Unusually frigid temperatures this winter caused a nearly one-third drop in the Chesapeake Bay’s blue crab population, but officials said Tuesday the adult population is self-sustaining and they are considering easing the catch limits put in place three years ago. The Maryland Department of Natural Resources’ annual winter dredge survey shows the crab population is at 460 million, down from 658 million in last year’s survey. In 2010, the population increased by 67 percent from 393 million in 2009.

The cold winter wiped out 31 percent of the Bay’s adult crabs, up from 11 percent last year.