coast.
When sea otters populations dropped, everything changed. Sea otters keep kelp forests healthy by eating animals that graze on (eat) kelp. Sea otters love to eat sea urchins and crabs, often using a rock as a tool to crack the animals' hard shell. When there is nothing to eat sea urchins, the sea urchins eat away and destroy kelp forests. In coastal areas where there are no sea otters, there has been a change from forests to deserts or barrens, and many fish and other creatures are without protective homes.
Sea otters were reintroduced in the 1970s to northern Vancouver Island, and we can now find healthy kelp forests in some remote areas of the BC coast.
Students will be able to:
- Describe the concept of a "keystone species" and explain the role that such an organism plays in its environment.
- Explain the term "species at risk" and list examples of marine species at risk.
These resources are free!
You must LOGIN to download the activity.
Full Lesson & other activities - Coastal Connections
Engaging Science Online Games - Secrets @ Sea
Engaging Science Online Games - Wild Wetlands