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Chesapeake Bay News: Chesapeake Bay Program


After being discarded, “ghost pots” continue to trap Bay’s blue crabs

More than 145,000 lost or abandoned crab traps may be resting on the bottom of the Chesapeake Bay, according to a recent report from the National Oceanic and Atmospheric Administration’s (NOAA) Marine Debris Program. Once lost, these so-called “ghost pots” can continue to catch crabs, fish and other species, resulting in the loss of an estimated 3.3 million blue crabs each year. Though this makes up a small proportion of the total number of blue crabs in the Bay—estimated at 553 million in 2016—the study suggests that the targeted removal of derelict fishing gear could help boost commercial crab harvest.

Each year, an estimated 600,000 crab pots are actively fished by watermen on the Bay. But whether accidentally lost or intentionally tossed overboard, 12 to 20 percent of these traps are lost each year. Lines connecting traps to buoys can come loose or be cut, strong storms can relocate the gear or pots may simply be abandoned.

This lost fishing gear can continue to “ghost fish,” trapping crabs, finfish and other underwater animals. According to the study, more than 6 million blue crabs are caught—and 3.3 million of those killed—by ghost pots each year. More than 3.5 million white perch and close to 3.6 million Atlantic croaker are also estimated to be trapped each year. And derelict gear can harm sensitive habitats like underwater grass beds and salt marshes as well.

In addition to the environmental impacts of derelict crab pots, the team of researchers—which included experts from the Virginia Institute of Marine Science—looked at how abandoned fishing gear could affect commercial crab harvest. By catching crabs that could otherwise be caught by actively-fished traps, ghost pots can potentially result in a loss of harvest. The study estimates that the removal of derelict pots from 2008 to 2014 resulted in an increased Bay-wide blue crab harvest of more than 38 million pounds—valued at $33.5 million—over the six-year period.

Removing derelict pots from heavily-fished areas could be a cost-effective way to boost harvest and reduce the gear’s harmful ecological effects, the study suggests. Biodegradable escape panels, which are inexpensive and easy to install, are another option that have been successfully tested in the Bay.

The report, Ecological and Economic Effects of Derelict Fishing Gear in the Chesapeake Bay, can be found online.


Photo of the Week: Elizabeth River Project connects community to its river

Robin Dunbar of the Elizabeth River Project conducts a teachers' workshop at Paradise Creek Nature Park in Portsmouth, Virginia. The area surrounding Paradise Creek—a tributary of the Elizabeth River—was once nicknamed "Paradise Lost" because of its close proximity to the former New Gosport landfill. Now, the creek has become a model for urban waterway restoration.

Since 1991, the Elizabeth River Project has worked tirelessly to restore the Elizabeth River, which flows between the cities of Norfolk, Portsmouth and Chesapeake, Virginia, before making its way to the Bay. For years, the river was one of the most polluted in the region. But in recent years, though the river still faces a long road to recovery, improving trends have brought new hope to a waterway once thought to be devoid of life.

In addition to on-the-ground restoration projects, part of the Elizabeth River Project’s mission is connecting with and educating the local community. Initiatives include the River Star Homes, River Star Schools and River Star Businesses programs; the Learning Barge, a 120-by-32 foot barge-turned-classroom; and Paradise Creek Nature Park, which hosts educational programs for both schools and the general public.

Learn more about the Elizabeth River Project.


Image by Will Parson

Stephanie Smith's avatar
About Stephanie Smith - Stephanie is the Web Content Manager at the Chesapeake Bay Program. A native of the Midwest, she received her Bachelor’s in Professional Writing from Purdue University and Master of Science degree from the University of Michigan. Stephanie’s lifelong love of nature motivates her to explore solutions to environmental problems and teach others what they can do to help.


By the Numbers: 458,000

When you imagine fish in the Chesapeake Bay, top predators probably come to mind. But the most important fish in the Bay weighs no more than a pair of playing cards, measures no longer than the width of your hand and is more abundant than any other fish that calls the Chesapeake home.

The bay anchovy is the most abundant fish in the Chesapeake Bay and serves as an important source of food for a diverse set of predators. Image by Ken-ichi Ueda/Flickr.

The bay anchovy (Anchoa mitchilli) can be found in great numbers along the Atlantic coast and in all parts of the Chesapeake Bay. “It is the single most abundant fish on the east coast of North America," said fisheries scientist Ed Houde. “That in itself says something about its importance.”

Because it is such an oft-consumed prey item for so many predators, the bay anchovy is considered a forage fish. But the bay anchovy stands out among forage species. Scientists have long known, for instance, that the bay anchovy is a major source of energy fueling the growth and production of predators in the Chesapeake, and can even comprise up to 90 percent of the diets of predatory fish in the fall. A recent investigation into the diets of five predatory fish found that the bay anchovy was the fishes’ most common prey, confirming the bay anchovy is the most important forage species in the Bay ecosystem.

“We’ve studied the production and consumption of bay anchovy in the Chesapeake Bay, and the numbers are impressive,” said Houde, who worked at the University of Maryland Center for Environmental Science’s Chesapeake Biological Laboratory for more than 35 years and served as the institution’s Vice President for Education before retiring in July 2016. According to Houde, about 50,000 tons of bay anchovy can be found in this estuary at any given time—but an average of 458,000 tons are produced here each year. “That means a huge amount is being eaten and is fueling the production of Bay predators,” Houde said.

According to fisheries scientist Ed Houde, several characteristics make the bay anchovy the perfect prey fish. “It’s highly available, it’s the right size and it’s widely distributed over the whole Chesapeake Bay.” Image by Dave Harp/Bay Journal.

According to Houde, several characteristics make the bay anchovy the perfect prey fish. First, it’s a small fish, which means a range of predators both big and small can fit the fish into their mouths. Second, it’s a fecund fish, which means it spawns large numbers of eggs; eggs, larvae, juveniles and adults are eaten by predators. Third, there are a lot of them, almost everywhere, all the time. While other prey species may only inhabit certain areas of the Bay at certain times of year, the bay anchovy is generally available throughout the Bay most of the year.

Indeed, the bay anchovy is surprisingly tolerant of both the normal fluctuations observed in an estuarine environment and the hostile conditions that can occur when this environment is stressed. Through laboratory experiments and field work, Houde and his students have found that low dissolved oxygen, for instance, may not impact the bay anchovy like it impacts many other species. Areas of low dissolved oxygen—which occur in the Bay each summer, and which can suffocate shellfish and other organisms living on or near the bottom—seem to affect the distribution of bay anchovy but not their death rates, driving adults into the lower portion of the Bay. Coincidentally, it is in this portion of the Chesapeake that bay anchovy larvae and young are most likely to thrive. It may seem counterintuitive, but in this way, low dissolved oxygen can enhance the bay anchovy’s reproductive success.

“This is not an argument to support benefits of low dissolved oxygen in the Bay,” Houde cautioned. “But in the case of the anchovy, it does seem to promote conditions that increase its productivity.”

The University of Maryland Center for Environmental Science tracks bay anchovy abundance as an indicator of Chesapeake Bay health. The institution has given bay anchovy abundance a Very Good score in its annual Bay report card for eight of the past ten years. Image by University of Maryland Center for Environmental Science.

The Maryland Department of Natural Resources and Virginia Institute of Marine Science have gathered survey data on bay anchovy abundance for decades, and the University of Maryland Center for Environmental Science has also tracked this number as an indicator of Bay health. While bay anchovy populations fluctuate seasonally and annually and the fish is less abundant now than in the decades before 1990, Houde does not believe the bay anchovy has declined since the mid-1990s.

That said, Houde acknowledges that there must be environmental thresholds the bay anchovy cannot successfully cross. Little research has been done into the effects that chemical contaminants could have on the fish, and environmental conditions that lower plankton productivity—the mainstay of the bay anchovy’s diet—could have substantial effects on anchovy production and abundance.

How can we ensure the continued abundance of the most important fish in the Bay? “Ensuring the bay anchovy population remains healthy depends on keeping estuaries healthy,” Houde said. “Good water quality that supports abundant zooplankton to fuel anchovy production is what we need to maintain the health of anchovies. That’s not so different from [protecting] most of the things in the Bay.”

Through the Chesapeake Bay Watershed Agreement, the Chesapeake Bay Program has committed to improving our understanding of the role of forage species in the Bay. Learn about our work to develop a strategy for assessing the Bay’s forage base.

Catherine Krikstan's avatar
About Catherine Krikstan - Catherine Krikstan is a web writer at the Chesapeake Bay Program. She began writing about the watershed as a reporter in Annapolis, Md., where she covered algae blooms and climate change and interviewed hog farmers and watermen. She lives in Washington, D.C.


Photo of the Week: Natural beauty and national history converge in Harpers Ferry

Paddlers travel on the Potomac River where it meets the Shenandoah River at Harpers Ferry, West Virginia. Described by Thomas Jefferson as “perhaps one of the most stupendous scenes in nature,” the town offers views of three states: West Virginia, Virginia and Maryland.

This scenic spot offers not only boundless natural beauty, but a rich piece of national history. The town was named for Robert Harper, a Quaker from Pennsylvania who in 1747 was sent to erect a mission house in the Shenandoah Valley. On his way, he passed through “The Hole”—the gap in the mountains where the Potomac and Shenandoah Rivers meet. He recognized the value of the site for water power and transportation, purchased 126 acres of land at the site, then established a mill and began operating a ferry across the Potomac.

In 1799, construction began on the Harpers Ferry Armory, which produced more than 600,000 muskets, rifles and pistols before 1859, when one of the most famous events in Harpers Ferry history—and indeed, United States history—occurred. Abolitionist activist John Brown and 21 companions led a raid on the armory, hoping to seize weapons from the warehouse to initiate a slave uprising throughout the South. The attempted takeover of the armory was unsuccessful, however, and the event stoked the already tense relationship between the North and South, ultimately hastening the onset of the Civil War.

Today, the town is home to a national historic park where visitors can explore the historic town, visit museums and battlefields or hike the nearby mountains. It’s also home to the Appalachian Trail Conservancy, and is known to hikers as the “psychological halfway point” of the 2,190 mile Appalachian Trail.


Image by Will Parson

Stephanie Smith's avatar
About Stephanie Smith - Stephanie is the Web Content Manager at the Chesapeake Bay Program. A native of the Midwest, she received her Bachelor’s in Professional Writing from Purdue University and Master of Science degree from the University of Michigan. Stephanie’s lifelong love of nature motivates her to explore solutions to environmental problems and teach others what they can do to help.

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