Sharks have been top dog in the Pacific for millions of years. They control the numbers of other fish, and so play a vital role in keeping the underwater ecosystem healthy and diverse. In French Polynesia, grey reef sharks gather. While scalloped hammerheads patrol the Galapagos Islands, these are rare hot spots where sharks converge in large numbers. But divers claim this is just a fraction of the number of sharks they used to see. Many sharks are ocean migrants, travelling hundreds of miles in search of prey, like the oceanic whitetip. Amazingly, this may once have been the most abundant large animal on the planet. But it's fallen prey to fishermen's hooks and nets. Surveys suggest oceanic whitetips may have declined by a staggering 99%. It's like the disappearance of bison from America's Great Plains, yet it's only happened in the past 50 years, and almost no one has noticed. Incredibly, the world's oceans may have lost more than 90% of their large predatory fish since industrialised fishing began.


几百万年来鲨鱼一直统治着海洋。他们控制着海洋里鱼的数量，因此鲨鱼在保持海洋生态系统的健康和多样性方面，扮演着重要作用。在法属波利尼西亚，灰礁鲨聚集在一起。而双髻鲨则游弋在加拉帕戈斯群岛。这是难得的几个鲨鱼聚集地。但是潜水者说他们现在可以看到的鲨鱼数量不多，其数量只占过去的几分之一。许多鲨鱼是“海洋移民”，为了追逐猎物，它们能够穿越数百英里，其中最具代表的是远洋白鳍鲨。令人惊奇的是，它们曾经是这个星球上数量最多的动物之一。如今却沦为渔夫的猎物，在鱼钩和渔网的夹击下努力求生。调查表明远洋白鳍鲨的数量已经锐减到原数量的1%了。这和美国平原上大野牛事件一模一样。过去50年里美国平原上的大野牛迅速消失却无人关注。令人难以置信的是，当工业化捕捞开始之后，全世界海洋中，有超过90%的大型捕猎型鱼类因此而亡。