Implementation of a fluorescent sensor for the detection of dissolved organic matter (DOM) in marine water (chemical sensor). The sensor is designed to detect both humic-like and protein-like substances, it will work on-line in order to give continuous measurements of organic matter fluorescence. Due to the central role of DOM in the functioning of marine ecosystem, the sensor can give information on the water quality with implications on the marine ecosystem health. In detail, the signal detected by the fluorescence sensor can be linked to: Pollution, River inputs, Big cities & ports. The study of the data collected at the LTER Portofino and of the historical data collected by CNR-IBF in the last 20 years in the Mediterranean Sea, combined with AI, will also help to elucidate processes that could be detected (or forecasted) by using the fluorescence sensor, such as: harmful algal blooms, Eutrophication, Anoxia, C sequestration.