VOA慢速英语 鲨鱼对海洋的重要性

　　VOICE TWO:

　　Yet the International Shark Attack File reports that the number of shark attacks has, in fact, decreased in recent years. During this period, there was an average of sixty-three attacks worldwide each year. That compares with a high of seventy-nine in two thousand.

　　The file gives some likely reasons for the decrease. One reason is that overfishing of sharks and related fish has reduced the size of some shark populations.

　　Another is that more people are careful to stay away from waters where sharks swim. And the file says workers responsible for boating and beach safety may be doing a better job of warning people when sharks are seen.

　　VOICE ONE:

　　The International Shark Attack File describes shark attacks as either provoked or unprovoked. An unprovoked attack means the person is alive when bitten. It also means the person must not have interfered with the shark.

　　Some divers interfere with sharks on purpose. They want to get the attention of sharks, perhaps to take pictures of them. The diver may put food in the water to get the animal to come close. Sharks do not normally want to be with people. But their excellent sense of smell leads them to food.