中英双语新闻 法属波利尼西亚海岸发现大群鲨鱼(在线收听) |
Now out of the clear blue seas off the islands of Polynesia where scientists have discovered an area teeming with sharks, normally there is a naturally balance with lots of prey and fewer predators, but not so in this case. Our science reporter Jonathan Web told us how this discovery came about. Well, actually scientists went to this at all. And it is an usual little place. There is a channel running through the middle of it, quite a small channel only about thirty metres deep. They went there because a different type of fish not sharks in fact but a group of fish are known to spawn there. They went there thinking they were gonna study those fish. They ended up finding a huge concentration of grey reef sharks, a higher concentration two or three times higher than it’s been found anywhere else in the world. And so they said about trying to understand what was going on. They tagged some of the sharks. They did a sort of census of the channel. Because that abundance of, sort of peak predator if you like, something right at the top of the food chain is really hard to sustain. Normally if you add up the biomass in a particular eco system, there’ll be much much more of the things down the bottom, lots and lots of prey and as you’re saying not very many predators so… So why do they think this happened? Yes, so they tried to work out exactly what was going on and it turns out that those spawning fish, the ones that they went there to study in the first place were effectively giving a great big delivery. Every winter time those fish would come just for a couple of months of the year from all around the area and spawn in that particular neighbourhood. Instead of running around to find their prey elsewhere, they will just hang out in the channel for even longer during the winter and feed on those abundant fish just who happened to be there spawning. So it’s an unusual way that the sharks have found to make the most of what’s available and in effect kind of flip the usual food pyramid. Our science reporter Jonathan Web. Researchers say they hope the discovery of a new antibiotic found inside the human nose could herald a new age in the fight against superbugs. It follows a research carried out at the University of Tübingen in Germany which found the antibiotic was effective in treating superbug infections in mice. New antibiotics are desperately needed as doctors face the growing challenge of infections that resist current drugs and could become untreatable. Our science editor David Schuchman examines how significant this new discovery could be. It was back in the 1980s that the last major new type of antibiotic was introduced. And since then several bacteria have built up resistance to the latest drugs. 在波利尼西亚群岛沿岸的湛蓝色海域,科学家们发现了一片鲨鱼的聚集区,正常情况下,大量猎物和少量捕食者是一种自然平衡,但在这里并非如此。本台科学记者乔纳森·韦伯告诉我们这个发现是如何产生的。 其实科学家们真的去到了这里,这是一个不同寻常的小地方,一条隧道贯穿其间,小隧道大概只有30米深。科学家们此行据说是因为一种不同的鱼类——事实上不是鲨鱼——在此产卵。他们去的时候想着要研究这些鱼,结果却发现了大群灰礁鲨在此聚集,密度是世界其他任何地方的二到三倍,科学家们说要试图搞清楚这是怎么一回事。他们对一些鲨鱼做了标记,对该隧道进行了种群调查。由于顶尖捕食者众多,食物链最顶端的生活极其难以维持。正常情况下,将某一生态系统中的生物量加起来,最底层的生物和猎物应占据大多数,就像你说的,捕食者不太多…… 那科学家认为这种情况为什么会发生? 对,他们想弄清楚究竟发生了什么,那些他们最初想要研究的鱼产卵数量巨大,每年冬天,这些鱼会从附近各海域游过来,在这里度过几个月的时间,在那周围产卵。鲨鱼不用四处游荡寻找猎物,只需在隧道中游逛,冬天待得时间更长一些,以那些刚好在这里产卵的大量的鱼为食。所以说这是鲨鱼为了充分利用资源找到的不寻常途径,事实上也掀动了平常的食物金字塔。 本台科学记者乔纳森·韦伯报道。 研究人员称希望在人类鼻子里发现的新抗生素能够开启对抗超级病菌的新时代。早前,德国蒂宾根大学的一项调查发现,这种抗生素在治疗老鼠超级病菌感染方面有效。传染病对现存药物有抗药性,而且将可能无法医治,这使得医生面临更大的挑战,因此急需新的抗生素。本台科学编辑大卫·舒克曼对此项新发现将来的重要性进行了调研。 最后一批重要新型抗生素是在上世纪80年代引入的,自此,几种细菌对最新药物产生了抗药性。 |
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