What Will it Take to Stop Overfishing? Complete Collapse

"I was shocked and disturbed by how consistent these trends are — beyond anything we suspected," Worm said.

While the study focused on the oceans, concerns have been expressed by ecologists about threats to fish in the Great Lakes and other lakes, rivers and freshwaters, too.

Worm and an international team spent four years analyzing 32 controlled experiments, other studies from 48 marine protected areas and global catch data from the U.N. Food and Agriculture Organization's database of all fish and invertebrates worldwide from 1950 to 2003.