Not long after publication, Jaws landed on the hardcover bestseller list of The New York Times and took up residence there for forty-four weeks. Never, however, did it make it to number one. (A pesky book about a rabbit, Watership Down, refused to budge from the top spot.) The story in paperback was entirely different. It was number one for months on lists all over the world. In the United States alone it sold more than nine million copies. But that success had to do, in part, with the shooting, preparation, and release of the movie, with brilliant cross-promotion by the paperback publisher and the movie company, and with phenomenal good luck.

I’ve derived great gratification over the years hearing from readers that Jaws was the first grown-up book they had read and that it taught them reading could be fun; that Jaws sparked an interest that led them to careers in marine biology (I’ve heard from a couple of college professors that they attribute the increase in graduate students in marine science in general and the study of sharks in particular directly to the book and the movie); or that Jaws taught them that sharks are so cool, they wanted to become conservationists. Every year, more than a thousand youngsters who weren’t alive when the book was published or the movie released write to tell me how worried they are about the decline in shark populations around the world and to ask me how they can help save these awesome animals that they discovered in Jaws.

Jaws has also given me a second career. For the past decade or so, I’ve been working in marine conservation pretty much fulltime, though I still find diving with big critters in remote locales irresistible and I’ll abandon almost anything for the chance to visit with great white sharks under water. I don’t know how much I can accomplish—I don’t know how much anyone can accomplish—but I do know that after all I’ve received from sharks, I’d feel like an ingrate if I didn’t give something back.

In 1973, before the book was published, I met with Richard D. Zanuck and David Brown, the producers for whom Universal Pictures had bought the movie rights to Jaws. Though I had no way of knowing it at the time, I was enormously lucky to be in their hands. (Later, we would all find ourselves lucky to be in the hands of a twenty-six-year-old genius named Steven Spielberg, but nobody had any way of anticipating that at the time.) Not only were Richard and David charming, gracious, and brilliant, with decades of movie-business savvy and experience, but they also were in the habit of violating two of Hollywood’s most time-honored clichés: They didn’t lie and they did return phone calls.

I had never written a screenplay, but I had asked for and been given permission to write the first couple of drafts of Jaws. At our first meeting, after an exchange of pleasantries, Richard Zanuck said to me (I’m paraphrasing here), “This picture is going to be an A-to-Z adventure story, a straight line, so we want you to take out all the romance stuff, all the Mafia stuff, all the stuff that’ll just be distracting.”