美国科学60秒 SSS 2013-07-15（在线收听）

　　　　It's boating season, which means it'll soon be time for that annoying ritual, the scraping of the barnacle. They latch on tight and don't let go. Barnacles can be a major pain. As they grow they build up calcium 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 vessels. Currently, hull paint can be doped with poison usually based on copper oxide that leaches out slowly to kill over little creatures. But the poison also escapes into the water and can kill other marine life. Now researchers might have a better opition: a paint additive that kills just the barnacles, using their own behavior against them. It's a toxin based on a molecule-created bio-bacterium. Researchers developed a method of embedding that toxin into the paint, so that it only gets released when the barnacle penetrates the paint. The info was published in a university thesis. The scientists determined that the toxin works in low concentrations and could be effective for years, which could lower the cost of paying the barnacle bill.