British naturalist and broadcaster David Attenborough will present a National Geographic documentary about the health of the world’s oceans. Attenborough, 98, is known for BBC documentaries including “Wild Isles” and the Planet Earth series, which has won Bafta TV Craft awards. In the new feature-length documentary special, which has the working title “David Attenborough: Ocean,” Attenborough will expose the biggest problems facing our oceans during what he calls “the great age of ocean discovery.” Attenborough: said: “My lifetime has coincided with the great age of ocean discovery. “Over the …