From the Spring 2025 challenge of Dwelling Hen journal. Subscribe now.
For Bryan Watts, the Chesapeake Bay’s thriving Osprey inhabitants offered a uncommon ray of hope in his 4 a long time of labor as a conservation scientist.
The native inhabitants crashed in the course of the Sixties and ’70s because of the widespread spraying of DDT and different pesticides, nevertheless it started to rebound within the Nineteen Eighties and ’90s, a restoration documented in surveys performed by native scientists. By 2020, over 10,000 breeding pairs of the fish-eating raptors referred to as the Chesapeake dwelling.
Which is why Watts, who’s director of the Heart for Conservation Biology at The Faculty of William & Mary, was shocked when he seen Osprey nests alongside the principle backbone of the Chesapeake Bay in Virginia and Maryland have been failing. One thing, he reasoned, have to be unsuitable.
It was. Watts’s nest survey information in 2023 confirmed that Osprey replica charges in a single nook of the Chesapeake had sunk even decrease than earlier than the DDT ban within the Nineteen Seventies, with solely 17 of 167 nests containing reside chicks in a single survey. The trigger—based on a subsequent research by Watts and fellow William & Mary scientists revealed within the journal Frontiers in Marine Science in January 2024—was insufficient numbers of a smallish, oily baitfish referred to as menhaden that type the majority of the Osprey eating regimen within the Chesapeake. Massive numbers of Osprey pairs weren’t laying eggs; lots of those who did couldn’t preserve their chicks alive to fledge. Grownup Osprey, it appeared, couldn’t discover sufficient fish to create the subsequent technology of birds.
A serious clue to the trigger comes from Chesapeake tributaries just like the James and Potomac Rivers. There, Osprey rely extra on different fish species, and inhabitants ranges of the raptors have continued to climb. To Watts, this discrepancy strongly suggests {that a} lack of menhaden is inflicting Osprey numbers to crash.
Not everyone seems to be satisfied by Watts’s conclusion. Omega Protein is the one business fishing firm that processes menhaden within the Chesapeake and mid-Atlantic waters, processing them into fish meal and fish oil. On its web site, the corporate—which is permitted to reap about 112 million kilos of menhaden from the bay yearly—states that the Atlantic menhaden fishery will not be being overfished. Omega Protein factors to its Marine Stewardship Council certification as a sustainable fishing operation. In 2012 and once more in 2017 the Atlantic States Marine Fisheries Fee lowered caps on menhaden fishing, and the corporate says that additional limits are pointless.
Robert Latour, a fisheries biology professor on the Virginia Institute of Marine Sciences, agrees that there’s not sufficient information to say with certainty what’s occurring.
“I don’t assume we all know sufficient to make dramatic adjustments in coverage,” Latour says.
But Watts insists that the traces of proof exist connecting Osprey and menhaden: “We all know what’s occurring as a result of we’ve watched it in actual time. We’ve watched these chicks die of hunger.”
A Parade of Empty Nests in Mobjack Bay
On a sizzling morning final June, Watts secures his tattered baseball cap with a tug earlier than easing his skiff into the tranquil brackish waters of Mobjack Bay, on the western shore of the Chesapeake. With bronzed pores and skin and a neatly trimmed beard tinged with grey, Watts appears extra like a waterman than an ornithologist. He has carried out this ritual numerous occasions, his motorboat virtually seeming to steer itself to the primary nest on his record, simply off the docks. Even at excessive tide, the wood platform utilized by the would-be Osprey dad and mom towers above. Solely when Watts extends a telescoping mirror overhead can he see inside.
“Empty,” he mutters, earlier than opening the throttle and heading to the subsequent nest. The method repeats itself as Watts checks nest after nest. Grownup Osprey sit on the wood platforms—many constructed by native owners at a value of a number of hundred {dollars} every—however no nest incorporates chicks. Lastly, on the eighth nest, the drought breaks.
One chick appears oblivious to Watts’s presence. Its sibling extends a big head to glare into Watts’s telescoped mirror with a fiery orange-red eye. The mom circles overhead, her shrill alarm name echoing off the Mobjack’s open waters. Watts scribbles down some measurements and strikes off, and the feminine shortly returns to her chicks.
On the subsequent nest, Watts logs a single surviving chick. When he final checked the nest a number of days earlier than, he famous two younger, though one chick was clearly bigger and stronger than the opposite. This dimension differential is a transparent marker of meals stress, Watts says.
Watts has been crisscrossing the decrease reaches of the Chesapeake and watching new generations of Osprey emerge from eggs and grow to be adults for the reason that late Nineteen Eighties, when he was a grasp’s pupil in biology at William & Mary aiding on the Osprey nest survey program. He grew to become fascinated by the Osprey as a species that’s an obligate piscivore (or chicken that solely eats fish).
“Their entire ecology has developed round fish. Their ft are tailored for fish. They’ve specialised scales on their ft for gripping fish,” Watts says. “The whole lot about them is about fish.”
Again within the ’80s, Osprey have been starting to get better from the impacts of DDT, which had left eggshells too fragile for the subsequent technology to hatch. After the pesticide was banned in 1972, Osprey slowly started to rebound. A few of Watts’s first duties as a pupil concerned monitoring the variety of nesting pairs to quantify their unbelievable restoration. From a low of 1,500 breeding pairs within the Chesapeake within the mid-Nineteen Seventies, numbers greater than quintupled by the mid-2010s.
After a brief stint on the College of Georgia for his PhD, Watts returned to William & Mary and the Chesapeake in 1991. His analysis pursuits have broadened to incorporate different chicken species, together with Pink-cockaded Woodpecker, Peregrine Falcon, and Black Rail. However he retained a love for Osprey. No different species extra carefully displays the well being of the bay, he says. And if Osprey are struggling, it’s solely a matter of time till different birds are, too.
The recognition of synthetic nesting platforms has offered houses not only for Osprey, Watts says, but in addition for sparrows and different small songbirds that generally make their very own nests on the sides of the Osprey edifice. Since Osprey eat solely fish, the songbirds reap the safety of the raptors with out changing into lunch themselves.
With such a thriving inhabitants, the annual nest counts performed by William & Mary scientists might need appeared like overkill. However due to their unique eating regimen of fish, the well being of the Osprey inhabitants additionally supplies scientists with an efficient barometer of fish abundance and the general well being of the bay—which made it all of the extra alarming when Watts began recording declines in Osprey fledglings a number of years in the past. In 2021, Watts logged just one younger Osprey for each three nests, far beneath the common wanted to take care of the inhabitants.
Testing the Menhaden–Osprey Connection
In 2021 Watts arrange a small experiment to review the connection between menhaden and wholesome Osprey nests. He labored with Michael Academia, a William & Mary grasp’s pupil he was advising, to complement some Osprey nests in Mobjack Bay with additional menhaden, whereas leaving different nests alone. Whereas the supplemented nests did effectively, the management group continued to say no. Watts forged an excellent wider internet in 2024, recruiting Barnett Rattner, an ecotoxicologist with the U.S. Geological Survey in Maryland. The expanded crew recorded declines in Osprey numbers throughout the complete bay.
When Watts seemed carefully, he discovered clear indicators that Osprey chicks have been ravenous within the nests. To him, that indicated a transparent drawback with the Osprey’s favourite fish: menhaden. If Osprey sit on the high of the Chesapeake meals net, menhaden are close to the underside. Education in shoals by the 1000’s, menhaden are the proper fun-sized sweet bar for marine life.
Osprey love menhaden for a similar cause that people do, particularly the excessive oil and power content material. However whereas Osprey eat menhaden as is, people course of it to be used as fertilizer, fish feed, and protein and pet meals dietary supplements.
Omega Protein insists that menhaden shares are usually not being overfished. In response to a request for remark, an Omega Protein spokesperson mentioned: “The Atlantic States Marine Fisheries Fee manages the menhaden fishery utilizing the most recent scientific information to set harvest limits that forestall overfishing. The fishery operates inside these quotas, making certain that menhaden stay ample whereas nonetheless supporting business harvesting.”
Extra on Ospreys on the U.S. East Coast
However others say that fishing strain on menhaden within the Chesapeake Bay wants extra scrutiny. The state of Maryland prohibits large-scale menhaden fishing in state waters. Virginia, nonetheless, has not. The Chesapeake Authorized Alliance petitioned the state in December 2023 for stricter regulation of menhaden fishing and a proper research to evaluate the scale and well being of the menhaden inhabitants, however officers declined to behave.
Chris Moore, Virginia govt director of the Chesapeake Bay Basis, says that the mix of environmental stressors within the bay—like air pollution, growth, and local weather change—and pressure from industrial-scale fishing demand a extra precautionary administration strategy.
“Virginia is the one state on the Atlantic coast that also permits menhaden discount fishing of their state waters,” Moore says. “In case you look, we see some very worrying indicators on the market.”
Fishing clothes shop Chris Greenback agrees with Watts that declining menhaden populations are inflicting ripple results all through the Chesapeake meals chain. Greenback has spent many afternoons alongside the Rappahannock River, north of Mobjack Bay, and says he now hardly ever sees the soccer subject–sized colleges of menhaden that have been as soon as much more frequent. He’s additionally seen declines in sportfish like purple drum and bluefish that, like Osprey, rely on menhaden.
“Menhaden are the one issue that ties all of this collectively,” Greenback says. “I would like proof that it isn’t menhaden.”
In August 2024, ASMFC established a working group to advocate a menhaden motion plan that may stability the wants of fisheries and wildlife. The difficulty grew extra contentious when a proper response pushing again in opposition to Watts’s work by Latour and two different VIMS scientists was revealed in Frontiers in Marine Science in October 2024. They level out that though Osprey reproductive difficulties are regarding, any variety of elements could possibly be contributing to nest failures, together with predation, illness, local weather change, and, sure, menhaden.
“There’s a lot we simply don’t know nonetheless,” Latour says. “Till we will research Osprey and menhaden collectively, we’ll simply be guessing.”
Even Watts’s collaborator Rattner on the USGS, who has documented the ravenous chicks and empty nests, says he nonetheless can not conclusively tie it to the Osprey’s incapability to search out menhaden.
“There may be good proof there’s one thing occurring,” Rattner says. “I believe a few of it’s associated to meals availability, however I haven’t been in a position to rule out different elements.”
Watts additionally admits he could possibly be unsuitable, however he doesn’t assume he’s. He has submitted a rebuttal to Latour’s commentary that’s at present in evaluate. Till somebody can present him with enough information that menhaden populations are usually not crashing, he’ll proceed his Chesapeake vigil.
“Ultimately, I believe issues will probably be sorted out. That’s what occurred with DDT,” Watts says. “It was the general public who in the end determined we didn’t wish to see these species disappear, they usually determined they wished the species greater than they wished a number of the pesticides. And so there was a rule change.”
As Watts opens the throttle on his boat to return to the dock, an Osprey soars overhead, its crystalline cry concurrently fierce and fragile. The chicken folds its wings and plummets towards the water. Its talons emerge, empty. Shaking the water from its feathers, the osprey flies off in pursuit of higher luck.
In regards to the Writer
Carrie Arnold is a contract journalist who reviews on well being and the setting. She lives in coastal Virginia. She has beforehand written for Dwelling Hen about Marbled Murrelets and Clark’s Nutcrackers.
