By Jeremy Cox/Chesapeake Bay Journal
The brown pelican population around the Chesapeake Bay has plummeted by about half from its peak in the late 2000s and early 2010s, avian researchers say. And what’s causing the decline, given the lack of funding to investigate the phenomenon, is anyone’s guess.
There are many theories. But the hypothesis gaining the most traction involves one of the Bay’s most controversial industries.
Asked why there are fewer pelicans, Dave Brinker, an ornithologist with the Maryland Department of Natural Resources, seemed at a loss: “They’re going down. That’s the simplest analysis.”
But after a pause, he added: “I suspect it’s a result of changes in menhaden. We don’t have food studies. But just thinking as an ecologist, [I know] these birds are very sensitive to prey availability.”
Atlantic menhaden are a small fish at the center of a huge debate over whether they are being overfished in the Bay. Critics accuse Omega Protein, a Canadian company that harvests menhaden and “reduces” them to make fish oil and fish meal. They say the company is taking so many menhaden that there aren’t enough left for birds and larger fish to feed on.
Since 2018, the “reduction fishery” has had a cap on its harvest in Bay waters of 51,000 metric tons per year — all of it coming from Virginia because Maryland bans the practice. Under pressure from conservationists and recreational fishing groups, federal fishery managers are now considering lowering that limit.
In recent years, researchers have been documenting a decline in ospreys around the Bay, which they blame at least partly on a lack of menhaden. The evidence, they say, includes female ospreys laying fewer eggs, emaciated chicks and the sight of young starved to death in the nest.
Some fishery scientists are not ready to make that conclusion, saying there is no solid evidence that the osprey hardships are tied to menhaden availability. “I don’t know that we have the data to support that yet, and I hope that’s where the new research goes,” said Reid Nelson, a fisheries scientist with George Mason University in Virginia.
Omega Protein officials also dispute those claims, including any suggestion that the woes extend to pelicans.
“Before there is additional speculation in the media blaming the menhaden fishery,” Omega spokesman Ben Landry said in a statement, “those suggesting a connection should produce peer-reviewed evidence demonstrating that commercial menhaden fishing is responsible.”
Although the Bay region is less vital to pelicans — their breeding range extends thousands of miles from the Mid-Atlantic southward through the Caribbean — their downturn is setting off alarms among ornithologists.
“It’s a sign that the fisheries in the Chesapeake Bay are beginning to struggle,” Brinker said.
The mysterious local decline of brown pelicans represents a dramatic reversal of fortunes.
Along with several other bird species, brown pelicans were listed as endangered in the early 1970s largely because of widespread DDT poisoning. But after the pesticide was banned, the population flourished, leading to its delisting.
As their numbers multiplied, the distinctively beaked birds ranged farther northward. Breeding pairs in the Chesapeake Bay region were recorded for the first time ever in 1987. Researchers and bird lovers marveled at their success as their population neared 3,000 breeding pairs around the Bay by the late 2000s.
But then came a shift. Researchers who survey waterbird populations every five years found during the most recent survey, in 2023, just 1,500 pairs in Virginia’s portion of the Bay. That was a nearly 20% decrease from its peak a decade earlier.
Bryan Watts, director of the Center for Conservation Biology at College of William and Mary and leader of Virginia’s waterbird survey, said anecdotal reports of recent colony collapses suggest that the downward trend has continued. He suspects the population is now down 40%-50%.
But Watts said he doesn’t have the resources to investigate the cause. “The population is definitely pulling back,” he said. “Is menhaden one of the dominant factors? I suspect that may be one of the factors, but we just don’t have the data to say.”
In Maryland, it’s been much the same. From that state’s peak in 2008, breeding pairs fell by more than 50% around the Bay by 2023.
“My concern is not for the brown pelican population as a whole. There are plenty of places along the Atlantic coast where they can breed,” said Brinker, who leads Maryland’s tracking. “What’s a bigger concern is the fact that they did so well when menhaden numbers were higher. Now, menhaden numbers appear to be much lower, and pelicans aren’t breeding so densely in the central Chesapeake.”
Bird lovers have noticed fewer pelicans, too. Jim Rapp regularly leads birding tours to the Smith Island archipelago along the Maryland-Virginia border in the middle of the Bay. One of his favorite stops was Shanks Island, which in its heyday was home to a colony of nearly 2,000 nesting pelican pairs.
“For a while, their numbers dwindled. In recent years, there have been none,” Rapp said. “I would not have had this on my bingo card.”
The colony has splintered, relocating to other islands in the vicinity but not in great enough numbers to compensate for the loss on Shanks Island, Watts said. In the research paper he lead-authored about the 2023 colonial waterbird survey, Watts suggested that the birds likely abandoned Shanks because of the island’s steady erosion.
In his statement, Omega Protein’s Landry said that Watts’s documented erosion theory should make observers think twice before blaming menhaden. “Anecdotal observations are no substitute for fisheries science,” he said, “particularly when published research already identifies a documented cause of the pelicans’ decline.”
What happened to the Bay’s missing pelicans? Did their young starve to death, like the ospreys? Did they decide to flock to another state? There isn’t research yet to answer those questions, Brinker said.
