Osprey Population Declines 50% Due to Menhaden Shortage

Bryan Watts, a biologist with an intimate relationship with ospreys, has observed a troubling trend in the Chesapeake Bay region. The osprey, a fish-eating raptor known for its acrobatic dives and distinctive calls, has seen a decline in successful breeding due to a lack of menhaden, a small schooling fish crucial to their diet. Watts, who has studied ospreys for decades, has documented that the birds are failing to fledge enough chicks, leading to starvation and death in nests.

Watts's findings have sparked controversy, pitting environmental groups against the fishing industry, trade unions, and sometimes government regulators. The fishing industry, which has caught at least 1.1 billion pounds of menhaden every year since 1951, argues that the decline in osprey populations may not be linked to fishing. They point to the sustainability of the menhaden fishery and suggest that factors such as climate change, pollution, and development could be at play.

Watts, however, has published studies in scientific journals backing his claims. He notes that osprey pairs need to average 1.15 chicks per year to maintain their population. In the 1980s, ospreys were reproducing at this level, but today, in some areas around the Chesapeake Bay, the reproduction rate is less than half of that. In particularly distressed areas, the reproduction rate is as low as one-tenth of the required level. Watts's research shows that the decline in available menhaden matches the areas of nesting failure, indicating a direct link between the availability of menhaden and osprey reproductive success.

The menhaden fishery is a significant industry, worth more than $200 million at the docks in 2023. The industry is dominated by Omega Protein, a subsidiary of Canadian aquaculture giant Cooke. The companies involved in the menhaden fishery have pushed back against the idea that fishing is the cause of osprey decline, acknowledging that fewer menhaden are showing up in some parts of the bay but attributing the decline to other factors.

The Atlantic States Marine Fisheries Commission, an interstate body that manages the menhaden fishery, has created a work group to address precautionary management of the species in the Chesapeake Bay. In April, this group proposed several potential management approaches, including seasonal closures, restrictions on quotas or days at sea, and limitations on kinds of fishing gear. The process of creating new rules could begin this summer.

Environmental groups are concerned about the decline in osprey populations and the potential impact on the ecosystem. They argue that any decline in osprey numbers is too much and that the country risks losing an iconic bird if no action is taken. Labor leaders, however, worry about losing jobs as the fishing industry declines and feel that the industry is being scapegoated.

Chris Moore, Virginia executive director for the Chesapeake Bay Foundation, emphasizes the importance of taking action to protect osprey populations. He cites Watts's studies, which show that ospreys will fail without access to menhaden. Moore warns that without intervention, the osprey population could face a steep decline, reversing the conservation success story of the past decades.