Peter Benchley, whose novel "Jaws" made millions think twice about stepping into the water even as the author himself became an advocate for the conservation of sharks, has died at age 65, his widow said Sunday.

Wendy Benchley, married to the author for 41 years, said he died Saturday night at their home in Princeton, N.J. The cause of death, she said, was idiopathic pulmonary fibrosis, a progressive and fatal scarring of the lungs.

Thanks to Benchley's 1974 novel, and Steven Spielberg's blockbuster movie of the same name, the simple pastime of ocean swimming became synonymous with fatal horror, of still water followed by ominous, pumping music, then teeth and blood and panic.

"Spielberg certainly made the most superb movie; Peter was very pleased," Wendy Benchley told The Associated Press.

"But Peter kept telling people the book was fiction, it was a novel, and that he no more took responsibility for the fear of sharks than Mario Puzo took responsibility for the Mafia."

Benchley, the grandson of humorist Robert Benchley and son of author Nathaniel Benchley, was born in New York City in 1940. He attended the elite Philips Exeter Academy in New Hampshire, then graduated from Harvard University in 1961. He worked at The Washington Post and Newsweek and spent two years as a speechwriter for President Johnson, writing some "difficult" speeches about the Vietnam War, Wendy Benchley said.

A 1974 article in People magazine described Benchley as "Tall, slender and movie-star handsome, with eyes like the deep blue sea." The author's interest in sharks was lifelong, beginning with childhood visits to Nantucket Island in Massachusetts and heightening in the mid-1960s when he read about a fisherman catching a 4,550-pound great white shark off Long Island, the setting for his novel.

"I thought to myself, `What would happen if one of those came around and wouldn't go away?"' he recalled. Benchley didn't start the novel, for which he received a $7,500 advance, until 1971 because he was too busy with his day jobs.

"There was no particular influence. My idea was to tell my first novel as a sort of long story ... just to see if I could do it. I had been a freelance writer since I was 16, and I sold things to various magazines and newspapers whenever I could."

The editor of "Jaws," Thomas Congdon, told The Associated Press on Sunday that he had been impressed by some articles Benchley wrote for National Geographic and arranged a lunch at a French restaurant in New York — "a second-class restaurant, not first class, since he was an unknown."

"The lunch didn't go very well," said Congdon, an editor at Doubleday at the time and now retired. "His nonfiction ideas did not seem very promising, but at the end of the meal, I said, `Have you ever thought of writing a novel?' And he said, `Well, I have an idea about a great white shark that marauds an Eastern coastal town and provokes a moral crisis in the community."'

Congdon loved the idea, but said Benchley was reluctant to start the book because he couldn't afford time away from his journalistic work. So Congdon got him $1,000 as a down payment, in return for an initial submission of 100 pages.

"Ninety-five percent of it was jokey stuff, because he thought that was the way you do it," said Congdon, who dismissed a longtime publishing legend that the book was heavily edited and as much his triumph as Benchley's.

"But the first five pages were wonderful. There were no jokes. I wrote heavily in the margin: `NO JOKES.' He went out and did it again, and it generated whole industries — the movie, amusement park rides. It changed the way people looked at sharks."

While Peter Benchley co-wrote the screenplay for "Jaws," and authored several other novels, including "The Deep" and "The Island," Wendy Benchley said he was especially proud of his conservation work. He served on the national council of Environmental Defense, hosted numerous television wildlife programs, gave speeches around the world and wrote articles for National Geographic and other publications.

"He cared very much about sharks. He spent most of his life trying to explain to people that if you are in the ocean, you're in the shark's territory, so it behooves you to take precautions," Wendy Benchley said.

The author did not abide by the mayhem his book evoked. In fact, he was quite at ease around sharks, his widow said. She recalled a trip to Guadeloupe, Mexico last year for their 40th wedding anniversary, when the two went into the water in a special cage.

"They put bait in the water and sharks swim around and play games," she said.

"We went at a time when the females came in and the females were much larger than the males. And at times we would have 4 or 5 of the most gorgeous female torpedoes drifting by the cage. We were thrilled, excited. We'd been around sharks for so long."

Besides his wife, Peter Benchley is survived by three children and five grandchildren. A small family service will take place next week in Princeton, Wendy Benchley said.