Quantcast

Climate Change May Stimulate the Chesapeake’s Blue Crab Population

Climate
The Washington Post / Contributor / Getty Images

By Amy McDermott

Jason McElwain isn't afraid of a pinch. He reached calmly into a basket of live crabs one Friday this June, and kept his cool even when a claw clamped down hard on his finger. "You get used to it after a while," he said, then yanked the crab off and tossed it into a plastic bin.


McElwain is a deckhand at Cantler's Riverside Inn, a crab shack nestled along a cove in coastal Maryland. He stood on the restaurant's dock, sorting blue crabs still damp with saltwater from the nearby Chesapeake Bay. Up a slope from McElwain, Cantler's patio buzzed with the afternoon rush. Young waitstaff shuttled plates of steamed crabs from the rustic indoor kitchen and bar, out to patio tables overlooking the water. The crew laughed and flirted like camp counselors in the salty, humid air.

Cantler's is a local institution, and so is blue crab. It's the Chesapeake's most valuable fishery by far, worth $54.5 million in 2016. Summer means crab cookouts in the backyard, and crowded crab shacks like Cantler's. On the highway, cars sport bumper stickers shaped like blue crabs and patterned with the Maryland flag. Time will tell if the summer love can last. The Chesapeake Bay faces major climate change impacts this century.

Blue crabs are one species poised to do well, said Anson "Tuck" Hines, director of the Smithsonian Environmental Research Center in Edgewater, Maryland. But certainty is elusive, because there are so many factors that could affect crabs in the bay. "We know the trends for some of these things," Hines said, "but how they're all interacting is very difficult." If climate change does end up bad for blue crabs, the whole region will feel a pinch.

Growing Opportunity

Way out beyond Cantler's dock, down in the murky water of the Chesapeake, blue crabs shuffle through the gloom, digging up clams and worms along the soft bottom. From spring to fall they grow and mate while the water is warm, then hibernate in winter.

Crabbing season lasts as long as the heat, assuming the population is a healthy size. Fishermen normally haul in their gear in late autumn, when the cold turns the crustaceans too lethargic to crawl into traps. But the season could stretch longer this century, as the bay warms by roughly 4 to 11 degrees Fahrenheit. Chesapeake crabbers already supply up to a third of the blue crabs eaten in the U.S. The number could rise with water temperatures.

"As the climate warms, crabs here in the Chesapeake Bay would grow continuously throughout the year," said fisheries scientist Thomas Miller, director of the Chesapeake Biological Laboratory in Solomons, Maryland. They'd "become available to the fishery year-round."

For crab shacks like Cantler's, a longer season would mean cheaper prices and higher-quality meat, said general manager Bruce Whalen, who's worked at the restaurant for 18 years. He orders blue crabs from the Gulf of Mexico over winter, but would prefer local all year.

"It'd be a great thing," Whalen said. The season's already "been stretching longer-and-longer. We've gotten crabs through December the last couple years."

A Big But

Year-round crabbing may be the future. Or, maybe not, said the Smithsonian's Hines. He's spent 40 years studying crabs, and seen his share of foregone conclusions turn out to be wrong.

The Chesapeake's blue crab fishery seemed untouchable at the start of Hines' career. But in the early 1990s, overfishing decimated the population. Maryland and Virginia lost more than $640 million in a collapse that was ultimately declared a federal disaster. That too seemed unthinkable, until it happened.

The problem with predicting the future is that climate change hits the whole bay, not just one species in isolation, Hines said. Scientists can plunk a blue crab in a tank, warm up the water and observe a happy specimen, but that misses a lot. Blue crabs don't live alone out in the wild, and warmer water isn't the only climate-related issue heading for the Chesapeake.

Consider the Baltic clam, another denizen of the bay, and one of the blue crabs' favorite foods. The crabs may like hot water, but the clams don't. They're a cold-water species at the southern end of their range, and could disappear if the bay gets much warmer.

For blue crabs, the future is suddenly less assured. Crabs could lose an important food supply if the Baltic clams go. Then again, other tasty clams might move in to take the Baltic's place, Hines said. Nobody knows how species interactions will change, and if crabs will ultimately win or lose.

Warmer water isn't the only factor to consider. Water chemistry is also expected to change, by becoming more acidic and more variably salty over time. How crabs will respond remains unclear. Overall, rising temperatures will speed up life in the Chesapeake, with a longer growing season, Hines said. "That will generally be better for blue crabs," he explained, "but other factors may come into play too, so it's hard to know."

With their hard shells and pinching claws, blue crabs look rough-and-tumble enough to ride the tides of change. Up on Cantler's patio, the crabs' place in Chesapeake culture seemed just as hardy. Heaping plates of the crustaceans crowned each lunch table, where eager diners cracked into shells and tore claws from carapaces. Crabs were steamed in water hot enough to turn a blue shell bright red.

It's fitting, then, that a hotter Chesapeake looks good for blue crabs. But just like Cantler's diners, climate change could ultimately rip them apart.

Related Articles Around the Web
From Your Site Articles

    EcoWatch Daily Newsletter

    David Gilmour performs at Anfiteatro Scavi di Pomei on July 7, 2016 in Pompei, Italy. Francesco Prandoni / Redferns / Getty Images

    David Gilmour, guitarist, singer and songwriter in the rock band Pink Floyd, set a record last week when he auctioned off 126 guitars and raised $21.5 million for ClientEarth, a non-profit environmental law group dedicated to fighting the global climate crisis, according to CNN.

    Read More Show Less
    U.S. Secretary of Agriculture Sonny Perdue speaks during a forum April 18, 2018 in Washington, DC. Alex Wong / Getty Images

    The Trump administration ratcheted up its open hostility to climate science in a move that may hide essential information from the nation's farmers.

    Read More Show Less
    Sponsored

    Zero Waste Kitchen Essentials

    Simple swaps that cut down on kitchen trash.

    Sponsored

    By Kayla Robbins

    Along with the bathroom, the kitchen is one of the most daunting areas to try and make zero waste.

    Read More Show Less
    Protestors and police stand on ether side of railway tracks. dpa / picture-alliance

    Police have cleared 250 climate activists who stayed overnight at the Garzweiler brown coal mine in western Germany, officials said Sunday.

    Read More Show Less
    Cecilie_Arcurs / E+ / Getty Images

    By Megan Jones and Jennifer Solomon

    The #MeToo movement has caused profound shake-ups at organizations across the U.S. in the last two years. So far, however, it has left many unresolved questions about how workplaces can be more inclusive and equitable for women and other diverse groups.

    Read More Show Less
    Sponsored
    Cigarette butts are the most-littered item found at beach clean ups. John R. Platt

    By Tara Lohan

    By now it's no secret that plastic waste in our oceans is a global epidemic. When some of it washes ashore — plastic bottles, plastic bags, food wrappers — we get a stark reminder. And lately one part of this problem has been most glaring to volunteers who comb beaches picking up trash: cigarette butts.

    Read More Show Less

    Andrea Rodgers, second from the right, takes notes during a hearing in the Juliana v. U.S. case before the 9th Circuit Court of Appeals in Portland, Oregon on June 4. Colleague Elizabeth Brown sits to her left, while colleague Julia Olson sits on her right, with co-council Philip Gregory on Julia's right. Robin Loznak / Our Children's Trust

    By Fran Korten

    On June 4, Andrea Rodgers was in the front row of attorneys sitting before a three-judge panel of the 9th Circuit Court. The court session, held in Portland, Oregon, was to determine whether the climate change lawsuit (Juliana v. United States) brought by 21 young plaintiffs should be dismissed, as requested by the U.S. government, or go on to trial.

    Read More Show Less
    Seventy Extinction Rebellion protesters were arrested outside The New York Times building Saturday. SCOOTERCASTER / YouTube screenshot

    Seventy Extinction Rebellion protesters were arrested outside The New York Times building Saturday as they demanded the paper improve its coverage of the climate crisis, Reuters reported.

    Read More Show Less