Answer:
It controls the population of sea urchins.
Explanation:
Sea otters are very important in maintaining the balance of ecosystems present near the sea or ocean, such as kelp forests etc. In the absence of sea otters, sea urchins can increase in population i.e. overpopulate the sea floor and feed all vegetation of the kelp forests that provide cover and food for many other marine animals which leads to imbalance of an ecosystem so that's why we can say that sea otters are important in the kelp forest.
