Ecological Destruction, the dams impacts on a larger global biosphere

Ecological Destruction
Perhaps one of the hardest realities of damming rivers is the ecological destruction which exists as a consequence.  Around the world we watch ad species are decimated, lands reclaimed by water and infrastructure taking over, some of these outcomes planned and others unforeseen in organizing. Ranging from land loss and negative effects on the soil and vegetation to unforeseen pollution to species loss, ecological disaster seems to follow dams.
According to PBS and their focus on the problems of the Three Gorges Dam, there is far more than meets they eye with this ecological controversy:
Over 265 billion gallons of raw sewage are dumped into the Yangtze annually. Currently the river flushes this downstream and out into the ocean. Upon completion of the Three Gorges project, the sewage will back up in the reservoir.

• Over 1,600 factories and abandoned mines will be submerged when the dam is completed. Environmentalists predict that toxins associated with industry and mining will create a hazard for the animals and people who depend on the river for survival.
• Over 700 million tons of sediment are deposited into the Yangtze annually, making it the fourth largest sediment carrier in the world. Experts believe that this sediment will build up behind the dam, with only an unproven system of sluice gates to release it.

An excerpt from a TIME Magazine article outlines associated issues with the Three Gorges Dam and the seemingly exponential environmental consequences of its construction:
   
“Now, however, scientists say things are getting worse. The water quality of the Yangtze's tributaries is deteriorating rapidly, as the dammed river is less able to disperse pollutants effectively. The incidence of algae blooms has risen steadily since the reservoir was completed in 2006. The rising water is also causing rampant soil erosion, resulting in riverbank collapses and landslides along the shores of the Yangtze's tributaries. Professor Lei Hengshun, an environmentalist at Chongqing University who has devoted years to studying and preserving the Three Gorges ecosystem, says that if the water level of the reservoir reaches its planned height of 165 meters next year, it will bring tributaries of the Yangtze River under even greater environmental threat. ‘Now it's a good time to review the problems that have arisen,’ he says, ‘before a larger flooded area brings an even bigger impact on the tributaries’"(Yang.)
The dam's environmental troubles go hand in hand with growing political issues.  "Li Peng, the dam's most ardent supporter, stepped down as Premier in 1998 and has little influence among China's current leadership. The recent storm of criticism the dam has garnered could be a result of political jockeying in the run-up to next week's Communist Party Congress, a five-yearly event in which the coming reshuffles of the Party's senior ranks are usually decided. But it's also possible that the criticism is a sign that the Chinese government has reached the point at which it must do something to address the country's serious — and growing — ecological concerns. It's been a turbulent year for China's environment. In May, a blue algae outbreak on picturesque Lake Tai in Wuxi city rendered tap water for 80% of the local families undrinkable for a week. In June, 10,000 citizens in the coastal city of Xiamen took to the streets to protest against the imminent construction of a new chemical plant. Pan Yue, Deputy Director of the State Environmental Protection Administration, said earlier this year that ‘environmental problems are posing a serious threat to the building of a harmonious society, and have become a significant economic, social and political issue’”(Yang.)
In addition to harming the general landscape and decreasing the availability of habitat for both people and animals alike, the Damming of the Three Gorges has possibly caused several species native to that area to drop so low in population numbers that survival is not likely.
     Damming the Three Gorges: What Dam-Builders Don’t Want You To Know by Grainne Ryder and Margaret Barber is a whole book dedicated to the problems caused by the damming of this large and powerful body of water.  They write extensively about the near species loss of many native animals of that area of the globe.  Their list of Rare and Endangered Aquatic life is comprehensive:

“Rare and Endangered Aquatic Life
The Chinese sturgeon, cut off from its traditional spawning grounds upstream of the Three Gorges, now spawns in the rapidly flowing water 10 kilometres downstream of Gezhouba. CYJV acknowledges that sand and gravel mining planned for this area could adversely affect the sturgeon, but that the necessary studies to examine project effects on this species have not been done. It suggests that sturgeon hatcheries could be useful to replace lost spawning grounds and to minimize the impact of gas bubble disease, but it is not clear whether this cost has been included in the cost-benefit calculations. 


The Chinese river dolphin, the rarest freshwater dolphin in the world, is found only in the Yangtze’s middle and lower reaches and at the confluence of Dongting Lake. According to CYJV, there are only 200 to 300 of these dolphins remaining and the expected increase in erosion downstream of the dam could adversely affect them and the semi-natural dolphin reserves established by the Chinese authorities along the Yangtze.* The Chinese environmental impact statement did not address the impact of the Three Gorges Project on the river dolphins. CYJV recommends more studies and that all means available to conserve and protect this species be considered appropriate.

The fin-less porpoise is commonly found along harbours and bays in the coastal area and up the Yangtze into Dongting Lake. CYJV predicts that the Three Gorges Project would have little impact on the porpoises – a judgment apparently based on the assumption that the porpoises have sufficiently adapted to a wide range of environments, and would therefore adjust to the environmental change caused by the dam.

The Chinese alligator is found only in the lower reaches of the Yangtze. Only 300 to 500 of these alligators remain, inhabiting irrigation and storage ponds, rice fields and shallow depressions in low-lying plains. CYJV optimistically concludes that the impacts of the Three Gorges Project on this species would be minimal, and that the real threat to this species is ongoing harvesting at a rate that will soon cause extinction”(Barber and Ryder)

The Baji Dolphin, once native to the Yangtze River is now functionally extinct.

Although some sources will speak of a variety of other species effected, the latter are those which are threatened to the point of extinction.  Other creatures impacted by the dam include but are not limited to the Giant Panda, Siberian cranes, and the giant Chinese river Sturgeon (PBS).  This not only effects the overall biodiversity of the the planet. The loss of a species is a tragic thing, but it effects the interactions between ecological niches and can have a domino effect on the rest of a given ecosystem.  These can have wide ranging effects on a larger biosphere, because instability in individual ecosystems and communities of species effects the stability of the larger whole.
        The construction of such a monumental dam has other ecological impacts mentioned briefly before ranging from earthquakes and land slides, to the accumulation of toxins and sediments to problems with waste management.  Siltation is always a concern with any dam construction, generally, silt is suspended in the river water and travels downstream with the currents.  Setting up a dam is like putting up a road block for sediments and all there sorts of hazardous things. Factories and sewage treatment lack the determination to take care of their waste effectively, and traditionally this would end up in the Yangtze.  The combination of silt and hazardous materials leaves the Chinese government with a bigger problem than originally expected. A CNN report quotes a Chinese author and her view of the problems with Three Gorges, “‘By severing the mighty river and slowing the flow of its water, the dam will cause pollution from industrial and residential sources to concentrate in the river, rather than be flushed out at sea,’ writes Chinese journalist Jin Hui in The River Dragon Has Come! a recently published collection of criticisms against the dam. ‘The result will be a poisoned river’”(Kennedy). An article in TIME Magazine writes similarly about the environmental dangers we have encountered following the completion of the dam,. “Now, however, scientists say things are getting worse. The water quality of the Yangtze's tributaries is deteriorating rapidly, as the dammed river is less able to disperse pollutants effectively. The incidence of algae blooms has risen steadily since the reservoir was completed in 2006. The rising water is also causing rampant soil erosion, resulting in riverbank collapses and landslides along the shores of the Yangtze's tributaries. Professor Lei Hengshun, an environmentalist at Chongqing University who has devoted years to studying and preserving the Three Gorges ecosystem, says that if the water level of the reservoir reaches its planned height of 165 meters next year, it will bring tributaries of the Yangtze River under even greater environmental threat. ‘Now it's a good time to review the problems that have arisen,’ he says, ‘before a larger flooded area brings an even bigger impact on the tributaries’”(Yang).