Baseline nutrient dynamics in shallow well mixed coastal lagoon with seasonal harmful algal blooms and hypoxia formation

Weekly inorganic nutrient and chlorophyll-a concentrations were measured to establish baseline conditions in Corpus Christi Bay, Texas during seasonal hypoxia and harmful algal bloom (HAB) formation. Two fixed stations along the southern shoreline were sampled weekly for a continuous year at the same time each day. Weekly shoreline observations were found to be statistically similar to quarterly observations in the bay center, but with a greater power to detect seasonal trends. Dissolved Oxygen (DO) < 4 mg/L was measured in June, 2012 along the southern shoreline of Corpus Christi Bay, which places lower DO conditions west of previous estimates. During a bay-wide HAB event in November of 2011 no changes were observed in any of the nutrient or chlorophyll-a observations. This study documents a baseline of nutrients and chlorophyll-a in Corpus Christi Bay during a dry (average salinity > 36 PSU) year.