Nippon Paint Marine announced results from an independent study showing that its biocide-free hull coating AQUATERRAS had no negative effects on marine invertebrates following simulated in-water cleaning.

The study, conducted by PML Applications Ltd, exposed estuarine sand and mud-dwelling species to coating particles generated from cleaning activities. After 28 days of exposure, ragworms and bivalve cockles showed no mortality or adverse effects. Both species gained weight at rates comparable to control groups.

Researchers also simulated hull cleaning using soft and medium brushes and water jets. Tests confirmed that zinc and copper levels remained at background levels, indicating no metal release from the coating.

The findings support growing interest in in-water hull cleaning as part of fuel efficiency strategies, while aligning with IMO best practices that encourage attention to environmental impacts from discharged materials.