| Shallow estuaries, such as Mobile Bay, are subject to frequent wind-driven sediment resuspension events. Sediment resuspension could affect phytoplankton production rates by influencing water column dissolved nutrient concentrations and light attenuation. In this study, simulated resuspension events were carried out in replicate mesocosms, during different seasons, to examine the effects of resuspension on nutrient and phytoplankton dynamics. During the winter and summer experiments, sediment resuspension generated a small, short-term pulse of phosphate, whereas dissolved inorganic nitrogen was not significantly affected. Phytoplankton biomass in these two trials increased significantly in response to sediment resuspension with peak biomass averaging 20 mug/L greater in the resuspended mesocosms than in the control mesocosms. In contrast, there were no significant effects of sediment resuspension on either nutrient or phytoplankton dynamics during the spring resuspension experiment, which was conducted during a substantial phytoplankton bloom. |
