Environmentalists Try To Determine Gender Ratio Of Crabs

BALTIMORE (WJZ) -- There are new concerns over the Chesapeake Bay crab population. Environmentalists worry that regulations to protect female crabs are causing a sperm shortage from the males.

Tim Williams looks at the new numbers and what they mean for your next crab feast.

In the dating world of crabs, it may take two but the current number of males to females is skewed.

"Male to female sex ratio has actually increased. That is, there are fewer females than males," said Anson "Tuck" Hines, Smithsonian Environmental Research Center.

Results of the latest independent survey census or dredge survey done this winter show the number of female crabs has decreased in abundance for the second straight year while juvenile crabs have increased. The result is confusing fishery managers.

"The ultimate goal of having more baby crabs is to have more adult crabs that are back into the fishery," Hines said.

The new findings are a complete turnaround from recent results. In January, there were three females to every male. We are now closer to the ideal number of eight males to every female.

Since regulations in Maryland, Virginia and the Potomac River currently prohibit overfishing of females, the questions over where the females have gone and the timing of their cycles still remain.

"There's a very narrow window in their life cycle in which they mate and receive all the sperm that they're gonna need and use for their lifetime. If there's not a male fully charged and ready to go at that point, it doesn't happen as effectively," Hines said.

Still, the overall blue crab numbers are good which, in a nutshell, means enough of both sexes to go around.

The latest crab assessment suggests that studying the ratio should be a research priority to understand potential problems with the population in the future.