Could fish social networks help us save coral reefs? | Mike Gil

譯者: Lilian Chiu 審譯者: SF Huang

Who here is fascinated by life under the sea?

在座有誰覺得海中的生命很迷人？

Fantastic.

好極了。

Now, what did we just do?

我們剛剛做了什麼？

Let's dissect this for a second.

咱們先來分析一下這件事。

The simple action of an individual raising a hand

一個人舉起手的這種簡單動作，

led many others to do the same.

讓許多其他人都跟著做。

Now, it's true that when individuals in a social network

的確，若在社交網路中的個人

have common priorities,

有共同的優先順序，

it's often beneficial to copy one another.

仿效彼此通常是有益處的。

Think back to grade school and dressing like the cool kids made you "cool."

回想小學時代，跟那些酷孩子 穿得很像就能讓你「很酷」。

But copying behavior is also common in wild animals.

但，仿效行為在野生動物中 也是很常見的。

For example, some birds copy the alarm calls of other birds

比如，有些鳥會仿效 其他鳥的警告叫聲，

to spread information about approaching predators.

來散播關於食肉動物靠近的警訊。

But could copying behavior in wild animals

但，野生動物的仿效行為有沒有可能

affect entire ecosystems that we humans depend on?

影響我們人類仰賴的整個生態系統？

I was led to this question while studying coral reefs,

當我在研究珊瑚礁時， 這個問題浮現出來，

which support millions of people through fisheries and tourism

數百萬人賴以為生的珊瑚礁， 從漁業到旅遊業，

here in Africa and around the world.

在非洲這裡以及全世界都是如此。

But coral reefs depend on fish

但，珊瑚礁要仰賴魚類

that perform a critical job by eating algae.

執行極重要的工作：吃掉水藻。

Because if left unchecked,

因為若不受約束，

these algae can kill coral and take over entire coral reefs,

這些水藻會害死珊瑚， 且佔據整個珊瑚礁，

a costly change that is difficult or impossible to reverse.

造成很難改變 或無法逆轉的高昂代價。

So to understand how fish may prevent this,

所以，為了了解 魚類如何預防這現象，

I spy on them

我監視牠們，

while they're eating algae,

觀察牠們吃水藻，

which can be difficult for them to do

這對牠們來說可能蠻困難的，

in open parts of the reef exposed to predators,

因為當牠們在珊瑚礁的開放區域時， 會暴露在食肉動物的危機下，

some of which, on rare occasion,

極罕見地，有些食肉動物

appear to realize I'm watching them.

顯然知道我在看牠們。

(Laughter)

（笑聲）

So clearly, clearly, for reef fish,

所以，很顯然，對珊瑚礁魚類而言，

dining out can be scary.

外出用餐是挺可怕的。

But I wanted to understand how these fish do their job

但我想要了解這些魚類如何在危險的

in risky situations.

情境中進行這項工作。

So my colleagues and I put massive video camera stands

所以我和同事架設了 巨大的攝影機腳架，

in a coral reef

架在一個珊瑚礁上，

to remotely monitor entire feeding grounds

讓我們從遠端監視整片就食地，

that produce a lot of algae

這裡有許多水藻，

but are exposed to predators.

但也暴露在食肉動物的危險中。

And this perspective from above

從上面看的這個視角，

shows us the feeding behavior and precise movements

能呈現出多種不同魚類的就食行為

of many different fish,

及精確的移動路線，

shown here with colored dots.

這些有顏色的點表示魚類。

And by analyzing thousands of fish movements

藉由分析數千筆魚類移動的資料，

to and from feeding grounds,

包括前往就食地以及在該處的移動，

we discovered a pattern.

我們發現了一個模式。

These fish, despite being from different species

這些魚類，儘管是不同種，

and not swimming in schools,

且沒有成群移動，

were copying one another,

牠們仍然會仿效彼此，

such that one fish entering these dangerous feeding grounds

當一條魚進入了危險的就食地時，

could lead many others to do the same.

可能會造成其他魚類跟進。

And fish stayed for longer and ate more algae

且當被更多來就食的魚類圍繞時，

when they were surrounded by more feeding fish.

牠們就會待得更久、吃得更多。

Now, this could be happening

會發生這種現象，

because even simple movements by individual fish

可能是因為單一條魚的簡單動作

can inadvertently communicate vital information.

會不經意地傳遞出重要資訊。

For example, if even one fish sees a predator and flees,

比如，即使是一條魚 看見食肉動物並逃跑，

this can alert many others to danger.

這動作就會警告其他魚有危險出現。

And a fish safely entering feeding grounds can show others that the coast is clear.

而一條魚安全地進入就食地， 就能讓其他魚知道這裡沒有危險。

So it turns out that even when these fish are different species,

所以，結果發現， 即使這些魚類屬於不同種，

they are connected within social networks

牠們仍然在社交網路中連結在一起，

which can provide information on when it's safe to eat.

這個網路能提供何時 可以安心去就食的資訊。

And our analyses indicate that fish simply copying other fish in their social network

我們的分析指出，被魚群吃掉的 水藻中，超過六成都是被

could account for over 60 percent of the algae eaten by the fish community,

在魚類的社交網路中單純仿效 其他魚的那些魚給吃掉的，

and thus could be critical to the flow of energy and resources

因此，對於珊瑚礁生態系統中的 能量與資源的流動，

through coral reef ecosystems.

這些魚是很重要的。

But these findings also suggest that overfishing,

但這些發現也顯示出，過度捕撈是

a common problem in coral reefs,

珊瑚礁的常見問題，

not only removes fish,

不僅會造成魚類消失，

but it could break up the social network of remaining fish,

也會破壞剩下魚類的社交網路，

which may hide more and eat less algae

導致牠們更常隱藏起來， 吃的水藻更少，

because they're missing critical information.

因為牠們得不到重要的資訊。

And this would make coral reefs more vulnerable than we currently predict.

這會讓珊瑚礁比我們 目前所預測的更脆弱。

So remarkably, fish social networks

所以，顯然魚類社交網路

allow the actions of one to spread to many

能將一條魚的行為散播給許多條魚，

and could affect entire coral reefs,

且可能影響到整個珊瑚礁，

which feed millions of us

這個餵養數百萬人、

and support the global economy

全球經濟都賴以為生的珊瑚礁。

for all of us.

Now, our discovery points us towards better ways

我們的發現，為我們 指出了更好的方式，

to sustainably manage coral reefs,

來永續地管理珊瑚礁，

but it also shows us,

但也讓我們知道，

we humans are not just affected by the actions of other humans,

我們人類並不只受到 其他人的行為所影響，

but we could be affected by the actions of individual fish

連遠方珊瑚礁上的一條魚所做的

on a distant coral reef

簡單仿效行為，也可能影響我們。

through their simple copying behavior.

Thank you.

謝謝。

(Applause)

（掌聲）