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

它们可能是最著名的水下创作歌手，但它们并不是唯一会发出声音的水生动物。

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

因此，对于任何水生动物来说，最好的交流方式之一，尤其是长距离交流，是通过声音，而不是视觉。

Not only do these organisms form the foundation of local food chains, their photosynthesis provides the oxygen necessary for aquatic animals to survive.

这些生物不仅形成了当地食物链的基础，它们的光合作用也提供海洋动物生存所需的氧气。

We think of fish as completely aquatic animals.

我们认为鱼完全是水生动物。

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

这种悲剧的发现只是，我们通过水生动物健康状况，来更好地了解地球海洋的方式之一。

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

水生动物中， 有许多自花受精的雌雄同体； 但这里的水流为偶尔的交叉提供了明显的途径。

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， 它们的陆生祖先最初都是在数百万年前从水生动物进化而来，这是它们第二次作为海洋动物出现。

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，它的发电站一直在排放大量二氧化硫，这些二氧化硫以酸雨的形式回落到地球上，对植物、水生动物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， 他们会看到很多鱼和其他水生动物，如企鹅、鲨鱼和鱿鱼。 但我们让乔回答了你关于鱼的问题。我们今天的第一个来自莱拉。