Frequency and Intensity of Exposure to Carbonate Corrosive Waters in a Near-shore Upwelling Environment

A primary consequence of increasing atmospheric CO2 is the lowering of ocean pH and associated stress on calcium carbonate bearing organisms. Coastal regions are vulnerable to low-pH due to seasonal upwelling which periodically introduces CO2–enriched deep water to the surface. Time-series of pH at Trinidad Head, California were analyzed to ascertain the frequency and intensity of exposure to carbonate corrosive waters from 2006-2011. Most years experienced 11-35 days of exposure to corrosive water, while enhanced upwelling in 2010 resulted in 61-84 days of exposure. Some instances show that corrosive conditions were ameliorated by enhanced photosynthesis in response to upwelled nutrients.