The automated monitoring of physico-chemical parameters in the coastal zone has been using large buoys and fixed infrastructures. A better understanding of many estuaries is needed in order to fulfil the agenda and requirements of the European Water Framework Directive. In order to address the fluxes of nutrients as well as algal blooms and low oxygen events, the "TROPHIMATIQUE" project has developed a new generation of instruments able to be deployed in sea waters. The smaller size of the new instruments is intended to facilitate the maintenance. A new multi-parameter probe has been developed. The measurements of all nutrients are performed thanks to the CHEMINI flow injection analysers for nitrate, ammonia, silicate and phosphate. A sampler using similar technologies is linked. Light buoys called SMATCH are monitoring the protected zones while a new umbilical anchored buoy called MOLIT is monitoring the open sea site. The deployment in the three water masses of the Vilaine estuary (estuary, intermediate and coastal) was started in 2008. This estuary is threatened by low oxygen events. An hypoxic episode in 1983 caused huge mortality in sea life. First results in 2008 demonstrated the advantage of hourly automated measurements. Main events are described in the PREVIMER quarterly newsletter issued on a public portal (http://www.previmer.org/en/newsletter). The PREVIMER modelling project of the Bay of Biscay is using the in-situ data gathered by Trophimatique project. The TROPHIMATIQUE project involves Ifremer and nke for the technical development and the Institution d'Amenagement de la Vilaine (management institution of Vilaine river basin); it is funded by the French National Research Agency Ecotechnology program PRECODD and benefits from funds of Brittany Region and Ifremer.