Peter Tyack: The intriguing sound of marine mammals

32,103 views ・ 2010-06-16

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翻译人员: Felix Chen 校对人员: Xiaoqiao Xie
00:15
Thank you so much. I'm going to try to take you
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非常感谢。我将要带大家领略
00:18
on a journey of the underwater acoustic world
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一下鲸和海豚的
00:21
of whales and dolphins.
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水下声音世界。
00:23
Since we are such a visual species,
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由于我们拥有视觉,
00:25
it's hard for us to really understand this,
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所以要真正理解这些有点难度。
00:27
so I'll use a mixture of figures and sounds
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因此我会用图表与声音结合起来说明
00:29
and hope this can communicate it.
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希望这样能把我想要表达的传达给大家。
00:31
But let's also think, as a visual species,
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但让我们也思考一下,作为拥有视觉的物种,
00:34
what it's like when we go snorkeling or diving
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当我们浮潜或潜水时,
00:36
and try to look underwater.
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看看水下的世界,它是什么样的?
00:38
We really can't see very far.
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实际上我们看不了多远。
00:40
Our vision, which works so well in air,
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我们在空气中工作良好的视觉,
00:42
all of a sudden is very restricted and claustrophobic.
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突然受到严重的限制、陷入幽闭中。
00:45
And what marine mammals have evolved
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海洋哺乳动物
00:47
over the last tens of millions of years
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在近数千万年来进化后,
00:50
is ways to depend on sound
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它们依赖于声音
00:52
to both explore their world
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探索周围的世界
00:54
and also to stay in touch with one another.
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并与其他同类保持联系。
00:56
Dolphins and toothed whales use echolocation.
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海豚和齿鲸使用回声定位。
00:58
They can produce loud clicks
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他们能产生响亮的喀喇声
01:00
and listen for echoes from the sea floor in order to orient.
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并倾听海底反射的回声来定位。
01:03
They can listen for echoes from prey
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他们能通过猎物所反射的回声
01:05
in order to decide where food is
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来确定它们的食物在哪里,
01:07
and to decide which one they want to eat.
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并决定要吃哪一个。
01:10
All marine mammals use sound for communication to stay in touch.
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所有海洋哺乳动物用声音来保持相互联系。
01:12
So the large baleen whales
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大型须鲸
01:14
will produce long, beautiful songs,
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能发出长且美丽的歌声,
01:17
which are used in reproductive advertisement
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这种歌声被雌鲸和雄鲸用于寻求配偶,
01:19
for male and females, both to find one another
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帮助它们找到同类,
01:21
and to select a mate.
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并且选择配偶。
01:23
And mother and young and closely bonded animals
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呼叫的声音也被用于母子之间的联系,
01:25
use calls to stay in touch with one another,
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或者在联系紧密的动物之间保持联系。
01:28
so sound is really critical for their lives.
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因此声音在他们的生活中确实很重要。
01:30
The first thing that got me interested in the sounds
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第一件让我对这些海底动物的
01:32
of these underwater animals,
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声音产生兴趣的事是,
01:34
whose world was so foreign to me,
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--这对我来说是个陌生的世界--
01:36
was evidence from captive dolphins
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从捕获的海豚中发现的证据证明:
01:38
that captive dolphins could imitate human sounds.
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它们能模仿人类的声音。
01:41
And I mentioned I'll use
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我说过我会用到
01:43
some visual representations of sounds.
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一些声音的可视图像。
01:45
Here's the first example.
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这是第一个例子。
01:47
This is a plot of frequency against time --
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这是幅频率对时间的图表--
01:49
sort of like musical notation,
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有点像音符,
01:51
where the higher notes are up higher and the lower notes are lower,
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高处的标记表示频率较高,低处的标记表示频率较低,
01:54
and time goes this way.
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时间朝这个方向流逝。
01:56
This is a picture of a trainer's whistle,
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这张图表示的是教练的哨声,
01:58
a whistle a trainer will blow to tell a dolphin
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这哨声是教练用来告诉海豚
02:00
it's done the right thing and can come get a fish.
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做对了并能得到一条鱼。
02:02
It sounds sort of like "tweeeeeet." Like that.
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它听起来有点像“tweeeeeet”。有点像这样。
02:05
This is a calf in captivity
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这是一只人工饲养的小海豚
02:07
making an imitation
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模仿的
02:09
of that trainer's whistle.
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教练的哨声。
02:11
If you hummed this tune to your dog or cat
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现在如果你对这你的猫猫或狗狗哼这个曲子,
02:13
and it hummed it back to you,
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而它也对着你哼这曲子,
02:15
you ought to be pretty surprised.
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你应该会大吃一惊。
02:17
Very few nonhuman mammals
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很少有除人类之外的哺乳动物
02:19
can imitate sounds.
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能模仿声音。
02:21
It's really important for our music and our language.
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这种能力对我们学习音乐和语言十分重要。
02:23
So it's a puzzle: The few other mammal groups that do this,
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因此这让人迷惑:少有其他哺乳动物能做到这点,
02:26
why do they do it?
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为什么它们能做到这点?
02:28
A lot of my career has been devoted
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我职业生涯中花了很多时间
02:30
to trying to understand
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试图弄明白
02:32
how these animals use their learning,
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这些哺乳动物如何运用它们的学识,
02:34
use the ability to change what you say
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运用这一能力:
02:36
based on what you hear
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基于所听到的改变所说的。
02:38
in their own communication systems.
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这些都在它们自己的沟通系统中。
02:40
So let's start with calls of a nonhuman primate.
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那么让我们从非人灵长类的叫声开始。
02:43
Many mammals have to produce contact calls
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比方说,当母亲和幼仔分开时,
02:45
when, say, a mother and calf are apart.
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许多哺乳动物会发出呼唤声。
02:48
This is an example of a call produced by squirrel monkeys
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这是个例子:当松鼠猴
02:51
when they're isolated from another one.
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与其它同类分开时发出的叫声。
02:53
And you can see, there's not much
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你能看到,这些叫声中
02:55
variability in these calls.
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没有多少变化。
02:57
By contrast, the signature whistle
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作为对照,海豚们用于
02:59
which dolphins use to stay in touch,
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保持联系的哨声,
03:01
each individual here has a radically different call.
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每只海豚都有完全不同的叫声。
03:04
They can use this ability to learn calls
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它们能用这种能力来学习叫声,
03:07
in order to develop more complicated and more distinctive calls
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以便能发展出更复杂、更独特的叫声
03:10
to identify individuals.
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来识别出不同的个体。
03:13
How about the setting in which animals need to use this call?
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在怎样的环境下动物需要用到这种叫声?
03:16
Well let's look at mothers and calves.
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好的,让我们看看母亲和幼仔。
03:18
In normal life for mother and calf dolphin,
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在海豚妈妈和海豚幼仔平常的生活中,
03:20
they'll often drift apart or swim apart if Mom is chasing a fish,
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如果海豚妈妈去抓鱼,他们常由于漂移或是游泳而分开。
03:23
and when they separate
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而当它们分开时
03:25
they have to get back together again.
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它们不得不重新聚在一起。
03:27
What this figure shows is the percentage of the separations
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这张图显示,它们分开时
03:30
in which dolphins whistle,
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海豚发出哨声的百分率,
03:32
against the maximum distance.
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与此相对的是最远距离。
03:34
So when dolphins are separating by less than 20 meters,
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因此,当海豚们分开少于20米时,
03:36
less than half the time they need to use whistles.
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少于半数的情况下他们需要用到哨声。
03:38
Most of the time they can just find each other
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多数情况下他们四处游动
03:40
just by swimming around.
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就能找到对方。
03:42
But all of the time when they separate by more than 100 meters,
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但只要它们分开超过100米,
03:45
they need to use these individually distinctive whistles
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它们就需要用这些各自独特的哨声
03:48
to come back together again.
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来再次聚在一起。
03:51
Most of these distinctive signature whistles
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多数这类有独特签名的哨声
03:53
are quite stereotyped and stable
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在海豚的一生中
03:55
through the life of a dolphin.
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都是定型且非常稳定的。
03:57
But there are some exceptions.
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但也有些例外。
03:59
When a male dolphin leaves Mom,
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当雄海豚离开海豚妈妈时,
04:01
it will often join up with another male
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它通常会联合另一只雄海豚
04:03
and form an alliance, which may last for decades.
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并形成一个联盟,这一联盟可能会持续几十年之久。
04:06
As these two animals form a social bond,
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由于这两只动物形成了一条社会纽带,
04:09
their distinctive whistles actually converge
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他们独特的哨声实际上会进行融合
04:11
and become very similar.
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并变得非常相似。
04:13
This plot shows two members of a pair.
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这张图显示了这样的组合中的两个成员。
04:16
As you can see at the top here,
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正如你在顶部看到的,
04:18
they share an up-sweep, like "woop, woop, woop."
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它们有着同样的升调,像“woop,woop,woop。“
04:20
They both have that kind of up-sweep.
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它们都有这样的升调。
04:22
Whereas these members of a pair go "wo-ot, wo-ot, wo-ot."
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然而另一对的两个成员拥有的升调是”wo-ot, wo-ot, wo-ot“
04:25
And what's happened is
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这是由于:
04:27
they've used this learning process
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他们运用这一学习过程
04:29
to develop a new sign that identifies this new social group.
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发展出了用于识别这一新社会群体的新信号。
04:32
It's a very interesting way that they can
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这是个非常有趣的方式,它们能
04:34
form a new identifier
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为新的社会群体
04:36
for the new social group that they've had.
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形成一个新的识别标志。
04:38
Let's now take a step back
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现在让我们后退一步
04:40
and see what this message can tell us
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看看这一讯息能告诉我们些什么
04:42
about protecting dolphins
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关于保护海豚
04:44
from human disturbance.
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远离人类干扰的信息。
04:46
Anybody looking at this picture
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任何看到这张图片的人都
04:48
will know this dolphin is surrounded,
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会认识到这只海豚被包围了,
04:50
and clearly his behavior is being disrupted.
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显然它的行为被打乱了。
04:53
This is a bad situation.
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这是个糟糕的情况。
04:55
But it turns out that when just a single boat
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但事实表明,
04:57
is approaching a group of dolphins
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当今仅有一艘船在数百米开外
04:59
at a couple hundred meters away,
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靠近一群海豚时,
05:01
the dolphins will start whistling,
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这些海豚会开始发出哨声,
05:03
they'll change what they're doing, they'll have a more cohesive group,
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它们会放弃正在做的事,聚集成更大的群体,
05:05
wait for the boat to go by,
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等待这艘船驶过,
05:07
and then they'll get back to normal business.
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然后它们会回复正常。
05:09
Well, in a place like Sarasota, Florida,
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好了,在一个类似佛罗里达州萨拉索塔的地方,
05:11
the average interval between times
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一艘船在百米之内
05:13
that a boat is passing within a hundred meters of a dolphin group
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驶过一群海豚的平均间隔时间
05:16
is six minutes.
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是六分钟。
05:18
So even in the situation that doesn't look as bad as this,
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因此即使在看起来不像这么糟糕的情形下,
05:21
it's still affecting the amount of time these animals have
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仍然会在许多时间里对这些动物的
05:23
to do their normal work.
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正常生活造成影响。
05:25
And if we look at a very pristine environment like western Australia,
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让我们看看像澳大利亚西部这样一个非常原始的环境,
05:28
Lars Bider has done work
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拉尔斯.比泰尔曾
05:30
comparing dolphin behavior and distribution
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比较了观海豚的游船产生之前和之后,
05:33
before there were dolphin-watching boats.
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当地海豚的行为和分布。
05:36
When there was one boat, not much of an impact.
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当只有一艘船时,对它们没多少影响。
05:39
And two boats: When the second boat was added,
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两艘船时,当第二艘船驶来时,
05:42
what happened was that some of the dolphins
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有些海豚
05:44
left the area completely.
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义无反顾的离开了这一区域。
05:46
Of the ones that stayed, their reproductive rate declined.
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而留下的那些海豚的繁殖率下降了。
05:49
So it could have a negative impact on the whole population.
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因此,这可能对整个种群产生负面影响。
05:52
When we think of marine-protected areas for animals like dolphins,
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当我们考虑动物比如海豚建立海洋保护区时,
05:55
this means that we have to be
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这意味着我们也要
05:57
quite conscious about activities that we thought were benign.
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非常慎重的考虑那些我们认为无碍的活动。
06:00
We may need to regulate the intensity
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我们也许需要控制
06:02
of recreational boating and actual whale watching
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休闲航行的密度,甚至观鲸船的密度,
06:05
in order to prevent these kinds of problems.
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以防类似问题发生。
06:08
I'd also like to point out that sound
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同样,我想指出那些
06:10
doesn't obey boundaries.
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没有办法设置防线的因素:声音。
06:12
So you can draw a line to try to protect an area,
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你可以画一条线,试图保护一个区域,
06:15
but chemical pollution and noise pollution
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但是化学污染和噪音污染,
06:17
will continue to move through the area.
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将不断进入这一区域。
06:19
And I'd like to switch now from this local,
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现在,我想从这种地方性的、
06:21
familiar, coastal environment
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为人熟知的沿海环境转换至
06:24
to a much broader world of the baleen whales and the open ocean.
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须鲸的更广阔的世界和公海。
06:27
This is a kind of map we've all been looking at.
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我们经常看到这类地图。
06:30
The world is mostly blue.
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世界大部分是蓝色的。
06:32
But I'd also like to point out that the oceans
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但我还想指出的是,海洋之间的
06:34
are much more connected than we think.
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联系我们所想象的更加紧密。
06:36
Notice how few barriers there are to movement
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请注意,相比陆地而言,对海洋间的
06:39
across all of the oceans compared to land.
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运动的阻碍非常的少。
06:41
To me, the most mind-bending example
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对我来说,最令人惊讶的海洋间
06:43
of the interconnectedness of the ocean
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的相互联系的例子
06:45
comes from an acoustic experiment
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来自一个海洋学家所做的
06:47
where oceanographers
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声音实验,
06:49
took a ship to the southern Indian Ocean,
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实验中,海洋学家行驶至南印度洋,
06:52
deployed an underwater loudspeaker
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放置一个水下扬声器
06:54
and played back a sound.
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并不断播放一个声音。
06:56
That same sound
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同一段声音
06:58
traveled to the west, and could be heard in Bermuda,
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向西能传播至百慕大群岛,
07:01
and traveled to the east, and could be heard in Monterey --
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向东能传播至蒙特雷--
07:04
the same sound.
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同一段声音。
07:06
So we live in a world of satellite communication,
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虽然我们生活在一个卫星通信的世界里,
07:08
are used to global communication,
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已经习惯了全球间的沟通,
07:10
but it's still amazing to me.
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但我仍为这感到惊奇。
07:12
The ocean has properties
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海洋拥有
07:14
that allow low-frequency sound
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让低频的声音
07:16
to basically move globally.
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基本上传遍全球的特性。
07:18
The acoustic transit time for each of these paths is about three hours.
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声音通过这些途径中的每一条进行传播所需的时间大约是三小时。
07:21
It's nearly halfway around the globe.
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这几乎穿越了半个地球。
07:24
In the early '70s,
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嗨,在70年代早期,
07:26
Roger Payne and an ocean acoustician
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一名海洋声学家,罗杰.佩恩
07:28
published a theoretical paper
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曾发表过一篇学术论文,
07:30
pointing out that it was possible
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论文中指出声音
07:32
that sound could transmit over these large areas,
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能够在大范围内传播,
07:35
but very few biologists believed it.
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但很少有生物学家相信这点。
07:38
It actually turns out, though,
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而实际上,尽管,
07:40
even though we've only known of long-range propagation for a few decades,
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虽然我们近几十年来才对这种远距离传播有所了解,
07:43
the whales clearly have evolved,
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而鲸显然在数千万年之前就已经
07:46
over tens of millions of years,
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进行了进化,
07:48
a way to exploit this amazing property of the ocean.
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进化出了一种方法来运用海洋的这一令人惊奇的特性。
07:51
So blue whales and fin whales
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蓝鲸和长须鲸
07:53
produce very low-frequency sounds
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产生一种频率非常低的声音,
07:55
that can travel over very long ranges.
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这种声音能传播很长的距离。
07:57
The top plot here shows
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上面这幅图显示
07:59
a complicated series of calls
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雄鲸所重复的
08:01
that are repeated by males.
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一系列复杂的叫声。
08:03
They form songs, and they appear to play a role in reproduction,
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这些叫声形成歌声,并且似乎能在繁殖中发挥作用,
08:06
sort of like that of song birds.
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有点类似鸟类的啼声。
08:08
Down below here, we see calls made by both males and females
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下面这幅图,我们看到无论是雄性还是雌性发出的叫声
08:11
that also carry over very long ranges.
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都能传播很远的距离。
08:15
The biologists continued to be skeptical
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生物学家在70年代内
08:17
of the long-range communication issue
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持续对远距离沟通的问题
08:19
well past the '70s,
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保持怀疑,
08:21
until the end of the Cold War.
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直到冷战结束。
08:23
What happened was, during the Cold War,
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在冷战期间,美国海军
08:25
the U.S. Navy had a system that was secret at the time,
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开发出一套当时处于保密的系统,
08:28
that they used to track Russian submarines.
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这套系统能用于探测俄国潜艇。
08:31
It had deep underwater microphones, or hydrophones,
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它有一个深水麦克风或者说一个水下测音器,
08:33
cabled to shore,
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这一水下测音器用线连接至海岸,
08:35
all wired back to a central place that could listen
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所有线缆连接至一个中心,在那儿能监听
08:37
to sounds over the whole North Atlantic.
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所有穿过整个北大西洋的声音。
08:39
And after the Berlin Wall fell, the Navy made these systems available
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在柏林墙倒塌之后,海军允许鲸生物声学家
08:42
to whale bio-acousticians
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使用这些系统
08:44
to see what they could hear.
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来看看他们能听到些什么。
08:46
This is a plot from Christopher Clark
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这幅图来自克里斯托弗.克拉克,
08:48
who tracked one individual blue whale
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他在一条蓝鲸
08:51
as it passed by Bermuda,
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经过百慕大时对它进行跟踪,
08:53
went down to the latitude of Miami and came back again.
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它游至迈阿密同一纬度时,开始往回游。
08:56
It was tracked for 43 days,
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它被跟踪了43天,
08:58
swimming 1,700 kilometers,
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游了1,700公里,
09:00
or more than 1,000 miles.
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或者说超过1,000英里。
09:02
This shows us both that the calls
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这告诉我们,这些叫声
09:04
are detectable over hundreds of miles
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能在数百英里外被探测出来,
09:06
and that whales routinely swim hundreds of miles.
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这些鲸经常游出数百英里远。
09:08
They're ocean-based and scale animals
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它们是海洋大型动物,
09:10
who are communicating over much longer ranges
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它们能够以远超人们预期
09:12
than we had anticipated.
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的距离进行沟通。
09:14
Unlike fins and blues, which
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与分布在温带和热带的
09:16
disperse into the temperate and tropical oceans,
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须鲸和蓝鲸不同,
09:18
the humpbacked whales congregate
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驼背鲸聚集在
09:20
in local traditional breeding grounds,
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传统繁殖地。
09:23
so they can make a sound that's a little higher in frequency,
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因此它们能发出频率更高些的声音,
09:26
broader-band and more complicated.
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音域更宽且更复杂。
09:28
So you're listening to the complicated song
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你们现在听到的是座头鲸
09:30
produced by humpbacks here.
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发出的复杂的歌声。
09:32
Humpbacks, when they develop
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当座头鲸发展出
09:34
the ability to sing this song,
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能发出这样的歌声的能力时,
09:36
they're listening to other whales
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它们就能听到来自其他鲸的声音,
09:38
and modifying what they sing based on what they're hearing,
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并且基于它们所听到的来改变音调,
09:41
just like song birds or the dolphin whistles I described.
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就像鸟的啼声或是我描述的海豚的哨声。
09:44
This means that humpback song
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这表示座头鲸的歌声
09:46
is a form of animal culture,
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是动物文化的一种形式,
09:48
just like music for humans would be.
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就像音乐对于人类。
09:50
I think one of the most interesting examples of this
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我认为关于这些最有趣的例子
09:53
comes from Australia.
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来自澳大利亚。
09:55
Biologists on the east coast of Australia
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生物学家在澳大利亚东海岸
09:57
were recording the songs of humpbacks in that area.
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录下了那一区域的座头鲸的歌声。
10:00
And this orange line here marks the typical songs
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这条橘色的线标出了东海岸座头鲸
10:03
of east coast humpbacks.
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的典型的歌声。
10:05
In '95 they all sang the normal song.
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在95年它们都唱出正常的歌声。
10:07
But in '96 they heard a few weird songs,
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但在96年,生物学家听到了少数奇怪的歌声。
10:09
and it turned out that these strange songs
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后来发现这些奇怪的歌声
10:12
were typical of west coast whales.
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是典型的西海岸鲸的歌声。
10:14
The west coast calls became more and more popular,
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西海岸的叫声变得越来越常见,
10:17
until by 1998,
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直到1998年,
10:19
none of the whales sang the east coast song; it was completely gone.
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再没有鲸发出东海岸的歌声;它完全消失了。
10:22
They just sang the cool new west coast song.
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它们都在唱着新的西海岸的酷歌。
10:24
It's as if some new hit style
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这仿佛是一种新的风格
10:26
had completely wiped out
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完全取代了
10:28
the old-fashioned style before,
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之前旧的时尚风格,
10:30
and with no golden oldies stations.
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而且没有金曲再现这一环节。
10:32
Nobody sang the old ones.
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没人再唱这些老歌。
10:35
I'd like to briefly just show what the ocean does to these calls.
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我想简要的展示一下海洋中的这些叫声。
10:38
Now you are listening to a recording made by Chris Clark,
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现在大家听到的是由克里斯.克拉克,
10:41
0.2 miles away from a humpback.
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在距离座头鲸0.2英里远处录制的声音。
10:44
You can hear the full frequency range. It's quite loud.
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你能听到整个频率范围内的声音。非常响亮。
10:47
You sound very nearby.
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听起来就像在附近。
10:49
The next recording you're going to hear
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下一段大家将听到的录音
10:51
was made of the same humpback song
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是由同一头座头鲸
10:53
50 miles away.
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在50英里外发出的。
10:55
That's shown down here.
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下面显示的这个。
10:57
You only hear the low frequencies.
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只能听到低频的声音。
10:59
You hear the reverberation
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能听到声音
11:01
as the sound travels over long-range in the ocean
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在海洋中长距离传播产生的回声
11:03
and is not quite as loud.
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它听起来并不响亮。
11:06
Now after I play back these humpback calls,
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在我播放了这些座头鲸的叫声之后,
11:09
I'll play blue whale calls, but they have to be sped up
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我要播放一些蓝鲸的叫声,但我不得不加快这些声音,
11:12
because they're so low in frequency
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因为它们的频率太低了,
11:14
that you wouldn't be able to hear it otherwise.
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否则大家就听不到它们了。
11:16
Here's a blue whale call at 50 miles,
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这是50英里外一头蓝鲸的叫声,
11:18
which was distant for the humpback.
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比那头座头鲸更远。
11:20
It's loud, clear -- you can hear it very clearly.
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它响亮且清晰--你能非常清楚的听到它。
11:23
Here's the same call recorded from a hydrophone
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这是由水下测音器在500英里外录制的
11:26
500 miles away.
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同一叫声。
11:28
There's a lot of noise, which is mostly other whales.
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因为有许多其他鲸,听起来有许多噪音。
11:31
But you can still hear that faint call.
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但你仍能听到这微弱的叫声。
11:34
Let's now switch and think about
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现在让我们切换下思路,考虑一下
11:36
a potential for human impacts.
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潜在的人类影响。
11:38
The most dominant sound that humans put into the ocean
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多数人类在海洋中产生的声音
11:41
comes from shipping.
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来自船只。
11:43
This is the sound of a ship,
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这是一艘船的声音,
11:45
and I'm having to talk a little louder to talk over it.
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为了盖过它我不得不更大声的说话。
11:47
Imagine that whale listening from 500 miles.
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想象一下鲸在500英里远处倾听。
11:50
There's a potential problem that maybe
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可能由这类船只造成的这一
11:52
this kind of shipping noise would prevent whales
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潜在问题将会阻止鲸们
11:54
from being able to hear each other.
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听到彼此。
11:56
Now this is something that's been known for quite a while.
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这是已经了解了相当长一段时间的事情。
11:58
This is a figure from a textbook on underwater sound.
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这是张来自课本的关于水下声音的图。
12:01
And on the y-axis
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Y轴是
12:03
is the loudness of average ambient noise in the deep ocean
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深海中以频率表示的环境噪音
12:06
by frequency.
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的平均音量。
12:08
In the low frequencies, this line indicates
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在低频时,这条线表明
12:11
sound that comes from seismic activity of the earth.
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来自地球地震活动的声音。
12:14
Up high, these variable lines
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上面这些线
12:16
indicate increasing noise in this frequency range
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表明在这一频率范围内由
12:19
from higher wind and wave.
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风浪增加的噪音。
12:21
But right in the middle here where there's a sweet spot,
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但在正中间有一个平衡点,
12:24
the noise is dominated by human ships.
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噪音主要来自人类的船只。
12:26
Now think about it. This is an amazing thing:
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现在考虑一下。这是个奇妙的事情。
12:28
That in this frequency range where whales communicate,
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就在鲸们用来交流的这个频率范围内,
12:31
the main source globally, on our planet, for the noise
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在我们的星球上,全球主要的噪音来自
12:34
comes from human ships,
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人类的船只,
12:36
thousands of human ships, distant, far away,
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数以千计的远处的人类船只产生的噪音
12:39
just all aggregating.
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汇聚起来。
12:41
The next slide will show what the impact this may have
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下一张幻灯片显示这可能对
12:44
on the range at which whales can communicate.
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鲸用于沟通的频率范围的影响。
12:46
So here we have the loudness of a call at the whale.
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这儿是鲸的叫声的音量。
12:49
And as we get farther away,
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当我们里的更远时
12:51
the sound gets fainter and fainter.
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声音越来越微弱。
12:53
Now in the pre-industrial ocean, as we were mentioning,
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在工业化前的海洋中,正如我们提到的,
12:56
this whale call could be easily detected.
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鲸的叫声很容易被监听到。
12:58
It's louder than noise
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在一千公里范围内
13:00
at a range of a thousand kilometers.
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叫声比噪音要大。
13:02
Let's now take that additional increase in noise
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现在,考虑到来自船只的
13:05
that we saw comes from shipping.
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不断增加的噪音。
13:07
All of a sudden, the effective range of communication
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沟通的有效距离突然
13:09
goes from a thousand kilometers to 10 kilometers.
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从一千公里降至十公里。
13:12
Now if this signal is used for males and females
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如果这些信号是用于雌性和雄性
13:14
to find each other for mating and they're dispersed,
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为交配而相互寻找的话,他们被分割开了,
13:17
imagine the impact this could have
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想象一下这可能对濒危种群的恢复
13:19
on the recovery of endangered populations.
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造成的影响。
13:22
Whales also have contact calls
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我们也有我所描述过的
13:24
like I described for the dolphins.
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海豚用于相互联系叫声。
13:27
I'll play the sound of a contact call used
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我将播放一段露脊鲸
13:29
by right whales to stay in touch.
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用于保持联系的叫声。
13:31
And this is the kind of call that is used by,
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这是当露脊鲸母鲸与幼仔分离后,
13:33
say, right whale mothers and calves
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当它们想再次重聚时
13:35
as they separate to come back again.
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用于相互呼唤的叫声。
13:37
Now imagine -- let's put the ship noise in the picture.
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现在想象一下,如果在其中加入船只的噪音。
13:39
What's a mother to do
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如果船只从旁经过,
13:41
if the ship comes by and her calf isn't there?
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而它的幼仔并不在身旁,母鲸应该做什么的?
13:43
I'll describe a couple strategies.
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我将描述几种对策。
13:46
One strategy is if your call's down here,
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一个对策是,如果你的叫声在下面这个位置,
13:48
and the noise is in this band,
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而噪音在这个波段内,
13:50
you could shift the frequency of your call out of the noise band
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你可以改变叫声的频率,摆脱噪音的波段,
13:53
and communicate better.
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以更好的沟通。
13:55
Susan Parks of Penn State has actually studied this.
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宾夕法尼亚州立大学的苏珊.帕克斯做了相关研究。
13:58
She's looked in the Atlantic. Here's data from the South Atlantic.
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她把注意力集中在大西洋。这儿是来自南大西洋的数据。
14:01
Here's a typical South Atlantic contact call from the '70s.
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这是自70年以来典型的南大西洋联系叫声。
14:04
Look what happened by 2000 to the average call.
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看看到2000年时平均叫声发生了什么变化。
14:07
Same thing in the North Atlantic,
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北大西洋中,对比50年代至2000年数据,
14:09
in the '50s versus 2000.
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也发生了同样的变化。
14:11
Over the last 50 years,
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在过去50年中,
14:13
as we've put more noise into the oceans,
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随着我们带入海洋的噪音越来越多,
14:15
these whales have had to shift.
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这些鲸不得不进行变化。
14:17
It's as if the whole population had to shift
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这就好像,整个种群不得不
14:19
from being basses to singing as a tenor.
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从弹奏贝司变成像男高音那样唱歌。
14:22
It's an amazing shift, induced by humans
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这是个令人惊奇的、由人类导致的变化,
14:24
over this large scale,
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这一变化无论在时间上还是空间上
14:26
in both time and space.
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都有很大的跨度。
14:28
And we now know that whales can compensate for noise
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现在我们知道,鲸能够弥补噪音的影响,
14:30
by calling louder, like I did when that ship was playing,
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通过发出更大的叫声,如我刚才在播放船只的声音时所做的,
14:33
by waiting for silence
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通过等待寂静的到来,
14:35
and by shifting their call out of the noise band.
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和通过改变他们的叫声来摆脱噪音干扰。
14:38
Now there's probably costs to calling louder
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对于发出更大的叫声
14:40
or shifting the frequency away from where you want to be,
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或者是改变原有叫声的频率可能需要付出些代价。
14:42
and there's probably lost opportunities.
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它们可能会错失良机。
14:44
If we also have to wait for silence,
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如果不得不等待寂静到来,
14:46
they may miss a critical opportunity to communicate.
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它们也许会错过交流的重要机会。
14:49
So we have to be very concerned
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因此我们要非常关注,
14:51
about when the noise in habitats
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当栖息地内的噪音
14:53
degrades the habitat enough
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对栖息地的分隔足以
14:55
that the animals either have to pay too much to be able to communicate,
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让动物们不得不付出更多才能沟通
14:58
or are not able to perform critical functions.
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或是它们无法进行某些关键功能。
15:00
It's a really important problem.
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这是个非常重要的问题。
15:03
And I'm happy to say that there are several
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我可以很高兴的说,在这一领域中有些
15:05
very promising developments in this area,
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非常有希望的进展,
15:08
looking at the impact of shipping on whales.
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看看船只对鲸的影响。
15:11
In terms of the shipping noise,
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就船只噪音而言,
15:13
the International Maritime Organization of the United Nations
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联合国国际海事组织
15:16
has formed a group whose job is to establish
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成立了一个组织来建立
15:19
guidelines for quieting ships,
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船只静音指南,
15:21
to tell the industry how you could quiet ships.
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以此告诉工业界如何让船只静音。
15:23
And they've already found
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并且他们已经发现,
15:25
that by being more intelligent about better propeller design,
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通过更智能的、更好的螺旋桨设计
15:28
you can reduce that noise by 90 percent.
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就能减少百分之九十的噪音。
15:31
If you actually insulate and isolate
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如果确实地把船壳和船只的机械装置
15:34
the machinery of the ship from the hull,
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隔离和分割开,
15:36
you can reduce that noise by 99 percent.
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就能够减少百分之九十九的噪音。
15:39
So at this point, it's primarily an issue of cost and standards.
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因此,在这一点上,这是主要是一个成本和标准的问题。
15:42
If this group can establish standards,
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如果这一组织能建立标准,
15:44
and if the shipbuilding industry adopts them for building new ships,
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并且造船业采用这些标准来建造船只,
15:47
we can now see a gradual decline
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现在,我们能看到这一潜在的问题
15:49
in this potential problem.
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会逐步的下降。
15:51
But there's also another problem from ships that I'm illustrating here,
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但船只还会造成另一个问题,看看这幅图,
15:54
and that's the problem of collision.
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碰撞的问题。
15:56
This is a whale that just squeaked by
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这只鲸勉强躲过了
15:59
a rapidly moving container ship and avoided collision.
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一艘快速通过的集装箱船,避免了碰撞。
16:02
But collision is a serious problem.
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但碰撞是个严重的问题。
16:04
Endangered whales are killed every year by ship collision,
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每年都有濒危的鲸由于船只的碰撞而死亡。
16:07
and it's very important to try to reduce this.
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尝试减少这种情况发生非常重要。
16:10
I'll discuss two very promising approaches.
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我将讨论一下两个非常有希望的方法。
16:13
The first case comes from the Bay of Fundy.
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第一个方法来自芬迪湾。
16:15
These black lines mark shipping lanes
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这些黑线标明了船只
16:17
in and out of the Bay of Fundy.
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进出芬迪湾的航线。
16:19
The colorized area
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彩色的区域
16:21
shows the risk of collision for endangered right whales
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表示由于船只在这航道上航行
16:24
because of the ships moving in this lane.
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产生的与濒危露脊鲸发生碰撞的风险。
16:26
It turns out that this lane here
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原来这条航线
16:29
goes right through a major feeding area of right whales in the summer time,
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正好穿过夏天露脊鲸的一个主要繁殖区域。
16:32
and it makes an area of a significant risk of collision.
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这就使得这区域有很大的碰撞风险。
16:35
Well, biologists
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好的,从不说不的
16:37
who couldn't take no for an answer
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生物学家们
16:39
went to the International Maritime Organization
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到国际海事组织
16:41
and petitioned them to say,
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请愿道,
16:43
"Can't you move that lane? Those are just lines on the ground.
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“能移动一下那条航线么?这只是些地面上的线条而已。
16:45
Can't you move them over to a place
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能把它们移到
16:47
where there's less of a risk?"
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其他风险更小的地方去么?“
16:49
And the International Maritime Organization responded very strongly,
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而国际海事组织的反应非常有力,
16:51
"These are the new lanes."
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”这些是新航线。“
16:53
The shipping lanes have been moved.
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航线已经移动过了。
16:55
And as you can see, the risk of collision is much lower.
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如你所见,碰撞的风险小了很多。
16:58
So it's very promising, actually.
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因而这一方法实际上非常有希望。
17:00
We can be very creative about thinking
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我们能非常有创造性的考虑
17:02
of different ways to reduce these risks.
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减少这些风险的不同方式。
17:04
Another action which was just taken independently
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另一个方法已经由一家
17:06
by a shipping company itself
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船运公司独自执行了,
17:09
was initiated because of concerns the shipping company had
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这一方法的启动涉及船运公司
17:12
about greenhouse gas emissions with global warming.
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导致全球变暖的温室气体的排放。
17:15
The Maersk Line looked at their competition
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马士基航运公司审视他们的竞争者,
17:18
and saw that everybody who is in shipping thinks time is money.
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看到船运业中所有人都认为:时间就是金钱。
17:21
They rush as fast as they can to get to their port.
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他们尽其可能的快速到达港口。
17:23
But then they often wait there.
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而接着常常在港口等着。
17:25
What Maersk did is they worked ways to slow down.
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马士基航运公司所做的是:放慢速度。
17:27
They could slow down by about 50 percent.
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他们会把速度下降一半。
17:30
This reduced their fuel consumption by about 30 percent,
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这降低了百分之三十的燃油消耗,
17:33
which saved them money,
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节省了费用,
17:35
and at the same time, it had a significant benefit for whales.
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而同时,这对鲸也有很大的好处。
17:38
It you slow down, you reduce the amount of noise you make
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如果放慢速度,会减少所产生的噪音
17:41
and you reduce the risk of collision.
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并降低发生碰撞的风险。
17:43
So to conclude, I'd just like to point out,
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因此,总结一下,我想指出,
17:45
you know, the whales live in
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你知道,鲸生活在
17:47
an amazing acoustic environment.
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令人惊异的声音环境中。
17:49
They've evolved over tens of millions of years
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它们进化了超过数千万年
17:51
to take advantage of this.
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来利用环境。
17:53
And we need to be very attentive and vigilant
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我们要非常小心谨慎的
17:56
to thinking about where things that we do
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考虑我们所做的
17:58
may unintentionally prevent them
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可能无意中对
18:00
from being able to achieve their important activities.
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它们的重要活动造成阻碍的事。
18:03
At the same time, we need to be really creative
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同时,我们需要真正的创新思考,
18:05
in thinking of solutions to be able to help reduce these problems.
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关于如何才能帮助减少这些问题的解决方案的创新思考。
18:08
I hope these examples have shown
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我希望这些例子展示了
18:10
some of the different directions we can take
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除了设立保护区外
18:12
in addition to protected areas
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还有一些不同的方向。
18:14
to be able to keep the ocean safe for whales to be able to continue to communicate.
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通过运用这些办法能够维护一个让鲸能继续沟通的安全的海洋。
18:17
Thank you very much.
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非常感谢。
18:19
(Applause)
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(掌声)
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