Atlantic salmon exposed to short springtime bursts of acidic runoff water are less able to migrate to the ocean because of important changes in their ability to balance salt, writes Karen Kidd in this EnvironmentalHealthNews report.
Although heavily acidified streams have fewer salmon, this is the first study to show that health effects occur in streams with only brief periods of acidification. The decline in water quality occurs when the salmon are at a critical period in their development and may contribute to the continued decline of this endangered species.
Despite large restoration programs, Atlantic salmon populations have continued to decline in many rivers in the northeastern US and eastern Canada. Although potential causes include dams, loss of spawning beds, and overfishing, acid rain and acidic water conditions also affect salmon conservation efforts, despite reduced emissions of acidifying substances in North America.
Acid rain occurs when sulfate and nitrate -- mainly generated from coal-fired power plants and other combustion of fossil fuels -- mix with the atmosphere and are carried by precipitation to the Earth. This deposition increases the acidity of and aluminum content in water and soil.
Fish, other wildlife and plants cannot always tolerate the high acid levels and can succumb to its health effects. Acid rain is blamed for exterminating Atlantic salmon populations in certain rivers in Nova Scotia and Norway.
Acid Runoff Damages Atlantic Salmon
US - Spurts of acidic runoff affect the health of young Atlantic salmon living in northeastern US streams, which adds to their demise by reducing their ability to migrate to the ocean.
