The mysterious case of disappearing Chesapeake ospreys
- Virginia Osprey Foundation
- Jun 28
- 4 min read
Bay Journal: Tom Horton, Jun 25, 2026
Colonial Beach, VA: It was a glorious spring here on the lower Potomac River in 2023 for ospreys and for the townsfolk like Joanie and Barry Millward who applaud their annual return from the tropics and thrill to watch them dive for fish.
This bird of prey, called a fish hawk by some, is known along shorelines from Japan to Australia, from India and the Strait of Hormuz to much of Europe and North America. “Ospreys and people have been overlapping since there were people,” said Alan Poole, author of two books about Pandion haliaetus.
In 2023, when Joanie began the Virginia Osprey Foundation out of their cottage at Colonial Beach, she observed robust production of 55 osprey chicks from 36 active nests around the community. Baywide, ospreys were continuing their heartening comeback from the dark days of DDT — from a historic 1972 low of about 1,500 nesting pairs to an estimated 10,000-12,000 pairs now throughout the Chesapeake Bay region.
Then, a sudden and mysterious population crash: Only five chicks reached adulthood in 2024, eight in 2025. Young ospreys were seen walking aimlessly, dazed and apparently starving. There were fish crows stealing osprey eggs as females left them in search of food the males could no longer provide. Adults were eating their dead babies.
“That is difficult to watch, and the whole town takes it to heart,” Barry said as they prepared for the town’s seventh annual osprey festival this spring.
Baywide, a similar picture was emerging, with poor nesting success throughout 80% of the estuary and its tidal rivers and an estimated 5,500 young ospreys starving to death, according to Bryan Watts, a Virginia scientist known for his decades of Chesapeake osprey research.
Ecologically, cannibalism of dead young “makes energetic sense when calories are scarce,” says Watts, who is the director of William & Mary University’s Center for Conservation Biology. But, Joanie said, it breaks your heart to watch.
The reversal of ospreys’ fortunes has been dramatic and well documented. While scientists mostly think there is no single cause, the decline has reinvigorated a dispute over the commercial harvest of menhaden by Omega Protein. a Canadian company with a fishing fleet based in Virginia.
Omega’s fleet of six ships, guided by spotter aircraft, takes about 125,000 metric tons of menhaden annually, fishing from the lower Chesapeake and along the Atlantic Coast.
Menhaden are small, oily fish that are packets of superbly calorie-dense energy, beloved by larger fish like striped bass, and by ospreys. Along with tinier but abundant Bay anchovies and silverside minnows, menhaden form the forage base underpinning the Chesapeake’s productivity.
Watts and others have documented that ospreys are doing worst in the saltier parts of the Chesapeake and Atlantic coastal bays where menhaden make up a critical part of their diets. Only in areas with less salty water, the upper Chesapeake and its tidal rivers, are ospreys producing enough young to sustain their populations — though not enough to offset the plummeting reproduction in the rest of the estuary.
Prey options in fresher water are more varied, with gizzard shad and catfish providing ample calories. Nesting ospreys with young need to catch five or six fish a day to sustain the family.
Of all the world’s hawks and eagles, the osprey is most completely adapted to fish — and obligated to feed exclusively on live fish. (The bald eagle’s embrace of eating carrion caused Ben Franklin to call it a species of “low moral character,” unfit to be the national bird.)
Ospreys’ eyes have about five times the density of photoreceptors of human eyes, enabling them to spot small fish from 100 or more feet aloft. Their legs can extend two feet underwater, further aiding dives at speeds up to 50 mph. Fearsome talons lock from four directions to secure their catch.
One of Watts’s graduate students has shown that osprey reproduction can be revived if humans give them extra menhaden. He has heard from “quite a few people” around the Bay who are feeding hungry ospreys. “I’m fine with that,” Watts said, “but it’s not a solution to the current deficits.”
At a recent osprey conference in Rock Hall, MD, Montgomery Diehl, CEO of Omega’s harvesting subsidiary, Ocean Harvesters, said their boats take less than 1% of the total menhaden biomass each year.
And, to general agreement from ornithologists present, he said the Atlantic coastal population of menhaden is healthy and not overfished. But he conceded that the numbers of adult menhaden, the favored prey of ospreys, don’t seem to be entering the Chesapeake like they used to.
Other factors could be contributing to the ospreys’ woes, scientists at the conference said. These range from nest predation by increasing numbers of bald eagles, to cooler, wetter spring nesting conditions, to poor water clarity making fishing harder. There may also be more competition for menhaden by fish, like red snappers, that are moving north into the Bay as climate change warms its waters.
Yet another pressure, minor so far but increasing, is that a growing number of non-migratory Canada geese are appropriating osprey nests. That was evident on a recent trip with Watts up the tidal, freshwater portion of Virginia’s James River. We saw several longtime osprey nests atop channel markers that now held nesting geese. The ospreys will be forced into nests on the shoreline that are more subject to predation by raccoons and foxes.
There is also a possibility, based on trends seen in other fish species, that today’s warmer Chesapeake is no longer as inviting to coastal menhaden as it once was.
Bottom line: One of the world’s great fishermen can’t catch enough fish anymore in much of the Chesapeake.
A better understanding of the reasons might come in the next couple of years from the first detailed study of menhaden in the Chesapeake, courtesy of $2.6 million recently secured by U.S. Senator Chris Van Hollen of Maryland. Let’s hope it gives us some answers.
Tom Horton has written about the Chesapeake Bay for more than 40 years, including eight books. He is a professor emeritus at Salisbury University and lives in Salisbury, MD.
The views expressed by opinion columnists are not necessarily those of the Bay Journal.
