Menhaden, Osprey, Human

Saturday afternoon seems like a good time to talk about the thing liberal communities care the most about–the complexity of natural resource politics. In this case, I wanted to highlight this good discussion of the complex issues around menhaden, a bony, oily fish that is basically a bait fish today. But like every other species in the ocean, humans are destroying it with tremendous rapidity and this is helping to send the ecosystem into disaster.

Researchers hoped to find evidence of a healthy new generation of ospreys when they checked 84 nests of the fish-eating bird in mid-June at Mobjack Bay, an inlet at the southern end of the Chesapeake Bay. They found only three young.

It was the lowest reproductive number in more than 50 years of monitoring the local population of the raptor, according to scientists at the College of William & Mary. And they said it represented the latest evidence in a long-term decline in breeding success due to the bay-wide depletion of the bird’s favorite food — Atlantic menhaden.

Hundreds of millions of the little, silvery fish play a crucial role in the ecology of coastal waters all along the Eastern Seaboard, feeding bigger fish like striped bass and weakfish; marine mammals including whales and dolphins; and birds like bald eagles, great blue herons and brown pelicans. The fish are nutrient-rich, a good source of Omega-3 fatty acids; they consume smaller organisms like plankton and they filter huge quantities of ocean water.

But they are also a mainstay of the commercial fishing industry, caught in mass quantities to be processed into bait for crabs and lobsters, and in greater volume for so-called reduction fisheries, in which they are ground up and turned into products including fish oil and fish meal.

This year, the Atlantic States Marine Fisheries Commission, a federal regulator, increased the amount of menhaden allowed to be caught to 233,550 metric tons throughout the Atlantic coast for the next two years, about 20 percent higher than the previous two years. The commission said the new quota would provide additional fishing opportunities while minimizing the risk of damaging the fish’s ecosystem.

The agency concluded last August that there was no evidence that menhaden were being “overfished” across its range, when measured by “ecological reference points,” a network of the fish’s predators and prey that has guided the commission’s menhaden policy since 2020, replacing its practice of management by single species.

While raising the coastwide catch for menhaden, the commission left its quota for the reduction fishery in the Chesapeake Bay unchanged at 51,000 metric tons, or about 244 million fish, based on an average of 0.46 pounds per fish. Across the whole Atlantic coast, the agency authorized a catch of around 1.2 billion fish.

I know there are regulatory agencies out there, both nationally and internationally, that create standards on what sustainable fishing consists of. But as a scholar of the timber industry, let me express my extreme doubts that any of this is actually sustainable. This is because a) most of the people who staff these agencies come out of the fisheries and b) there is a lot of economic pressure to increase the catch. So they will redefine what sustainability means. Of course, you can make adjustments that matter and sometimes they can and do.

Outside the Chesapeake Bay, the number of menhaden has increased since the Atlantic commission determined in 2012 that the fish was being harvested at a rate that would exceed its reproductive capacity if not corrected. In response, the agency temporarily cut its total allowable catch by 20 percent coastwide, and the fish population recovered within two years.

Evidence of its recent abundance can be found off the coasts of New York and New Jersey, where more of their predators, including humpback whales, tuna, sharks and bald eagles, have returned, Mr. Eidman said.

At Mobjack Bay, the latest ratio of osprey young raised per nest is only 0.03, sharply lower than the 1.15 rate needed for the population to sustain itself, said Michael Academia, an osprey researcher at the Center for Conservation Biology at the College of William & Mary in Williamsburg, Va.

The record-low level of osprey chicks in the area follows successive declines in the reproductive rate of 1.39 per pair in 1984, 0.91 in 1990 and 0.75 by 2006, all reflecting the local depletion of menhaden stocks, Mr. Academia said.

The Atlantic commission’s assessment that menhaden stocks were not overfished was not accurate for the Chesapeake Bay where the numbers were locally depleted, he said.

Since there are no accurate data on the number of menhaden in the bay, the William & Mary team has used a supplemental feeding program to confirm that birds fed on the fish raise more young than those that do not receive the supplemental fish. Although osprey can feed on other kinds of fish, they much prefer menhaden because the species schools on the surface, and so are easily accessible.

To rebuild the local population of osprey and other creatures that depend on menhaden, the commercial fishing industry, both for bait and reduction fishing, should move out of Mobjack Bay — an important barometer of the osprey population — and from the Chesapeake Bay as a whole, Mr. Academia said. “The menhaden population in Mobjack Bay is not currently adequate to sustain the osprey population,” he said.

Yeah, I’m sure Virginia and Maryland will fight like hell to stop that from happening.