Estimating biofilm biomass on objects in an aquatic environment

A system for estimating aquatic environment-originating biofilm biomass on a coating of an object, including a digital camera or imager and a processor configured for:

• obtaining one or more digital images of a fouled portion of the coating on the object;
• determining from each of the one or more images a respective reflectance value for the portion of the coating;
• determining on the basis of the one or more reflectance values a value of a spectral index representative of biomass;
• calculating a biomass pigment surface area density on the basis of the spectral index, SI, and one or more calibration values determined for a reference coating;
• and
• compensating the calculated biomass pigment surface area density for the reflectance of the coating of the object by applying a compensation associated with the difference of the reflectance of the coating of the object relative to the reference coating thereby generating a compensated biomass pigment surface area density;
• wherein a map of biofilm biomass on the fouled portion of the coating of the object is produced from the compensated biomass pigment surface area density.