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　　　　It's boating season, which means it'll soon be time for that annoying ritual, the scraping of the barnacle. They latch¹ on tight and don't let go. Barnacles can be a major pain. As they grow they build up calcium² deposits under a boat's paint. And their interference with smooth fluid flow can decrease fuel efficiency by up to 40% --- a major problem for large vessels³. Currently, hull⁴ paint can be doped with poison usually based on copper⁵ oxide⁶ that leaches⁷ out slowly to kill over little creatures. But the poison also escapes into the water and can kill other marine⁸ life. Now researchers might have a better opition: a paint additive⁹ that kills just the barnacles, using their own behavior against them. It's a toxin¹⁰ based on a molecule-created bio-bacterium. Researchers developed a method of embedding¹¹ that toxin into the paint, so that it only gets released when the barnacle penetrates¹² the paint. The info was published in a university thesis. The scientists determined¹³ that the toxin works in low concentrations and could be effective for years, which could lower the cost of paying the barnacle bill.