Effects of Prevailing Winds on Turbidity of a Shallow Estuary

Estuarine waters are generally more turbid than lakes or marine waters due to greater algal mass and continual re-suspension of sediments. The varying effects of diurnal and seasonal prevailing winds on the turbidity condition of a wind-dominated estuary were investigated by spatial and statistical analyses of wind direction, water level, turbidity, chlorophyll a, and PAR (Photosynthetically Active Radiation) collected in Lake Pontchartrain, Louisiana, USA. The prolonged prevailing winds were responsible for the long-term, large-scale turbidity pattern of the estuary, whereas the short-term changes in wind direction had differential effects on turbidity and water level in varying locations. There were temporal and spatial changes in the relationship between vertical light attenuation coefficient (K d ) and turbidity, which indicate difference in phytoplankton and color also affect K d . This study demonstrates that the effect of wind on turbidity and water level on different shores can be identified through system-specific analyses of turbidity patterns.