Enviromental Factors

Dolphins 

"Apart from these threats to the dolphin population, Baird says that the future dam construction by the Lao government in the Mekong tributaries—contained in its development plans—would hurt the endangered species further.
If these dams are carried out, he says, Irrawaddy dolphins and many species of fishes in the Mekong River are likely to become extinct because their habitats would be devastated and altered permanently.
According to an IUCN paper, "possibly the most significant threat to river cetaceans is the construction of large water development structures, most notably dams, barrages, and levees".
"The environmental consequences of water development projects are significant and far reaching. These structures fragment populations and reduce the environmental complexity that makes rivers suitable for aquatic species," it added, pointing out that other Asian river dolphins are, like the Irrawaddy dolphin, under serious threat.
"The future of the Irrawaddy dolphin may well be determined by the forces of ecotourism and commercial development," the Bangkok-based English newspaper 'Bangkok Post' said in a recent report.
Apart from Laos, other countries have plans to build hydroelectric dams along the Mekong or its tributaries. A navigation agreement signed last year also seeks to widen the Mekong to facilitate commercial travel. " - tp://ipsnews.net/mekong/stories/dolphins.html


Irrawaddy dolphins are one of the most endangered animals in the world, and the Mekong river is one of the few places where they can be found. There are only about 100 dolphins left in the Mekong, and it is rapidly decreasing. Since the dam's are being built, the dolphins patterns are disturbed. During the dry season, they usually head upstream, but if a dam is blocking it, they can't, meaning they are forced to swim in low water area's which is dangerous.  

CatFish 

" The dam would be the first constructed on the lower Mekong River. It would likely prevent the Mekong giant catfish from migrating between Tonle Sap in Cambodia and the Mekong River in Thailand. Although there is still a great deal to be learned about the habitat use and spawning areas for the Mekong giant catfish, the area up to 50 miles north of Chiang Khong, Thailand is assumed to be the site of the primary spawning grounds.

Alternative Site for Hydroelectric Dam May Protect the Mekong River Basin's Fish

The report acknowledges that development in all of the Tonle Sap/Mekong River system countries is necessary but suggests an alternative. Moving the hydroelectric dam to one of the tributaries of the Mekong River would provide the needed power source without compromising the health of the Mekong River system. The future of the Mekong giant catfish and the other rare species of the Mekong River Basin may depend on such a compromise, allowing for development in Lao PDR utilizing other waterways."  - http://www.suite101.com/content/proposed-dam-threatens-critically-endangered-mekong-giant-catfish-a268709 

The dams are also affecting the Giant catfish species. This species is only found in the Mekong and the Tonie Sap river. They are also one of the most endangered species of fish. With the dam's being built in the lower Mekong river then the Catfishes wouldn't be able to migrate between Tonie Sap in cambodia and the Mekong river in Thailand. Without being able to do this, they would not be able to reproduce as quickly, meaning the species may become extinct. 






http://www.mrcmekong.org/catch-culture/vol14_3dec08/mainstream-dams-barriers.htm 


This website is about how people came together for a meeting regarding how the dam's being built on the Mekong, will affect the migration of many fish species. Several questions were asked, which they answered. They say there will be major economic and social effects because of the dam's. I have to research the sources they use, as this website uses a lot of sources.