From acid rain to ocean acidification: how atmospheric pollutants threaten aquatic resources

In the 1970's and 80's, there was growing realization that emissions of sulfur and nitrogen oxides to the atmosphere from fossil fuel combustion was causing acid deposition that could harm freshwater ecosystems even in remote areas. The understanding of linkages between atmospheric deposition and deleterious effects in aquatic systems grew in the following years; examples are studies linking atmospherically-deposited mercury to mercury accumulation in fish and wildlife and health threats to consumers. Now there is growing evidence that elevated atmospheric CO2 levels result in ocean acidification, and altering carbon and mineral cycling in the seas. Linkages between atmospherically-transported pollutants and responses of aquatic organisms and ecosystems are discussed, and data from older studies are compared and contrasted to information about current threats to coastal resources.