Maryland carb seasons starts April 1. (Photo by James Buck/The Washington Post)

The majestic Chesapeake Bay blue crab, with its delicious white meat, will soon be available fresh at a restaurant or fish monger near you. April 1 is the start of commercial crab season in Maryland and watermen will be placing their pots and crossing their fingers for a fat catch.

The Chesapeake Bay is the largest estuary in the world. It is fed by numerous rivers flowing down the eastern slopes of the Appalachians, and from the Atlantic Ocean that ebbs and flows through the tidewater area of Virginia. This unique mix of salt and fresh water is what gives blue crabs – callinectes sapidus, translated from Latin means “beautiful savory swimmer” – their mouthwatering taste coveted by chefs and backyard crab-feasters alike.

The weather plays a large role in the crab harvest. Conditions in the bay need to be “just right” – like Goldilock’s porridge. If it’s too cold, too warm, too rainy, too dry, or too windy, the bay’s water chemistry and the health of the crab population will be negatively impacted.

Heavy rains and the influx of too much freshwater can prevent crabs from migrating to their spawning grounds. Strong winds can disrupt the delicate two-tier water circulation, and as a result, the salinity of the bay by mixing fresh water near the surface with saltwater near the bottom.


Blue crabs are sensitive to weather conditions in the Washington region. Too much wind can mix fresh water down to the bottom of the bay. Too much storm runoff can kill off the crabs’ grassy habitat. (REUTERS/Jonathan Ernst)

Excessive heat is no friend of the blue crab, either. The bay is rather shallow, with an average depth of only 21 feet. It is also the southern extent of eelgrass, where many crabs breed and juveniles find protection from predators. During extended periods of warmth, the bay can turn into bathwater and kill off the eelgrass, leaving crabs exposed.

Storm water runoff dumps excess nutrients, sediment and pollution into the bay, which also causes a host of problems for the blue crab. Suspended sediment can decrease visibility and sunlight needed to sustain the crabs’ critical seagrass habitat. An over-abundance of nutrients can cause algae blooms that lead to hypoxia – or deadzones – where dissolved oxygen is absent, along with all life.

Blue crabs face an uncertain future. Once abundant, the crustacean’s population has now declined to a historic low. There are so few of them left that it is possible the “Chesapeake Bay” crab cake listed on the menu is not as advertised – it may have come from somewhere else. A recent study found that out of 90 crab cakes tested at area restaurants, 38 percent contained the DNA of a different species.

Let’s all cross our fingers for “just right” weather and good water conditions this summer, so we can enjoy plenty of beautiful savory swimmers.