Effects of Acidic Precipitation on Atlantic Salmon Rivers in New England

摘要

A water chemistry survey was conducted in nine Atlantic salmon rivers in New England. Eight rivers are in Maine and contain native Atlantic salmon populations. One river is in Vermont and is undergoing restoration of the Atlantic salmon population. The rivers ranged in size from first order tributary streams to third order main stem rivers. All contained actual or potential Atlantic salmon spawning and nursery habitat. The chemistry of the Maine rivers was similar to that reported for other rivers located in areas where bedrock is low in acid neutralizing capacity and where precipitation is similarly acidic. The Vermont river had much higher concentrations of all ions except aluminum and hydrogen than the Maine rivers, especially calcium, magnesium, and bicarbonate, indicating the presence of carbonate mineral in the watershed of the river. The pH and aluminum concentrations in second and third order streams were well within safe limits for Atlantic salmon, even during periods of high discharge.