Sea otters live along the pacific coast of the u. s. and canada. the otters feed upon sea urchins, and urchins feed upon kelp. reduction in the number of sea otters leads to an explosion in sea urchin populations, declines in kelp, and declines in all other species that feed upon kelp. given this information, sea otters are an example of a(n):

Given this information, sea otters are an example of a keystone species.

Explanation:

Keystone species:

A keystones species refers to those plants or animals which plays a major role within the function of the ecosystem in such that in their absence the ecosystem may completely stop to exist.

Keystone Species Example

Sea Otter

The sea otter is a keystone species because when they consume see urchins this helps to maintain the kelp species which is usually demolished by see urchins. Kelp are crucial to other various species in nearshore ecosystem. When sea otters are reduced this increases sea urchins and as they increase in number they feed upon kelp which will decrease kelp species affecting a number of organism which depends on kelp and this disrupt the whole ecosystem.

i think its toxic gasses but i could be wrong