The Effect of Dams on Wildlife Species

Olivia Wyatt

What is a Dam?
In an ideal world, our rivers and freshwater sources would be able to flow freely without obstruction. Since early civilization, humans have been damming rivers and bodies of water for many purposes, and today they act as a storage system for excess water when the water levels rise and fall, which helps limit flooding occurrences. Once that water is stored, it can be turned into hydropower, and even provide water for communities, agriculture, and industries. The dams also make the water much more navigable, and provide fishery reservoirs and make recreational boating and outdoor activities for people more convenient. All of these reasons make dams seem like appealing and effective solutions, but there are many “side effects” when it comes to dams.

Why it Matters 
First, the damming process changes the composition of the water and negatively transforms the ecosystems. According to the National Oceanic and Atmospheric Administration, rising temperatures in dammed waters limit the ability of species of cold water fish, like salmon, to inhabit them. Dams may also result in a lack of oxygen in the water, an excess of nitrogen causing animal death, and eutrophication. Eutrophication takes place when there are too many nutrients in a body of water resulting in an overabundance of plant life growth. This excessive growth releases too much nitrogen and phosphorus, which causes animal deaths due to lack of oxygen. Some species affected are Sturgeons, Egrets, Irrawaddy Dolphins, Salmon, River dolphins, Mussels, Trout, and even snails. 

What Needs to be Done 
We must provide better stewardship for our local rivers. Many people have called for the removal of dams, and there has been a constant discussion between government officials and the people who speak with respect for these bodies of water. For decades, federal protection plans have been constructed to remove dams or to work on protecting the fish, ultimately to just be shot down and ruled against. In 2013, Obama’s salmon protection plan for the Columbia and Snake River dams was rejected by Judge James Redden, and in 2014 another one of these federal plans was rejected by Judge Michael Simon. On top of that, current policy changes have resulted in the removal or lessening  of many of the programs protecting these species, while at the same time negatting  efforts to remove dams and provide solutions for deaths due to damming. 

Moving forward, dams must be designed with consideration for wildlife. The location, logistics, and design should all be based on the information gathered from the area before construction, and the long term impacts on the native species and environment should be a determining factor in whether the not the dam project is reasonable. Although these environmental impact studies would not prevent the species loss, they would at least place parameters on their future construction, and inhibit creation of dams in places where migratory or endangered species live. 

For the past century people have been trying to come up with effective solutions. These have ranged from an experiment in the 1970s at the Snake and Columbia Rivers where they flew the fish over the dams and deposited them into their spawning areas, to constructing fish elevators at the Grand Coulee dam. Obviously those initiatives are non-conventional, but they are a few solutions for the dams that have already been constructed and tested as viable options. Our primary focus should be dam removal, but this option is extremely costly and often receives immense push back from communities. The removal of dams is the most beneficial solution to the species’ extinction problems inflicted by damming. Once removed the River is able to return to a state where the ecosystem can normalize, temperatures and gases stabilize, and fish and other creatures can return to their original migratory and reproduction patterns. Another solution would be the creation of parallel river passages or the addition of fish ladders, as pictured below, next to the constructed dams to act as a side bar for fish and wildlife to pass through to make migration possible for them. This is a great idea, but is also costly and ineffective for many species such as salmon and mussels. Fish ladders do not take into account the other toxic conditions that dams create for wildlife like the extreme temperature escalation, the excess nitrogen and lack of oxygen, the eutrophication, and many other issues. 

The Earth offers such biodiverse ecosystems and waterways, however it is such a shame dams have destroyed our precious wildlife for this long. Conservation efforts need to be increased, and the construction of dams should be halted. If you would like to get involved or have concerns about dams in your area, there are a few things you can do. While there is legislation about dams and their removal, it is not often publicized through media outlets. Currently, most legislation is focused on dam safety in response to the 1972 National Dam Inspection Act. Incorporating awareness of animal safety into these legislations could be the key to keeping animals in the forefront of these conversations. Stay up to date so you can contact your local legislators, raise community awareness, or even sign online petitions. 

Sources: Environment America, FEMA, International Rivers, National Oceanic and Atmospheric Administration Fisheries , Northwest Power and Conservation Council, Oregon Public Broadcasting, United States Geological Survey