Chesapeake blue crabs had an unusual rebound after years of decline. Scientists don't know why

After half a decade of worryingly low numbers, the Chesapeake Bay's blue crab population appears to be fighting its way out of a slump. Scientists still have no clear explanation for why, and say the growth deserves cautious optimism.

After half a decade of worryingly low numbers, the Chesapeake Bay's blue crab population appears to be fighting its way out of a slump. Scientists still have no clear explanation for why, and say the growth deserves cautious optimism.