Final answer:
Sea otters play a crucial role in maintaining the balance of the food web in coastal areas. Their overhunting can cause the population of sea urchins to explode, leading to the decline of kelp forests and a decrease in biodiversity in coastal ecosystems.
Step-by-step explanation:
When sea otters were overhunted along the Pacific coast, it had a significant impact on the ecosystem. Sea otters play a crucial role in maintaining the balance of the food web in coastal areas. They are keystone species that help control the population of sea urchins. Without sea otters, the population of sea urchins can explode, leading to the overconsumption of kelp forests. Kelp forests provide important habitat for a variety of species and are essential for the overall health of the ecosystem.
For example, in the Aleutian Islands, sea otters were nearly exterminated by fur traders in the 18th and 19th centuries. As a result, the sea urchin population skyrocketed, and the kelp forests dwindled. This had a cascading effect on other species such as fish, birds, and invertebrates that rely on kelp forests for food and shelter. Therefore, when sea otters are overhunted, it disrupts the delicate balance of the food web, leading to the decline of kelp forests and a decrease in biodiversity in coastal ecosystems.