Title: Transfer of a low-cost tidal wetland water level monitoring system: hyperlocal calculations of inundation and tidal datums for understanding change and restoration planning

Affiliation: Okeanolog/WBNERR

Funding Source:  NERRS Science Collaborative Science Transfer gran

Contact/Email: Megan Tyrrell, Research Coordinator, WBNERR (megan.tyrrell@mass.gov)

Abstract: Waquoit Bay Reserve ongoing water level monitoring program focusing on discrete salt marsh microhabitats and employing a simple and inexpensive system of water level monitoring developed by PI Vitalii Sheremet. The ‘Arm-and-Float’ water level instrument uses a HOBO Pendant G accelerometer. These easy to deploy loggers have been used in several types of salt marsh habitats (e.g., pools, creeks and upstream of a tidal restriction) at WBNERR and other NERRs.

The principle of operation is based on converting the raw signal of the arm tilt into the elevation of the float relative to a fixed pivot by multiplication by the arm length. In this way, accuracy of 5-10 mm is achieved, which is adequate for calculating tidal datums for each feature where the logger is deployed. In May 2021, 20 arm-and-float loggers were deployed across Sage Lot Pond for water level monitoring in conjunction with seven other Reserves spanning a range of climactic and tidal regimes which also received arm-and-float loggers as part of the science transfer grant. At the conclusion of this project, locally relevant tidal datums will be calculated, and enhanced understanding of the differences in inundation regime for 20 salt marsh features including creeks, pools, nascent pools, surrounding potential tidal restrictions will be available.