Integrated Listening and Reading — 3

Salmon, a fish prized for both food and sport, has a complex life cycle. After spending several years in the ocean, adult salmon travel back to the freshwater streams where they were originally spawned, to lay their eggs. The females bury the eggs under the sand at the bottom of the streams. When the fish are large enough, two years after hatching, the young salmon, called smolts, drift into rivers from smaller streams. The smolts use the strong flow from the melting snows to get to the Pacific Ocean, where they travel until they return to start the cycle again.

The damming of river systems in the northwestern region of the United States has had devastating effects on salmon. Not only are dams an obstacle for salmon navigating upstream, but they are also an impediment for the smolts travelling to the sea. The current itself has become very slow, not just because of the construction of numerous dams but also because companies intentionally operate the dams to slow the current. They store the water from the melting snow until the winter, when more electric power is needed. As fewer smolts reach the oceans and fewer adults return, salmon fail to produce a sufficiently numerous new generation. This could eventually lead to the extinction of the fish.

Attempts are being made to get the young salmon downriver more quickly. One such attempt has consisted of transporting the smolts by barge. Another suggestion, proposed by environmentalists, is to increase the rate of water flow. Also under consideration is the reduction of the water level in the reservoirs for a period in the spring when the smolts are migrating downstream. This would also increase the flow rate temporarily, without requiring massive amounts of water, and thus enable the young salmon to move downstream faster.