The researchers said the switch threatened the environment because sea otters control the sea urchin population, which strips kelp forests that many marine species need to survive. But with the number of sea otters dwindling, sea urchins were flourishing, with kelp forests of the western Alaska coastal ecosystem disappearing quickly, said James Estes, a marine ecologist at the University of California, Santa Cruz, who led a study published in the journal Science.
Sea urchins are tiny round spiny creatures that feed on kelp and are related to starfish.
The whole concept is to maintain an ecosystem and that is not being done in this one. Sea otters are a keystone species, meaning their impact on the ecosystem is far greater than their abundance in nature, he said in a telephone interview. The well-being of many fish, birds and marine ducks depended on the kelp forests that the sea otters helped maintain, he added. Things that are rare can impact the ecosystem quite a bit. Before switching to sea otters, killer whales ate sea lions and seals, he said.