Estes JA, Tinker MT, Williams TM, Doak DF
Science. 1998 Oct 16;282(5388):473-6. doi: 10.1126/science.282.5388.473.
After nearly a century of recovery from overhunting, sea otter populations are in abrupt decline over large areas of western Alaska. Increased killer whale predation is the likely cause of these declines. Elevated sea urchin density and the consequent deforestation of kelp beds in the nearshore community demonstrate that the otter's keystone role has been reduced or eliminated. This chain of interactions was probably initiated by anthropogenic changes in the offshore oceanic ecosystem.
在从过度捕猎中恢复了近一个世纪后，海獭种群数量在阿拉斯加西部大片地区突然下降。虎鲸捕食增加可能是这些下降的原因。海胆密度升高以及随之而来的近岸群落海带床的破坏表明，海獭的关键作用已经减弱或消除。这种相互作用链可能是由近海海洋生态系统的人为变化引发的。
