Washington, D.C. ? Overfishing of powerful sharks – a top predator in the ocean – may endanger bay scallops, a gourmet delicacy.

With fewer sharks to devour them, skates and rays have increased sharply along the East Coast and they are gobbling up shellfish, particularly bay scallops, researchers report in today’s issue of the journal Science.

Ecologists have known that reducing key species on land can affect an entire ecosystem, but this study provides hard data for the same thing in the ocean, said lead author Charles H. Peterson of the Institute of Marine Sciences at the University of North Carolina.