Negative Environmental Impact of Hydropower on Wildlife - Essay Example

Negative Environmental Impact of Hydropower on Wildlife Dams have been in existence for a long time. Their primal purpose was to serve as irrigation and flood control. At the beginning of the 19th century, their role was altered to include the generation of hydroelectricity, and by the early 20th century dams had become the mainstay for generation of electricity. In the recent decades, Dams have been the subject for debate, bringing a lot of controversies amongst environmentalist. The argument has centered on the local environment cost of the dams to the river ecosystems. Phelan in his article on Hydropower Doesn't Count as Clean Energy indicates clearly that, Hydropower has more negative consequences on environment (30). She implies despite the positive benefits brought about by Hydro power, the environment suffers a great deal of its side effects, notably, extinction of some form of wildlife. With the emergence of Global warming, dams have received a lot of attention despite the fact that they generate huge quantities of electricity without really burning fossil fuels. In this context, multiple questions have been raised concerning the environmental effects of hydropower. Among them, Are dams carbon neutral? What of the energy used in the construction of Dams and the reservoir that are created behind them (deforestation and decomposition). Notably, endless questions have been raised over the impact of Hydropower on the surrounding environment and more particularly, its impact on wildlife. As opponents of hydropower indicate, it appears as if enough evidence has been found to discredit Hydropower as an efficient energy source. Having that in mind, the paper seeks to discuss the negative environmental effects posed by Hydropower with a view to elucidate on the destruction of wildlife habitats. In a study by FWEE on provision of balanced information for water as a renewable energy resource in the North West, it is indicated that, some specific impacts due to a hydroelectric power projects mainly depends on the following variables (FWEE 1). Firstly, the size and the flow rate, secondly, the climatic and habitat conditions, thirdly, design type and operation of the project. Additionally, the habitat and climatic conditions as well as, the project locations play a significant role. In terms of the project location, upstream or downstream location often comes in focus. This clearly reveals that the dynamics involved in hydropower generations affect various sectors that are directly or indirectly related to its production. McCully, in his article of big Dams big trouble, published by New internationalists, close to sixty percent of the world’s largest river system are mostly fragmented by numerous dams and considerable water withdrawals for irrigation purposes. This implies that the massive fragmentation of and replumbing of the world largest rivers has led to an increased loss of fresh water species. In this regard, close to a third of the world fresh water fish species have been reported as extinct, vulnerable or endangered. Additionally, IEA Hydropower Agreement on Hydropower and the environment: present context and the guidelines for future Action, indicates that construction of the reservoir increased the storage water, thus covering riparian areas stream banks (23). Following these, inundation occurs. A change in the habitat conditions leads to the emergence of a new equilibrium. While this is happening, different set of dynamics begin to affect how species grow feed, spawn and grow within these regions. Though a rise in water levels increase electricity production, the riparian zone is affected since some of the vegetation initially covered by water may never re-establish McCully further indicates that a significant but unknown number of , amphibians, shell fish, as well as plants and birds that depend on Fresh water ecosystems are on the verge of extinction or as such, at risk (620). He further points it out that Flooding from Dams has the potential to disrupt Wildlife populations. As such, the upstream flooding emanating from dams and their long lasting reservoirs permanently displaces wildlife from their previously inhabited lands. More worrying, is that, a significant number of this wildlife is not only displaced, they are actually killed. It has also been indicated that, the use of Dams as a means of flood Control is not a good idea, since large dams have the potential to cause very severe earthquakes due to the pressure of the water within their reservoirs. Notably, such weight induces tectonic and geological activities that can be damaging to the surrounding environment. Additionally, Patrick explains that Big Dams have the potential to lead to coastal erosion, this majorly occurs as a result of the sediment fill up in the reservoirs which is eventually washed away to through estuaries to the coastal land. He concludes, by asserting that, Dams have the potential to destroy marine fisheries. By and large, Fearnside, in his article on china three Gorges Dam, fatal project on step toward modernization published by world development indicate that, the three Gorges dam had far reaching negative impact to both man and wildlife (620). He indicates that, the development of the Three Gorges dam negatively affected the diversity of the existing ecosystems which depended mainly on the Yangtze River. This implies that, the Yangtze River changed into a slower moving mass of water. Secondly, fish migration from upstream to downstream will be halted. Thirdly, land will be inundated and pollutants will be drawn out from the decomposing vegetation and the flooded soil. This point is further expounded by Phelan, that changing water levels and the absence of stream vegetation increases erosion (40). This implies that the riparian zone and species within the ecosystem are negatively affected by the varying water levels. In addition, McCully indicates super saturation negatively affects the ecosystem (36). It occurs when the air gets entrapped in the water due to turbulence, and because air has 78% nitrogen the level of dissolved nitrogen increases tremendously. However, the affected water fails to lose nitrogen much quickly. As a result, supersaturated water enters tissues of fish species which eventually causes injuries to the fish when it swims from highly concentrated regions to lowly concentrated regions Rydergren in his article on Hydropower- environmental impacts remedial measures and costs in regulated waters, reveals that, Stratification causes chemicals to be released into the reservoir thus causing water quality problems as well as the potential negative impact on the aquatic food base (5). It should be noted that reservoirs are created when storage water dams are constructed. Reservoirs can significantly reduce the flow rate of water downstream. Consequently, water surface temperatures tend to become warmer to the slower movement of since water absorbs heat from the sun. Notably, colder surface water sinks to the bottom creating a layering effect known as stratification. In this regard the bottom layer becomes the coldest and the top layer becomes the warmest. In this regard stratification poses as an ecosystem effect. More specifically, the sinking water contains little amounts of oxygen. This finally affects downstream habitat conditions due to the low levels of oxygen. He concludes by asserting that Hydropower severely affects water quality, biological processes and indeed the volume of water flowing downstream. According to Gunkel publication on whether hydropower is a green Energy in the tropical reservoirs and green gas reservoirs, he indicates that reservoirs are manmade lakes that severely impacts on river ecosystems, and still the new lake ecosystem risks to risks to be damaged by several process (730). His study clearly indicates that the benefits of constructing a reservoir must be weighed against the potential impact on nature. As such emissions from green houses have been reported to cause climate change emanating from methane and carbon II oxide released. Moog, in the article of Quantification of Daily Peak Hydropower Effects on Aquatic Fauna and Management to Minimize Environmental Impacts, it is indicated reservoirs lead to some negative impacts on the ecosystem, for instance, inhibition of fish migration, and the destruction of the inundated area. Additionally, reservoirs cannot sustain organisms due to the still waters (13). It has also been observed that, periodic fluctuations in water levels lead to littoral erosion and the subsequent damage of littoral flora and fauna. Furthermore, Lu and Higgit in their article on sediment deliver to Three Gorges explain that, a lot of sedimentation can be associated with the construction of a hydropower (159). Nutrients are lost due to sedimentation thus depriving aquatic organism of important nutrients. He concludes by asserting that, the damming effect cause a trophic upsurge of the reservoirs which eventually leads to more eutrophic conditions of the reservoir. In this regard, such high level of erosion renders the soil unfit for cultivation or support for other terrestrial life forms. When sediments collect within the reservoir, the ecosystem is affected in two ways. First, the downstream habitat conditions declines since the sediments can hinder the provision of vital organic and inorganic nutrients (Fearnside 622). Secondly, after sediment build up, a dam effect normally referred to as nutrient loading leads to a reduction in oxygen supply. This occurs because more nutrients are available and hence more organisms populate within the region thus, consuming the nutrients. Eventually, depletion of nutrients leads to a reduction in oxygen supply. In conclusion, it has been observed that hydropower affects wild life in many ways. Firstly, through the changing water levels the riparian zone stays at risk of failing to reemerge after a long period under water. Secondly, the supersaturated water created by the dissolving Nitrogen stands at risk of injuring aquatic species such as fish. Thirdly, Erosion resulting from the changing water level and absence of vegetation can further alter the riparian zone and the species within the region. Furthermore, sedimentation of the Dam results in nutrient loading which eventually leads to a depletion of the available oxygen, this eventually reduces alters the ecosystem. Lastly, the resulting reservoirs and stratification causes a change in the ecosystem, where, oxygen levels significantly reduces at the downstream thus, causing a change in the habitat conditions. Work cited FWEE. Providing balanced information for using water as a renewable energy resource in the North West, 2013, Accessed on 15th May 2013 Fearnside, Philip, M. "China's Three Gorges Dam: "fatal" Project on Step Toward Modernization?" Journal of World Development,165 (1988): 615-630. Print. Gunkel, Gunter. "Hydropower - a Green Energy? Tropical Reservoirs and Greenhouse Gas Emissions." Clean - Soil, Air, Water journal, 37.9 (2009): 726-734. IEA Hydropower Agreement. Hydropower and the environment: present context and the guidelines for future Action. A journal of Annex, 1 (2000): 1-40 Lu, Xu. X., and Higgitt, Douglas, T. "Sediment Delivery to the Three Gorges:2: Local Response."Geomorphology, 42.6 (2001): 157-169. McCully, Patrick. “Big Dams, Big trouble.” Journal of New internationalist, 1 (2003): 12- 45. Moog, Otto. "Quantification of Daily Peak Hydropower Effects on Aquatic Fauna and Management to Minimize Environmental Impacts."  Research & Management journal, 8, 1993: 5-14. Phelan, Sarah. "Hydropower Doesn't Count as Clean Energy." Earth Island Journal, 4 (2007). 23-45. Rydergren, Bernt. “Hydropower- environmental impacts remedial measures and costs in regulated waters.” Journal of scientific review panel, 1. (2006): 1-18. Read More