The kelp forest is more than just a home for underwater animals.

海草林并不只是水生家园。

They are semiaquatic, spending most of their time in and around the water.

它们属于半水生，绝大部分时间在水里和水边。

In fact, paleontologists once thought duckbill dinosaurs were aquatic, but that theory eventually fell out of favor.

事实上，古生学家曾经认为鸭嘴恐龙是水生，但这个理论最终失宠了。

These substances support the growth of cyanobacteria, which can have poisonous effects on water animals and humans.

这些质支持蓝绿藻生长，而蓝绿藻可能对水生和人类产生有毒影响。

They may be the most well-known underwater singer-songwriters, but they're far from the only aquatic animal that makes noise.

它们可能是最著名水下创作歌手，但它们并不是唯一发出声音水生。

We think of fish as completely aquatic animals.

我们认为鱼完全是水生。

That makes all of these groups secondarily aquatic.

这使得所有这些群体都是次要水生。

Unlike Palaeocastor and its burrowing cousins, these animals were semiaquatic.

与 Palaeocastor 及其穴居近亲不同，这些是半水生。

But we do not know what one-tenth of the water-things eat; so we are not answerable for the water-babies.

但是我们不知道十分之一水生吃什么； 所以我们不对水宝宝负责。

So one of the best things for any aquatic animal to communicate, especially across long distances, is by sound rather than sight.

因此，对于任何水生来说，最好方式之一，尤其是长距，是通过声音，而不是视觉。

This tragic discovery is just one of the many ways the health of aquatic animal communities can help us better understand Earth's oceans.

这种悲剧发现只是，我们通过水生健康状况，来更好地了解地球海洋方式之一。

Others like seals and sea lions are semi-aquatic, spending most of their time in the water for coming up every now and then.

其他，如海豹和海狮是半水生，它们大部分时间都在水中度过，偶尔浮出水面。

Likewise, if you were aquatic, your habitat and your food supply, might have been less disturbed by the fires.

同样，如果你是水生，你栖息地和食供应可能不受到大火干扰。

Now, as you can tell by now, becoming secondarily aquatic required a lot of changes to many different parts of the body.

现在，正如你现在所知道，成为二级水生需要对身体许多不同部位进行大量改变。

Of aquatic animals, there are many self-fertilising hermaphrodites; but here the currents of water offer an obvious means for an occasional cross.

水生中， 有许多自花受精雌雄同体； 但这里水为偶尔叉提供了明显途径。

And if a water animal can continually change into a land animal, why should not a land animal sometimes change into a water animal?

如果水生可以不断地变成陆生， 为什么陆生有时不能变成水生呢？

From Red Caps they moved on to Kappas, creepy water-dwellers that looked like scaly monkeys, with webbed hands itching to strangle unwitting waders in their ponds.

他们从红帽子又到了卡巴，这是一种爬行水生，看上去像有鳞猴子，双手有蹼，忙着要扼死不知深浅地走在它们池塘里涉水者。

That means that, in each case, their terrestrial ancestors originally evolved from aquatic animals millions of years earlier, making this their second time around as marine animals.

这意味着，在每一种情况下， 它们陆生祖先最初都是在数百万年前从水生进化而来，这是它们第二次作为海洋出现。

For years, its power stations had been emitting large amounts of sulphur dioxide, which was falling back to Earth as acid rain, causing harm to plants, aquatic animals and infrastructure.

多年来，它发电站一直在排放大量二氧化硫，这些二氧化硫以酸雨形式回落到地球上，对植、水生和基础设施造成伤害。

And when they visit, they get to see lots of fish and other aquatic animals like penguins, sharks and squid. But we asked Jo to answer your questions about fish. Our first one today comes from Laila.

当他们参观时， 他们看到很多鱼和其他水生，如企鹅、鲨鱼和鱿鱼。 但我们让乔回答了你关于鱼问题。我们今天第一个来自莱拉。