Most dams have side-runs, fish ladders, tubes or tunnels for salmon to move past the dam. The problem remains that the dam may have flooded the salmon's original breeding grounds. Most dam agencies try to maintain some of the salmon's original breeding habitat. If all of this habitat is destroyed, then those salmon can not reproduce.
Dams can and have prevented the fish from getting to their normal breeding grounds which they have used for thousands of years.
Many forces threaten salmon populations, there are forces such as over fishing, fishing techniques (purse seine), dams that block the upstream travel of salmon, reservoirs and lakes behind dams, damage from logging in the form of disturbed soil, and mining damage.
Over the last two centuries, dams, overfishing, excessive logging, shoreline development, pollution, and industrial water withdrawals have degraded rivers, streams, and oceans critical to the salmon's survival. Dams and pollution are hazards for the Atlantic salmon on its run to the spawning beds.
Jessie W. Erickson has written: 'The decline of salmon in the Columbia River System' -- subject(s): Salmon, Salmon fisheries, Effect of dams on
HELL YES! According to Save Our Wild Salmon, a coalition of environmental groups and commercial and sport fishing associations, dams alone are responsible for the loss of 92 percent of salmon headed out to sea and of up to 25 percent on their way back upstream. "Fish are gone entirely from almost 40 percent of their historic rivers," says Dietrich, who adds that most of the remaining fish are at risk, too, qualifying for full protection under the Endangered Species Act. Quite simply, the fish just cannot swim past the dams.
Hydroelectricity is bad points: -Environment loss Salmon and trout spawning routs have been destroyed thanks to dams, scientists came up with a not so affective if solving it by creating salmon ladders that run beside the dams. - Relocation of homes -Greenhouse gas affect
Dams have been build blocking fish like salmon from climbing upstream to reproduce. The Dams are built to generate electricity with their generators and the make towns inhabitable though.
A study published in 2010 shows that there is not much effect on salmon and other anadromous fish due to dams. The greatest effect on the numbers of salmon, the sutdy pointed out, is their being eaten while in the ocean, and from fishing by American aboriginal people who have no limits on the size of their catch.
Yale Lewis has written: 'River dammed, river redeemed' -- subject(s): Salmon stock management, Pacific salmon, Dam retirement, Effect of dams on
Clinton E. Stockley has written: 'The 1977 Columbia River spring chinook test fishing program' -- subject(s): Salmon fisheries, Chinook salmon 'Injury and disease in Columbia River fishes associated with dams' -- subject(s): Fishes, Dams, Fishways, Diseases
As many other fish breathe through lungs, so do salmon.
Because they disrupt the natural flow of the body of water they built in ! A simple example would be salmon spawning. The adult salmon, though spending its life at sea must by instinct return to the river where it spawned in order to breed. If a dam is built across the river, the salmon is blocked from reaching its spawning ground - and dies without reproducing.Man-made dams affect lots of different wildlife.