Crosby, Stills, & Nash’s Graham Nash was in Woods Hole over the weekend to accept an honor from the Stellwagen Bank National Marine Sanctuary, an 842-square-mile stretch of water at the mouth of Massachusetts Bay that is celebrating its 20th anniversary. On Saturday, Nash (right) accepted the first-ever Conservation and Environmental Stewardship Award for promoting water and nature, in general. It wasn’t advertised as a concert, but Nash treated the crowd of about 400 to a performance of “Wind on the Water” and “Teach Your Children.” The event was held at the Marine Biological Laboratory’s Lillie Auditorium.