CHLOROPHYLL A AND ITS USE AS AN INDICATOR OF EUTROPHICATION IN THE CALOOSAHATCHEE ESTUARY, FLORIDA

• Published in: Florida scientist Vol. 69; pp. 51 - 72
• Main Authors: Doering, Peter H., Chamberlain, Robert H., Haunert, Kathleen M.
• Format: Journal Article
• Language: English
• Published: Orlando The Florida Academy of Sciences, Inc 01.01.2006; Florida Academy of Sciences, Inc
• Subjects: Brackish; Chlorophylls; Estuaries; Eutrophication; Fresh water; Freshwater; Nitrogen; Oxygen; Phosphorus; Phytoplankton; Pollution load; Water quality
• ISSN: 0098-4590

The use of phytoplankton chlorophyll a to indicate eutrophication in the Caloosahatchee Estuary and San Carlos Bay was evaluated. Responses of chlorophyll a to nutrient loading and freshwater discharge at the Franklin Lock and Dam located at the head of the estuary were examined. Relationships between chlorophyll a and dissolved oxygen and light attenuation in the downstream estuary and bay were also investigated. Statistically significant positive correlations with nutrient loading in the lower estuary and San Carlos Bay, significant association between increasing chlorophyll a and decreasing dissolved oxygen in bottom waters in the estuary, and positive correlation between light attenuation and chlorophyll a in San Carlos Bay argue for the use of chlorophyll a to indicate eutrophication. Relationships between chlorophyll a and freshwater discharge indicated a flushing or 'wash out' effect. Review of the literature suggested that discharge of dark, colored water enhanced light attenuation. Both effects of discharge would suppress the accumulation of chlorophyll biomass. While chlorophyll a might be used to indicate eutrophication in the Caloosahatchee, useful interpretation of the response of this indicator to future reductions in nutrient loading must account for the modulating effects of freshwater discharge exerted through flushing and reductions in light availability.