SECTION 4

I've been looking at ocean biodiversity, that's the diversity of species that live in the world's oceans.

我最近一直在关注海洋生物多样性，也就是生活在世界海洋中的生物的多样性。

About 20 years ago biologists developed the idea of what they called 'biodiversity hotspots'.

大约20年前，生物学家提出了他们称为"生物多样性热点地区"的概念。

These are the areas which have the greatest mixture of species, so one example is Madagascar.

这些地区拥有最大的混合物种群体，其中一个例子就是马达加斯加。

These hotspots are significant because they allow us to locate key areas for focusing efforts at conservation.

这些热点地区至关重要，因为它们给了我们锁定关键地区集中力量进行生物保护的机会。

Biologists can identify hotspots on land, fairly easily, but until recently, very little was known about species distribution and diversity in the oceans, and no one even knew if hotspots existed there.

生物学家们能够相当轻易地辨认出陆地上的热点地区，但是直到最近之前，人们对海洋中的生物分布和多样性都知之甚少，甚至没人知道海洋中是否存在这样的热点地区。

Then a Canadian biologist called Boris Worm did some research in 2005 on data on ocean species that he got from the fishing industry.

接着在2005年，一个叫鲍瑞斯温姆的加拿大生物学家从捕鱼业中获得了关于海洋物种的数据，并对其进行了研究。

Worm located five hotspots for large ocean predators like sharks, and looked at what they had in common.

温姆锁定了海洋中像鲨鱼这样的大型食肉动物生活的五个热点地区，然后研究了它们的共同点。

The main thing he'd expected to find was that they had very high concentrations of food, but to his surprise that was only true for four of the hotspots - the remaining hotspot was quite badly off in that regard.

他预计会出现的主要共同点是，在这些地区都有高度集中的食物来源，但是令他感到意外的是，这一观点只适用于其中四个热点地区，剩下的那个地区在这方面境况十分不佳。

But what he did find was that in all cases, the water at the surface of the ocean had relatively high temperatures, even when it was cool at greater depths, so this seemed to be a factor in supporting a diverse range of these large predators.

不过他在所有案例中都发现了一件事，那就是，即使那些海域深处的水温较低，但它们表层水温都相对较高。这一点似乎能够成为支持大型海洋食肉动物多样化分布的因素。

However, this wasn't enough on its own, because he also found that the water needed to have enough oxygen in it - so these two factors seemed necessary to support the high metabolic rate of these large fish.

但是只有这一点还远远不够，因为他还发现海水中需要饱含足够的氧气，于是这两个因素一起便足够证明这些大型鱼类的高代谢率观点了。

A couple of years later, in 2007, a researcher called Lisa Ballance, who was working in California, also started looking for ocean hotspots, but not for fish - what she was interested in was marine mammals, things like seals.

几年之后，在2007年，一位在加利福尼亚州工作的研究人员，Lisa Ballance也开始寻找海洋热点地区，不过她感兴趣的不是鱼类，而是海洋哺乳动物，比如海豹。

And she found three places in the oceans which were hotspots, and what these had in common was that these hotspots were all located at boundaries between ocean currents, and this seems to be the sort of place that has lots of the plankton that some of these species feed on.

她在海洋中找到了三个热点地区，它们的共同之处在于，所有的这些热点地区都位于洋流的交界处。这些海域中似乎拥有大量的浮游生物可供海洋哺乳动物食用。

So now people who want to protect the species that are endangered need to get as much information as possible.

如今人们想要保护濒危物种的话，就要尽可能多地获取相关信息。

For example, there's an international project called the Census of Marine Life.

举个例子来说，有一个国际工程叫做海洋生物统计。

They've been surveying oceans all over the world, including the Arctic.

他们调查了世界上所有的海洋，包括北极地区的海洋。

One thing they found there which stunned other researchers was that there were large numbers of species which live below the ice - sometimes under a layer up to 20 meters thick.

他们在那儿发现了令其他研究人员瞠目结舌的一件事，那就是冰层之下生活着大量的生物物种，有些甚至生活在20米厚的冰层之下。

Some of these species had never been seen before.

这些物种中有些人们之前从未见过。

They've even found species of octopus living in these conditions.

他们甚至还发现一种章鱼也生活在这种环境中。

And other scientists working on the same project, but researching very different habitats on the ocean floor, have found large numbers of species congregating around volcanoes, attracted to them by the warmth and nutrients there.

其他科学家也从事同样的研究，但他们研究的是海底的一些非常与众不同的栖息地。他们发现有大量生物聚集在海底火山周围，吸引它们过来的是那里温暖的海水和丰富的营养物质。

However, biologists still don't know how serious the threat to their survival is for each individual species.

但是，生物学家仍不知道每种生物的生存受到的威胁有多么严重。

So a body called the Global Marine Species Assessment is now creating a list of endangered species on land,

于是现在一个名叫全球海洋物种评估的组织正在编写一份陆地上濒危物种的名单，

so they consider things like the size of the population - how many members of one species there are in a particular place — and then they look at their distribution in geographical terms,

他们考虑的是像族群规模（特定地区内某一生物的数量有多少）这样的因素，然后，他们便着眼于这些生物在地理上的分布，

although this is quite difficult when you're looking at fish, because they're so mobile, and then thirdly they calculate the rate at which the decline of the species is happening.

不过这一点在观察鱼类的时候相当困难，因为它们流动性太大了。第三步是计算这种生物数量减少的比率。

So far only 1,500 species have been assessed, but they want to increase this figure to 20,000.

到目前为止，他们只评估了1500种生物，不过他们希望将这一数字增加到20000。

For each one they assess, they use the data they collect on that species to produce a map showing its distribution.

他们在评估每一种生物时，都会用他们收集到的关于这种生物的数据来绘制一幅地图，显示它们的分布。

Ultimately they will be able to use these to figure out not only where most species are located but also where they are most threatened.

最终，他们将不仅可以通过这些地图发现大部分生物生活的地点，还能弄清楚它们在哪里受到的威胁最大。

So finally, what can be done to retain the diversity of species in the world's oceans?

那么，要保持世界海洋中的生物多样性，我们能做些什么呢？

Firstly, we need to set up more reserves in our oceans, places where marine species are protected.

首先，我们要在海洋中设置更多自然保护区，在保护区内海洋生物可以受到保护。

We have some, but not enough.

目前海洋中已经有了一些保护区，但是还远远不够。

In addition, to preserve species such as leatherback turtles, which live out in the high seas but have their nesting sites on the American coast, we need to create corridors for migration, so they can get from one area to another safely.

另外，还有一些生物比如棱皮龟，它们生活在外海中，但是筑巢点却在美国海岸，为了保护它们，我们需要建立一些迁徙廊道，这样它们就能从一个地区安全地到达另一个地区了。

As well as this, action needs to be taken to lower the levels of fishing quotas to prevent overfishing of endangered species.

除此之外，我们还需要采取行动降低捕鱼限额，以防止濒危物种被过度捕捞。

And finally, there's the problem of 'by-catch'.

最后，还存在"副渔获"的问题。

This refers to the catching of unwanted fish by fishing boats - they're returned to the sea, but they're often dead or dying. “

副渔获”指的是渔船会捕捞到不想要的鱼类，他们通常会把这些鱼放回大海，但是放生时这些鱼一般已经死了或者命不久矣。

If these commercial fishing boats used equipment which was more selective, so that only the fish wanted for consumption were caught, this problem could be overcome.

如果这些商业捕渔船能够使用更加精心挑选过的的设备，以便只捕捞想要食用的鱼类，那么这个问题就能得以解决了。

OK. So does anyone have any questions ...

好了，有人想要问我问题吗……