Bay’s blue crab population grows

Spawning-age females double, survey finds

The Chesapeake Bay blue crab population increased by 35 percent over the last year, according to a survey conducted by the Maryland Department of Natural Resources.

The 2016 Blue Crab Winter Dredge Survey results reveals the bay’s crab population is 553 million. The annual survey, conducted by DNR and the Virginia Institute of Marine Science since 1990, is the primary assessment of the Chesapeake Bay’s blue crab

population.

“All indications [are] that they have doubled — they are a bit more abundant than last year,” said Tommy Zinn, president of the Calvert County Watermen’s Association.

The nonprofit association’s goal is to improve working conditions for those making a living from the water, as well as to improve water quality and the environment. Zinn’s personal goal is to help people be good stewards of water.

Zinn attributes the increase in numbers to a milder winter with warmer water temperatures and the restrictions on crabbers, including limiting the hours they can work. Crab potters can only work nine hours a day and trot liners can work 10 hours a day. They are required to take at least one day off each week.

“We don’t target the females until fall. We get males all summer,” said Zinn.

According to a news release from DNR, this year’s improvement was seen in both male and female crabs.

The number of female blue crabs of spawning age, or those capable of releasing eggs, nearly doubled from 101 million to 194 million. Female blue crabs are key to restoring the crab population in the bay. Despite the increase, spawning-age female crabs remain below the 215 million target but above the minimum threshold established in 2011.

The number of adult male crabs more than doubled from 44 million to 91 million. This is the second-highest level since 1995, according to the state agency.

This growth in crab population is believed to be the fourth-highest level in two decades. Last year, there was a 38 percent increase.

“The highly variable nature of the blue crab population means that we must maintain a degree of caution in considering management adjustments,” Chesapeake Bay Stock Assessment Committee Chairman Glenn Davis said in a press release.

The Chesapeake Bay Stock Assessment Committee includes scientists and experts who review the results of the annual blue crab survey and harvest data in order to develop management strategies for Chesapeake Bay jurisdictions, including Maryland and Virginia. The committee plans to release a full analysis this summer.

According to DNR, crabs tend to bury in the mud during the cold winter months, making it possible for scientists to develop accurate estimates of the number of crabs. Specifically, biologists use dredge equipment to capture, measure, record and release blue crabs at 1,500 sites throughout the bay from December through March.