Peter Nelson is the director of “The Pollinators,” a documentary that follows his travels around the United States following migratory beekeepers as they pollinate the flowers that produce the nation’s fruits, nuts, and vegetables. The movie was released in late 2019 and is screening at a Berkshire International Film Festival event as a part of its Environmental Film Focus at Bard College at Simon’s Rock in Great Barrington, Massachusetts this Sunday at 3 p.m. Also a beekeeper, Nelson tells WAMC that “The Pollinators” explores the problems that bees, beekeepers, and the country’s agricultural system face – and why he’s still optimistic.