VIM Scientists Question Osprey/Menhaden Narrative

WHRO, VIMS scientists critique research linking osprey declines to menhaden industry

Research that touches on menhaden in the Chesapeake Bay has long been contentious, because it helps inform how officials choose to regulate the controversial fishery.

The latest disagreement is playing out in scientific literature. Three scientists at William & Mary’s Virginia Institute of Marine Science, which conducts research for state regulators, recently published a formal critique of a study linking declines in the local osprey population to the menhaden industry.

The study they critiqued came from another arm of William & Mary: the Center for Conservation Biology, which studies birds.

 

The center has monitored ospreys for years. Director Bryan Watts said they’ve now seen the birds struggling to reproduce for more than a decade.

His team published a study earlier this year recording the lowest number of osprey chicks since the 1970s. They said the baby birds are dying of starvation, and posit that’s because there aren’t enough menhaden for them to eat.

In their new critique of that study, the VIMS scientists say there’s simply not enough data to make that claim.

“It may turn out that the linkage is real, and I'm certainly willing to admit that, but right now I just don't feel like we can say that,” said Rob Latour, a professor who has long studied menhaden.

 

Latour said he respects his William & Mary colleagues’ research on osprey, and VIMS is also concerned about the struggling population.

But he felt compelled to write the commentary after seeing members of the public use the study to ask for changes in policy.

“There was so much pressure being put on industry and policymakers to make decisions, and the scientific basis for doing that was not very solid at all,” he said. “So the point of the commentary was to give an alternative perspective.”

This is an example of how science is supposed to work. Some scientists, those with expertise in Ospreys advance the hypothesis that lower Menhaden numbers in the Bay caused by the reduction fishery is causing Osprey chicks to suffer malnutrition. Other scientist, more familiar with the Menhaden data doubt that conclusion. Now, we need the two groups to get together to construct reasonable tests of the hypothesis, not easy given the large scale of the system.