The MOOSE Network (Mediterranean Ocean Observing System on Environment) has been set up as an interactive, distributed and integrated observatory system of the NW Mediterranean Sea to detect and identify long-term environmental anomalies. Another target is to build efficient indicators of the health of the NW Mediterranean basin. MOOSE also provides a large flux of real-time data to facilitate validation of operational oceanographic models. It is based on a multisite system of continental-shelf and deep-sea fixed stations as well as Lagrangian platforms network to observe the spatio-temporal variability of processes interacting between the coastal-open ocean and the ocean-atmosphere components. It currently provides and maintains long-term time series, the only data sets to highlight climatie trends.