Impact assessment of biofouling resistant nano copper oxide–polyaniline coating on aquaculture cage nets

Abstract

Biofouling is a major issue in aquaculture cages and nano materials based antifouling strategies became more prominent in recent years. Polyethylene aquaculture cage net surface which is modified with polyaniline and nano-copper oxide (CuO), reported to have biofouling resistance. Leaching of nano CuO from the net to the aquatic environment and its bioaccumulation in fish is the major concern against the technology adoption. The present study aimed to understand the accumulation of copper in fishes grown in a nano CuO treated aquaculture cage net. Studied the leaching pattern of nano CuO, biofouling inhibition and changes in strength of the cage net due to the nano CuO treatments. Fishes grown in the treated cages exhibited normal growth characteristics with no signs of abnormalities and also copper in their organs were within the prescribed standard limit. The CuO treated cage net exhibited excellent biofouling resistance and the percentage of occlusion of mesh by foulers were 56.77% more efficient than untreated cage net. Rate of nano CuO leached to the aquatic system was less than 8 μg/g·d. The fouling organism assemblage on untreated and treated net was 18 and 11 species, respectively. Major calcareous shelled foulers were absent on treated nets. The study highlighted the potential application of nano CuO treatment to control biofouling in aquaculture cages.