Undergraduate students from Stanford University got to work with hands on field tools under the direction of two lead instructors including Stephen Monismith, the Obayashi Professor in the School of Engineering. In the Republic of Palau, students donned snorkeling gear and got in the water to collect data on the coral reefs and its surrounding ecosystem.
Heidi Hirsch participated in the Ecology and Management of Coral Reefs of Palau program seminar and deployed several tilt current meters/ TCM-1s for her project which “coupled biogeochemical and hydrodynamic measurements to provide a high-resolution record of seagrass productivity”. A meter was deployed at either end of a 571m seagrass bed in conjunction with Acoustic Doppler Velocimeters (ADVs) and Acoustic Doppler Profilers (ADPs), “to determine the dominant current flow direction and velocity at either end of the seagrass bed”.
The TCM’s were deployed in the seagrass for less than a month while some TCM’s were deployed for longer periods for other student run projects. “In order to calculate oxygen flux (net community production, NCP) over the seagrass bed it was important to show that there was tidally driven uniaxial current flow over the bed which allowed us to determine NCP using an ‘upstream-downstream’ approach (any changes in pH or dissolved concentration over the bed were due to seagrass productivity along the transect line)“, Hirsch said.
The meters were attached to cinder blocks with pavers and a line was added for easier retrieval. “The tilt current meters were very easy/straightforward to program and deploy. We did not have to worry about the orientation of the meter or having it deployed exactly level as we do for the ADVs and ADPs.”
Of the portability of TCM’s, Heidi said, “transportation was also much easier. We could pack the current meters (buoyant part) in a regular suitcase and hand carry the loggers on the plane. Our other instruments required their own cases which quickly becomes expensive for field work.”To learn more about the study and coral reef research in Palau, click here:
Products Used
TCM-1
The TCM-1 Tilt Current Meter is ideal for measuring water velocity from inland to the edge of the continental shelf.
Anti-Fouling Paint
Depending on deployment conditions, it may be a good idea to apply anti-fouling paint to a Tilt Current Meter (TCM).