Peter Tyack: The intriguing sound of marine mammals

32,103 views ・ 2010-06-16

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譯者: Geoff Chen 審譯者: chufung dou
00:15
Thank you so much. I'm going to try to take you
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非常感謝。我要帶大家進入一段
00:18
on a journey of the underwater acoustic world
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鯨魚和海豚的
00:21
of whales and dolphins.
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水下聲音世界
00:23
Since we are such a visual species,
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由於我們多依賴視覺,
00:25
it's hard for us to really understand this,
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所以,要真正理解這些有點難度
00:27
so I'll use a mixture of figures and sounds
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因此我會結合圖表與聲音 來說明
00:29
and hope this can communicate it.
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希望這樣能把我想要表達的傳達給大家
00:31
But let's also think, as a visual species,
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但讓我們也思考一下,作為擁有視覺的物種,
00:34
what it's like when we go snorkeling or diving
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當我們浮潛或潛水時,
00:36
and try to look underwater.
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看看水下的世界時,它是什麼樣的?
00:38
We really can't see very far.
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其實我們看不了多遠
00:40
Our vision, which works so well in air,
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在地表上我們的視覺良好
00:42
all of a sudden is very restricted and claustrophobic.
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但突然間 我們會在水下受到嚴重的限制與幽閉
00:45
And what marine mammals have evolved
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而海洋哺乳動物
00:47
over the last tens of millions of years
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經過了近數千萬年來的進化後,
00:50
is ways to depend on sound
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牠們依賴聲音
00:52
to both explore their world
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探索周圍的世界
00:54
and also to stay in touch with one another.
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並與其他同類保持聯繫
00:56
Dolphins and toothed whales use echolocation.
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海豚和齒鯨使用回聲定位
00:58
They can produce loud clicks
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牠們能產生響亮的喀喇聲
01:00
and listen for echoes from the sea floor in order to orient.
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並傾聽海底反射的回聲來定位
01:03
They can listen for echoes from prey
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牠們能通過獵物所反射的回聲
01:05
in order to decide where food is
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來確定牠們的食物在哪里,
01:07
and to decide which one they want to eat.
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並決定要吃什麽
01:10
All marine mammals use sound for communication to stay in touch.
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所有海洋哺乳動物用聲音來保持相互聯繫
01:12
So the large baleen whales
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於是大型鬚鯨
01:14
will produce long, beautiful songs,
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能發出悠長美麗的歌聲,
01:17
which are used in reproductive advertisement
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這種歌聲被雌鯨和雄鯨用於尋求伴侶,
01:19
for male and females, both to find one another
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幫助牠們找到同類,
01:21
and to select a mate.
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並且選擇配偶
01:23
And mother and young and closely bonded animals
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呼叫的聲音也被用於母子之間的聯繫,
01:25
use calls to stay in touch with one another,
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或者在聯繫緊密的動物之間保持聯繫
01:28
so sound is really critical for their lives.
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因此,聲音在牠們的生活中是非常重要的
01:30
The first thing that got me interested in the sounds
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第一個引起我對這些海底動物的
01:32
of these underwater animals,
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聲音興趣的是,
01:34
whose world was so foreign to me,
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這對我來說是個陌生的世界
01:36
was evidence from captive dolphins
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從捕獲的海豚中 所發現的證據表示:
01:38
that captive dolphins could imitate human sounds.
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牠們能模仿人類的聲音
01:41
And I mentioned I'll use
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我說我會使用
01:43
some visual representations of sounds.
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一些聲音的視覺化圖像
01:45
Here's the first example.
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這是第一個例子
01:47
This is a plot of frequency against time --
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這是幅頻率對時間的圖表--
01:49
sort of like musical notation,
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有點像音符,
01:51
where the higher notes are up higher and the lower notes are lower,
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高處的標記表示頻率較高,低處的標記表示頻率較低,
01:54
and time goes this way.
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時間朝這個方向流逝
01:56
This is a picture of a trainer's whistle,
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這張圖表示教練的哨聲,
01:58
a whistle a trainer will blow to tell a dolphin
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這哨聲是教練用來告訴海豚
02:00
it's done the right thing and can come get a fish.
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做對了 就能得到一條魚。
02:02
It sounds sort of like "tweeeeeet." Like that.
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它聽起來有點像 “tweeeeeet”。有點像這樣。
02:05
This is a calf in captivity
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這是一隻人工飼養的小海豚
02:07
making an imitation
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模仿的
02:09
of that trainer's whistle.
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教練的哨聲
02:11
If you hummed this tune to your dog or cat
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現在如果你對這你的貓貓或狗狗哼這個曲子,
02:13
and it hummed it back to you,
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而牠也對著你哼這曲子,
02:15
you ought to be pretty surprised.
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你應該會大吃一驚。
02:17
Very few nonhuman mammals
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很少有除人類之外的哺乳動物
02:19
can imitate sounds.
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能模仿聲音
02:21
It's really important for our music and our language.
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這種能力對我們學習音樂和語言十分重要。
02:23
So it's a puzzle: The few other mammal groups that do this,
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因此這讓人迷惑:少有其他哺乳動物能做到這點,
02:26
why do they do it?
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為什麼牠們能做到這點?
02:28
A lot of my career has been devoted
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我職業生涯中花了很多時間
02:30
to trying to understand
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試圖弄明白
02:32
how these animals use their learning,
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這些哺乳動物如何運用牠們的學習能力
02:34
use the ability to change what you say
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運用此一能力:
02:36
based on what you hear
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基於所聽到的改變所說的。
02:38
in their own communication systems.
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這些都在牠們自己的溝通系統中
02:40
So let's start with calls of a nonhuman primate.
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那麼讓我們從非人靈長類的叫聲開始
02:43
Many mammals have to produce contact calls
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許多哺乳動物會發出呼喚聲
02:45
when, say, a mother and calf are apart.
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比如說,當母親和幼兒分開時
02:48
This is an example of a call produced by squirrel monkeys
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這是一個例子:這是松鼠猴
02:51
when they're isolated from another one.
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與其他同類分開時所發出的叫聲。
02:53
And you can see, there's not much
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如你們所見,在這些叫聲中
02:55
variability in these calls.
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沒有多少變化
02:57
By contrast, the signature whistle
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相對地,海豚用於
02:59
which dolphins use to stay in touch,
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保持聯繫的哨聲,
03:01
each individual here has a radically different call.
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每一隻海豚都有完全不同的聲調
03:04
They can use this ability to learn calls
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牠們用這種能力來學習叫聲,
03:07
in order to develop more complicated and more distinctive calls
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以便能發展出更複雜、更獨特的聲納
03:10
to identify individuals.
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來辨別不同的個體
03:13
How about the setting in which animals need to use this call?
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在怎樣的環境下 動物必須使用這種叫聲?
03:16
Well let's look at mothers and calves.
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好,讓我們看看母親和幼海豚
03:18
In normal life for mother and calf dolphin,
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在海豚媽媽和海豚幼兒平常的生活中,
03:20
they'll often drift apart or swim apart if Mom is chasing a fish,
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如果海豚媽媽去抓魚,牠們經常因為漂移或是游泳而分開
03:23
and when they separate
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當牠們分開時
03:25
they have to get back together again.
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必須重新聚在一起
03:27
What this figure shows is the percentage of the separations
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這張圖顯示,牠們分開時
03:30
in which dolphins whistle,
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海豚發出哨聲的百分比,
03:32
against the maximum distance.
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與此相對的是最遠距離
03:34
So when dolphins are separating by less than 20 meters,
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因此,當海豚分隔少於 20 公尺時,
03:36
less than half the time they need to use whistles.
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低於半數的情況下,牠們需要用到哨聲
03:38
Most of the time they can just find each other
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大多數時間,牠們四處遊動
03:40
just by swimming around.
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就能找到對方
03:42
But all of the time when they separate by more than 100 meters,
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然而一旦牠們分開超過100公尺,
03:45
they need to use these individually distinctive whistles
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牠們就需要使用這些各自獨特的哨聲
03:48
to come back together again.
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再次聚在一塊。
03:51
Most of these distinctive signature whistles
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多數這類帶有獨特個別特徵的哨聲
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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都是定型的、而且非常穩定
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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當雄海豚離開海豚媽媽時,
04:01
it will often join up with another male
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牠通常會聯合另一隻雄海豚
04:03
and form an alliance, which may last for decades.
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形成一個聯盟,這一聯盟可能會持續幾十年之久
04:06
As these two animals form a social bond,
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由於這兩隻動物形成了一條社會紐帶,
04:09
their distinctive whistles actually converge
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牠們獨特的哨聲實際上會進行融合
04:11
and become very similar.
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變得非常相似
04:13
This plot shows two members of a pair.
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這張圖顯示了組合中的兩個成員,
04:16
As you can see at the top here,
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正如你們於頂部所看到的,
04:18
they share an up-sweep, like "woop, woop, woop."
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牠們有著同樣的上升調,像“woop,woop,woop“
04:20
They both have that kind of up-sweep.
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牠們都有這樣的上升調
04:22
Whereas these members of a pair go "wo-ot, wo-ot, wo-ot."
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然而,另一對成員擁有的上升調是”wo-ot, wo-ot, wo-ot“
04:25
And what's happened is
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這是由於:
04:27
they've used this learning process
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牠們運用此一學習過程
04:29
to develop a new sign that identifies this new social group.
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發展出識別新社會群體的新信號
04:32
It's a very interesting way that they can
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這是非常有趣的方式,牠們可以
04:34
form a new identifier
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為新的社會群體
04:36
for the new social group that they've had.
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形塑一個新的識別標誌
04:38
Let's now take a step back
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現在讓我們退後一步
04:40
and see what this message can tell us
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看看這訊息能告訴我們些什麼
04:42
about protecting dolphins
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關於保護海豚
04:44
from human disturbance.
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遠離人類干擾的資訊
04:46
Anybody looking at this picture
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任何看到這張圖片的人都知道
04:48
will know this dolphin is surrounded,
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這隻海豚被包圍了,
04:50
and clearly his behavior is being disrupted.
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顯然牠的行為被打亂了。
04:53
This is a bad situation.
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這是個糟糕的情況。
04:55
But it turns out that when just a single boat
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但事實表明,
04:57
is approaching a group of dolphins
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當僅有一艘船在數百公尺外
04:59
at a couple hundred meters away,
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靠近一群海豚時,
05:01
the dolphins will start whistling,
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這些海豚會開始發出哨聲,
05:03
they'll change what they're doing, they'll have a more cohesive group,
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牠們會放棄正在做的事,聚集成更大的群體,
05:05
wait for the boat to go by,
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等待這艘船駛過,
05:07
and then they'll get back to normal business.
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然後回復正常
05:09
Well, in a place like Sarasota, Florida,
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嗯,在一個佛羅里達州 Sarasota 的地方,
05:11
the average interval between times
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一艘船在百公尺之內
05:13
that a boat is passing within a hundred meters of a dolphin group
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駛過一群海豚的 平均間隔時間
05:16
is six minutes.
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是六分鐘
05:18
So even in the situation that doesn't look as bad as this,
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因此,即使在看起來不像這麼糟糕的情形下,
05:21
it's still affecting the amount of time these animals have
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在多數時刻,仍然會對這些動物的
05:23
to do their normal work.
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正常生活造成影響
05:25
And if we look at a very pristine environment like western Australia,
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讓我們看看像澳洲西部這樣一個非常原始的環境,
05:28
Lars Bider has done work
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Lars Bider 曾經
05:30
comparing dolphin behavior and distribution
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比較了賞海豚的遊船產生之前和之後,
05:33
before there were dolphin-watching boats.
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當地海豚的行為與分佈
05:36
When there was one boat, not much of an impact.
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當只有一艘船時,對牠們的影響不大
05:39
And two boats: When the second boat was added,
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兩艘船時,當第二艘船駛來時,
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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完全離開了這一區域
05:46
Of the ones that stayed, their reproductive rate declined.
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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,這可能對整個群體數量產生負面影響
05:52
When we think of marine-protected areas for animals like dolphins,
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當我們考慮動物比如海豚建立海洋保護區時,
05:55
this means that we have to be
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這意味著我們也要
05:57
quite conscious about activities that we thought were benign.
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非常慎重地考慮那些我們認為無礙的活動
06:00
We may need to regulate the intensity
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我們也許需要控制
06:02
of recreational boating and actual whale watching
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遊船的密度,甚至賞鯨船的密度,
06:05
in order to prevent these kinds of problems.
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以防類似問題的發生
06:08
I'd also like to point out that sound
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同樣,我想指出那些
06:10
doesn't obey boundaries.
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沒有辦法設置防線的因素:聲音
06:12
So you can draw a line to try to protect an area,
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你可以畫一條線,試圖保護一個區域,
06:15
but chemical pollution and noise pollution
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但是化學污染和噪音污染
06:17
will continue to move through the area.
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將不斷進入這一區域。
06:19
And I'd like to switch now from this local,
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現在,我想從這種地方性的、
06:21
familiar, coastal environment
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為人熟知的沿海環境轉換至
06:24
to a much broader world of the baleen whales and the open ocean.
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鬚鯨的更廣闊的大海
06:27
This is a kind of map we've all been looking at.
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我們經常看到這類地圖
06:30
The world is mostly blue.
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世界大部分是藍色的
06:32
But I'd also like to point out that the oceans
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但我還想指出的是,海洋之間的
06:34
are much more connected than we think.
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聯繫地比我們所想像的更加緊密。
06:36
Notice how few barriers there are to movement
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請注意,相較於陸地而言,對海洋間的
06:39
across all of the oceans compared to land.
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運動的阻礙非常的少。
06:41
To me, the most mind-bending example
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對我來說,最令人驚訝的海洋間
06:43
of the interconnectedness of the ocean
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的相互聯繫的例子
06:45
comes from an acoustic experiment
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來自一個海洋學家所做的
06:47
where oceanographers
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聲音實驗,
06:49
took a ship to the southern Indian Ocean,
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實驗中,海洋學家行駛至南印度洋,
06:52
deployed an underwater loudspeaker
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放置一個水下揚聲器
06:54
and played back a sound.
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並不斷播放一個聲音。
06:56
That same sound
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同一段聲音
06:58
traveled to the west, and could be heard in Bermuda,
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向西能傳播至百慕達群島,
07:01
and traveled to the east, and could be heard in Monterey --
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向東能傳播至蒙特雷(Monterey)--
07:04
the same sound.
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同一段聲音。
07:06
So we live in a world of satellite communication,
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雖然我們生活在一個衛星通信的世界裏,
07:08
are used to global communication,
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早已習慣了全球間的溝通,
07:10
but it's still amazing to me.
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但我仍然感到驚訝
07:12
The ocean has properties
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海洋擁有了,基本上
07:14
that allow low-frequency sound
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能讓低頻聲音
07:16
to basically move globally.
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傳遍全球的特性。
07:18
The acoustic transit time for each of these paths is about three hours.
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聲音通過這些途徑中的每一條進行傳播所需的時間大約是三小時。
07:21
It's nearly halfway around the globe.
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這幾乎穿越了半個地球。
07:24
In the early '70s,
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在70年代早期,
07:26
Roger Payne and an ocean acoustician
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一名海洋聲學家,Roger Payne
07:28
published a theoretical paper
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曾發表過一篇學術論文,
07:30
pointing out that it was possible
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論文中指出
07:32
that sound could transmit over these large areas,
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聲音能夠在大範圍內傳播,
07:35
but very few biologists believed it.
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但少有生物學家相信這點。
07:38
It actually turns out, though,
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事實上,
07:40
even though we've only known of long-range propagation for a few decades,
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雖然我們近幾十年來才對這種遠距離傳播有所瞭解,
07:43
the whales clearly have evolved,
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而鯨魚顯然在數千萬年之前就已經
07:46
over tens of millions of years,
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進行了進化,
07:48
a way to exploit this amazing property of the ocean.
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進化出一種方法來運用海洋的這種驚奇特性,
07:51
So blue whales and fin whales
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藍鯨和長鬚鯨
07:53
produce very low-frequency sounds
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產生一種頻率非常低的聲音,
07:55
that can travel over very long ranges.
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這種聲音能傳播很長的距離,
07:57
The top plot here shows
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上面這幅圖顯示
07:59
a complicated series of calls
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雄鯨所重複的
08:01
that are repeated by males.
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一系列複雜的叫聲。
08:03
They form songs, and they appear to play a role in reproduction,
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這些叫聲形成歌聲,並且似乎能在繁殖中發揮作用,
08:06
sort of like that of song birds.
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有點類似鳥類的啼聲。
08:08
Down below here, we see calls made by both males and females
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下面這幅圖,我們看到 無論是雄性還是雌性發出的叫聲
08:11
that also carry over very long ranges.
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都能傳播很遠的距離。
08:15
The biologists continued to be skeptical
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生物學家在70年代
08:17
of the long-range communication issue
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持續地懷疑
08:19
well past the '70s,
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遠距離溝通的問題,
08:21
until the end of the Cold War.
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直到冷戰結束為止。
08:23
What happened was, during the Cold War,
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冷戰期間,美國海軍
08:25
the U.S. Navy had a system that was secret at the time,
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開發出一套在當時處於保密的系統,
08:28
that they used to track Russian submarines.
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這套系統能夠探測俄國潛艇,
08:31
It had deep underwater microphones, or hydrophones,
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它有一個深水麥克風,或者說,一個水下測音器,
08:33
cabled to shore,
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水下測音器用纜線連接至海岸,
08:35
all wired back to a central place that could listen
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所有纜線連接至一個中心,在那兒能監聽
08:37
to sounds over the whole North Atlantic.
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所有穿過整個北大西洋的聲音。
08:39
And after the Berlin Wall fell, the Navy made these systems available
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在柏林牆倒塌之後,海軍允許鯨生物聲學家
08:42
to whale bio-acousticians
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使用這些系統
08:44
to see what they could hear.
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看看他·們能聽到些什麼。
08:46
This is a plot from Christopher Clark
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這幅圖來自Christopher Clark,
08:48
who tracked one individual blue whale
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他在一條藍鯨
08:51
as it passed by Bermuda,
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經過百慕達時,跟蹤牠,
08:53
went down to the latitude of Miami and came back again.
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牠游至邁阿密同一緯度時,開始往回游,
08:56
It was tracked for 43 days,
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牠被跟蹤了43天,
08:58
swimming 1,700 kilometers,
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游了1700公里,
09:00
or more than 1,000 miles.
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或者說超過1000英里。
09:02
This shows us both that the calls
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這告訴我們,這些叫聲
09:04
are detectable over hundreds of miles
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能在數百英里外被探測出來,
09:06
and that whales routinely swim hundreds of miles.
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這些鯨魚經常遊出數百英里遠。
09:08
They're ocean-based and scale animals
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牠們是海洋大型動物,
09:10
who are communicating over much longer ranges
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能夠以遠遠超出人們預期的距離
09:12
than we had anticipated.
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進行溝通。
09:14
Unlike fins and blues, which
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牠們與分佈在溫帶和熱帶的
09:16
disperse into the temperate and tropical oceans,
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鬚鯨和藍鯨不同,
09:18
the humpbacked whales congregate
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座頭鯨聚集於
09:20
in local traditional breeding grounds,
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傳統繁殖地,
09:23
so they can make a sound that's a little higher in frequency,
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因此牠們能發出頻率更高的聲音,
09:26
broader-band and more complicated.
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音域更寬且更複雜。
09:28
So you're listening to the complicated song
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你們現在聽到的是座頭鯨
09:30
produced by humpbacks here.
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發出的複雜歌聲。
09:32
Humpbacks, when they develop
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當座頭鯨發展出
09:34
the ability to sing this song,
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這樣的歌聲能力時,
09:36
they're listening to other whales
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牠們就能聽到來自其他鯨魚的聲音了,
09:38
and modifying what they sing based on what they're hearing,
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並且基於牠們所聽到的來改變音調,
09:41
just like song birds or the dolphin whistles I described.
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就像鳥的啼聲或我描述的海豚哨聲。
09:44
This means that humpback song
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這表示了座頭鯨的歌聲
09:46
is a form of animal culture,
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是動物文化的一種形式,
09:48
just like music for humans would be.
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就像音樂對於人類一般。
09:50
I think one of the most interesting examples of this
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我認為,關於這些最有趣的例子
09:53
comes from Australia.
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來自澳洲。
09:55
Biologists on the east coast of Australia
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生物學家在澳洲東海岸
09:57
were recording the songs of humpbacks in that area.
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錄下了那一區域的座頭鯨的歌聲,
10:00
And this orange line here marks the typical songs
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這條橘色的線顯示了東海岸座頭鯨
10:03
of east coast humpbacks.
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的典型歌聲。
10:05
In '95 they all sang the normal song.
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在1995年,牠們都唱出正常的歌聲。
10:07
But in '96 they heard a few weird songs,
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但在1996年,生物學家聽到了少數奇怪的歌聲。
10:09
and it turned out that these strange songs
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後來發現這些奇怪的歌聲
10:12
were typical of west coast whales.
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是典型的西海岸鯨的歌聲。
10:14
The west coast calls became more and more popular,
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西海岸的叫聲變得越來越常見,
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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再也沒有鯨魚發出東海岸的歌聲,它完全消失了,
10:22
They just sang the cool new west coast song.
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牠們都在唱著新的西海岸的酷歌。
10:24
It's as if some new hit style
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這仿佛是一種新的風格
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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之前舊的時尚風格,
10:30
and with no golden oldies stations.
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而且沒有金曲再現這一檔事,
10:32
Nobody sang the old ones.
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沒人想唱老歌了。
10:35
I'd like to briefly just show what the ocean does to these calls.
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我想簡要的展示一下海洋中的這些叫聲,
10:38
Now you are listening to a recording made by Chris Clark,
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現在大家聽到的是由 Chris Clark
10:41
0.2 miles away from a humpback.
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在距離座頭鯨0.2英里遠處所錄製的聲音。
10:44
You can hear the full frequency range. It's quite loud.
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你們能聽到整個音頻範圍內的聲音,非常響亮,
10:47
You sound very nearby.
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聽起來就像在附近;
10:49
The next recording you're going to hear
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下一段大家將聽到的錄音
10:51
was made of the same humpback song
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是由同一頭座頭鯨
10:53
50 miles away.
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在50英里外發出的。
10:55
That's shown down here.
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下面顯示的這個,
10:57
You only hear the low frequencies.
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只能聽到低頻的聲音,
10:59
You hear the reverberation
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能聽到聲音
11:01
as the sound travels over long-range in the ocean
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在海洋中長距離傳播產生的回聲
11:03
and is not quite as loud.
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它聽起來並不響亮,
11:06
Now after I play back these humpback calls,
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在我播放了這些座頭鯨的叫聲後,
11:09
I'll play blue whale calls, but they have to be sped up
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我要播放一些藍鯨的叫聲,但我不得不加快這些聲音,
11:12
because they're so low in frequency
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因為它們的頻率太低了,
11:14
that you wouldn't be able to hear it otherwise.
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否則大家就聽不到它們了,
11:16
Here's a blue whale call at 50 miles,
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這是50英里外一頭藍鯨的叫聲,
11:18
which was distant for the humpback.
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比那頭座頭鯨更遠,
11:20
It's loud, clear -- you can hear it very clearly.
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它清晰、響亮——你能非常清楚的聽到它,
11:23
Here's the same call recorded from a hydrophone
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這是由水下測音器在500英里外錄製的
11:26
500 miles away.
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同一叫聲。
11:28
There's a lot of noise, which is mostly other whales.
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因為有許多其他鯨魚,聽起來有許多噪音,
11:31
But you can still hear that faint call.
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但你仍能聽到這微弱的叫聲。
11:34
Let's now switch and think about
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現在讓我們切換思路,考慮一下
11:36
a potential for human impacts.
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潛在的人類影響。
11:38
The most dominant sound that humans put into the ocean
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多數人類在海洋中產生的聲音
11:41
comes from shipping.
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來自船隻,
11:43
This is the sound of a ship,
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這是一艘船的聲音,
11:45
and I'm having to talk a little louder to talk over it.
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為了蓋過它我不得不更大聲的說話。
11:47
Imagine that whale listening from 500 miles.
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想像一下鯨在500英里遠處傾聽。
11:50
There's a potential problem that maybe
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可能由這類船隻造成的這一
11:52
this kind of shipping noise would prevent whales
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潛在問題 將會阻止鯨魚
11:54
from being able to hear each other.
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聽到彼此。
11:56
Now this is something that's been known for quite a while.
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這已經是個長久以來的問題了,
11:58
This is a figure from a textbook on underwater sound.
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這是一張來自課本的關於水下聲音的圖:
12:01
And on the y-axis
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Y軸代表
12:03
is the loudness of average ambient noise in the deep ocean
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深海中以頻率表示的環境噪音
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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在低頻時,這條線表明
12:11
sound that comes from seismic activity of the earth.
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來自地球地震活動的聲音。
12:14
Up high, these variable lines
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上面這些線
12:16
indicate increasing noise in this frequency range
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表明在這一頻率範圍內由
12:19
from higher wind and wave.
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風浪所增加的噪音;
12:21
But right in the middle here where there's a sweet spot,
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但在正中間有一個平衡點,
12:24
the noise is dominated by human ships.
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噪音主要來自人類的船隻。
12:26
Now think about it. This is an amazing thing:
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現在考慮一點,這是個奇妙的事情。
12:28
That in this frequency range where whales communicate,
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就在鯨魚用來交流的這個頻率範圍內,
12:31
the main source globally, on our planet, for the noise
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在我們的星球上,全球主要的噪音來自
12:34
comes from human ships,
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人類的船隻,
12:36
thousands of human ships, distant, far away,
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數以千計遠處的人類船隻產生的噪音
12:39
just all aggregating.
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全都彙集在一起。
12:41
The next slide will show what the impact this may have
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下一張幻燈片顯示了
12:44
on the range at which whales can communicate.
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這些噪音對鯨魚用於溝通的頻率範圍的可能影響。
12:46
So here we have the loudness of a call at the whale.
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這是鯨的聲量,
12:49
And as we get farther away,
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當我們離更遠時
12:51
the sound gets fainter and fainter.
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聲音越來越微弱。
12:53
Now in the pre-industrial ocean, as we were mentioning,
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在工業化前的海洋中,正如我們所提到的,
12:56
this whale call could be easily detected.
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鯨魚的叫聲很容易被監聽到。
12:58
It's louder than noise
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在一千公里範圍內
13:00
at a range of a thousand kilometers.
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叫聲比噪音還要大;
13:02
Let's now take that additional increase in noise
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現在,考慮到來自船隻
13:05
that we saw comes from shipping.
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不斷增加的噪音,
13:07
All of a sudden, the effective range of communication
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溝通的有效距離突然
13:09
goes from a thousand kilometers to 10 kilometers.
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從一千公里降至十公里了,
13:12
Now if this signal is used for males and females
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如果這些信號是用於雌性和雄性
13:14
to find each other for mating and they're dispersed,
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為了交配而相互尋找的話,牠們被分隔開了,
13:17
imagine the impact this could have
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想像一下這可能對瀕危族群的復育上
13:19
on the recovery of endangered populations.
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所造成的影響。
13:22
Whales also have contact calls
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我們也有我所描述過的
13:24
like I described for the dolphins.
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海豚用於相互聯繫的叫聲
13:27
I'll play the sound of a contact call used
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我要播放一段露脊鯨
13:29
by right whales to stay in touch.
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用來保持聯繫的叫聲,
13:31
And this is the kind of call that is used by,
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這是當露脊鯨母鯨與幼兒分離後,
13:33
say, right whale mothers and calves
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當牠們想再次重聚時
13:35
as they separate to come back again.
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相互呼喚的叫聲。
13:37
Now imagine -- let's put the ship noise in the picture.
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現在,想像一下,如果在其中加入船隻的噪音,
13:39
What's a mother to do
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如果船隻從旁經過,
13:41
if the ship comes by and her calf isn't there?
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而牠的孩子並不在身旁,母鯨應該做什麼的?
13:43
I'll describe a couple strategies.
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我將描述幾種對策,
13:46
One strategy is if your call's down here,
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一個對策是,如果你的叫聲在下面這個位置,
13:48
and the noise is in this band,
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而噪音在這個波段內,
13:50
you could shift the frequency of your call out of the noise band
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你可以改變叫聲的頻率,擺脫噪音的波段,
13:53
and communicate better.
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以進行更好的溝通。
13:55
Susan Parks of Penn State has actually studied this.
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賓州州立大學的 Susan Parks 做了相關研究。
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,這兒是來自南大西洋的資料,
14:01
Here's a typical South Atlantic contact call from the '70s.
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這是自70年以來典型的南大西洋聯繫叫聲,
14:04
Look what happened by 2000 to the average call.
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看看到2000年時,平均叫聲發生了什麼變化。
14:07
Same thing in the North Atlantic,
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在北大西洋中,相較於50年代至2000年的資料,
14:09
in the '50s versus 2000.
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也發生了同樣的變化,
14:11
Over the last 50 years,
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在過去50年中,
14:13
as we've put more noise into the oceans,
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隨著我們帶入海洋的噪音越來越多,
14:15
these whales have had to shift.
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這些鯨魚不得不改變。
14:17
It's as if the whole population had to shift
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這就好像,整個族群不得不
14:19
from being basses to singing as a tenor.
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從彈奏貝司變成像男高音那樣唱歌。
14:22
It's an amazing shift, induced by humans
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這是個令人驚訝的、由人類導致的變化,
14:24
over this large scale,
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這一變化無論在時間還是空間上
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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現在我們知道,鯨魚能夠彌補噪音的影響,
14:30
by calling louder, like I did when that ship was playing,
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通過發出更大的叫聲,如我剛才在播放船隻的聲音時所做的,
14:33
by waiting for silence
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通過等待寂靜的到來,
14:35
and by shifting their call out of the noise band.
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和通過改變牠們的叫聲來擺脫噪音干擾,
14:38
Now there's probably costs to calling louder
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對於發出更大的叫聲
14:40
or shifting the frequency away from where you want to be,
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或者是改變原有叫聲的頻率可能需要付出些代價,
14:42
and there's probably lost opportunities.
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牠們可能會錯失良機,
14:44
If we also have to wait for silence,
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如果不得不等待寂靜一刻的到來,
14:46
they may miss a critical opportunity to communicate.
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牠們也許會錯過交流的重要機會。
14:49
So we have to be very concerned
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因此我們要非常關注,
14:51
about when the noise in habitats
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當棲息地裡頭的噪音
14:53
degrades the habitat enough
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對棲息地的分隔
14:55
that the animals either have to pay too much to be able to communicate,
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足以讓動物不得不付出更多心力才能溝通、
14:58
or are not able to perform critical functions.
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或牠們無法進行某些關鍵功能時,
15:00
It's a really important problem.
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這是個非常重要的問題。
15:03
And I'm happy to say that there are several
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我可以很高興的說,在這一領域中
15:05
very promising developments in this area,
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具有極為前瞻的進展,
15:08
looking at the impact of shipping on whales.
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看看船隻對鯨的影響。
15:11
In terms of the shipping noise,
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就船隻噪音而言,
15:13
the International Maritime Organization of the United Nations
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聯合國國際海事組織(IMP)
15:16
has formed a group whose job is to establish
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成立了一個團體
15:19
guidelines for quieting ships,
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這個團體要建立船隻靜音指南,
15:21
to tell the industry how you could quiet ships.
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藉此告訴工業界如何讓船隻靜音。
15:23
And they've already found
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並且他們已經發現,
15:25
that by being more intelligent about better propeller design,
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通過更智慧的、更好的螺旋槳設計
15:28
you can reduce that noise by 90 percent.
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就能減少百分之九十的噪音。
15:31
If you actually insulate and isolate
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如果確實地把船殼和船隻的機械裝置
15:34
the machinery of the ship from the hull,
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隔離、分割開來,
15:36
you can reduce that noise by 99 percent.
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你就能夠減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,就這一點來說,這主要是成本與標準的問題,
15:42
If this group can establish standards,
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如果這一組織能建立標準,
15:44
and if the shipbuilding industry adopts them for building new ships,
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並且造船業採用這些標準來建造船隻,
15:47
we can now see a gradual decline
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我們現在就能看到此一潛在問題
15:49
in this potential problem.
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的逐步下降;
15:51
But there's also another problem from ships that I'm illustrating here,
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但船隻還會造成另一個問題,看看這幅圖,
15:54
and that's the problem of collision.
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碰撞的問題。
15:56
This is a whale that just squeaked by
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這隻鯨魚剛好勉強躲過了
15:59
a rapidly moving container ship and avoided collision.
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一艘快速通過的貨櫃船,避開了碰撞,
16:02
But collision is a serious problem.
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然而,碰撞是個嚴重的問題,
16:04
Endangered whales are killed every year by ship collision,
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每年都有瀕危的鯨由於船隻的碰撞而死亡。
16:07
and it's very important to try to reduce this.
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嘗試減少這種情況發生是非常重要的,
16:10
I'll discuss two very promising approaches.
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我會討論一下兩個非常有效的方法:
16:13
The first case comes from the Bay of Fundy.
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第一個方法來自芬迪灣(Bay of Fundy),
16:15
These black lines mark shipping lanes
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這些黑線標明了船隻
16:17
in and out of the Bay of Fundy.
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進出芬迪灣的航線;
16:19
The colorized area
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彩色的區域
16:21
shows the risk of collision for endangered right whales
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表示船隻在這航道上航行
16:24
because of the ships moving in this lane.
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所產生的與瀕危露脊鯨發生碰撞的風險。
16:26
It turns out that this lane here
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原來的這條航線
16:29
goes right through a major feeding area of right whales in the summer time,
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正好穿過夏天露脊鯨的一個主要繁殖區域,
16:32
and it makes an area of a significant risk of collision.
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這使得此區存在極大的碰撞風險。
16:35
Well, biologists
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而從來不說不的
16:37
who couldn't take no for an answer
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生物學家們,這回
16:39
went to the International Maritime Organization
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一起來到了國際海事組織
16:41
and petitioned them to say,
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他們請願道:
16:43
"Can't you move that lane? Those are just lines on the ground.
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「你們能移動那條航線嗎?這只是些地表上的線條而已,
16:45
Can't you move them over to a place
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可否能把它們移到
16:47
where there's less of a risk?"
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其他風險更小的地方去?」
16:49
And the International Maritime Organization responded very strongly,
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國際海事組織的反應非常迅疾,
16:51
"These are the new lanes."
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「這些是新航線。」
16:53
The shipping lanes have been moved.
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航線已經移動過了,
16:55
And as you can see, the risk of collision is much lower.
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如你所見,碰撞的風險小了很多。
16:58
So it's very promising, actually.
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因此,實際上,這一方法非常有希望。
17:00
We can be very creative about thinking
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我們能以創意的方式思考
17:02
of different ways to reduce these risks.
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減少這些風險的不同方式;
17:04
Another action which was just taken independently
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另一個方法已經由一家
17:06
by a shipping company itself
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船運公司獨自落實了,
17:09
was initiated because of concerns the shipping company had
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啟動這一方法 涉及了船運公司
17:12
about greenhouse gas emissions with global warming.
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造成全球暖化的溫室氣體的排放:
17:15
The Maersk Line looked at their competition
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快桅航運公司(The Maersk Line)審視了他們的競爭者,
17:18
and saw that everybody who is in shipping thinks time is money.
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看到船運業中所有人都認為:時間就是金錢
17:21
They rush as fast as they can to get to their port.
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他們盡其可能的快速到達港口,
17:23
But then they often wait there.
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但是卻常常在港口等著。
17:25
What Maersk did is they worked ways to slow down.
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快桅航運公司所做的是:放慢速度
17:27
They could slow down by about 50 percent.
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他們會把速度降低一半,
17:30
This reduced their fuel consumption by about 30 percent,
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這降低了百分之三十的燃油消耗,
17:33
which saved them money,
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節省了費用,
17:35
and at the same time, it had a significant benefit for whales.
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同時,這對鯨魚也有很大的好處。
17:38
It you slow down, you reduce the amount of noise you make
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如果放慢速度,會減少噪音產生,
17:41
and you reduce the risk of collision.
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並降低發生碰撞的風險。
17:43
So to conclude, I'd just like to point out,
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因此,總結一下,我想指出,
17:45
you know, the whales live in
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你知道,鯨魚生活在
17:47
an amazing acoustic environment.
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令人驚異的聲納環境中,
17:49
They've evolved over tens of millions of years
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牠們進化了數千萬餘年
17:51
to take advantage of this.
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來利用環境
17:53
And we need to be very attentive and vigilant
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我們要非常小心謹慎的
17:56
to thinking about where things that we do
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考慮我們所做的事
17:58
may unintentionally prevent them
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可能無意中對
18:00
from being able to achieve their important activities.
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牠們的重要活動造成阻礙,
18:03
At the same time, we need to be really creative
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同時,我們需要真正的創新思考,
18:05
in thinking of solutions to be able to help reduce these problems.
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關於減少這些問題的創新思考,
18:08
I hope these examples have shown
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我希望這些例子展示了
18:10
some of the different directions we can take
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除了設立保護區之外,
18:12
in addition to protected areas
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還有一些不同的方向。
18:14
to be able to keep the ocean safe for whales to be able to continue to communicate.
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透過這些辦法,維護一個讓鯨魚能繼續溝通的安全海洋。
18:17
Thank you very much.
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謝謝各位。
18:19
(Applause)
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(掌聲)
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