The Land/Ocean Biogeochemical Observatory: A robust networked mooring system for continuously monitoring complex biogeochemical cycles in estuaries

Abstract

An ocean observatory that consists of an array of moored sensor platforms, telemetry, and data collection and dissemination software was designed for monitoring the biogeochemistry and physical dynamics of coastal and estuarine ecosystems. The Land-Ocean Biogeochemical Observatory (LOBO) consists of robust moorings that can withstand tidal currents and weather. The moorings are highly configurable, can be deployed in waters as shallow as 0.5 m, are relatively easy to maintain, and accommodate a complete array of standard and novel sensors. The sensors communicate with an on-board controller which relays data to shore in near-real time. Up to five LOBO moorings have been simultaneously deployed and maintained in Elkhorn Slough, California, since November 2003. Continuous hourly data of biological, chemical, and physical properties are relayed to shore, processed, and disseminated to users through a web interface in near-real time. This article describes the design, implementation, and functionality of the LOBO monitoring system. *Corresponding Author: E-mail johnson@mbari.org AcknowledgmentsThis work was funded by the NSF Biocomplexity in the Environment program through grant ECS-0308070 and by the David and Lucile Packard Foundation through a grant to the Monterey Bay Aquarium Research Institute. The authors would like to acknowledge the significant help of John Douglas and the Moss Landing Marine Laboratories Marine Operations group for supplying the boats and equipment needed for deploying and maintaining the moorings. We also appreciate help from the staff at the Elkhorn Slough Reserve and the Sea Harvest Fish Market who provided locations for the wireless network stations. Limnol. Oceanogr.: Methods 6, 2008, 263-276 © 2008, by the American Society of Limnology and Oceanography, Inc. LIMNOLOGY and OCEANOGRAPHY: METHODSElkhorn Slough located at the head of Monterey Bay along the Central California coast. The system is capable of operation in a variety of estuaries and protected coastal waters. Materials and proceduresThe observing system consists of two versions of moorings, a suite of standard and novel in situ sensors, and two-way wireless communications. Software controls data collection, archiving, quality control, and dissemination via the Internet. A network of five moorings located within various environments within Elkhorn Slough has been deployed and tested since November 2003.The mooring system was designed to fulfill criteria that include (a) holding a suite of physical, chemical, and bio-optical sensors just below the surface and, optionally, at deeper depths; (b) the ability to withstand environmental forces such as currents, waves, and fouling for sustained (~1 y) periods in typical estuaries and relatively sheltered coastal environments; (c) collection of real-time data from the sensors and relaying those values to shore; and (d) the ability to be robust, yet easy to maintain, using small boats. A list of functional and system design requirements are shown in Table 1. The design criteri...

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