虎鲨因海洋变暖转移栖息地

This is Scientific American's 60-second Science, I'm Christopher Intagliata.

这里是科学美国人——60秒科学系列，我是克里斯托弗·因塔利亚塔。

As it happens, tiger sharks have something in common with certain East Coasters.

碰巧，虎鲨和某些东海岸动物有一些共同之处。

During the winter, when it’s cold, they snowbird down near the Bahamas and off of Florida. 、

冬天天气寒冷时，虎鲨会在巴哈马群岛附近和佛罗里达附近过冬。

And then, during the summer, they migrate north.

然后，在夏天，它们向北迁移。

Neil Hammerschlag is director of the Shark Research & Conservation Program at the University of Miami.

尼尔·哈默施拉格是迈阿密大学鲨鱼研究与保护项目的负责人。

He and his colleagues analyzed 40 years of fishing catch data and found that as ocean waters warm, the sharks’ range has shifted some 250 miles to the north.

他和他的同事分析了40年来的捕鱼数据，发现随着海水变暖，鲨鱼的活动范围向北移动了250英里。

The sharks, it seems, are chasing their preferred water temperatures to the north.

鲨鱼似乎是在追逐它们喜欢的北方水温。

They also tracked dozens of tiger sharks with satellite tags for nine years and found similar results.

研究人员还用卫星标签追踪了数十只虎鲨，历时9年，发现了类似的结果。

So taken together, we have several lines of evidence that tiger shark distributions and migrations are changing from ocean warming, causing their distributions and migrations to expand further north.

综上所述，我们有几条证据表明，随着海洋变暖，虎鲨的分布和迁徙正在发生变化，这导致它们的分布和迁徙向更北的地方扩展。

And in these areas, they occur earlier in the year from ocean warming.

在这些地区，由于海洋变暖，虎鲨会在一年的早些时候出现。

Their findings appear in the journal Global Change Biology.

他们的发现发表在《全球变化生物学》杂志上。

This shift matters, Hammerschlag says, because tiger sharks are apex predators, and where they go influences the food web beneath them.

哈默施拉格表示，这种转变很重要，因为虎鲨是食物链顶端的掠食者，它们的去向会影响它们下面的食物网。

The sharks are also moving outside marine protected areas and into places where they’re more vulnerable to commercial fishing.

这些鲨鱼也离开了海洋保护区，来到了更容易遭受商业捕捞的地方。

What this points to is: these marine protected areas need to consider current but also future changes in species distribution due to ocean warming.

这表明:这些海洋保护区需要考虑目前以及未来由于海洋变暖而造成的物种分布的变化。

And they certainly have to be adaptive and maybe, you know, work with not only having marine protected areas but also other protections, like catch limits and other types of more traditional species conservation and management tools, in addition to protecting places.

这些保护区必须具有适应性，不仅要有海洋保护区，还要有其他的保护措施，比如捕捞限制和其他更传统的物种保护和管理工具，除了保护场所以外。

Now, if you don’t find the ecological argument convincing, Hammerschlag pointed out one more implication.

现在，如果你觉得生态论证不令人信服，哈默施拉格还指出了另一个可能的影响。

Although shark bites are relatively rare, he says, if tiger sharks shift their range—and warmer waters draw more bathers to the ocean—that could up the odds of an unfortunate encounter beneath the waves.

他表示，虽然鲨鱼咬人的情况相对少见，但如果虎鲨改变它们的活动范围——温暖的海水吸引更多的游泳者——那么在水下遭遇不幸的几率就会增加。

Thanks for listening for Scientific American's 60-second Science. I'm Christopher Intagliata.

谢谢大家收听科学美国人——60秒科学。我是克里斯托弗·因塔利亚塔。