Grade Level: 2nd to 8th grade

Objective
Students will simulate oiled sea otter fur, see how oil effects the fur, test methods to clean it, determine the best cleaning method and how difficult it is to clean. This activity can also be done with bird feathers.

Background Information
Like all marine mammals, sea otters must keep warm in cold ocean waters. Unlike other marine mammals, which have a layer of blubber to keep warm, sea otters rely on their thick coat of fur. In fact, at approximately a 600,000 to one million hairs per square inch, they have the thickest fur of any mammal. It is made of a double layer, an undercoat and guard hairs. Sea otters spend much of their time grooming to keep their fur in good condition. A healthy, well-groomed sea otter's fur traps an insulating layer of air in the fur, keeping the otter's skin dry and adding another layer of protection from the cold.

Sea otters were once found along the Pacific Coast from Mexico to Alaska, even in Japan. Their numbers were reduced in the 1800's due to hunting for their fur. The southern sea otter is listed as threatened under the Endangered Species Act and they are listed as endangered with the California State Department of Fish and Game. Even though laws protect sea otters, they face other threats due to humans, such as oil spills. If oil gets on their fur, it will mat the fur together and the cold ocean water soaks their skin, causing them to chill and eventually freeze to death. Oil may be ingested during grooming or while feeding on oil exposed food. Poisonous fumes alone can affect the sea otter and many in the 1989 Exxon Valdez oil spill in Alaska died from lung problems.

During disasters, such as the Exxon Valdez oil spill, ocean water and the animal's grooming alone are not sufficient to clean oil from fur or feathers. Special rehabilitation facilities are established and people clean and care for oiled marine life. Rescue volunteers clean oiled sea otter's fur with a diluted solution of Dawn© dishwashing detergent or other specialized cleansers. After many rinses with water and thoroughly drying the fur with hair dryers, the otters are left alone. Once all the oil is gone, only they can groom their fur to recondition it back to its natural state. After additional time to gain strength, sea otters are released back to the wild.

Materials
Fake fur cut in 3-4 inch square, round, and triangle shapes, or have older students devise their own way of keeping track of similarly shaped swatches. Rather then sea otter brown, use light colored fur so students can see the oil better. Black tempera paint
Vegetable oil
Dawn© dishwashing detergent
Water
Plastic forks (1 per group)
Paper towels
One medium-sized yogurt container to mix oil (1 per group)
3 small dishpans or buckets per group
Pictures if otters
Art smocks
Small hand-held hair dryer (optional)
Feathers (optional)

Procedure:
1. Introduce background information, use pictures or posters if possible. Break the class into small groups of three students. For younger students, you may want to do the activity as a demonstration. See * step below. You may want to have this prepared beforehand. However, students will still need the fork to mix it a final time and observe the consistency.

2. Distribute supplies to each group; three swatches of fur (circle, square, and triangle), paper towels, two dishpans of rinse water, and one dishpan of Dawn©/water.

3. Have students feel the fur. Have them describe what they see and feel. Note its thickness and insulating capabilities (fluffy fur traps air). Each group should put the triangle shaped fur aside as a control, and label it. A control is a standard of comparison for checking or verifying the results of an experiment. In our case the control is a piece of fur that does not get oiled, wet, cleaned or dried.

4. *Using the fork stir/whip a combination of black tempera paint and vegetable oil. Students should take note of the "oils" qualities. Have them describe what they see and feel (thick, oily, viscous, black, sticky, gooey, etc).

5. Dip the square swatch in the oil mixture. Examine the oiled fur. Describe how the fur has changed. Rinse the square swatch with water alone, and simulate how a sea otter would try to groom itself by rubbing with paper towels. How well does the sea otter do at cleaning off the oil on his own? Clean it as best you can, then set it aside to dry. Label the swatch so that you know what was done to it.

6. Dip the round swatch in oil. Rinse it in water and rub it as the otter cleans fur. Then, using Dawn©/water solution, rub and rinse the fur. It may take a few times. Dry the round swatch with paper towel. Use a warm hair dryer on this one (if available); this is how sea otters are dried in the rehabilitation facilities.

7. Make the following observations and, if possible, wait overnight until the fur dries completely to see if your observations change. Compare the two "cleaned" fur swatches. Is one still oily? Which one and why? Compare them with the control. Does either of the "cleaned" fur swatches look and feel the same as the control? (Be careful not to get the control oily or wet.) You may notice that even the fur cleaned with Dawn© is different than the control, describe. Only more grooming by the sea otter will return the fur to its fluffy insulating/healthy condition. Have students try to work with the cleanest fur swatch by rubbing it with their fingers and blowing on it to see if they can ever make the "cleaned" fur look and feel like the control. Sea otters can!

Further Explorations and Discussions
Ask the students why they think it is stressful for otters to be cleaned? Why are sea otters more susceptible to oil spills then seals or whales? Think about: Where sea otters prefer to be in the ocean. How long can they swim under water? What types of food do they prefer? Where are those foods on the food chain? What adaptations do seals and whales have that help them in the event of an oil spill?

What other animal life is affected by oil spills? Try the same activity with feathers. What other forms of pollution are problematic for ocean animals? What can we do to help? (Conserve energy, car pool, support legislation that helps keep our oceans clean or sets up reserves by writing your legislator, write to oil companies encouraging them to develop safer transport technology/more strict regulations, etc.)

Discuss other adaptations that help sea otters survive in their marine environment.