Integrating High-Resolution Coastal Acidification Monitoring Data Across Seven United States Estuaries.

Beginning in 2015, the United States Environmental Protection Agency's (EPA's) National Estuary Program (NEP) started a collaboration with partners in seven estuaries along the East Coast (Barnegat Bay; Casco Bay), West Coast (Santa Monica Bay; San Francisco Bay; Tillamook Bay), and the Gulf of Mexico (GOM) Coast (Tampa Bay; Mission-Aransas Estuary) of the United States to expand the use of autonomous monitoring of partial pressure of carbon dioxide (CO) and pH. Analysis of high-frequency (hourly to sub-hourly) coastal acidification data including CO, pH, temperature, salinity, and dissolved oxygen (DO) indicate that the sensors effectively captured key parameter measurements under challenging environmental conditions, allowing for an initial characterization of daily to seasonal trends in carbonate chemistry across a range of estuarine settings. Multi-year monitoring showed that across all water bodies temperature and CO covaried, suggesting that CO variability was governed, in part, by seasonal temperature changes with average CO being lower in cooler, winter months and higher in warmer, summer months.

Acidification in the U.S. Southeast: Causes, Potential Consequences and the Role of the Southeast Ocean and Coastal Acidification Network.

Coastal acidification in southeastern U.S. estuaries and coastal waters is influenced by biological activity, run-off from the land, and increasing carbon dioxide in the atmosphere.

Baseline monitoring of the western Arctic Ocean estimates 20% of Canadian basin surface waters are undersaturated with respect to aragonite.

Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has limited our understanding of the extent of Arctic undersaturation and of regional variations in rates and causes. The lack of data has also hindered refinement of models aimed at projecting future trends of ocean acidification.

In situ spectrophotometric measurement of dissolved inorganic carbon in seawater.

Autonomous in situ sensors are needed to document the effects of today's rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification).