Coastal Acidification by Rivers:A Threat to Shellfish?

Increasing atmospheric CO 2 is likely to cause a corresponding increase in oceanic acidity by lowering pH by 0. 20. 5 pH units by the end of the 21st century Royal Society, 2005. In light of increasing acidity, there are growing concerns about the future health of a variety of marine organisms, particularly shellfish, which in the United States is a 1. 6 billion industry. Shellfish predominantly inhabit coastal regions, and in addition to the projected stress caused by the global trend in ocean acidification, some coastal ecosystems receive persistent or episodic acid inputs as a result of interactions with river water, bottom sediments, or atmospheric deposition of terrigenous materials. Most river plumes are acidic relative to the receiving ocean, and river water is mixed extensively over the continental shelf. Moreover, the chemical nature and magnitude of discharge are changing rapidly due to climate change and land‐use practices.