the dark side of dams

As we learned in class, dams are an efficient way to generate electricity without burning fossil fuels. However, dams have a huge negative impact on the environment.

1) Naturally flowing organic matter would normally pass on down the river without a problem. But when you put a dam there, the sediment and organic matter slowly builds up and begins to decompose which can take away oxygen from the water and turn the biologically diverse river into algal blooms. From  there, the aquatic life begins to die off the the river becomes empty of organisms.

2) Dams disturb migratory paths of fishes that rely on returning upstream to spawn, such as salmon. This is a huge concern for major salmon populations where dams have been placed because their populations have been dwindling as a result.

3) As mentioned earlier, the sediment that would normally be found at the mouth of the river gets caught upstream, which prevents those organisms at the mouth of the river from gaining those resources. As a result, they have a loss of habitat from those missing materials.

4) It also disturbs the community of people that used to live by a beautiful healthy river and it is now a dam because the whole ecosystem starts to diminish and the community becomes disconnected with nature.

When it comes down to it, its all about cost vs benefits of the dam. Is the energy it is producing worth destroying an ecosystem? Or should the ecosystem be saved? As of recent years, more and more dams are being taken out because people are realizing the effects they are having on the ecosystem.

Just an interesting topic!

http://www.scientificamerican.com/article.cfm?id=how-do-dams-hurt-rivers