Fisheries

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Saving the River Herring: Don’t Let the Good Die Young

Wednesday, November 26th, 2014

by Kristen Minogue

Image: Alewives, a species of River Herring. (Credit: Geoffrey Gilmour-Taylor)

Alewives, one of two species of River Herring in Chesapeake Bay. (Geoffrey Gilmour-Taylor)

It’s no secret that River Herring are in trouble. There was a time, back in the 1950s, when Maryland fishermen regularly pulled in 4 million pounds or more a year of the silver fish. Then something mysterious happened. Herring harvests generally fluctuate from year to year. But in the 1970s, they fell and never came back up. For the last four decades, commercial fishermen in Maryland have been lucky to catch a few hundred thousand a year. Now they catch none.

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Oysters and the Chesapeake’s Jellyfish Wars

Tuesday, September 30th, 2014

Image: Jellyfish Chrysaora quinquecirrha (Credit: Lori Davias)

Jellyfish Chrysaora quinquecirrha (Lori Davias)

by Kristen Minogue

Every summer, the food web in Chesapeake Bay gets jostled around as two plankton-eating predators jockey for power: comb jellies and jellyfish. Most smaller species don’t have a stake in the battle—both predators eat zooplankton and fish eggs, after all. But for young oyster larvae, the victor could make the difference between being protected civilians or collateral damage.

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Banishing the Ghosts on the Bay Floor

Tuesday, August 12th, 2014

by Kristen Minogue

Image: A ghost pot pulled out of Chesapeake Bay. (Credit: Michael Reid/Southern Maryland Newspapers)

A ghost pot pulled out of Chesapeake Bay. (Michael Reid/Southern Maryland Newspapers)


Every year, thousands of crab pots disappear, their lines snapped by violent storms or severed by the propellers of passing boats. Cut off from the buoys that once marked their presence, they become “ghost pots,” lost at the bottom of the Chesapeake.

But ghost pots aren’t dead pots. They’re still quite capable of trapping crabs, including mature females undergoing their spawning migration. And with no one to retrieve them, crabs too large to escape are condemned to a slow death by starvation. This often has the eerie effect of luring even more animals to their demise, says Laura Patrick, aquatic ecologist at the Smithsonian Environmental Research Center (SERC).

“The crabs are just going in and they’re dying,” Patrick says. “And one of the problems is that the dead animals that are in there can be bait for new crabs to come in. So it’s kind of a self-baiting pot.”

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Virtual crabs could help real recovery

Friday, August 8th, 2014

by Sarah Hansen

Image: Julie Sepanik holds up a large male blue crab caught in the Rhode River. (Credit: SERC)

Julie Sepanik holds up a large male blue crab caught in the Rhode River. (SERC)

No one disputes that blue crab numbers in Chesapeake Bay are low.  There is much discussion, however, about what to do to fix the problem.  Smithsonian Environmental Research Center intern Julie Sepanik is working with SERC postdoctoral fellow Matt Ogburn to develop a computer model that will help improve our understanding of blue crab population dynamics in the Bay. The model works to identify where female crabs mature in the Bay and track their migration to lower Bay spawning areas. Ultimately, they hope the model will help inform decisions about preserving habitat and restoring the population.

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Blue Crabs Need (More Than) A Few Good Men

Thursday, July 24th, 2014

by Kristen Minogue

Photo: Male blue crabs can mate with multiple females. But with fewer men to go around, their female partners are left with less sperm to reproduce. (Credit: SERC)

Male blue crabs can mate with multiple females. But with fewer men to go around, their female partners are left with less sperm to reproduce. (SERC)

The practice of selectively fishing male blue crabs in the Chesapeake—intended to give females a chance to reproduce—may have a hidden cost. A Bay without enough males could reduce the number of offspring females produce, ecologists at the Smithsonian Environmental Research Center found in a paper published in the July issue of Marine Ecology Progress Series.

Maryland and Virginia began reducing the harvest of female crabs by commercial and recreational watermen in 2008, the year officials declared the blue crab fishery a federal disaster. Since then, the crabs have shown signs of a shaky recovery. But a lasting comeback hinges on females producing enough offspring to sustain the population.

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Thousands of Tags Could Unearth Clues to Saving Blue Crabs

Tuesday, July 8th, 2014

by Kristen Minogue

Photo: Technician Laura Patrick holds up a blue crab caught in the Rhode River. (Credit: SERC)

Technician Laura Patrick holds up a blue crab caught in the Rhode River. (SERC)

This summer and fall, biologists at the Smithsonian Environmental Research Center are looking to tag 10,000 blue crabs in Chesapeake Bay. They’re pursuing the project in spite of the two-year slump the crabs have suffered in the latest reports of the Chesapeake Bay Stock Assessment Committee. They’re hoping some of those crabs will help answer two unresolved questions on the path to recovery: the role of recreational crabbing, and the struggling population of adult females.

Every year watermen on Chesapeake Bay haul in between 40 and 110 million pounds of blue crabs on trotlines or in crab pots. The vast majority come from commercial watermen who rely on the crustaceans for their livelihoods. But recreational crabbers also take their share, and today no one knows exactly how large or small that share is.

“We really have very little idea how big the recreational fishery is now,” says Matt Ogburn, a postdoc at SERC’s Fish and Invertebrate Ecology Lab.  Click to continue »

Curiouser and Curiouser: A Motor at the Front?

Tuesday, February 18th, 2014

by Heather Soulen

A Chesapeake Bay NOAA mullet skiff. Note the moter near the bow. (SERC)

A Chesapeake Bay NOAA mullet skiff. Note the motor near the bow. (SERC)

With its motor located near the bow (front) of the boat, the modern-day mullet skiff could have been a character in Lewis Carroll’s novel “Alice’s Adventures in Wonderland.” Similar to the unpunctual rabbit, vanishing cat and hookah smoking caterpillar, it seems illogical…or does it?

Commercial mullet fishing in 1955. (Monts de Oca, C. Morris courtesy of State Archives of Florida)

Commercial mullet fishing in 1955. (Monts de Oca, C. Morris courtesy of State Archives of Florida)

In the early 1900s, the mullet skiff was originally designed for use in the commercial mullet fishery of the south. Popular for its simple construction, flat-bottom dory style hull with vee entry, and rounded stern (back) design, the mullet skiff was ideal for operating in shallow waters while carrying heavy loads of fish. However, during Prohibition, entrepreneurs souped up their mullet skiffs with straight-8 engines (precursor V8s) to run rum from the Bahamas and Cuba to the states. Since then, many mullet skiffs have undergone less scandalous modifications and have evolved to have an outboard motor in a well near the bow.

Why place a motor here? For three important reasons: 1) It places the motor higher in the water for maneuvering in shallow water, 2) it leaves the stern (back) open to work a net, and 3) it eliminates the risk of net entanglement in the propeller. So, with “the wrong end in front,” the mullet skiff was the perfect choice for the near-shore predator study our field crew conducted this summer throughout the Chesapeake Bay.

Predators of the Not-So-Deep

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Blue Crabs Come to Life in 3D

Monday, January 6th, 2014

by Karen McDonald

Image capture of the blue crab from Smithsonian X3D. (Credit: Smithsonian Institution)

Image capture of the blue crab from Smithsonian X3D. (Credit: Smithsonian Institution)

Can’t get to water to fish up a blue crab? Want to teach about blue crabs and Smithsonian research but can’t make it to SERC or the Chesapeake Bay? Landlocked, but you want students to measure a crab’s carapace and learn about its life cycle? SERC has the answer: a virtual blue crab.

The blue crab is just part of the new Smithsonian X3D—a revolutionary way for visitors to interact with Smithsonian collections and research. In November 2013 the Smithsonian launched the Smithsonian X3D (beta) program, which allows visitors to flip, rotate and zoom in on digitized 3D images of objects from across the Institution. Right now they can explore more than 20 objects, including Amelia Earhart’s flight suit, the Wright brothers’ plane and a life mask of Lincoln.

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From the Field: High and Dry in Chesapeake Bay

Thursday, December 19th, 2013

How an invasive marsh plant could leave many fishes and invertebrates homeless, hungry and vulnerable to predators

Ecologist Heather Soulen (right) wades through a patch of Phragmites in Chesapeake Bay. (SERC)

Ecologist Heather Soulen (right) wades through a patch of Phragmites in Chesapeake Bay. (SERC)

by Heather Soulen, SERC marine ecology lab technician

It’s no surprise that invasive species can dramatically alter an ecosystem. Often, invasive species outcompete native species and disturb ecosystems that have not evolved to handle the new intruder(s). One such invader is the introduced common reed (Phragmites australis australis). Introduced Phragmites alters native plant communities that native animals use. Over the past several decades, native marshes containing plants such as marsh elder, saltmeadow hay, black needlerush, sea lavender, cordgrasses, threesquares and bulrushes have fallen to introduced Phragmites in the Chesapeake Bay and throughout the Atlantic coast, turning once diverse marshes into a thick monoculture forest.

The Great Marsh Surface Uprising
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Cracking Down on Mercury

Monday, December 9th, 2013

by Kristen Minogue

Ally Bullock, a technician in SERC's mercury lab, draws pore water samples from Berry's Creek. (SERC)

Ally Bullock, a technician in SERC’s mercury lab, draws pore water samples from Berry’s Creek. (SERC)

It isn’t safe to eat the blue crabs from Berry’s Creek.  American eels and white perch are also off-limits. White catfish are permissible, but only once a year, according to a New Jersey advisory for the Newark Bay Complex, where the creek is located. Crabbing in the 6.5-mile stream is illegal and can carry up to a $3000 fine. Waste from a now-defunct chemical processing plant, combined with more than a century of manufacturing, has made Berry’s Creek and its surrounding wetlands hot spots for mercury pollution.

The Environmental Protection Agency calls places like Berry’s Creek “Superfund sites”—a label for abandoned or neglected sites that became dumping grounds for hazardous waste. Some of the highest levels of mercury contamination in the U.S. exist in Superfund sites. Cynthia Gilmour knows this first-hand. As a microbial ecologist at the Smithsonian Environmental Research Center, she has worked in several.  But short of digging up the polluted sediments and dumping them elsewhere (an expensive and ecologically risky proposition), not many methods exist to get rid of the problem.

“If we use the traditional technologies of removing that and putting it in a landfill, we don’t have a wetland anymore,” says Upal Ghosh, an environmental engineer from the University of Maryland, Baltimore County, who works with Gilmour.

This fall, Gilmour and Ghosh explored a new technique: using charcoal to trap it in the soil.

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