时差N小时 过度捕鲸的危害超乎想象!(上)（在线收听）

Until recently, when scientists studied changes in open-ocean ecosystems,

直到最近，当科学家们在研究开放海洋生态系统的变化时，

they looked at changes in the bottom of the food chain that gradually make their way to the top, like food shortages and shifts in the ocean environment.

他们观察了位于食物链最底层且不断上升的生物的变化，例如食物短缺、海洋环境变化。

A recent study, however, suggests that more attention needs to be given to top-down influences as well.

然而，最近一项调查显示，人们还应该更加关注（食物链）自上而下的影响。

For example, over the past few decades, there's been a major collapse of the populations of harbor seals, fur seals, sea lions, and sea otters living on the coasts of western Alaska.

例如，在过去的几十年里，生活在阿拉斯加西海岸的斑海豹、海狗、海狮和海獭数量锐减。

Now a new study suggests that all this destruction can be traced back to humans overfishing sperm and baleen whales between 1946 and 1979.

现在，一项新的调查显示，所有的这些毁坏皆可归咎于人类在1946年到1979年间过度捕捞抹香鲸和须鲸。