The oceans play a crucial role in the prosperity and future of our civilisation; as a source of natural resources, as host to industry (e.g. transport and offshore energy) and in controlling climate (global warming). Marine environmental science has reached a bottleneck where further advances in knowledge and understanding of the oceans can only be obtained if a new generation of integrated multi-parametric sensors is developed, capable of mass-deployment in the oceans. This cross research council grant application (NERC/EPSRC) is aimed at solving this technology gap. Sensors that measure ocean life and chemistry (not to be confused with physical parameters; temperature etc) are extremely limited. Such measurements underpin many scientific fields, not least the accurate modelling of the oceans' role in climate change. In addition, these sensors are also required by many industrial sectors for routine high resolution, temporal monitoring of environment parameters.Current measurement methods are based on traditional sampling and laboratory analysis, although some macro sensors and devices are being developed. Clearly this approach which will never be able to measure the oceans with sufficient resolution in space and time. New innovative sensor technologies are required - this is the theme of this project. It is proposed to develop a new ruggedised Micro System Technology (RMST) to fabricate a new generation of integrated micro-devices capable of operating in harsh environments, without bulky, expensive and power hungry support systems. The project will focus on two classes of sensing systems: Lab-on-a-chip chemical analysers to detect nutrients and pollutants at the ultra low concentrations found in the oceans; and miniature cytometers to sample and identify individual phytoplankton in the oceans. The systems will be benchmarked against traditional lab-based analytical methods and field tested in the oceans and in Scottish sea lochs aboard submersible gliders, autonomous submarines and profiling floats.