Moke McGowan announced plans Thursday to retire in September from his post as president of the Long Island Convention & Visitors Bureau, a job he's held for 10 years. Greg DeClemente, chairman of the bureau, said the group's board will launch a search for a replacement. McGowan, 64, of Bellport, has 44 years of experience in the tourism industry. He had been state tourism director for South Carolina before taking his local post. He said in an email he plans to retire to Columbia, S.C., where he owns a home in a golf course community. Based in Hauppauge, the Long Island bureau is a not-for-profit corporation that promotes tourism and convention trade.