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Guidelines for Measuring Changes in Seawater pH

Published August 13, 2018

The eastern coastline of the United States is a key ecosystem for millions of people, ranging from New England clam fisherman to families taking their summer vacation at the beach. To better support the livelihoods of Americans living on the Atlantic Seaboard, EPA studies our coastal waters in a variety of ways.

One developing area of research is measuring the pH of seawater in coastal and estuarine areas. The pH of coastal waters is more variable than seawater in the open ocean so there needs to be more data to determine how water pH affects life in and around these areas.

To help interested stakeholders work on these issues, the EPA has published Guidelines for Measuring Changes in Seawater pH and Associated Carbonate Chemistry in Coastal Environments of the Eastern United States. The guidelines are intended for anyone to use—from shellfish growers interested in monitoring pH with inexpensive equipment, to citizen water quality monitoring groups, to advanced chemistry laboratories interested in expanding their capabilities to monitor carbonate chemistry.

This publication explains the causes of ocean acidification on the east coast, and gives a detailed set of guidelines on effective and affordable methods of collecting and analyzing seawater. It also includes a set of references to existing open scientific literature to help readers understand our guidelines.