From CNN:

(CNN) — Shark attacks on humans were at the lowest levels in half a decade last year, and a Florida researcher says hard economic times may be to blame…

“To have a shark attack, you have to have humans and sharks in the water at the same time,” Burgess said. “If you have a reduction in the number of people in the water, you’re going to have a reduction in the opportunities for people and sharks to get together.”