When sea otters were removed from the ecosystem one hundred years ago, urchin populations increased and kelp forests along rocky coastlines declined, a profound ecological change that went largely unnoticed or recorded. In areas without sea otters, urchin grazing restricts seaweed to inaccessible areas which are shallow and wave-swept or have unstable substrate. Over the last ten years biologists have documented dramatic changes associated with the return of sea otters. As sea otters re-inhabit their historic range, urchins disappear and kelp forests grow. Kelp in turn affects the ecosystem, increasing nearshore productivity, providing particles of kelp for detritus-based food webs, creating habitat for adult and juvenile fish, and altering water currents which affects invertebrate settlement and even reduces coastal erosion.
Sea otters represent a valuable reminder of the interdependency of ecosystems.
With continued non-intervention, and in the absence of environmental problems, the prospects for the sea otter should continue to look promising. All rights reserved.