2019 REUs presented at the CERF Conference in Mobile, AL
Roles of Microphytobenthos in Dial Chlorophyll Variation
Microphytobenthos may contribute significantly to the primary productivity of an estuarine system and may reduce sediment resuspension. Resuspension of microphytobenthos was measured under controlled frictions velocities (u.). Additionally, a two week observational study of the microphytobenthos in the Horn Point Cove was conducted to determine whether resuspension due to friction velocity can account for the concentration variability of chl found in the water column. In the microcosm, we found a logarithmic relationship between u* and resuspension. However, there was a linear relationship between sediment chl concentration and resuspended chl concentration. These data suggest a positive feedback loop. As microphytobenthos grow near the sediment surface, they stabilizethe sediment. As the sediment becomes more stable, the water column becomes clearer, contributing to higher photosynthesis rates. In Horn Point Cove, there was a strong correlation between total suspended solids and turbidity in the water column. However, there was very little relationship between either of these parameters and chl concentration in the water column. This suggests that the resuspension of sediment and the concentration of phytoplankton in the water column are not controlled by the same forces. Although the relationship between u* and chl resuspension in the laboratory is strong, this relationship is weak in a natural system. This means that chlorophyll variation cannot be calculated from the measurement of other parameters in the system.