Robotic networks of platforms carrying physical, chemical, and biological sensors that can monitor basic metabolic processes are required to observe ocean health. The sensors must operate for the 5 to 10 year period between research vessel visits with no direct human intervention and little or no chance for sensor recalibration. The sensors and the platforms that carry them must operate from the surface to depths of several kilometers. Here I describe work done by marine scientists to develop integrated networks of chemical sensors with these properties. Much of the focus will be on chemical sensors that can operate for years at a time without laboratory recalibration.