Sea otters regulate the presence of the sea urchins and thus, kelp is regulated for all organisms in the ecosystem. They help to keep enough kelp for other wildlife to feed on. Also, due to their ability to absorb carbon dioxide, the kelp aid in mitigating climatic change and also reduce erosion by reducing the speed of water at the coast. However, if there were too many sea urchins and no sea otter to regulate their production, the kelp would reduce and thus with no food in the ecosystem, it would collapse. As a result, the sea otter protects the kelp forests by checking the local sea urchin population. The sea otter is an example of a

keystone species

Explanation:

The sea otter is an example of a keystone species in the scenario.

A keystone species is an organism that has a significant influence on the functioning of the entire ecosystem. Without this species, the ecosystem would either cease to exist in total or entirely different in structure. In other words, a keystone species is a fastener that holds the ecosystem together.

In this case, the sea otter indirectly regulates kelp for all organisms in the ecosystem by directly regulating the presence of sea urchins. Without kelps, several ecosystem functions such as climate change mitigation and erosion reduction would cease. Thus, the sea otter is playing a significant role as a keystone species.

your answer is going to be physical weathering