Southern California estuaries are increasingly the focus of management decisions around estuary mouth closures, water quality improvement plans, and sewage impact monitoring. Currently, decisions largely use abiotic water quality measurements, such as the water level, dissolved oxygen, and salinity data provided by the long-term NERR System-Wide Monitoring Program. Managers typically are left to infer biotic responses from observed abiotic conditions. Regional partners in Southern California expressed the need to better understand when water quality conditions threaten the biotic community, specifically by using living organisms such as oysters and mussels that serve as indicators, or “biosentinels”. Complementing existing monitoring with biological data provides for real-time feedback about these important members of the estuary community. Including indicators of ecosystem health can help determine how the estuaries respond to environmental variation and human impacts, and inform the timing and necessity of costly management decisions like estuary mouth re-openings.

Abstract

Bivalve molluscs have been the focus of behavioral and physiological studies for over a century, due in part to the relative ease with which their traits can be observed. The author reviews historical methods for monitoring behavior and physiology in bivalves, and how modern methods with electronic sensors can allow for a number of parameters to be measured in a variety of conditions using low-cost components and open-source tools. Open-source hardware and software tools can allow researchers to design and build custom monitoring systems to sample organismal processes and the environment, systems that can be tailored to the particular needs of a research program. The ability to leverage shared hardware and software can streamline the development process, providing greater flexibility to researchers looking to expand the number of traits they can measure, the frequency and duration of sampling, and the number of replicate devices they can afford to deploy.