Three R.E.MO.S. (Remote Environmental MOnitoring System) telemetric networks have been installed in the catchment area of River Nestos, by research team PERSEAS. The first network has been installed in Nestos Delta. This network consists of two Remote Stations (R.S.): The first one is called R.S. "Nestos" and is settled in Nestos Delta in Chrysoupoli and the second one is called R.S "Agiasma" and is settled in the homonymous Lagoon. This paper deals with R.S. "Agiasma", which operates in Agiasma Lagoon, an area of great environmental importance in the west part of River Nestos Delta. The gradients of the water quality and quantity monitored parameters are very important for the ecological preservation of the lagoon. Moreover, this case can be an excellent example of how the real-time monitoring data can work as an alarm system to prevent environmental hazards. The scientific issues this paper is focused on are: 1. The three years systematic daily electronic monitoring data (1/1/2000-31/12/2002). The monitored parameters are Water level-H (cm), Salinity-Sal (parts per thousand), Redox Potential-RP (mV), Dissolved Oxygen-DO (mg/l), Water Temperature-T-w (degrees C) and Air Temperature-T-a (degrees C). 2. The assessment of water quality and quantity parameters and the aquatic environment of Agiasma lagoon. 3. The detection of trends. using the non-parametric Spearman's criterion. This trend analysis proved the existence of trends for the parameters H, Sal and RP. 4. The necessity of real-time monitoring, which can prevent and confront possible natural hazards and disasters and work as an alarm system for the local authorities. (C) 2009 Elsevier B.V. All rights reserved.