You know the scene: A black dorsal fin slices through the surf toward a solitary swimmer. From the crowded beach come cries of "Shark!" But it's too late. That's vintage Jaws, of course, and it's become a staple of summertime pop culture since the first Jaws film, released 30 years ago, stirred up shark hysteria worldwide. Even in Canada, where there has never been a recorded shark attack fatality, swimmers looked at the water with new suspicion. Over the next 12 years, the studios churned out three progressively more terrible Jaws instalments until, in the final film, a descendant of...