After 450 million years of evolutionary history, shark populations are collapsing, and more than a third of shark species and their relatives face extinction. Now scientists are trying to use the lure of “Jaws” to advance shark conservation efforts.

The toothy villain of “Jaws” terrified audiences in 1975. Offscreen, the hit film — which is celebrating its 50th anniversary — impacted sharks in unexpected ways.

He was behind schedule, his actors were fighting, the crew were mutinous and worst of all, his shark was broken. It looked like Jaws was destined for failure, but the movie that came out defined the Hollywood blockbuster.