AN ASSESSMENT OF WATER-QUALITY AND PRIMARY PRODUCTIVITY IN PERDIDO BAY, A NORTHERN GULF-OF-MEXICO ESTUARY

Perdido Bay is a shallow estuarine system of approximately 130 km(2) w ith three major freshwater inputs. On a seasonal basis the productivit y and chlorophyll a concentration of phytoplankton in Perdido Bay are controlled by temperature. One input, Eleven Mile Creek, is influenced by a paper mill discharge. Eleven Mile Creek exhibits high levels of light attenuation, high concentrations of dissolved nutrients, and low rates of carbon fixation that are significantly different from the ot her inputs or areas of Perdido Bay and productivity in Eleven Mile Cre ek is light limited. Upper Perdido Bay had slightly elevated concentra tions of dissolved nutrients which correlate with significantly higher rates of carbon fixation and phytoplankton biomass. Nutrients and col or from Eleven Mile Creek are diluted by the Perdido River inflow, res tricting nutrient and light limitations to the area at the mouth of El even Mile Creek.