Grand Canyon 12

"Improvements" don't always improve. Construction of the Glen Canyon Dam has adversely affected the ecology of the Grand Canyon. Flash floods that would at one time scour the inner-canyon clean and deposit fresh sand along the beaches no longer occur. The water temperature, which used to get as warm as 80 degrees F, is now icy-cold all year and averages around 42 degrees F. Because of the changes in the water temperature some of native fish that used to inhabit the river have become extinct and still others are endangered. The Rainbow Trout, a non-native specicies which was introduced by man, thrives in the colder waters and makes it even more difficult for the native fishes to survive.