Christopher Fan, University of Connecticut

Class Year:

2024

Mentor:

Lora Harris, Ph.D.

Abstract:

Water flow impacts many oyster reef processes, such as food availability and the transport and composition of particulate matter. The three-dimensional structure of the reef in turn creates feedback on local hydrodynamics and particle transport processes, generating drag on current velocities that slows down particles in the water column. This drag allows for more concentrated particle settling and increased filtration rates. Here we describe an effort to deploy tilt meters to document hydrodynamic conditions on oyster reefs alongside water quality measurements of chlorophyll and turbidity. Typically, current velocity is measured using Acoustic Doppler Current Profilers (ADCP) which utilize sound waves. For our study, we explored tilt meters as a low-cost alternative. Previous studies have suggested that tilt meters and ADCP can yield similar water velocity readings in saltwater systems. However, there is not much prior work done utilizing tilt meters in mesohaline systems such as the Chesapeake Bay. This gap in application led to two components of this study. First, we evaluated the accuracy of tilt meters in a mesohaline setting. Tilt meter and ADCP water velocity data were collected at the Chesapeake Biological Laboratory research pier. Timeseries and regression models were then created to observe patterns and correlations of the two sensors. Second, we deployed the tilt meters and analyzed the relationship between water quality and water velocity in a restored oyster reef in the St. Mary’s River. Three tilt meters and a water quality sonde were deployed at various locations around the reef. Timeseries and regression models were created to observe trends and relationships between water quality parameters, such as turbidity and chlorophyll concentrations, and water velocity. Tilt meters were found to overestimate ADCP readings by an average of 0.56 cm/s. Preliminary results from the oyster reef suggest there was no significant relationship between water quality and velocity. 

Location:

Chesapeake Biological Laboratory