And it's not just traditions that are threatened.
其实不仅仅是传统文化正饱受威胁。
In some seas around the world, a growing shortage of fish is forcing people deeper and deeper, just to land a decent catch.
在很多海域，鱼类数量的持续下降迫使人们越潜越深，只为一次可观的打捞。
So deep, they venture to the very limits of human survival.
深到他们不得不冒险挑战人类极限。
Welcome to the world of the Pa-aling divers, perhaps the most dangerous fishing method of all.
欢迎来到帕阿林潜水者的世界，这也许是最危险的捕鱼方式。
80 men, many of whom are still teenagers, are preparing to dive to over 40 metres,
这八十个人里，大部分都是少年，他们准备好了要潜至40多米之深，
breathing air pumped through these makeshift tubes by this rusty compressor.
通过这简陋的空气管，将就着呼吸那生锈的空气压缩机压出的空气。
Joseph is one of the youngest aboard, but he's aware of the risks.
约瑟芬是最年轻出海人之一，但他却很清楚可能的危险。
He's already witnessed just how lethal his job can be.
他目睹过这份工作中存在着的致命危险。
The seas around the Philippines were once rich with life, but they've been so over-exploited that decent fish numbers are only found at perilous depths.
菲律宾海域曾海产丰富，但由于过度开发，要获得丰收就要下潜到危险的深度。
The divers guide the huge ball of nets 40 metres down to the sea floor, but all the while their air supply is at risk.
渔网聚成了一个巨大的球体，由潜水员带至40米深处的海床，但他们的氧气供给始终存在着危险。
Back on the boat, the ailing compressor and the ever-worsening tangle of tubes need constant attention.
回到船上，破烂的压缩机和每况愈下的空气管需要随时监控。
Like a failing heart pumping through clogged arteries, if this circulation system fails, at this depth, it's almost certain death.
正如衰弱的心脏给阻塞的动脉泵血一般，如果循环系统受阻，潜至如此深度就几乎意味着死亡。
Joseph and the team unravel the nets and lay them out by securing them to rocks.
约瑟芬和队友解开了渔网，并将它们系牢在石头上。
They must work fast.
他们必须速战速决。
Joseph knows, the longer he spends at these depths, the more dangerous it becomes.
约瑟芬清楚，在如此深度待得越久，处境就越危险。
With every breath, more nitrogen dissolves in his body, making him increasingly vulnerable to decompression sickness "the bends".
每呼吸一次，就会有更多氮气进入体内，使身体更易受到减压病的侵害，即潜水病。
The top of the net is suspended by plastic containers filled with air, creating a huge cavernous trap beneath.
网的顶端悬浮着注满空气的塑料容器，在下方形成了一个巨大的孔状陷阱。
Now it's time to set the scare line.
现在该布下惊吓线了。

The boats drag the 1,000-metre line to form a huge circle around the net, and the divers position themselves along it.
船拖着长达千米的惊吓线，围着网布成了一个巨大的圈，潜水者则沿着线分布。
Joseph and the team begin closing the trap by swimming towards the net.
约瑟芬和队友们向渔网游去，开始收紧陷阱。
The waving streamers and the curtain of rising bubbles panics the fish and they flee.
涌动的水流和上升的水帘惊散了鱼儿。
As the line of divers tightens, more and more fish swim straight into the gaping net.
随着潜水者们逐步将线收紧，越来越多的鱼向上游入了张开的渔网。
This deep-sea round-up is so effective, it can take 50% of the fish from a reef.
这种深海围鱼法十分有效，能捕到礁带范围内的半数鱼儿。
The net is closed, and now Joseph must do something even more dangerous, get inside and herd the catch to the far end.
网已经收了，现在约瑟芬要去做一件更危险的事，进入网中将鱼们赶入网的深处。
On deck, the tangled web of tubes is getting worse.
船上，互相缠绕的空气管情况更糟了。
Once the catch is concentrated, the net is released from its anchor points.
一旦集中了鱼群，他们就会将网从固定点松开。
Now comes the most lethal stage of all -- guiding the net as it shoots to the surface.
现在到了最危险的步骤--牵着网浮至水面。
All too often, the divers ascend too quickly and get the bends.
经常有潜水员因上升太快而得了潜水病。
As the catch is hauled onto the boat, its size is revealed.
战利品已成功拉上船，成果也可见一斑。
Just under a tonne of fish isn't bad, but it's nowhere near what these fishermen were landing a few years ago.
一吨左右的鱼量不算太差，但离几年前的收成还差得远。
And this isn't the only problem. Some of the crew do have the bends.
而且这不是唯一的问题。有些队员已经患上了潜水病。
One diver has returned to the bottom to relieve the symptoms, whilst, closer to the surface, another is massaged to release the painful bubbles in his spine.
一名潜水员不得不回到海底以缓解症状，同时，离水面更近的地方，另一名正接受按摩以缓解脊梁上作痛的水泡。
Every day, these Pa-aling divers are taking greater risks for dwindling rewards.
每天，这些潜水员们都为日益变少的回报承受着剧增的风险。
Joseph has his dreams, but the harsh reality is he'll be diving twice again today just to make ends meet.
约瑟芬有一个梦想，但是现实是残酷的，为了糊口他今天必须再下潜两次。