Sea Otters and Kelp Forests

The video discusses the importance of sea otters in maintaining the health of kelp forests. It highlights the extinction of sea otters in Oregon due to hunting and the resulting ecological imbalance, leading to urchin barrens. The video explores the role of sea otters in controlling sea urchin populations and the efforts to reintroduce them to Oregon to restore ecological balance and boost tourism.

Why are sea otters considered important to the ecosystem?

• They have a blubber layer to keep warm.

• They can survive without eating much.

• They are a major predator that helps maintain balance.

• They are the largest marine mammals.

What is the primary reason for the absence of sea otters in Oregon?

• They could not adapt to the environment.

• They were outcompeted by other predators.

• They migrated to warmer waters.

• They were hunted to extinction.

What makes a kelp forest similar to a terrestrial forest?

• It does not support any wildlife.

• It has a canopy and understory.

• It is made entirely of trees.

• It is found only in cold climates.

What percentage of Oregon's kelp forests are located on the south coast?

• 60%

• 75%

• 50%

• 90%

What has caused the decline of kelp forests in Oregon?

• Lack of sunlight reaching the ocean floor.

• Overpopulation of sea urchins.

• Pollution from nearby cities.

• Overfishing of salmon.

What is the main diet of purple sea urchins that affects kelp forests?

• Small fish

• Plankton

• Kelp

• Coral

How do sea otters help maintain the balance in kelp forests?

• By controlling the population of invertebrates.

• By eating the kelp directly.

• By increasing the water temperature.

• By providing shelter for fish.

What indirect effect do predators have on kelp forests?

• They cause kelp to produce more oxygen.

• They help prevent kelp from being eaten.

• They reduce the number of fish.

• They increase the growth rate of kelp.

What is a potential concern for commercial fishers regarding the reintroduction of sea otters?

• Sea otters might eat all the fish.

• Sea otters could spread diseases.

• Sea otters might eat Dungeness crabs.

• Sea otters could damage fishing equipment.

What is a potential benefit of reintroducing sea otters to Oregon?

• Reduced fish populations

• Increased pollution

• Improved kelp forest health

• Decreased tourism