Apr. 14 was "the darkest day" in the history of protecting endangered Yangtze Finless Porpoises, according to Xu Yaping, president of the Finless Porpoise Protection Association in Yueyang City, central China's Hunan Province.

On that day, four porpoises were found dead, "one of which was even pregnant with a baby." From Mar. 3 to Apr. 15, twelve dead porpoises were discovered.

Currently, the Yangtze Finless Porpoise is a second class national-level protected animal. Figures from 2006 show there were 230 finless porpoises left in Dongting Lake. By 2007, that figure had reached 180, which sunk to 145 by January 2009 and 114 by January 2010.

By this March, scientists estimated there were only 85 finless porpoises left in the lake, 145 less than six years ago.

Xie Yongjun, associate professor of veterinary medicine in Yueyang Vocational Technical College, conducted a dissection for one of the dead porpoises retrieved from Dongting Lake on Apr. 9 and found no food residue in its digestive system.

And He Daming, a local fisherman, expressed his doubts that the porpoises had died only from starvation.

On Apr. 16, experts from the Institute of Hydrobiology of the Chinese Academy of Sciences were invited to perform autopsies on two more dead porpoises. They announced the death reasons two days later: one was wounded to death by propellers, while the other suffered a sudden death due to electrofishing or other man-made causes.

Sand excavation, huge profits and alarming extinction rate

Pointing at the continuous flow of ships transporting sand, He Daming gave a look of disapproval. From Dongting Lake, most of the loaded dredges make their way to Nanjing or Shanghai by way of Wuhan.

The busy shipping activities, such as transporting sand, block the porpoise's migration channel between Dongting Lake and the Yangtze River and prevent gene exchange, said Jiang Yong, the Changsha program director of the World Wide Fund for Nature. Besides, as sand excavation destroys the lake bed, its existing hydrological condition has changed, threatening the natural supply of fish the mammals feed on.

"Even the fish cannot survive. How can finless porpoises not become extinct?" Jiang said.

According to Jiang, these sand dredges with huge power make a lot of noise, which could disturb the sonar ability of finless porpoises and increase the difficulty for them to find food.

Peng Xianglin is the boss of a local company in Yueyang. In his eyes, those who can get approval for sand excavation on Dongting Lake "are never ordinary people." "Behind a sand dredge there is a multimillionaire," he said.

According to Peng, who is also president of the Association for Wetland Conservation in Yueyang, one 1,000-horsepower sand dredge can generate yearly profits of up to 10 million yuan (US$1.57 million). Therefore, sand excavation has proven to be an important source of financial income for the local governments of Yueyang County and Miluo City, where Dongting Lake is located.

In 2005, a local company won the right of sand excavation on east Dongting Lake for five years for a price of 51.28 million yuan. The Yueyang county government requires that the number of its sand dredges should not exceed six and the total power used should not exceed 13,000 horsepower.

However, according to a report by Huang Jianwen, a CPPCC member of Yueyang County, from July 2006 to May 2010, the company actually sent 16 sand dredges every day, with the total power of 66,800 horsepower, five times higher than the contract stipulates.

Then in 2010, the Yueyang county government ended the contract with this company and launched a new bid with a minimum price of 100 million yuan.

This year, due to the multiple deaths of finless porpoises, the Yueyang Water Conservancy Bureau issued a notice on April 23 that all sand excavation activities on east Dongting Lake should be suspended for seven-day inspection. The total number of sand dredges in this area should not exceed 20. Their total power should not surpass 55,000 horsepower, with no more than 2,400 horsepower each.

在湖南省岳阳市江豚协会会长徐亚平看来，4月14日堪称江豚保护史上“最黑暗的一天”。

当天有4条江豚死去，“还有一头江豚肚子里正怀着胎儿。”从3月3日到4月15日，共有12具江豚尸体被发现。

目前，长江江豚是国家二级保护动物。统计数据显示，2006年，洞庭湖江豚数量为230头；2007年，江豚数量为180头；2009年，江豚数量为145头；2010年，江豚数量为114头。

到了今年3月，水生所的专家测算到的江豚只有85头。近6年内，洞庭湖已累计减少了145头江豚。

4月9日，岳阳职业技术学院兽医学副教授谢拥军对洞庭湖打捞出来的一具江豚尸体进行了解剖，发现其胃部没有任何食物残留。

“江豚是饿死的吗？”当地渔民何大明发出了疑问。

4月16日，中科院水生所的专家又对两具江豚尸体进行了解剖。两天后，水生所发布消息说，一头江豚是遭螺旋桨击伤致死，另一头则疑为电捕鱼或其他原因导致猝死。

暴利采砂疯狂，江豚濒临灭绝

手指着湖面上川流不息的运沙船，何大明神色凝重。它们载满沙子，目的地大多经由武汉，长途跋涉到南京、上海。

据世界自然基金会长沙项目办主任蒋勇介绍，繁忙的运砂等航运活动阻塞了江豚在洞庭湖与长江之间迁徙通道，妨碍了基因交流。同时，采砂作业掏空了洞庭湖湖床，改变了既有水文状况，对鱼类资源的繁殖、生存形成挑战。

“鱼都活不下来，江豚能不灭亡吗？”蒋勇说。

他表示，采砂船的马力巨大，产生的噪声扰乱江豚的声纳定位，使其捕食困难。

彭祥林是岳阳当地的一公司老板，在他眼里能在岳阳洞庭湖水域审批到采砂权的，“那都不是一般人。”“一艘采砂船背后就是一个千万富翁。”他这么说道。

彭祥林还是岳阳市湿地环保促进会的会长，据他介绍，一条1000马力的采砂船，一年的利润可达千万元上下。由此，出让砂石资源就成了洞庭湖所在的岳阳县、汨罗市的重要财政收入来源。

2005年，岳阳当地一家公司曾以5128万元的价格取得东洞庭湖5年的砂石开采权。其时，岳阳县规定采砂船数量只能是6条，总功率为1.3万马力。

但据时任岳阳县政协委员黄建文的提案显示，自2006年7月至2010年5月，该公司每日采挖船的功率达到6.68万马力，超过合同规定5倍，采砂船达到16条。

到了2010年，岳阳县终止与该公司的开采合同，遂以1亿元的底价重新招标。

今年，由于发生了多起江豚死亡事件，岳阳市水务局曾在4月23日专门下发通知，要求在东洞庭湖暂停所有砂石开采工作，开展7天的专项督查，要求在东洞庭湖区域控制企业船数在20艘以内、总功率不超过55000马力、单船功率不超过2400马力。