Scientists have notched upward their concern about the Bay's blue crab population, warning in their latest report that agencies need to begin crafting new plans to rebuild the Chesapeake's most valuable fishery.

The report from the Chesapeake Bay Stock Assessment Committee, which includes scientists and fishery managers from around the Bay, said the crab population remains at low levels and that this year's crab catch will almost certainly exceed the committee's overfishing threshold.

Scientists say a single year of overfishing is not necessarily a cause for alarm.

"One year of bouncing above that line does not a catastrophe make," said Lynn Fegley, a fisheries scientist with the Maryland Department of Natural Resources and chair of the stock assessment committee. But if crab abundance does not start to increase, she added, "then we're compounding the problem."

The committee's report predicted that when this year's harvest data is compiled, it will show that about 63 percent of the Bay's legal size crabs were harvested. The overfishing threshold-the percentage of adults that can be sustainably taken-is 53 percent. In 2006, the exploitation rate was 50 percent.

The jump is not caused by an unusually high catch-scientists expect the 2007 harvest to be about 48.7 million pounds, roughly the same as the 48.9 million pounds landed in 2006.

The problem is that last year's reproduction, as measured in the annual Baywide winter dredge survey, was the second lowest since the survey began in 1989. The same level of fishing on a smaller population pushes the exploitation rate higher.

Blue crabs have tremendous reproductive capability; a single female can produce up to 8 million eggs. That creates the possibility that this winter's survey could find an upward tick in reproduction, in which case the 2008 harvest could fall below the overfishing threshold.

"We'd all love to see recruitment have a banner year and not be in this situation next year," said Derek Orner, a fisheries biologist with the National Oceanic and Atmospheric Administration's Chesapeake Bay Office. "But the way everything is pointing right now isn't good."

Part of the reason for concern is that the blue crab stock has showed no real sign of rebounding. After a precipitous drop in the crab population in the late 1990s, states imposed regulations to reduce fishing pressure. Those actions are credited with halting the population drop, but instead of increasing, crab abundance stabilized at a level well below the long-term average.

No one is sure why crabs have not bounced back. Some say predation on blue crabs may have increased over time, perhaps as a result of the robust striped bass population. Other possibilities include changes in local ocean currents, which influence the survival of larval crabs, or the decline of underwater grasses in the lower Bay, which juvenile crabs use as shelter.

Whatever the cause, scientists have long warned that a low stock size makes it particularly vulnerable to natural fluctuations, such as last year's poor reproduction.

As a result, the committee's annual advisory report recommends that agencies begin making plans for the next steps in management. Specifically, it called on agencies to "work with stakeholders to define goals for the blue crab fisheries and subsequently develop a comprehensive management plan for achieving these goals."

It added, "This plan should include specific management actions for rebuilding a depressed stock, for promoting sustainability and for ensuring blue crabs do not become overfished."

Although the committee has expressed concern about the low abundance of blue crabs for years, this was the first time its report specifically called for the development of new blue crab management plans.

"We want to start having a collaborative effort with the people who have the largest economic stake in this, and that is the watermen," Fegley said. "We are not asking them to tell us what to do. But we are asking them to participate in a process because we would like to get out ahead of this. We'd rather be proactive than reactive."

Committee members said the plan should outline management actions to be taken if, for example, overfishing continues to take place, or if crabs fall below a certain level of abundance. The idea, they say, is to have actions ready to go if those thresholds are reached.

Larry Simns, president of the Maryland Watermen's Association, said that's a good idea. In the past, he said watermen felt regulations were rushed through that were unduly harmful.

"We need to start ahead of time and think of what we might need to do," he said. "Right now, we're not in a position that we need to do anything. But if it gets any worse, we need to have something ready so we know what we're going to do. We want it to be worthwhile and not disastrous to the watermen."

Some preliminary efforts are already under way. The Virginia Marine Resources Commission this year convened a panel of experts, including scientists from Maryland and other states, to review all of its blue crab fishing regulations.

The idea is to identify the regulations that overlap, are ineffective, or need to be modified to achieve desired results, and then to recommend possible changes, said Robert O'Reilly, the VMRC's deputy chief of fisheries management and a member of the stock assessment committee.

One issue they are looking at is how to address "latent effort." Right now, not all fishing licenses are being used. If all that potential fishing effort were to suddenly be exerted, fishing pressure on blue crabs could increase sharply.

Any recommendations could be sent to stakeholder groups and ultimately help shape future regulations.

"In the past, it was almost after the fact that the stakeholders and the industry was provided the opportunity to provide input," O'Reilly said. "Here's an opportunity to have that same kind of input from various concerns, and in the beginning stages."

Some believe a comprehensive overhaul of the fishery is needed-not just revising existing regulations- to benefit both crabs and fishermen.

Current regulations are complex and regulate the days and number of hours blue crabs can be fished, where they can be fished, the types and amounts of gear that can be used for different types of crabs-soft, hard and peelers.

Ultimately, those regulations are designed to make fishing inefficient as a means of controlling the harvest, said Bill Goldsborough, a fisheries scientist with the Chesapeake Bay Foundation.

Instead, he said, management agencies should look at alternative management schemes, such as a "rights based" system in which the number of commercial fishermen would be limited, and each would be assigned a level of fishing effort-such as the number of crab pots that could be fished. Those rights could be bought and sold among fishermen in ways that ensure the blue crab is not overfished, but also ensure that those who remain in the fishery can still make a living.

Such alternative management scenarios were being suggested by economists to a special Bi-State Blue Crab Committee created by the Chesapeake Bay Commission in the late 1990s. That committee's work led to new actions that cut fishing pressure by 15 percent starting in 2000 and stabilized the population. But the committee was disbanded by the states before alternative fishing scenarios were fully explored.

Those alternatives were intended to promote larger crabs in the fishery that would have been more valuable to fishermen, and have more reproductive capacity to help sustain the stock.

"We were on the cusp of considering some fundamental changes in the way crabs are managed, and that's when the whole thing was disbanded," Goldsborough said. "The only way you get something like that is if you have some kind of formal bi-state deliberation. This nipping around the edge just isn't going to cut it anymore."

Tom Miller, a fisheries scientist with the University of Maryland Center for Environmental Science and a member of the stock assessment committee, agreed that identifying long-term goals were as important as identifying abundance levels that would trigger further action.

The crab fishery is particularly difficult to manage because it runs most of the year and involves multiple types of gears and sectors which often target different portions of the stock.

Depending on what people want, Miller said it's possible watermen could be allowed to take more crabs with less regulations for shorter periods of time, rather than fewer numbers of crabs with more regulations over a longer period of time. But those decisions require managers and stakeholders to agree on a common goal for Bay blue crabs-and the fishery they support.

"These are all trade-off questions that there is not a scientific answer to," Miller said. "It doesn't matter to the stock whether 1,000 crabs are caught in one day, or 100 crabs are caught for 100 days. It is the same impact. Those are policy and socio-political questions. And I'm glad I don't have to solve them, they're much harder."

Worrisome Signs

While the sharp drop seen in the blue crab stock in the late 1990s has halted, the overall population has shown little evidence of a rebound. Among the worrisome signs cited by the Chesapeake Bay Stock Assessment Committee in its 2007 blue crab advisory report:

  • The 2006 harvest of 48.9 million pounds was among the lowest reported since 1945.
  • Recruitment (a measure of reproduction) in the 2006-07 winter dredge survey was the second lowest since the survey began in 1989.
  • The number of spawning age females in the winter dredge survey was below the survey's long-term average.
  • The density of adult and juvenile crabs found by the survey in recent years is less than half of densities found in the early 1990s.

Overfishing vs. Overfished

When this year's blue crab harvest figures are collected, scientists believe it will show that overfishing was taking place. But overfishing, they note, is not as serious as being overfished-which they say is not taking place.

An overfished population is one in which the absolute stock size drops to a point where it may not be able to maintain itself. Tom Miller, a fisheries scientist with the University of Maryland Center for Environmental Science, compares being overfished to being bankrupt. "You don't have enough money in your account to meet all your obligations," he said. "The overfished definition means there just aren't enough crabs around to meet what we think are the obligations of the stock." Those obligations may include not only maintaining the population, but also fulfilling ecosystem roles.

A 2005 blue crab stock assessment set the overfished threshold at 86 million age 1-plus blue crabs, as estimated from the annual winter dredge survey. According to the stock assessment, the population has hit that level only once-in 1999. Last winter's dredge survey estimated 122 million age 1-plus crabs in the Bay.

Overfishing occurs when the rate of fish harvest exceeds the rate needed to sustain the stock over time. If overfished is like being bankrupt, then overfishing means you're spending too much, Miller said. "You can have money in your bank account and be spending it too fast, but as long as you don't spend it too fast for too long a period, you are probably are going to be all right," he said. "If you continue spending it too fast over several years, then you increase the risk of becoming bankrupt. If you overfish, you increase the risk of becoming overfished."

In the case of the blue crab, the 2005 stock assessment set the overfishing threshold at 53 percent of the adult population. The threshold has been exceeded several times in recent years, including 1999, 2000, 2001, 2002 and 2004.