Question

The following is one of the food chains within the Alaskan coast. The sea otter feeds on the sea urchins and the sea urchins feeds on the kelp (sea weed). It has been observed that the population of the sea otter is decreasing while the population of sea urchins is exploding. Consequently, the sea urchins have almost depleted the kelp. Which of the three species can be regarded as a keystone species/predator?

Answer 1

Answer:

The correct answer is sea otter.

Explanation:

A keystone species is that species that have a major impact on its ecosystem relative to its number. A keystone species stabilize an ecosystem by controlling the population of other species.

For example, sea otter is a keystone species that feeds on sea urchin and control its population. As the sea urchin population is under control seaweed population is also stable because sea urchin feeds on seaweeds.

As the population of sea otter declines the population of sea urchin increases because of having fewer predators and then this overpopulation of urchin depletes all the kelp by feeding on them.  

Therefore the right answer is- sea otter is the keystone species.