Apparently, the ratio between fish and fishers has changed greatly within a hundred years. There were various kinds of fish in the sea and few fishing-boats in early years of 20th century, while boats in amounting numbers in contrast with scarce fish in 1995.（语句有些罗嗦，用It is shown in the picture that one boat caught numbers of fishes in 1900 while in 1995 the phenomenon was on the contary.表达会更简洁，之后加上一个非限制性定语从句which inplies that over-fishing is becoming an issue.既说明了画的内容也点明了画的主旨。）(原创作文投稿考满分作文网 www. sanwen ) The brief history of world commercial fishing indicates the result of over-fishing, which caused many problems of environment and economy. In the first place, sharp cut-off of marine organism would result in broken ecological balance, including an excess of aquatic plant followed with water polluted. In the second place, fishery without limits does not fit for sustainable development.[导致的影响不全面，一个是导致食物链(food chain)失衡，再者是对生物族群进行了自然选择，改变了动物习性，使得原本食肉的鱼类没有东西吃了就可能转而进攻人类。] Thus, policies and regulations should be taken to impose restrictions on fishing. At the same time, making the commercial fishermen realise the harm of unplaned fish-catching is another point government should emphasis on. Only through these ways can human beings benefit from the nature for a long time.[写得比较笼统，不具体。例如可以写改变一些传统习惯（例如日本每年要捕鲸，加拿大每年要屠-海豹），大力发展近海养殖技术，减少对大洋鱼类的依赖等。]