The blue crab stock shows no sign of rebounding from near-record lows that have persisted in recent years and the Bay states may want to take faster action to reduce harvests, a new report suggests.
The annual blue crab advisory report of the Chesapeake Bay Stock Assessment Committee calls the current situation “risky” and warns that the population could be vulnerable to a stock collapse if the wrong combination of factors come together.
Derek Orner, a biologist with the National Oceanic and Atmospheric Administration’s Chesapeake Bay Office, who chairs the CBSAC, said multiple surveys continue to show that the blue crab stock remains low, with no sign of recovery.
The longer the stock is reduced, he said, the more susceptible it is to a range of impacts that could send the biomass to even lower levels.
“The bottom line really shows we’re concerned,” Orner said. “The committee didn’t come out and say the stock has crashed. But the population is at a low level, and we don’t know what is going to happen. Is it is going to rebound? Or is it going to continue to go down?”
The report, and whether efforts to reduce the fishing pressure should be sped up, is expected to be discussed by the Bi-State Blue Crab Advisory Committee when it meets in mid-June.
That committee, after two years of meetings, last December recommended that fishing pressure be reduced 15 percent over three years to protect the crab population. This year, the states took the first step toward that goal, acting to reduce the catch by 5 percent.
The advisory committee, in an effort to coordinate management for the most valuable Chesapeake fishery, last fall adopted the first-ever Baywide spawning stock threshold, which represents the minimum allowable blue crab stock that can sustain a fishery. The threshold seeks to ensure that the crab spawning stock biomass does not drop below 10 percent of what it would be in an unfished population.
The committee also established a more conservative target that is intended to allow more crabs to survive spawning age and provide a margin of safety for the population. The target would maintain the spawning stock biomass at 20 percent of an unfished spawning population.
Scientists say the blue crab stock has been at the threshold for several years. Achieving the target would require about a 15 percent reduction in harvest from recent years.
“We have a threshold, we have a target. We have an action plan. Now the question is, do we have the time?” said Ann Swanson, executive director of the Chesapeake Bay Commission, which represents the Bay state legislatures and created the Bi-State Blue Crab Advisory Committee to better coordinate crab management.
The blue crab is the most valuable remaining commercial fishery in the Bay. But last year’s catch of 51 million pounds was below the average of 75 million.
The stock assessment committee’s report, which each year analyzes multiple blue crab surveys to determine the overall status of the crab stock, found most indices either the same or worsening.
It concluded that there has been a declining trend in reproduction in recent years, and that the spawning stock has decreased since the mid-1990s.
It also said that the number of 1-year-old crabs, the main part of the reproducing population, is near its 1968 level, which was the lowest ever observed in the Bay.
That, coupled with other indices that have remained below average for years, caused the new report to say that “current management may be risky” although it stopped short of recommending that the states speed up action.
“From a scientific standpoint, you would rather see modifications in the regulations within two years as opposed to three because it would more quickly benefit the stock,” Orner said. “But we didn’t have the 100 percent consensus that yes, we need to do that.”
Adding to the concern, Orner also said new research suggested that fishing mortality on the blue crab population is higher than previously thought. But, he added, that work has not yet been fully peer-reviewed by other scientists and its findings were not included in the report.
Scientists have expressed concern that the crab population is so low that it leaves managers with little margin for error.
Female blue crabs migrate toward the mouth of the Bay in late summer to spawn, and each can produce millions of larvae. The larvae leave the Bay and swim in coastal waters for several months before returning to the Bay. Climactic conditions along the coast during that period largely determines the number of larvae that return to the Chesapeake and are “recruited” into the population.
But if a reduced population were combined with poor environmental conditions, it could lead to a stock collapse because of recruitment failure, the assessment committee’s report said.
Several scientists have compared the situation to “skating on thin ice.”
Bill Goldsborough, senior scientist with the Chesapeake Bay Foundation and a member of the Bi-State Blue Crab Advisory Committee, said that the risk to the stock is also higher today than it was in 1968 because the Bay is in poorer condition.
“We have a very different Bay,” he said. “We don’t have anywhere near the water quality, and nowhere near the acreage of grass beds.”
The advisory committee, which included state regulators, environmentalists, watermen, lawmakers and industry representatives, reached consensus on its recommendation in December.
But the proposed reductions ran into sharp criticism from some watermen in both states, who had already endured a spate of other regulations aimed at protecting the blue crab in the past decade.
The Virginia Marine Resources Commission, after earlier delays, approved its regulations April 24. Its actions closed the crab pot and peeler pot fishery on Wednesdays between June 6 and August 22. The fishery was already closed on Sundays. The commission also put new daily limits on the winter crab dredge fishery.
For licensed recreational crabbers, the commission set daily catch limits of one bushel of hard crabs and two dozen peeler crabs. Previously, there had been no limits on recreational crabbing.
The same day that Virginia acted, the Maryland Administrative, Executive and Legislative Review Committee refused to adopt proposed regulations on an emergency basis — something that would have let them take immediate effect.
After that, Gov. Parris Glendening announced he would impose new crabbing restrictions, but that move can’t take effect before July 23. To make up for the late implementation, the state plans to close the crabbing season at the beginning of November, a month early.
The new regulations limit watermen to eight-hour workdays and require that they take off one day a week. Earlier, the General Assembly also approved new license requirements and catch restrictions for recreational crabbers.
Before either state acted, the Potomac River Fisheries Commission in late March voted to shorten its crab season by a month, reduce the number of crab pots allowed per boat and impose restrictions on recreational crabbers.
Overall, the regulations were intended to achieve roughly a 5 percent reduction in fishing pressure this year in each jurisdiction.
Combined, their efforts constitute the first Baywide effort to manage the crab catch. The catch has historically been managed independently in Virginia, Maryland and the Potomac River.
Ultimately, scientists and fishery managers hope that moving toward the lower catch target will not only add a margin of safety to management, but also improve the value of the fishery. By allowing more crabs to survive, it should increase the number of larger, more valuable crabs in the Bay.
Those larger crabs would also disproportionately increase the spawning potential of the population, as older crabs produce more young than younger ones.
But in adopting its “action plan” for blue crabs last year, the Bi-State Blue Crab Advisory Committee acknowledged that other factors affect the crab as well, and it called for greater efforts to improve water quality and restore grass beds around the Bay.
Grass beds provide critical shelter for young crabs, but cover only a fraction of their historic acreage in the Bay.
During public hearings, many watermen expressed frustration with facing increasingly stringent regulations while they said too little was being done to control nutrients and sediment that foul water quality and destroy grass beds. “We’re doing little things here and there [about nutrients] but nobody is doing enough,” Larry Simns, president of the Maryland Waterman’s Association, said at one of the hearings.
Copies of the Bi-State Blue Crab Advisory Committee’s report, “Taking Action For The Blue Crab: Managing and Protecting the Stock and its Fisheries,” are available for the Chesapeake Bay Commission, 410-263-3420. It is also available on the commission’s web site, www.chesbay.state.va.us
Copies of the Chesapeake Bay Stock Assessment Committee’s “2001 Blue Crab Advisory Report” are available from the NOAA Chesapeake Bay Office, 410-267-5660. It is also available on the office’s web site, noaa.chesapeakebay.net