He has written 23 books, including The Book of Sharks, The Book of Whales, Dolphins and Porpoises, Men and Whales, Great White Shark (with John McCosker), Encyclopedia of the Sea, Aquagenesis: The Origin and Evolution of Life in the Sea, Deep Atlantic, Monsters of the Sea, Imagining Atlantis, The Search for the Giant Squid, Tiger Bone & Rhino Horn, No Turning Back: The Life and Death of Animal Species, Sea Dragons: Predators of Prehistoric Seas, Tuna, The Empty Ocean, and Swordfish: A Biography of the Ocean Gladiator.