Eco-Friendly Biocide Prevents Biofouling on Ships' Hulls

Biocide "medetomidine" achieves "antifouling" effect in concentrations of about 0.1% w/w

The University of Gothenburg in conjunction with Chalmers University of Technology, in Sweden, have developed an eco-friendly "antifoulant" for marine bottom paints, to prevent "biofouling" on ships' hulls, from barnacles and other shell-forming marine organisms.

Medetomidine, the biocide in Selektope™, which will be marketed by I-Tech AB (I-Tech), the commercial partner of the Gothenburg and Chalmers universities, works by stimulating the barnacle larvae's swimming behavior, making it hard for it to adhere to the painted surface.

Entirely Reversible

The distinguishing feature of medetomidine is that it is entirely reversible, and once the barnacle larvae leaves the painted surface, the effect of the biocide on the organism and the marine environment, disappears.

I-Tech said on their website that, "In contrast to being toxic, Selektope stimulates a specific protein on the cell surface, changing the larvae's behavior from searching for a surface to settle on, to a swimming behavior."

When ship hulls are painted with the environmentally-friendly biocide-based marine paint, barnacle larvae are unable to attach themselves to the painted surface, forcing it to "swim away".

"The effect is reversible and the larvae will regain its normal behavior away from the painted surface," and it is effective at "nano-molar concentrations", said I-Tech.

Researchers assessed different biocides for different creatures and evaluated them against their environmental impact.

These 'blends' were then mixed with "hi-tech paint systems", that "slowly release the biocides from the paint into the water."

Regulatory approvals for I-Tech's Selektope in Japan and Korea were granted in 2011, and it is currently being evaluated by the Biocidal Products Directive for use within the EU.

Biofouling creates "an increase in the resistance to movement of the hull through the water - a phenomenon known as frictional resistance", leading to higher fuel consumption, increased emissions and also spreads alien species of marine life that are not indigenous to the local marine environment.