Question

In the aleutian islands of alaska, sea otters were hunted to near extinction. as a result, the number of urchins (invertebrate herbivore) increased rapidly because sea otters used to eat them. the overgrowth of urchins led to a dramatic decrease of kelp (large algae) production. in this system, which being is the keystone species? group of answer choices

O the sea otter
O both animals (otter and urchin)
O the urchin
O the kelp

Answer 1

The sea otter is the keystone species in the Aleutian Islands ecosystem, as their presence controls sea urchin populations and supports kelp forest ecosystems.

Step-by-step explanation:

In the described scenario from the Aleutian Islands of Alaska, the correct identification of the keystone species is the sea otter. As the otters were hunted to near extinction, their absence allowed the population of sea urchins, which are herbivorous grazers, to increase substantially. The unchecked growth of the urchin population led to the overconsumption of kelp, resulting in a significant decline in kelp forests. This cascade effect underscores the critical role sea otters play in maintaining the balance of the ecosystem by preying on urchins, thus controlling their numbers and subsequently supporting kelp forest ecosystems.