帮忙翻译下。全文
Whenprehistoricmanarrivedinnewpartsoftheworld,somethingstrangehappenedtothelargeanima...
When prehistoric man arrived in new parts of the world, something strange happened to the large animals. They suddenly became extinct. Smaller species survived. The large, slow-growing animals were easy game, and were quickly hunted to extinction. Now something similar could be happening in the oceans.
That the seas are being overfished has been known for years. What researchers such as Ransom Myers and Boris Worm have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their latest paper published in Nature, the biomass of large predators (animals that kill and eat other animals) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation. In some long-fished areas, it has halved again since then.
Dr Worm acknowledges that the figures are conservative. One reason for this is that fishing technology has improved. Today's vessels can find their prey using satellites and sonar, which were not available 50 years ago. That means a higher proportion of what is in the sea is being caught, so the real difference between present and past is likely to be worse than the one recorded by changes in catch sizes. In the early days, too, longlines would have been more saturated with 展开
That the seas are being overfished has been known for years. What researchers such as Ransom Myers and Boris Worm have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their latest paper published in Nature, the biomass of large predators (animals that kill and eat other animals) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation. In some long-fished areas, it has halved again since then.
Dr Worm acknowledges that the figures are conservative. One reason for this is that fishing technology has improved. Today's vessels can find their prey using satellites and sonar, which were not available 50 years ago. That means a higher proportion of what is in the sea is being caught, so the real difference between present and past is likely to be worse than the one recorded by changes in catch sizes. In the early days, too, longlines would have been more saturated with 展开
展开全部
当史前人类到达世界的一个新的,大型动物就会发生奇怪的事情。它们突然灭绝了。小型的物种存活了下来。大型的,生长缓慢的动物是容易的游戏,很快被猎杀而灭绝。现在相类似的事情可能会发生在海洋中。那海洋的过度捕捞已相识多年。研究人员例如Ransom梅尔斯和鲍里斯Worm事情的变化有多快。他们看半个世纪世界各地的渔业数据。他们的方法并不是试图估计的实际生物量(活的生物的数量)在特定海域中鱼类,而生物量随时间的变化。根据发表在自然杂志上的最新论文,大型食肉动物的生物量(杀死并吃掉其他动物的动物)在新的渔场平均减少了80%,在15年的开发开始。在一些长期捕鱼的区域,从那时起再次减半。Worm博士承认这些数据是保守的。一个原因就是捕鱼技术的提高。今天的船只可以利用卫星和声纳发现猎物,而不是50年前。这意味着更高比例的海洋鱼类被捕捞,所以现在和过去之间的真正差异可能比捕捞量变化的更糟。在早期,太,延绳钓将会更加饱和
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询