过度捕捞.ppt.pptx

Over-fishing by 成丽华 王云凤 Definitions: Fishing too much of certain fishes, making it not enough to multiply and replenish the number of their populations， which degrades(使退化) the whole ecosystem. Present situation: In the whole world: Date given by Food and Agriculture Organization of UN in 2006 showing that among the worldwide fish resourses,52% have been fully exploited;20% have been moderately exploited; 17% have been over-exploited; 7% have been basically exhausted; 1% are recovering from exhaustion. In China： Compared with 10 years ago , China’s fishery resources have been influenced by over-fishing. China’s four major fishery: the fishing ground of Bohai , Zhoushan, the South sea and the fishing ground of Beibu Gulf have badly degraded(退化) since the 1950’s. Influence: Over-fishing blow the ecosystem destructively , without it, fishery is impossible. First of all, over-fishing destroys fish resources. with the kinds of fishes becoming less , there are fewer fishes to hunt for. For example , the quality of available fishes is declining . Due to over-fishing, the nutritional declining , younger age and miniaturization(小型化) and the overall quality are getting worse and worse. Secondly : over-fishing destroys biodiversity. For instance, the large yellow croaker and the little yellow croaker, which were universal delicacy in our daily life ,have been listed into protected fishes. Lastly: over-fishing presses ecosystem heavily. Recently ,the jellyfish has increased numerously in the waters of the Yellow Sea to the Sea of Japan. For example, the reduce of large carnivorous fish imbalances the ecosystem. Solutions : The urgent circumstances require us to take immediate measures. First of all , we must make strict restriction over the amount of fishing . What’s more, capturing all in one net(一网打尽) must be forbidden. Secondly : protection zones should be set up in some key areas where haven’t been subjected to large-