In a country like the us , laws once framed are supposed to be implemented. An excellent example is the Endangered Species Act ( esa ). Adopted in 1973, the law was framed with the sole intention of saving species on the brink of extinction -- saving them at all costs.
The salmon is one such species. A symbol of the health of a river -- in fact, the health of an entire ecosystem -- the survival of salmon is important for maintaining the continuity of the natural heritage of Western nations. According to Chris Zimmer of the us -based environmental organisation Save Our Wild Salmon, where salmon runs have become extinct, the local ecosystem has suffered. "Populations of wildlife, such as bear, eagle, mink and river otter, for whom the salmon is a source of food, drop drastically," he says, adding: "Besides the dangers posed to wildlife, the northwest forests in the us are partly built on the nutrients salmon bring back from the sea." Wild salmons are quite literally the energy fuels of the environment. Every individual salmon is important and when a river is dammed their very existence is threatened.
To save the salmon from extinction, the us government is at present imposing curbs on the construction of dams. Further, the us -based Federal Energy Regulatory Commission ( ferc ) is refusing to renew the license of those dams owned by private hydropower companies in view of the immense environmental damage. ferc is also demanding that fish ladders (special dam structures to facilitate the migratory path of fish) be built into the existing dams if their licenses are to be renewed. That is often so expensive that companies usually opt to destroy the dam instead. In a more drastic step, dams obstructing the migratory path of the salmon are being razed to allow the fish free passage. At least 100 dams have been removed from waterways in the us -- another 100 are either committed or are under active consideration for removal.
According to reports, about 75,000 big dams on us rivers bear testament to the conviction that any river flowing into the sea unimpeded is considered a waste of water and power. This attitude has, however, undergone a drastic change in the past four decades.
Construction of dams was the mantra of the 1950s. With the emphasis shifting to restoration of degraded aquatic environment, the '90s saw a drastic reversal: nations began to contemplate letting the rivers run free again. Why? The social, economic and environmental costs far exceeded the benefits (see diagram: Construction of a dam ).