As dawn painted the sky over the Potomac River, Ed Arnest began another day of oystering. He dropped a small, steel-toothed dredge called a hand scrape into the water. After towing it along the bottom for a few minutes, the Virginia waterman hauled it up so loaded with bivalves that his workboat tipped slightly to that side.
Arnest dumped the dredge’s contents onboard and dropped the gear in the water for another tow. As the boat circled, his gloved hands flew over the pile, quickly filling a bushel basket with oysters big enough to keep. Then he shoved the rest overboard, including the occasional wary crab, and winched the scrape aboard with another load.
Credit: Dave Harp
In a little over an hour on that recent October day, Arnest had harvested his daily limit of eight bushels. By midmorning he was back in Colonial Beach, VA, joining a line of workboats waiting to offload their catch to a tractor trailer bound for a nearby shucking house.
The Potomac is brimming with oysters this fall, most notably a 10-mile stretch of the river above the U.S. 301 bridge where salinity levels have been so low for decades that oysters couldn’t survive, let alone grow and reproduce. Dozens of workboats like Arnest’s are reaping the surprising bounty there, the byproduct of a rare confluence of natural conditions.
Credit: Dave Harp
“I’ve never seen anything like it,” said Jim Wesson, a member of the Potomac River Fisheries Commission who spent 25 years working to restore oysters in Virginia’s portion of the Chesapeake Bay. He estimated that the area upriver of the bridge, where until a few years ago almost no oysters grew, now harbors several hundred thousands of bushels.
That’s good news for the Potomac, which has had its share of bad news this year. Eleven months ago, a massive sewage spill near the District of Columbia prompted a brief precautionary shellfish harvesting closure above the U.S. 301 bridge, even though none of the spill was ever detected that far downriver. Now, the Bay’s second largest tributary could yield its best oyster harvest in more than 30 years.
“I didn’t think I’d live to see this river come back,” Virginia waterman Roger Hill said earlier this fall. “By God, it’s great.”
Like the rest of the Chesapeake, the Potomac once teemed with oysters, with 678,000 bushels landed in the 1966-1967 season. In 1972, though, Tropical Storm Agnes flooded the river with muddy freshwater, wiping out many reefs. Harvests limped along after that and nearly halted altogether in the early 2000s amid an epidemic of oyster diseases. The commercial fishery has since made a modest recovery, with 50,000 bushels landed last season, the highest since 1993.
Salinity rules
Only a few times since the 1960s, though, has the area above the U.S. 301 bridge produced more than a relative handful of oysters. Bivalves need water with a salinity level of at least 10 parts per thousand (ppt) to grow and reproduce, and that stretch of the Potomac has generally been too fresh.
Water monitoring records going back decades show that salinity there has rarely gotten higher than 10 ppt. Oysters can die if the salinity level drops below 5 ppt for more than a short time, and periodic freshets have pushed salinity close to zero in spring and summer, a crucial time for reproduction and growth.
Like ancient ruins, though, a trove of shells remained behind from a nearly forgotten time when oysters once thrived in that stretch of river. Six years ago, fisheries managers went prospecting above the bridge. Their sampling found no live oysters, but multiple “lumps” of shell rising from the river bottom, which they estimated could fill 700,000 to 1 million bushels if dredged up.
Credit: Dave Harp
With shell in short supply Baywide for aquaculture and restoration, managers considered taking those shells for use elsewhere in usually saltier water. They did remove a relatively small quantity but decided to leave the rest alone. That proved fortuitous. In 2023, a prolonged dry spell raised the salinity to a level ideal for natural reproduction. The oysters downriver produced a bumper crop of larvae, many of which apparently drifted above the bridge and settled as spat on the shell-covered lumps.
In another piece of good luck, salinity has remained elevated enough since then for those oysters to survive and grow. Now, Ingrid Braun-Ricks, the fisheries commission’s assistant executive secretary, estimates that the oysters above the bridge could help boost the river’s total harvest by 50% in the season that began Oct. 1.
Thirty to 40 boats worked above the bridge in early October. As word spreads about how they did, officials expected that number to grow. The commission issued oyster licenses last season to about 260 individuals using about 120 boats, according to Braun-Ricks.
“We’ve been given a gift horse. We definitely want to take advantage of it,” said Billy Rice, a longtime Maryland waterman who sits on the bi-state commission that regulates commercial and recreational fishing in the Potomac.
A bigger harvest brings in more revenue for the fisheries commission from oyster licenses ($300 per person) and a $2 per bushel tax — money that can augment the group’s limited budget for replenishing and restoring reefs.
It’s a fragile gift from nature, however. Managers and watermen alike are acutely aware that the current salinity (11.2 ppt at the bridge in mid-October) is way above normal. Those oysters, produced and sustained the past three years by a rare run of prolonged dry weather, could be in jeopardy if heavy rains or snow produce another freshet.
“If we have a bad storm or if we have a hurricane, these oysters are gone,” said Arnest, president of the Twin Rivers Waterman’s Association on Virginia’s Northern Neck.
Get ’em while they last
For that reason, the Potomac River Fisheries Commission decided to encourage watermen to harvest as much as they can from that vulnerable area. The eight-member panel voted to open it to all oyster gear, including powered hand scrapes, on Oct. 1, while areas below the bridge would open to power gear a month later, on Nov. 1. They also extended the harvest above the bridge to the end of April, a month beyond the normal season closure on the rest of the river.
“We’ve got to ride this horse,” Rice said during the commission’s September meeting, “because I’ve never seen an opportunity like this in my life.”
Wesson wanted to go one better. He recommended increasing the daily harvest limit from 8 to 10 bushels, suggesting that might leave fewer oysters behind at the end of the season, when they would be at risk of dying from a weather-driven drop in salinity in spring or summer.
Credit: Dave Harp
Others said they worried that increasing the harvest limit could produce a glut of oysters, prompting seafood businesses to stop buying any from watermen for one or more days a week — as has happened before.
“You can only catch what you can sell,” acknowledged Robert T. Brown Sr., president of the Maryland Watermen’s Association. But he said he favored increasing the daily harvest limit, arguing that those two extra bushels would help watermen cover their higher fuel and gear costs.
The market for oysters, though, started this season not much better than the last one ended. Potomac harvesters were being offered $40 per bushel by oyster processors at the beginning of October. That’s the same price, Arnest recalled, that they got 15 years ago.
It didn’t seem to put many off.
“I don’t know about the market,” said Hill, the Virginia waterman. “But I know there’s oysters out there to be caught, and they ought to be caught.”
Credit: Dave Harp
Brown added another reason to harvest as many as possible now. Besides the threat of freshwater killing the shellfish bonanza above the bridge, Brown said he worried that the continued high salinity could trigger another flareup of the two oyster diseases that devastated the Bay’s bivalve population from the 1980s through the early 2000s.
“MSX and Dermo are facing us square in the eyes,” he warned.
In the end, the commission decided to leave the bushel limit as is for now but agreed to revisit the issue later in the season.
Tim Wheeler is a senior contributing writer to the Bay Journal. You can reach him at 410-409-3469 or twheeler@bayjournal.com.
