Development and deployment of a long-term aquatic eddy covariance system

Abstract

The aquatic eddy covariance (AEC) technique is a versatile tool for understanding benthic fluxes, and calculating primary production, respiration, and net ecosystem metabolism rates of benthic communities. A limitation for researchers has been the length of deployments where the major constraints have primarily been sensor breakage and degradation over time and battery consumption. This paper evaluates the design and deployment of a long-term eddy covariance system (LECS) that was deployed in a temperate seagrass meadow for 6 months that resulted in reliable data 79% of the time. The system consisted of a fixed bottom lander that measured the AEC and a surface buoy that transmitted real time data and provided solar power. This study found a gradual reduction in sensor response time, likely due to fouling, that reduced the response time from 1 to 22 s and resulted in a normalized root square mean error of 8% when comparing the LECS with a second short-term AEC system. New spectral analysis techniques allow for these changes in sensor response time to be monitored in real time so the sensor can be replaced or cleaned as needed. This ensures future deployments will be able to collect high-quality data and allow for long-term analyses of benthic fluxes using the new technology and analyses of the presented LECS.