A scientific paper documenting widespread reproductive deficits among Chesapeake Bay osprey is drawing attention from the commercial fishing industry, with Ocean Harvesters arguing that the study does not establish a causal link between the declines and Virginia’s commercial menhaden fishery.
The paper, Widespread Reproductive Deficits in Chesapeake Bay Ospreys, published in Frontiers in Marine Science, suggests that reduced availability of Atlantic menhaden may be a primary factor contributing to poor osprey nesting success in high-salinity regions of the Chesapeake Bay.
In a June 11 email statement provided by Ocean Harvesters, they claimed the study raised important question about osprey productivity but “does not prove that Virginia’s commercial menhaden fishery caused the problem.”
"The study documents osprey concerns, but it does not prove that our fishery caused it," Ocean Harvesters CEO Monty Deihl said in the company's statement. "Many of the study areas discussed are not places where our vessels fish, and the paper appears to accuse commercial harvest without showing a clear connection between actual fishing activity and the nesting problems it describes."
According to Ocean Harvesters, the paper relies on a series of inferences connecting poor osprey reproduction to food stress, reduced menhaden availability and ultimately commercial fishing activity, but stops short of demonstrating direct causation.
Peter Himchak, senior fisheries scientist at Omega Protein, also cautioned against interpreting the paper as definitive evidence linking the reduction fishery to osprey declines.
"This paper is likely to draw attention because it reads, at least up front, like an indictment of menhaden availability in the Chesapeake Bay," Himchak said. "But the paper also details numerous other possible mechanisms that may affect osprey productivity, and those caveats are critical considerations in evaluating this issue."
Ocean Harvesters outlined several areas where it believes additional scrutiny is warranted.
The company argues that the timing of osprey nesting does not align with the reduction fishery, noting that egg laying begins in early April and significant chick losses occur during May, before most commercial reduction fishing activity takes place in the Chesapeake Bay. Citing data presented to the Atlantic Menhaden Plan Development Team, the company said only a small percentage of annual Bay landings occur before the end of June.
The company also questioned geographic associations made in the study, arguing that several of the areas reporting poor osprey productivity, including locations in Maryland’s Choptank and Patuxent river systems, are not areas where the reduction fleet operates.
Ocean Harvesters further contended that the paper lacks a fisheries-independent index of adult Chesapeake Bay menhaden abundance and that prey availability can be influenced by numerous environmental factors including salinity, dissolved oxygen, water temperature, freshwater flow and seasonal fish movements.
The company also noted that ospreys consume a variety of forage species beyond menhaden and said change in broad prey availability, including striped bass, bay anchovy, catfish, spotted seatrout and gizzard shad, could also influence reproductive success.
In addition, Ocean Harvesters said environmental conditions such as shoreline development, pollution, hypoxia, weather, disease and changes in fish communities may all contribute to osprey productivity and should be considered alongside any forage fish hypotheses.
The company also emphasized that the study should not be interpreted as a stock assessment for Atlantic menhaden. And it noted that the Atlantic States Marine Fisheries Commission currently considers the coastwide stock not overfished and that overfishing is not occurring under existing ecological reference point management.
Ocean Harvesters also pointed to Maryland’s 2025 juvenile menhaden survey, which reported high juvenile abundance for the third consecutive year, while acknowledging that juvenile surveys do not directly measure adult menhaden availability in osprey feeding areas.
“The more accurate conclusion is this: Dr. Watts’ paper documents poor osprey productivity in some high-salinity Chesapeake Bay areas and advances a menhaden-availability hypothesis,” the company said in its statement. “It does not prove that commercial menhaden fishing caused the problem.”
The publication of the study is likely to continue discussion over predator-prey relationships in the Chesapeake Bay and the role of forage fish management, while industry representatives and researchers debate the factors influencing osprey reproductive success across the region.
