FOULSTOP: Fouling Protection for marine optical systems

User group PI: Laurent Delauney, Ifremer – Detection, Sensors and Measurements Laboratory, France

Hosting infrastructure: UPC Expandable Seafloor Observatory, Spain

Main Objectives

Biofilm and Biofouling growth on marine in situ sensors and optical devices (Camera, lights) is a well-known bottleneck when autonomous in situ monitoring is performed in seawater. Technological solutions have been under investigations for many years now. Still new improvements are studied.

This project consist to test in the Mediterranean sea environment an innovative technique to protect optical windows that are part of optical oceanographic sensors or more generally part of optical devices like underwater cameras and lights. The biofouling protection is achieved by a conductive layer that coats the optical window and is used to generate very low quantity of hypochlorous acid by controlled in situ chlorination of seawater.

Moreover, this innovative low power demand and very efficient biofouling protection technique can be controlled by a loop system based on a biofilm sensor (Collaboration with ISMAR-CNR, Marco Faimali (Italy) and ALVIM Srl Giovanni Pavanello (Italy)) that can trigger the active biofouling protection device only when biofilm formation is detected. The final purpose of such arrangement is to save energy by controlling the operation of active biofouling protection systems (wipers, bleach, localized chlorination, etc.) and then to lower as much as possible the energy demand and/or biocide release.

Our biofouling protection technology has been fully integrated to TriOS commercial optical sensors and an HD camera. The deployment at sea is performed on an underwater-cabled structure equipped with an EMSO COSTOF II junction box, and an ALVIM biofilm sensor for the antifouling protection control system loop.

These technologies were matured during the EU NeXOS project that will end in September 2017 (

Project Report: FOULSTOP Report Final (1.0 MiB)