Carbon dioxide from water pollution, as well as air pollution, may adversely impact oceans

William G. Sunda and Wei-Jun Cai point out that atmospheric levels of CO₂, the main greenhouse gas, have increased by about 40 percent since the Industrial Revolution due to the burning of fossil fuels and land-use changes. The oceans absorb about one-third of that CO₂, which results in acidification from the formation of carbonic acid. However, pollution of ocean water with nutrient runoff from fertilizer, human and animal waste, and other sources also is adding CO₂ via the biological breakdown of organic matter formed during algal blooms, which also depletes oxygen from the water.

Sunda and Cai developed a computer model to project the likely consequences of ocean acidification from this process both currently and with future increases in atmospheric CO₂. The model predicted that this process will interact synergistically with the acidification of seawater from rising atmospheric CO₂ in seawater at intermediate to higher temperatures. Together, the two ocean processes are predicted to substantially increase the acidity of ocean waters, enough to potentially impact commercial fisheries in coastal regions receiving nutrient inputs, such as the northern Gulf of Mexico and Baltic Sea. Clams, oysters, scallops and mussels could be the most heavily impacted, the report indicates.

The authors acknowledge funding from the National Science Foundation, the National Aeronautics and Space Administration and the National Oceanic and Atmospheric Administration.