Derelict pots killing 3.3 million crabs annually in the Bay
Scientists, watermen seek solutions to danger that lost gear poses to marine life
When Virginia closed its winter dredge fishery in 2008, waterman Clay Justis turned his attention from catching crabs that season to collecting the gear that captures them.
He was one of several watermen hired under a program that taught them to use sonar to find and remove lost and abandoned fishing gear, primarily crab pots, littering the bottom of the Bay.
“As a waterman, I knew there was stuff on the bottom, but when I turned the machine on, I was like, ‘Wow!’” said Justis, who fishes out of Accomack on the Eastern Shore.
Out of sight in the Bay’s often murky water, crab pots lay scattered all over the bottom, the sonar showed — along with other fishing gear such as gill nets, and all manner of trash, even a laundry machine.
But the so-called “ghost pots” are a special concern because the wire mesh cages with openings to draw crabs in but not let them out can continue to catch — and kill — crabs and fish for years. They are taking a bite out of both the crab populations and the wallets of watermen. More often than not, Justis noted, the derelict pots he pulled up had something in them. “You’ve got fish, you’ve got crabs, you’ve got ducks. All kinds of things,” he said. But, he added, “most of the time, they are dead.”
Concern about delict crab pots in the Bay has been growing for a decade, and a new report for the first time attempts to estimate their Baywide impact. It found that more than 145,000 pots litter the bottom of the Bay — a number the report authors consider to be conservative.
Each year, the report estimated that those pots kill about 3.3 million crabs, 3.5 million white perch, 3.6 million Atlantic croaker, and smaller numbers of other species, including ducks, diamondback terrapins and striped bass.
The number of crabs killed amounts to 4.5 percent of the 2014 Baywide harvest, the report said. Nor is the problem limited to the Bay. Studies have found similar problems with fisheries that use “trap” devices to catch crabs and lobsters globally.
“It’s an issue that, around the country, folks may not be aware of unless you live close to an area where commercial fishing is a way of life,” said Amy Uhrin, senior scientist with the National Oceanic and Atmospheric Administration Marine Debris Program, which funded the study. “It is one of those ‘out-of-sight, out-of-mind’ issues.”
Financial impacts of lost pots
The report, which will soon be presented to Bay fishery managers, said impacts from lost pots could be reduced through collection programs and by requiring panels in pots that would degrade and create an escape hatch for crabs if left in the water. It also suggested trying to reduce conflicts between crabbers and boats, which is a major source of pot loss — and sometimes damages the boats.
“A lot of boats go up and down these waterways, and a lot of times if the tides are low [lost pots] can tear up an expensive motor quick,” Justis said. And the lost pots are an ongoing problem. “Each year, even if you go back to the same spot, a lot of times you find new stuff.”
Nor is it just crabs and fish that suffer from lost pots. Watermen take a financial hit, too. Baywide, 12–20 percent of the 600,000 to 800,000 pots they fish annually are lost and never come out of the water, the report estimated. Fishermen collectively have to shell out $3.6 million to $5 million a year to replace the lost gear, it said.
But lost pots have an even bigger economic impact by reducing catches in nearby pots. Crabs are attracted to structures, including derelict pots, even if they’re so damaged or broken they no longer trap crabs. Crabs hanging around the abandoned gear don’t make it to the pots being actively fished.
“The derelict pots are essentially competition for the active pots,” said Donna Marie Bilkovic, a researcher at the Virginia Institute of Marine Science, and lead author of the new report. “The crabs are definitely attracted to the structure.”
In “hot spots” with lots of derelict pots, the fishery becomes measurably less efficient, said Andrew Scheld, a VIMS fisheries economist who worked on the report. “It requires more people and pots to catch the same amount that they could if the derelict gear just wasn’t out there.”
The study was not able to directly estimate the economic impact of the lost pots on catches. But conversely, it found that crab catches increased in areas of Maryland and Virginia where derelict pots were removed by watermen like Justis, when compared with areas where pots were not removed.
Based on that, scientists estimated that removal programs increased cumulative crab catches in those areas by slightly more than 38 million pounds from 2008 to 2014. That was worth about $33.5 million over that six-year period.
Scientists from the NOAA Chesapeake Bay Office discovered the problem when they began detecting large numbers of pots as they were using side-scan sonar to map bottom habitats during the winter — long after crab season had ended.
While other types of fishing gear, such as gill nets, are also lost, crab pots are the main derelict fishing gear in the Bay because so many are deployed — and lost — in pursuit of the Chesapeake’s most valuable fishery.
When a severe decline in the blue crab population prompted NOAA’s National Marine Fisheries Service to declare the Bay’s fishery a failure in 2008 — spurring new catch restrictions and the closure of Virginia’s winter dredge harvest — it provided $30 million to Virginia and Maryland for conservation projects.
Both states used some of that money to hire watermen hard-hit by the new regulations to pull thousands of abandoned pots out of the Bay over a period of years.
The pots are typically baited with dead fish to lure crabs inside, then placed in the water, where they are typically checked every day or so. They have “cull rings” that allow small crabs to escape, but large crabs are trapped.
Watermen mark their pots with small buoys that float on the water’s surface. But if the lines linking the pots to the buoys are severed, they often cannot find the gear. Sometimes the lines break. Frequently, the lines get snagged and tangled in the propellors of recreational or commercial boats, prompting boaters to cut them. Some are lost in the violent winds and waves of major storms. More than 100,000 pots disappeared during hurricanes Dennis and Floyd in 1999. And, sometimes, old pots are simply discarded in the Bay.
The report estimated that Virginia had 87,048 derelict pots and Maryland 58,185. More are lost in Virginia, researchers say, because the state permits pots to be placed in Bay tributaries, where they are more likely to run afoul of boats.
Maryland does not allow crab pots in tributaries, though pots are densely deployed near their mouths, where heavy boat traffic accounts for derelict pot “hot spots” in those areas, the report suggests.
Lost pots ‘ghost fish for years’
However they are lost, pots that remain in the water can keep “ghost fishing” for crabs and fish, sometimes for years, until they begin to fall apart. Once the original bait is gone, traps often “self-bait” by trapping fish or crabs inside, and the cycle continues. On average, a derelict pot in the Bay catches 23 crabs a year, the report said.
Besides crabs, more than 40 species have been found in pots where they can perish from starvation, predation, low dissolved oxygen or disease. Unlike actively fished pots — they’re not checked so turtles and other species are never set free. In some Virginia tributaries, crab pots have been suspected of depleting local populations of diamond terrapins.
“One year, I pulled a pot that had 20-some turtles in there,” Justis said. “They were all dead.”
Scientists working on the study said that derelict crab pots are likely even deadlier than they reported.
In part, that’s because for the study, they assumed that lost pots only function for two years before they fall apart from corrosion. But many stay intact much longer, especially more expensive pots where the wire mesh is coated with vinyl, which makes them degrade more slowly.
Ward Slacum, a co-author of the report who has studied derelict crab pots in Maryland for nearly a decade, said he once placed pots in the Bay for 14 months to see what they would catch.
“When we took them out and cleaned them off, they had not degraded very much at all,” Slacum said. They were “trapping crabs and other organisms just as efficiently as something that was a month old.”
Also, the study did not examine the impact of ghost pots in habitats where crabs are particularly abundant, such as underwater grass beds and marsh edges. “We think we’ve underestimated that potential impact with those habitats,” Bilkovic said.
Lost peeler pots deadly
Peeler pots, which constitute a relatively small part of the crab fishery, may cause more harm than regular pots because they target smaller crabs when they are molting. As a result, they usually have finer mesh and often don’t have cull rings to allow smaller crabs to escape.
“When they are lost, they have a larger potential to capture smaller crabs and bycatch,” said Kirk Havens, a VIMS scientist who oversaw the Virginia pot removal program. “They are potentially a little more deadly.”
Even when fish and crabs are able to escape from derelict pots, some likely die from injuries, stress or fatigue related to their capture, but the scientists said they had no way to estimate that mortality.
Peyton Robertson, who heads NOAA’s Chesapeake Bay Office, said he expected Bay fishery managers to be briefed on the final report soon, and he expected the study would go to the Chesapeake Bay Stock Assessment Committee — a panel of scientists and fishery managers — to review for possible recommendations.
The report offers a number of possible actions, but finding solutions won’t be easy.
Because many pots are lost due to impacts from boats or ships, it suggested actions to help reduce those conflicts. That could include using reflective tape on buoys so they are easier for boaters to see, educating recreational boaters about the impact of pot losses, restricting commercial traffic to channels and keeping crab pots out of busy channels.
But restricting those areas from crabbers wouldn’t be popular.
High traffic areas “happen to be some of the better places to crab,” said Robert T. Brown, president of the Maryland Watermen’s Association. But Brown said he would like to see the derelict pot removal program resumed. “It got rid of a whole lot of them,” he said. “There’s nothing wrong with doing that again. We’d be in favor of that.”
The report did encourage reviving pot retrieval efforts, and said that targeting areas with high densities of lost pots could be particularly effective to increase catches. Removing just 10 percent of the derelict pots from the five most heavily fished sites in each state could increase harvest by about 14 percent, the study estimated.
“A removal program wouldn’t necessarily have to target the entire Bay,” Uhrin said. “It would be more efficient to target these hot spots.”
But with the federal money used to pay for the pot removal programs gone, that means cash-strapped agencies would have to come up with a way to fund pot removal programs.
“It’s a resource thing,” said David Blazer, fisheries director for the Maryland Department of Natural Resources. “It takes a lot of time and money and effort and resources.”
Also, while removal programs could reduce the economic impact of lost pots, they would have less of an impact on reducing the Baywide toll on crabs and other species. While targeting certain areas for retrieval might help watermen’s catches there, most derelicts pots would remain in the water, continuing to kill.
One way to reduce the biological toll of derelict pots, the report said, would be to require that each has a biodegradable panel, instead of cull rings. The panels would still have holes big enough to let small crabs escape, but they would break down in a matter of weeks if the pots were left in the water, creating a large enough opening for fish and crabs to get out.
The report said biodegradable escape panels would reduce crab mortality in derelict pots from more than 3.3 million per year to less than 440,000.
While biodegradable panels would reduce the number of crabs killed, the derelict pots would remain on the bottom and still lure crabs away from actively fished pots.
“The big economic benefits we saw for the removal program were for taking the entire structure out of the water,” Scheld said.
That means, scientists said, that managers may need to use different strategies depending on whether they are more concerned about the economic or biological impacts of derelict pots — or, they may need multiple strategies.
“It could be there is not a one-size-fits-all solution in the Bay,” Slacum said.
Rob O’Reilly, chief of fisheries management with the Virginia Marine Resource Commission, said interest seems to be growing in that state in biodegradable panels. The idea is slated for discussion by the commission’s crab management advisory committee, and some watermen have expressed interest in testing the panels.
“I think we want to encourage, as we go on, these biodegradable panels,” O’Reilly said, but added, “It will take a little coaxing, I’m sure.”
Some people are already using them. One is Dan Knott, who joined the ranks of Virginia watermen this year after 23 years in the Army.
“I’m kind of a geek when it comes to cleaning up things and looking out for the environmental side of the house,” Knott said.
He grew up in Virginia and spent his summers on the Bay fishing with his grandfather, who was a waterman. But when Knott researched getting into the business, he grew concerned about the derelict pot problem and decided to voluntarily incorporate biodegradable panels.
“At least I’m doing my little bit in helping them out,” he said. Of the first 50 pots he put out this summer, 25 were either lost or stolen, he said.
While Knott said biodegradable panels might be a good idea, he said if watermen were required to use the panels, they should be allowed to offset the cost, perhaps by increasing catch limits. The panels cost between $1 and $2, and have to be replaced annually — which can add up for someone fishing hundreds of pots.
“Not everybody feels the way I do,” Knott said. “There has to be something to make these guys want to do it.
“They are not like me where I have a retirement coming in from the military,” he added. “And I tell you, it’s a hard living to make. You’ve got to put a lot into it to make anything.”
- Category: Fisheries
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