by JEREMY COX, Bay Journal News Service
A half-century ago, a former hurricane (downgraded to a tropical storm) named Agnes detonated a water bomb over the Mid-Atlantic. Over a handful days in June 1972, relentless rain triggered record-breaking floods.
The storm’s human toll was monumental: a path of destruction through a dozen East Coast states; 122 people dead, 48 in Pennsylvania alone; and $3.1 billion in damage. It was the nation’s costliest natural disaster at the time.
And the environmental consequences, in the eyes of contemporary observers, were simply unimaginable: a shock wave of filthy water pummeling the Chesapeake Bay from nearly every direction, replacing its fragile balance with chaos.
In some ways, North America’s largest estuary, experts say, has never been the same.
“What’s interesting, given that it’s 50 years later, is we still see some of these alterations that have persisted,” said Rom Lipcius, a longtime scientist with the Virginia Institute of Marine Science. “A lot of [the memories] have faded. The historical baseline shifts, and we think this is the way it’s always been. And that’s just not the case.”
Agnes forever altered the way the public regarded the Chesapeake Bay. And as the fourth employee at the Chesapeake Bay Foundation, Mary Tod Winchester had a front-row seat for the shift.
She grew up on the West River in Galesville, Md., a member of a family that has owned and operated a boatyard on the waterway for eight generations.
“When I was growing up, obviously, [the Bay] was really pretty healthy,” Winchester recalled. “And then in the ’60s is when we really noticed a change.”
Underwater grasses, the centerpiece of the Bay’s food web, were dying off.
Problems such as diseases and overharvesting had ravaged oysters, crabs, clams and other important fisheries. But beyond a relatively small group of scientists and activists, few people paid much heed to the estuary’s growing ecological woes, Winchester said.
“And that was one of the things about Agnes,” she said. “It was a wake-up call, and it really helped to ring the bells that there was a problem here.”
Swirling and twisting its way northward from the Gulf of Mexico, Agnes could only muster sustained winds of 45 mph by the time it reached the Chesapeake region. But it literally rewrote the books on rainfall. The system stalled over the Susquehanna River basin June 21–24, dropping, dropping as much as 18 inches of rain.
Agnes heralded a decade of soggy weather and unusually high river flows, which unleashed tons of nutrients and sediment into the beleaguered Bay. As a result, Winchester said, the public and their elected representatives could no longer ignore the environmental disaster unfolding before their eyes.
“Everyone began to realize how important it was for Pennsylvania, Maryland and Virginia to be working together on Bay issues,” she said.
The Chesapeake Research Consortium, a hub for Bay-related research, was born in the immediate aftermath of Agnes as scientists scrambled to understand the full breadth of its impact. By the end of the decade, Congress acted, funding a five-year, $27 million study to examine the Bay’s rapid deterioration.
Winchester stayed with the Bay Foundation for more than 40 years, rising from the executive director’s secretary in 1971 to vice president of administration. There were several important milestones as the advocacy group flowered into a powerful regional political force with nearly $30 million in annual revenue. But Agnes was certainly one of them, she said.
“It helped to energize CBF,” Winchester said of the organization, which formed in 1966. “It helped us show the public we’re not just a bunch of hippies trying to say ‘the Bay is dying’ and raising money so that we can, you know, pay people to have jobs. Agnes made it real.”
Rarely is a single event to blame for the decline of a species. One exception may be the soft shell clam population of the Chesapeake Bay.
Soft shells (Mya arenaria), named for their brittle, oval shells, were so abundant in the Bay region during the 1950s and ’60s that Maryland crowned an annual “clam queen” to promote the vibrant fishery. Their meat has been sought over the years as a staple in New England-style stews and for baiting blue crab pots.
Annual clam landings peaked in the state at 680,000 bushels in 1964 but remained higher than 500,000 through 1971.
Agnes’ consequences were immediate and devastating. The storm delivered an onslaught of sediment to the Bay, slathering most of the clam’s bottom habitat with a layer of thick mud.
About nine out of 10 soft clams died from the suspected combined stress of low salinity and abnormally high water temperatures, according to the Chesapeake Research Consortium. Scientists conducting painstaking surveys failed to locate a single living soft clam in the Rhode and South rivers near Annapolis in the months after the storm.
Maryland authorities temporarily banned clamming three months after the storm to promote its recovery. Over the next two decades, the population perked up somewhat, but nowhere near its pre-Agnes levels. Today, the fishery is classified as a remnant of its former self.
Diseases and worsening water quality certainly played roles in suppressing the clam’s numbers, experts say. But computer modeling by Lipcius and some of his colleagues suggests that Agnes was the tipping point for clams.
Blue crabs had always been one of their major predators. But with clam numbers significantly thinned after the storm, they couldn’t reproduce enough to outpace the crabs’ appetite.
“So, those are two species that got hit — one that has never recovered and one that did recover,” Lipcius said.
Another victim of the era: Shad once numbered in the tens of millions during their spring spawning runs up the Chesapeake’s rivers. But overfishing, increasing water pollution and dam construction sent their population into a downward spiral during the middle of the last century. Agnes all but finished it off, experts say.
Maryland banned Bay shad fishing in 1980, the Potomac River was closed in 1982 and Virginia shuttered its portion of the Bay in 1994. Today, the shad population remains at historic lows in the Bay region and throughout its East Coast range, hovering around 1 percent of its late-1800s abundance, scientists say.
The drastic reduction in shad was also a sharp blow to the Bay’s aquatic life. The fish had served as a vital link in its food chain.
Jeremy Cox is a Bay Journal staff writer based in Maryland. You can reach him at email@example.com. This article first appeared in the June 2022 issue of the Bay Journal and was distributed by the Bay Journal News Service.