The Chesapeake Bay Blue Crab is an omnivore. If a favorite food like worms, plants or baby clams is unavailable, it switches to something else. Maryland's human denizens may want to seriously consider doing that same thing.
That's because the latest news regarding one of Maryland's favorite seafood delicacies isn't good. For the second straight year, the bay's crab population is in decline, with the number of female crabs — the most critical factor for future reproduction — below what biologists regard as safe to maintain the current stock.
This will translate to a reduced crab harvest this summer and likely higher prices at the local restaurant or seafood market as well. And it will almost certainly mean that fishery regulators in Maryland and Virginia will have to further tighten the screws on watermen, particularly those in places like the lower Eastern Shore who are more likely to harvest "sooks," or adult female crabs.
Those watermen, already unhappy with tougher catch restrictions adopted last year, will likely be none too pleased to hear that more are in the works. Some may even argue that big year-to-year variations in the number of crabs is commonplace and not necessarily a cause for alarm.
But it's clear something has fundamentally changed about the Maryland blue crab. Not the life cycle of the crab itself, of course, nor even the nature of the watermen who catch them, but the crab's habitat, which has been altered in a way that scientists are only now beginning to fully understand. The ability of crabs to bounce back from poor spawning years seems to have been greatly compromised by a less hospitable Chesapeake Bay.
This past winter, cold weather may have been a factor in killing more wintering crabs than usual — as much as 28 percent, according to one Maryland estimate. But reproduction has also been poor, and even when there is good reproduction, as happened several years ago, fewer young crabs are surviving into adulthood.
Why? The loss of underwater grasses is likely a big factor, as young crabs have fewer places to hide from predators. So too are large summer "dead zones" where the growth of algae blooms and a resulting loss of dissolved oxygen snuff out plants and animals in the middle of the bay, driving crabs into more shallow waters and denying them food. And then there are the watermen themselves who work harder to catch fewer crabs, a vicious cycle aggravated by the higher prices crabs command when they are scarce.
Make no mistake, blue crabs are not yet an endangered species. The Maryland Department of Natural Resources now estimates that there are 297 million swimming around the Chesapeake, and they are fully capable of staging a comeback in short order. A single female crab produces, on average, 2 million eggs. How many of the resulting larvae remain alive and viable in local waters and not swept out into the Atlantic Ocean is thought to be the single most important factor in the reproductive process and that's largely dependent on timing and the weather.
Marylanders can dine on blue crab this year without guilt, but the danger is that too great a harvest of female crabs could be disastrous, and that's what regulators must avoid. The DNR can't change winds or tides nor wave a wand and clear out the pollution that's caused the loss of bay grasses or created dead zones. But officials can make sure there are enough mature female crabs left in the water to allow the species to bounce back.
Still, merely tightening the belt may not be enough. What Maryland and Virginia ought to do is fundamentally alter the way the fishery is regulated. That means instead of defining the days or hours of watermen or even their daily catch limits, the states should simply decide how big a catch to allow in any given year and divvy it up among the licensed watermen and recreational crabbers as a seasonal quota.
That would not only be a more precise way to prevent overfishing, it would prevent the so-called "tragedy of the commons" that causes a resource to be depleted. Environmentalists have been advocating such a change for years, and it's time action was taken. A system of allocation would not only preserve the prized blue crab, it would do wonders for keeping Maryland's long-suffering watermen in business as well.
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