A shoal of fish will do this.

鱼群也反射声音。

Alas, merely observing a shoal does not make it clear which individuals lead and which follow.

然，只观察一个鱼群并不能清楚地区分哪个是领导，哪个是随从。

This group is led by Mr Zhang, an expert in tracking down shoals of bighead carp.

这一队的队长是张先生，他可是追踪胖头鱼群的行家里手。

This gulfweed, the swimming gulfweed or berry carrier, is the chief substance making up this immense shoal.

这海藻是浮水藻，或承湾藻，主要构成这广大的草叶海面。

So it is a comparatively simple step from locating the sea bottom to locating a shoal of fish.

从测定海深到测定鱼群，这一进展比较容易。

Thirty miles away, shoals of squid are jetting upwards towards the surface.

30英里外的海上，大量的鱿鱼游到海面上。

With countless shoals and reefs to negotiate, accidents may happen any time.

还有盗匪 ——实在是最可怜的同胞，他们种地没得吃，有力气没处出卖，当了兵经常饿肚皮，无奈何只好出此下策 。——假如遇见了，把铺盖或者身上衣服带下去，也是异常难处的事儿 。

It's these shoals that support most of the world's sea mammals.

鱼群也养育了世界上大多数海洋哺乳动物。

Wherever they went, sailors kept scrupulous logs, detailing narrows and shoals for future adventurers.

无论走到哪里，水手们都会一丝不苟地记录下日志，为未来的冒险者详细描述狭窄的水域和浅滩。

This will give some idea of the havoc it makes among shoals of fish.

由这可想知，它是如何肆意蹂躏浅滩上的鱼类的。

Most recently, he has modelled the behaviour of shoals of fish.

最近，他建立了鱼群行为模型。

He swam above the fish shoal, and then...he slapped the water, killing or stunning the fish.

鲸鱼游到鱼群上方，然后拍打水流将鱼杀死或击昏。

Squid, which can be found mainly in estuarine, deep-sea, and open-water habitats, often swim together in shoals.

乌贼，主要分布在河口，深海和开阔水域的栖息地，经常在浅滩游泳。

That is a start. But real shoals do not exist to swim in circles.

那只是一个开始。不过真实的鱼群并不只是转圈游动。

By contrast, the baleen whales the researchers looked at, once they have encountered a shoal of prey, are in nutritional nirvana.

相比之下，研究员观察到的须鲸一旦遇到一群猎物，就处于营养极乐世界。

Come on, sir! We're gonna hit the shoal!

先生！我们要撞上浅滩了！

They include a World War 2 transport ship that struck a shoal in the late 1990s.

其中包括一艘在 1990 年代末撞上浅滩的第二次世界大战运输船。

He is now making a robot predator to see how the shoal reacts to less benign intruders.

他现在正在制作一个机器猎食者，用来观察鱼群对凶猛入侵者的反应。

About twelve, immense shoals of seaweeds came in sight.

大约十二个， 巨大的海藻浅滩映入眼帘。

But these attacks have little effect on the immense shoals.

但对庞大的鱼群来说这些攻击微不足道。