Natural Antifouling Potential of Fucus vesiculosus and Arthrospira platensis

Biofouling is the accumulation of marine organisms on submerged surfaces and has negatively impacted several industries while aiding in the spread of invasive species. Traditional antifouling paints, such as tributyltin and copper-based paints, have proven toxic to marine environments, necessitating the use of novel, less toxic alternatives. Previous research has shown that antifouling paints made from essential oil-rich superfruits and medicinal herbs have been effective in preventing precipitation accumulation, including bacterial and mineral accumulation. This study examined the antifouling potential of spirulina and fucus, two algae rich in antioxidants and essential oils. Extracts were analyzed for antioxidant and essential oil content before being subjected to a three-week-long antifouling test. A post-test surface analysis was then performed, and the precipitation count per mm of slide was calculated, followed by a comparison with previous extracts from superfruits and medicinal herbs. After testing, fucus has a minimum bacterial count of 41.4 ± 2.0 per mm in freshwater and 14.0 ± 0.7 per mm in saltwater. Spirulina had a minimum precipitation count of 13.9 ± 2.8 per mm for freshwater and 6.6 ± 1.3 per mm for saltwater. As such, spirulina performed better than fucus, superfruits, and medicinal herbs in both saltwater and freshwater, except for when compared to results from ginger extracts in saltwater.