蓝色星球2（2017）

They can grow up to five metres in length...
鼬鲨的身体可长至五米
..and have powerful crushing jaws.
它们那有力的双颚能让猎物皮开肉绽
Green turtles are their prey.
它们的猎物是绿海龟
The turtles feed almost entirely on sea grass.
绿海龟几乎完全以海草为食
A single one can consume up to two kilos of it in a day.
一只绿海龟每天食用的海草就多达两公斤
But they can never rest easy.
不过它们始终不能放松警惕
Healthy turtles will keep well away from an approaching shark.
健康的绿海龟要与不断逼近的鲨鱼保持一定的距离
And just by keeping the turtles on the move,
鲨鱼在迫使绿海龟逃离的同时
the sharks prevent any one patch of sea grass from being overgrazed.
也避免了海草地遭到过度啃噬
And that has benefits for us all.
这对我们大家都有好处
A patch of sea grass can absorb and store
与同面♥积♥的热带雨林相比
35 times as much carbon dioxide
海草地吸收并储存的二氧化碳量
as the same area of a rainforest.
是前者的35倍
So, the prairies and their sharks are surprising allies
因此在这场对抗气候变暖的战役中 草地和鲨鱼
in the fight against a warming climate.
竟然是同一阵营的盟友
The struggle to survive in our green seas
绿色海洋里艰难的生存环境
can have far-reaching consequences.
可能会带来深远的影响
Once a year, one particular meadow in Australia is transformed.
每年 澳洲的一块草地会发生变化
Around the first full moon of winter,
在冬季的首个满月日子前后
an army materialises.
一支军队形成了
Spider crabs.
蜘蛛蟹
For the past year, they've been feeding in deeper waters.
过去一年 它们一直在深海区里觅食
Now they march across the sea-grass plains.
现在它们要穿过海草平原
Hundreds of thousands of them.
数以十万计的蜘蛛蟹
They clamber over one another...
它们爬到彼此身上
..creating great mounds...
形成了巨大的山丘
..nearly 100 metres long...
绵延近百米
They're not seeking mates, neither are they laying eggs.
它们并不是在求偶 也不是在产卵
They have come here in order...
它们来到这里是为了
to grow.
长大
Like all crabs,
和所有的螃蟹一样
their bodies are enclosed
它们的身体也是包裹在坚硬
in a hard, un-expandable shell.
不具伸缩性的壳内
So, to grow, they have to break out of it...
因此为了长大 它们必须要破壳而出
..and that allows the soft one that has developed beneath to expand.
这样硬壳底下发育的软壳就能够逐渐变大
It will take days for the new shell to harden.
新壳要花上好几天时间才能变硬
Its legs are so limp that they won't work properly.
它们的腿瘸得很厉害 所以现在还无法自如行动
The crab is unprotected and in great danger.
失去保护的蜘蛛蟹处境非常危险
A smooth stingray.
短尾刺魟
It's huge - about four metres long.
它的体型很大 体长将近达到四米
It wants a soft, freshly-moulted crab
它想要抓只刚换壳的软嫩蜘蛛蟹尝尝
that will be easier to eat.
这样的蜘蛛蟹吃起来更省事
The crabs try to stick together.
蜘蛛蟹们想要聚在一起
But now, disturbed by the ray,
但是经刺魟一搅和
they're scattering.
蜘蛛蟹们便四处散开了
A newly-moulted crab
刚换壳的蜘蛛蟹
is too weak to keep up with the crowd.
还很虚弱 无法跟上队伍
The safest place is right in the middle of the pile.
最安全的位置就是蟹群的中♥央♥
That is why they have all assembled here.
这也是它们全聚到这里的原因
There is safety in numbers.
蜘蛛蟹越多的地方也就越安全
The vast majority of the crabs escape...
不过大多数蜘蛛蟹都逃走了
..and within the next few days,
在接下来的几天内
they will be ready to return to the depths
它们就要准备回到深海里
and resume their lonely wanderings in search of food.
继续孤单地漫游 寻找食物
This is no graveyard...
这不是墓地
..but the triumph of a 100,000 crabs successfully moulted.
而是十万只蜘蛛蟹在这里成功脱下了壳
The green seas of Southern Australia
在澳洲南部的绿色海洋里
are particularly rich in such spectacular assemblies...
这样规模浩大的动物聚集现象特别多见
..but most of the creatures come together
不过大多数动物聚到这里
for a very different reason.
是出于截然不同的原因
To breed.
为了交♥配♥繁殖
The giant cuttlefish,
伞膜乌贼
the largest of all cuttlefish.
这是世界上最大的乌贼
They live for just one or two years.
它们的寿命只有一两岁
Now, as the Australian summer draws to an end,
随着澳洲的夏季渐渐接近尾声
they have one last act to complete.
伞膜乌贼现在还有最后一件事情要做
To find a mate.
那就是找到配偶
But there are over 100,000 males,
但是单单在这一个海湾内
competing for the arriving females in this one bay.
就有十万多只雄乌贼要争夺即将到来的雌乌贼
Among them a giant - a true Goliath.
这里头有一个名副其实的庞然大物
He probably weighs about ten kilos.
它的体重大概为十公斤
Bands of colour sweep across his skin.
皮肤上覆满了弯弯曲曲的带状条纹
That's how cuttlefish communicate.
这是伞膜乌贼的沟通方式
This smaller male couldn't possibly take him on.
这只体型较小的雄乌贼无法与它匹敌
Beside Goliath, and under his protection,
大块头旁边是一只受它保护的雌乌贼
a female who has just mated with him.
它们俩刚刚交♥配♥完
But other rivals are still interested.
不过其他对手还是不死心
It seems a small male wouldn't stand a chance.
看来小个儿雄乌贼的希望要落空了
The female is now displaying a white stripe
雌乌贼紧贴着巨型乌贼
along her side nearest Goliath.
身体外圈呈现出了白色条纹
It's a clear signal that she no longer wants to mate with him.
这一信♥号♥♥是在明确地表示它不想再与巨型乌贼交♥配♥了
It's all the encouragement that the little male needs.
这正是小个儿雄乌贼需要的鼓励
He's going to have to use trickery.
它得耍点花招才行
He tones down his colours
它把身体的颜色变得柔和些
and tucks in his arms.
把触须缩紧
He's just the right size to mimic a female.
它的体型正好能够伪装成雌乌贼
Goliath is deceived.
巨型乌贼上当了
The small male now displays a white stripe,
小个儿雄乌贼和雌乌贼一样
just like the real female, to deter his advances.
现出白色条纹 回绝了巨型乌贼的追求
He slips beside her...
它溜到雌乌贼的旁边
..and they mate.
它们俩交♥配♥了
By mating with multiple partners...
和好几只雄乌贼交♥配♥
..the female ensures the greatest genetic diversity for her young.
雌乌贼便能确保后代基因的多样性
The sneaky male leaves,
这只狡猾的雄乌贼离开了
his final act complete.
它完成了最后的行动
So, even among giant cuttlefish, it seems...
就算是处在体型巨大的乌贼群里
..it's not all about size.
尺寸也并不是全部
Other males in these Australian green pastures,
在澳洲这些绿油油的草地里
take greater responsibility for their young.
有些雄性动物对后代负有更大的责任
A weedy sea dragon.
草海龙
This is a male and he's carrying a precious cargo.
这是雄性草海龙 它身上携带着宝贵的货物
While mating with the female,
在与雌性草海龙交♥配♥时
he collected the eggs and attached them to his underside.
它把雌性草海龙产的卵收集起来 一一粘到身体下侧
Now, he's leaving these seaweed thickets...
现在它要离开这些海藻丛
..and travelling into more open waters
游往更开阔的水域
where elaborate camouflage is less effective.
在那里 动物苦心经营的伪装很容易被识破
And there are many predators out here.
而且这里还有很多捕食性动物
And this is what the fathers risk their lives for.
草海龙父亲们就是为了这个 才甘愿冒着性命危险
Dense clouds of minute shrimp.
密密麻麻的小虾团
Mysids, one of a sea dragon's favourite foods.
糠虾 这是海龙最喜欢的食物之一
They're drawing other sea dragons out here, too.
它们把其他海龙也引到这里来了
Finally, it's time for the young to break free.
它总算等到了这一刻 是时候让孩子们脱落了
But algae has grown over these developing eggs...
但是海藻却长到了这些海龙卵的上方
..and it risks smothering them.
仍在发育的海龙卵可能会被闷死
Nonetheless, the babies are emerging.
不过海龙宝宝还是撑了过来
They've hatched successfully.
它们成功地孵化出来
The fathers return to the tangle of kelp,
草海龙父亲们回到海藻密植丛中
where they're virtually invisible...
在密植丛中它们几乎没办法被发现
..while the young remain out here.
而它们的孩子则留在原地
But they will grow quickly,
不过海龙宝定会快速长大
surrounded as they are by their ideal food.
与此同时 它们的周围也将环绕着理想的食物
Vast numbers of the oceans' young fish
大量新出生的小鱼
start their lives in the green seas.
要在绿色海洋里开始生活
One of the richest nurseries of all are the mangrove forests.
其中一个资源最丰富的生长地当属红树林
Fringing the coastline of the tropics,
红树林沿着热带地区的海岸线生长
they form a natural protective barrier between land and sea...
在海陆之间形成了一道天然的保护屏障
..and are some of the world's most productive forests.
这些红树林也是全世界最富饶的森林之一
Below the water, their arching aerial roots
在水底下 红树林的拱形气生根
give them a firm footing.
形成了稳固的基础
Here, there's abundant food for baby fish.
这儿有着丰富的食物供鱼宝宝食用