Authors of a new Natural Resources Defense Council report said the results prove that critically overfished species can be rebuilt, even from very low levels, when Mother Nature is given a chance to recover. That's good news in a world where rampant overfishing is a critical concern.

"This demonstrates that when we trace the historic arch of these fisheries in which rebuilding requirements were put in place 15 years ago, we see real positive news. We see populations that were depleted or in decline turned around and rebuilt or well on their way to rebuilding," said principal author Brad Sewell.

"It's not 100 percent. It's two-thirds, so it's not unbridled good news but it does show the effectiveness of