The two-day October conference, which focused on the impact of airborne nitrogen deposition on coastal waters, drew representatives from state and federal air pollution programs as well. Linking air emissions to water quality would be a fundamental shift in 25 years of pollution control policy during which air and water issues have been strictly segregated. Air and water officials within state and federal agencies often do not even know each other. Yet recent research, coupled with computer models, has pointed to air pollution as a major source of nitrogen, one of the two nutrients of concern in the Bay system. Generated by fossil fuel combustion, the nitrogen oxides emitted from tailpipes and smokestacks account for anywhere between 20 percent and 35 percent of all the nitrogen entering the Bay.
Most aquatic species require oxygen to survive, only less of it than land dwellers.
Much of the Bay's water quality woes in recent decades are linked to nutrient pollution that has reduced oxygen levels in the water. Excessive amounts of the nutrients phosphorus and nitrogen spur large algae blooms in the Bay. When the algae dies, it sinks to the bottom and is decomposed by bacteria in a process that depletes the water of oxygen. When water becomes anoxic, depleted of oxygen, many species must abandon those areas. Species that can't move may die or suffer other ill-effects, such as poor reproduction or stunted growth.