A regional fisheries agency has called for stepped-up research to assess whether the Chesapeake’s ecology is being affected by the menhaden catch taken from the Bay.

Menhaden are a major food for striped bass and an important water-clearing, filter feeder. But their numbers have declined in the Chesapeake, although the Atlantic States Marine Fisheries Commission, which manages migratory fish, says the coastwide menhaden stock is healthy.

Fishermen blame the lack of menhaden for an abundance of thin rockfish in the Bay, and a recently formed coalition of environmental and fishing groups, called Menhaden Matter, is pushing for caps on the Bay harvest. Menhaden support, by far, the largest commercial Bay fishery.

Menhaden reproduction has been poor in recent years, leading to fewer small fish for striped bass. But because the ASMFC’s stock assessment shows a healthy number of spawning-age menhaden, many scientists say overfishing is not a problem. Others contend that because the stock assessment covers the entire coastal population, it could miss localized problems for the Chesapeake.

In November, the ASMFC’s Menhaden Management Board called for a series of studies, including a review of whether a localized depletion of the menhaden stock is taking place in the Bay. It also wants a review of likely causes for the declining numbers of young fish, and an analysis of whether Bay-specific restrictions are warranted. It asked for a preliminary report by next August.

“The Board wants to ensure that its decisions are scientifically sound and represent the consensus of all interested stakeholders,” said board chair Jack Travelstead, of the Virginia Marine Resource Commission.

But the Menhaden Matter group expressed dismay, saying the commission should have at a minimum capped the menhaden catch in the Bay at current levels. “What we’re looking for is a long-term solution, but also short-term protection,” said Bill Goldsborough, senior scientist with the Chesapeake Bay Foundation, which is a member of the coalition. “What we proposed was really modest.”

The commercial catch in the Bay has declined in recent years, but the industry, based in Reedville, VA, has opposed capping catch levels, saying the move lacks scientific justification, and opens the door to further restrictions in the future. Industry representatives, and some scientists, have suggested the shortage of young menhaden in the Bay is more likely the result of predation by striped bass.

Jim Price, president of the Chesapeake Bay Ecological Foundation and a former charter boat captain who has raised concerns about the lack of menhaden in the Bay for years, called the ASMFC action a good “first step. I’m pleased that the states did what they did,” he said. “If they had asked for any more at this time, they probably wouldn’t have gotten enough states to do anything.”