英语听力：自然百科 大堡礁 堡礁内外(9)（在线收听）

 They are one of the ten species of whales that visit the reef each year.

座头鲸是每年造访大堡礁十种鲸鱼当中的一种。

They were once hunted almost to extinction, but numbers here have bounced back to 15 thousand, about half the pre-whaling population.

它们曾遭受大肆捕猎，几乎处于绝迹，但现在数量已经回升至15000只，这个数字是捕鲸业开始之前数量的一半。

Like Minkes, humpbacks come up from the Antarctic to mate and to calve.

和小须鲸一样，座头鲸也是从南极来这里进行交配分娩。

This mother gave birth a couple of weeks ago.

这头母鲸数周前产下幼鲸。

And already her calf weighs over two tons and it is more than six meters long.

她的小宝宝已经有2吨多重，身长也超过6米。

For the turtle mother, the final and what may turn out to be the most arduous part of her journey has only just begun.

对海龟妈妈而言，此行途中最后也可能是最为艰辛的部分只不过刚刚开始。

With thousands of turtles arriving at the same time, their trails crisscross the sand like tank tracks on a battlefield.

数千只海龟同时抵达，它们在沙滩上的痕迹纵横交错，就像战场上坦克过后留下的痕迹。