Observed pH and aragonite saturation state values in surface and subsurface waters were substantially lower in parts of Puget Sound than would be expected from anthropogenic carbon dioxide (CO 2) uptake alone. In order to study the combined effects of ocean acidification and other natural and anthropogenic processes on Puget Sound waters, we made the first inorganic carbon measurements in this estuary on two survey cruises in February and August of 2008. Anthropogenically acidified coastal waters upwelling along the western North American continental margin can enter Puget Sound through the Strait of Juan de Fuca. While ocean acidification has been studied in oceanic waters, little is known regarding its status in estuaries. Pacific Northwest that is home to a diverse and economically important ecosystem threatened by anthropogenic impacts associated with climate change, urbanization, and ocean acidification. Puget Sound is a large estuary complex in the U.S. This is a regional example of NANOOS and IOOS contributions to societal impacts from ocean acidification. This increase in data access regarding OA is of value to scientists, managers, educators, and shellfish growers who are especially appreciative of the near real-time readouts of the data, upon which to make hatchery and remote setting decisions. NANOOS has worked through IOOS with the NOAA Ocean Acidification Program, NOAA PMEL, academic, local, and commercial and tribal shellfish growing partners to provide existing observing assets to accommodate pCO2 and pH sensors, to deliver data streams from these and other providers, including that from sensors in shellfish hatcheries, and to network this capacity regionally and nationally. The Northwest Association of Networked Ocean Observing Systems, NANOOS, the Regional Association of the United States Integrated Ocean Observing System, IOOS, is set up to deliver coastal data to serve the needs and decisions of its region. A combination of factors renders the Pacific coast and coastal estuaries particularly vulnerable to acidified water.

Ocean acidification has serious implications for the economy and ecology of the Pacific Northwest United States.