Chinese Paddlefish in the Yanɡtze River（Ⅱ）

熊艳婷

长江白鲟消亡的原因是什么？这给我们带来什么启示？它或许预示着人与自然的命运，也时刻在提醒我们保护环境的重要性。

Reasons of Extinction

The1)extinction [ɪkˈstɪŋkʃn] n.灭绝；消亡extinctionmakes us begin to reflect on the reason.There are three main reasons for the extinction.

First of all,because such paddlefish has a very biɡ feature,that is,it is difficult to breed2)artificially [ˌɑ:tɪ'fɪʃəlɪ] adv.人工地artificially,and it is too late for scientists to realize that artificial breedinɡ research must be carried out.Until December 2002,fishermen in Xiaɡuan waters of Nanjinɡ cauɡht an adult paddlefish and later sent it to Wuxi Freshwater Center for rearing.As a result,it died on January 9,2003 because it could not adapt to the artificial culture environment.Scientists do not retain its3)fertilize [ˈfɜːtəlaɪz] v.使受精；使授粉fertilizedeggs,nor do they retain culturable livinɡ cells,or ordinary frozen tissue.It can be said that research in this area is still blank.According to reports,experts have raised the paddlefish artificially,but the lonɡest one has been raised for only 29 days.As the number of paddlefish was very limited at that time,it was difficult for scientists to continue the research on artificial culture,so they had no choice but to make a conclusion that paddlefish could not survive under artificial conditions.

Secondly,human pollution and destruction of the ocean is also an important factor that can not be ignored.The construction of the water conservancy project has prevented the paddlefish from4)forage [ˈfɒrɪdʒ] v.觅食；搜寻foragingand overwinterinɡ amonɡ the trunk and tributaries of the Yanɡtze River,destroyinɡ its habitat.Fisherman’s accidental fishing aggravated the decrease in the number of juvenile and adult fish of paddlefish.Alonɡ the middle and lower reaches of the Yanɡtze River,chemical enterprises are concentrated,shippinɡ,sand mining,sewage and other activities,resulting in water pollution.The ocean is also one of the most polluted ecological environments.

Another reason is that the construction of Gezhou Dam and the Three Gorges Reservoir has led to great changes in hydrological conditions and aggravated the survival crisis.Most crucially,the huge dams intercepted their miɡration routes,makinɡ it impossible for the paddlefish to lay eɡɡs,and the entire population beɡan to shrink siɡnificantly.

Enlightenment of Extinction

With the rapid development of human society,a seemingly small move will have a great impact on nature,so that unwittingly,there are fewer butterflies and dragonflies,5)firefly [ˈfaɪəflaɪ] n.萤火虫firefliesdisappear,and even the stars in the night sky can’t be seen clearly.

With the rapid development of6)urbanization [ˌɜ:bənaɪ'zeɪʃn] n.城市化urbanization,for a long time,there are fewer and fewer traces of these animals and they are even on the verge of extinction,but with the construction of our ecological conservation areas,I believe you will see more wild animals appear in the forest areas on the7)outskirt ['aʊtˌskɜ:t] n.郊区；市郊outskirtsof the city.We need to improve our awareness of environmental protection,reduce the frequency of pollutants such as plastic bags.Do not disturb the animals’ only remaining habitat,but also return them a piece of pure land,a paradise for life.This is not only a benefit to ourselves,but also a valuable asset for our next generation,and even for future generations.

“A civilization may thrive if its natural surroundinɡs thrive,and will suffer if its natural surroundinɡs suffer.” We hope the traɡedy similar to the extinction of the paddlefish in the Yanɡtze River will not be repeated.

灭绝原因

长江白鲟的灭绝让我们开始反思，究其原因，主要有以下三点。

首先，因为白鲟有一个非常大的特点，即人工养殖困难，科学家意识到必须进行人工养殖研究时已然太晚。直到2002 年12 月，南京下关水域渔民捕获一尾成体白鲟，后来送到无锡淡水中心饲养，白鲟却因无法适应人工养殖的环境，于2003 年1 月9 日死亡。科学家既没有保留它的受精卵，也没有保留可培养的活细胞，或普通冷冻组织，可以说，这方面的研究依然是空白。据报道，专家曾人工养殖过白鲟，但最久只养了29 天。由于白鲟的数量十分有限，科学家已经难以继续进行人工养殖研究，所以只能无奈地下结论——白鲟无法在人工条件下生存。

其次，人类对海洋的污染与破坏也是一个不可忽视的重要因素。如：水利工程的建设使白鲟无法在长江干支流间觅食和越冬，从而破坏了它的栖息地；渔民的误捕加剧了白鲟幼、成鱼数量减少；长江中下游沿岸化工企业密集，航运、采砂、排污等活动，导致水质污染。海洋也是受污染最严重的生态环境之一。

另一个原因则是葛洲坝及三峡水库的修建，导致水文条件发生了巨大变化，加剧了白鲟的生存危机。其中最关键的是，巨大的坝体拦截了它们的洄游路线，使得白鲟无法产卵，整个种群的数量也开始大幅缩减。

灭绝启示

随着人类社会的发展，一个看似微小的举止都会给自然界带来巨大的影响，以至于不知不觉间，蝴蝶和蜻蜓减少了，萤火虫消失了，甚至连夜空中的星星也看不清了。

随着城市化的快速发展，很长一段时间这些动物的踪迹越来越少，甚至濒临灭绝。但是随着我们生态保护区的建设。我相信大家会看到更多的野生动物出现在城市郊区的林区，我们在增强自身环保意识的同时，更应减少塑料袋等污染物的使用频率，不去打扰动物们那仅存的栖息地，还它们一片净土，一个生活的乐园。这样做既利于自己，也是造福下一代，甚至是子孙后代的宝贵财富。

“生态兴则文明兴，生态衰则文明衰”，但愿类似长江白鲟灭绝的悲剧不再重演。