Chesapeake Bay’s Misguided War on the Ray

Science can go wrong—sometimes with deadly consequences.

Published June 14, 2017

The state of Maryland has imposed a moratorium on a blood sport that had been taking place across its slice of the Chesapeake Bay for nearly a decade. Each year, contestants congregated with boats and bows and arrows. Their goal: to hunt and kill as many cownose rays as possible.

Thousands of dollars in cash prizes were dished out for killing the most and biggest rays. Tournament organizers profited. And the otherwise plankton-rich emerald waters of the Chesapeake Bay turned red with blood in the name of misguided conservation. Welcome to The Cove, America.

The Chesapeake Bay is the largest estuary in the United States, and one of the largest in the world. The clash of fresh and salt waters creates a profusion of life, and a wildly productive fishery for Maryland and Virginia. Commercial fishers there target some 17 different species including oysters, blue crabs, and striped bass, and in 2010, following an imprudent interpretation of science, the two states added another species to that list: the cownose ray.

A decade ago, the journal Science published a paper by renowned biologist and conservationist Ransom Myers. The widely cited paper was published just days after Myers’s death, and painted a dim picture of a collapsing trophic cascade in the northwestern Atlantic.

Every species of great shark (those that reach 1.8 meters or longer) in the northwestern Atlantic, the scientists wrote, had seen its population decline by up to 99 percent since the 1970s. In their paper, Myers and his colleagues outlined how the sharks’ decline had set off a chain reaction. With great sharks being wiped out by overfishing, the species a rung down on the trophic ladder suddenly found itself without predatory checks and balances. Freed from population controls, the paper contended, prey species such as cownose rays had exploded with disastrous consequences for North Carolina’s scallop fisheries—once considered the largest in the United States.

In 1928, North Carolina commercial fishers brought to market 635,000 kilograms of scallop meat. By 2004, fewer than 70 kilograms were harvested from the state’s waters. And in 2007, North Carolina closed the scallop fishery.

Up the coast in Virginia and Maryland, this report was exactly what people wanted to hear. For oystermen on the Chesapeake Bay, it was direct and to the point: the abysmal harvests they were seeing were not their fault. Conservationists read Myers’s paper as a testament to the importance of sharks.

The paper emboldened efforts to protect sharks. It also, inadvertently, vilified the ray. Any nuance in Myers’s paper was lost.

Suddenly, everyone on the Chesapeake thought they knew what needed to be done: save the sharks, kill the rays, save the bay.

Even though Myers’s paper focused on rays and scallops in North Carolina, and the study’s authors noted that further research would be needed to determine what effects rays may be having elsewhere, the community had latched on. Reports of endless schools of rays decimating oyster beds started flooding in, and conservation groups worried their hard work was being undone.

Virginia was the first to act with the opening of its cownose ray fishery. The solution seemed simple: if rays are to blame for dwindling oyster harvests, why not eat the rays? A related species of ray is a delicacy in South Korea, after all.* With a public relations overhaul, perhaps the American public could be turned on to the winged fish? Virginia even changed the name of the species to the Chesapeake ray, thinking this was more epicurean than cownose.

In 2010, a campaign designed to save the bay by eating rays was born. The initiative was supported by a number of Virginia state organizations—and by taxpayer dollars.** Though, to date, ray meat has yet to really catch on around the bay.

Ray biologists immediately protested the campaign. They wrote counter arguments, the American Elasmobranch Society drafted a resolution in opposition, and researchers from Miami to Massachusetts warned of dramatic repercussions that could result from the hunt. There were holes in the argument to eat the rays, scientists said. The cownose ray is a native species, it’s not the lionfishan invasive species that’s destroying ecosystems. Plus, applying data on scallop beds in North Carolina to oysters in Virginia doesn’t make sense.

No one listened.

At the same time as Virginia was designing its campaign, bow hunters caught wind of an opportunity.*** Bow hunting rays was not new, nor was it illegal. There weren’t even limits on how many could be killed. In the past, people simply hunted for sport—there was no market for the fish. But now, hunters had science on their side. Hunting rays became conservation in action. And with this, came the rise of tournaments, such as Mechanicsville, Maryland’s Battle of the Rays.

Picture a fleet of 80 boats. Its mission: to locate large schools of pregnant rays that are migrating into the Chesapeake Bay to give birth. When viewed from above, the rays create a brilliant work of art—a living mosaic gliding beneath the water’s surface. When such a mosaic is found, contestants fire a barrage of arrows at close range, killing as many rays as possible.

a group of cownose rays

Cownose rays reproduce slowly, with females giving birth to only a single pup at a time. This means ray populations take a long time to grow, and to recover. Photo by Doug Perrine/SeaPics.com

Online videos of the tournaments are tough to watch. One video depicts contestants beating rays to death with baseball bats after pulling them onto the boat. A pregnant ray gives birth during one such beating, only to have her pup stuffed back inside—to keep her as heavy as possible for the final weigh-in. The cruelty at play, at times, gives the dolphin slaughter in Taiji, Japan, a run for its money.

When asked about how the Chesapeake Bay states and the conservation community used his research to justify killing rays, Charles “Pete” Peterson, a University of North Carolina marine ecologist who coauthored the 2007 paper, is blunt. “This was never the point. It was never about killing rays,” he says. “The purpose of our research was simply to show that overfishing does affect food webs.”

The scientists were trying to understand what happens when a top predator disappears from a marine ecosystem. “Cownose rays are not overabundant,” Peterson says. “Their population varies over time. Who are we to play God?”

In recent years, the tide has turned against the Chesapeake Bay’s brazen fishing contests. One major catalyst was another scientific paper, published in February 2016.

The team behind this paper, led by Florida State University marine biologist Dean Grubbs, conducted its own study of cownose rays in the Chesapeake Bay. Compiling research from a range of disciplines, Grubbs and his team painted a vastly different picture of the Chesapeake Bay rays than the one used to justify the cull.

For starters, Grubbs and his team showed that cownose ray predators—sandbar, dusky, and black tip sharks—had all been increasing in numbers while the alleged ray takeover was underway. The sharks’ population gains stemmed from federal restrictions on shark fishing. A corresponding increase in both sharks and rays clearly did not make sense.

Though Grubbs’s paper did not state this, the increase in ray populations could be attributed to a number of other variables such as the use of Turtle Exclusion Devices by shrimp trawlers, which the US National Oceanic and Atmospheric Administration claims have had a statistically significant impact on reducing by-catch of rays.

Secondly, cownose rays are not super reproducers. They take about eight years to mature, and females are only capable of giving birth to one pup a year. The idea that their numbers could blossom overnight doesn’t align with their biology—a discrepancy that Myers’s paper does address.

Most importantly, Grubbs’s paper showed that cownose rays were not to blame for the declining oyster fishery in the Chesapeake Bay. Research analyzing the stomach contents of thousands of rays showed that cownose rays rarely eat oysters. These flat sharks just don’t have the crushing capabilities in their jaws needed to crack open mature oysters. Instead, they are more adept at eating shellfish with thin valves, such as razor clams, softshell clams, and scallops.

Peterson says he was unsurprised by Grubbs’s findings.

Peterson says things unfolded very differently in North Carolina, where Peterson and his team developed a way to keep farmed scallop beds safe from rays: a simple palisade of white PVC piping.

“The rays can’t swim through the wall of pipes. It’s cheap. It is completely effective. And there is no killing here,” he says.

Between citizens’ petitions, videos being leaked on the Internet, and the mounting scientific evidence against the effectiveness of the Chesapeake Bay’s ray hunting contests, the Maryland Department of Natural Resources (MDNR) finally called for a moratorium on the killing contests. When the governor of Maryland signed off on MDNR’s request on May 4, open season was over. The stay will last until at least 2019, giving MDNR a window to conduct further research on the impact such contests had, and to develop a management plan for the ray. Down in Virginia, however, there is still no law banning such contests.

The story that unfolded across the Chesapeake Bay is one that should give reason to pause: people were quick to read into unrelated research; to scapegoat; to find blame where they wanted. It’s a lesson about the dangers of oversimplifying science. But there is nothing simple about coastal ecosystems, where a multitude of species and processes interact—many of which have yet to be discovered.

Back on the Chesapeake, cownose rays are now in the midst of their annual migration to their traditional pupping grounds. The great mosaics of golden diamonds can be seen, once again, gliding through green waters. With the moratorium in place, these flat sharks can find some reprieve in the great estuary. At least for now.

*This sentence originally read, “Cownose rays are a delicacy in South Korea, after all.” While the Brazilian cownose ray (Rhinoptera brasiliensis) is a delicacy in South Korea, the same did not prove true for the species of cownose ray found in the Chesapeake (Rhinoptera bonasus).

**This sentence originally read, “In 2010, Save the Bay, Eat a Ray—a campaign initiated by the state of Virginia and its marine products board, paid for with taxpayer dollars—was born.” Though the Virginia Marine Products Board did work to promote the consumption of rays in the Chesapeake Bay, it did not have a campaign called “Save the Bay, Eat a Ray.” It was also not the only organization working to promote the consumption of rays. 

***This sentence originally read, “As Virginia was designing Save the Bay, Eat a Ray, bow hunters caught wind of an opportunity.” As noted above, the campaign was not called “Save the Bay, Eat a Ray.”