Environmental Science Wednesday, February 26, 1997
             Among the many kinds of fish harvested each year by commercial fisheries is the
             Oncorhynchus tshawytscha or Chinook salmon. The United States catches an
             averages of about three hundred million pounds of salmon each year. However
             some Chinook salmon have been recently listed as threatened. Man has been the
             main cause for the decline in Chinook salmon populations.
             The populations of Chinook salmon have declined for several reasons. Hydropower
             and it's destructiveness to the environment, pollution, and overfishing are the
             three main causes for the decline. The Chinook salmon is known for traveling
             the greatest distance back to its spawning grounds, often traveling one to two
             thousand miles inland. This long journey is now often interrupted by
             hydroelectric plants. Hydropower is a very good alternative resource for power,
             however it is very damaging to our salmon populations. The dams block off
             rivers, which block the salmon's path back to their breeding grounds. The
             salmon go back to the same areas, just as their ancestors did, to lay their eggs.
             The hydropower plant's turbines are also very dangerous to young salmon. Many
             of them are killed by the giant turbines on their way back to the ocean.
             Killing off many of the salmons new generation. Pollution is also a killer of
             many Chinook salmon. Pollution caused by sewage, farming, grazing, logging and
             mining find it's way into our waters. These harmful substances kill many
             species of fish and other marine life. The Chinook salmon is no exception. The
             chemicals are dumped into the rivers and streams and eventually these chemicals
             find their way to the ocean, polluting and effecting each area they pass through.
             The largest contributor to the decline in the Chinook salmon population is the
             commercial fishing industry. From a period of 1990-1992 815,000 Chinook salmon
             ...