![]() ![]() We couldn’t do this work without someone taking measurements every day off the pier. “The data from right off our pier is a unique data set because it is so long. Average daily temperatures have increased 3.2˚F since 1938. From the pier at the Chesapeake Biological Laboratory, water temperatures have been taken by hand at noon from 1938–2012 and by automatic instrumentation from 2012 to 2016. In order to create a model that was directly relevant to the Chesapeake Bay near Solomons, Maryland, they were able to access a long-term (1938-2016) dataset of daily water and air temperature measurements collected right in their backyard in the Patuxent River. The researchers used computer-modeled projections of future temperature from the World Climate Research Programme’s Coupled Model Intercomparison Project to explore how changes in water temperature may impact the overwintering behavior and winter survival of blue crab in the Chesapeake Bay in the next 100 years. “If crabs start moving and feeding year-round, they represent an added predation pressures on the bay’s ecosystem, and we don’t know how the ecosystem will respond,” said Miller. A particularly cold winter could devastate a year-round fishery. It’s a cultural challenge,” said Miller.Ĭlimate change not only signals warming temperatures but also increased variability in temperatures, further complicating wintertime management of the species. However, this challenges the traditional pattern in which waterman fish for striped bass in the spring and crabs in the summer and oysters in the winter-that traditional seasonal rotation of the harvest. ![]() “People will be able to fish for them almost year-round. However, an increase in wintertime crab activity may encourage a lengthening of crabbing season similar to states such as North Carolina and Louisiana, where crabs are active year-round. While this may sound great, don’t stock up on your mallets and Old Bay yet.Ĭrabbing is prohibited December through March in the lower Chesapeake Bay, which has helped in maintaining the population at sustainable levels. “In 100 years, we would expect winter for crabs in Solomons to look more like winter currently looks in southern North Carolina,” said Glandon. Scientists predict that the shortening of winter combined with increases in average wintertime temperatures will cause a significant increase in juvenile blue crab winter survival so that the population behavior comes to resemble that currently observed in the Sounds of North Carolina and further south. Warmer water means they grow faster,” said Hillary Lane Glandon, who conducted this research as a graduate student at the University of Maryland Center for Environmental Science and is now a post-doctoral research associate at the University of North Carolina in Wilmington. “Water temperatures are warming and the crabs are cold blooded so their metabolic rate is directly related to warmer temperature. In recent years, this dormancy period has been becoming shorter, and trends indicate it will become shorter still-and could potentially become nonexistent. Maryland’s blue crabs spend their winters dormant in the muddy sediment at the bottom of the Chesapeake Bay, emerging only when water temperatures near 50° F. Under better circumstances, scientists believe that blue crabs could live as long as 8 years.The blue crab is found along the Atlantic Coast from New England to Argentina. For the survivors, life expectancy in the Chesapeake Bay is estimated at 2 and 1/2 to 3 years (most are harvested before they get any older). As they grow from a larval stage into a recognizable crab, most fall prey to predators. Over the years the harvests of the blue crab dropped and the Maryland Department of Natural Resources has created stricter guidelines for harvesting blue crabs to help increase populations (including raising the legal size from 5 to 5¼ inches and limiting the days and times they may be caught). Blue crabs typically consume thin-shelled bivalves, annelids, fish, plants and nearly any other item they can find, including carrion. The blue crab is an omnivore (eating both plants and animals). The blue crab is native to the western edge of the Atlantic Ocean from Nova Scotia to Argentina. The blue crab's scientific name (Callinectes sapidus Rathbun) translates as "beautiful swimmer that is savory." The name also honors Mary Jane Rathbun, the scientist who described the species in 1896. The Chesapeake Bay is famous for its blue crabs. Maryland designated the blue crab as the official state crustacean in 1989.
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