ABSTRACT
These systems are now equipped with sophisticated sensing equipment. Sensors, housings and support structures are subject to fouling problems and emphasis has to be put on the long-term quality of measurements that may face very short-term biofouling effects (Delauney et al. 2009). Figure 1 is the biofouling of marine monitoring instruments. Consequently, systems without efficient biofouling protection are likely to be compromised. The protection must be applied to the sensors and to any underwater communication equipment most often based on acoustic technologies (Delauney et al. 2009). Autonomous monitoring instruments should provide in real time reliable measurements without costly and or frequent maintenance. In deep sea conditions this maintenance is nearly impossible to realize. For coastal applications it is quite accepted, that a two-month interval for maintenance is the minimum duration for economically viable in-situ monitoring instruments (Blain et al. 2004).
