英语听力：自然百科 鲨鱼的危机（在线收听） |
The sharks are under increasing threat around the world from overfishing. They are used as a food item in many parts of the world. Shark fin soup is particularly popular in Asian countries. And sharks are easy to catch. You put a baited hook in the water, and if there’re sharks nearby, they’re gonna bite the hook. So they are easy to catch, easy to kill, but unfortunately what works against them, apart from the catching part, they have a very low reproductive rate. So when you kill a shark, the next shark around may have pups. They only carry a few pups at a time. Unlike many of the reedfishes you might see behind me which produce microscopic eggs by the millions, sharks only produce a handful of pups. So when sharks are removed from the water from overfishing, it is very hard for them to replace those missing sharks, and they also have to be several years old before they are capable of reproducing. So worldwide we are seeing unfortunate declines in the numbers of sharks. Across the board and all the, to the species or?
No, it’s not across the board, there are still some you know very deep water sharks which are not fished and are presumably in good condition population wise. Sharks that are not eaten, or not targeted by any fisheries, by and large, are still in reasonably good numbers. But the larger sharks, the carnivore sharks that bite hooks very easily, some of the oceanic sharks that are easily picked up by long liners and so forth, those are the ones that seem to be most in danger. Not necessarily endangered, some of them are, but in danger. |
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