What should we each be doing to help preserve the environment and especially the oceans? We’ll talk this hour with adventurer and environmentalist David de Rothschild, who (along with his crew) crossed the Pacific Ocean last year on a boat made from 12,500 reclaimed plastic bottles and other fully recyclable materials. His recounts the experience in “Plastiki: Across the Pacific: An Adventure to Save Our Oceans” (Chronicle Books, 2011).