Part of the show Parasites and Clean Water
A microscopic fungus known as Streptomyces avermitilis could be the solution to a problem that has dogged sailors for centuries. Barnacles attach to the hulls of boat, increasing friction and slowing down the vessels. This leads to increased fuel costs and emissions. At the moment, there are various anti-barnacle treatments that can be used on boats, but they are not very friendly to the environment as the copper-based chemical compounds can leach into the sea and poison marine life. Now researchers at Goteborg University in Sweden have managed to extract a compound from the Streptomyces fungus that is a powerful barnacle killer. When tested as a paint mixture, the paint can keep boats barnacle-free for up to a year. The fungus normally lives in the sea, and releases chemicals as a defence against being eaten. The chemicals are toxic to acorn barnacles and other crustaceans, as even a tiny amount of the toxin affects the animals' nervous systems. One really important finding is that the fungal extract is toxic only as long as the paint is on a painted surface. When the paint is dissolved in sea water, the activation of the poison appears not to take place, making the paint apparently harmless to organisms in the open sea. The researchers think that as little as 0.1% of pure fungal extract is needed to mix into pint to make it barnacle-proof. They are now working to develop their compound into a commercial product.