What began as a question about the ecological impact of the Atlantic menhaden catch in the lower Chesapeake - the largest commercial fishery in the Bay - has turned into a heated debate.

The controversy began after the Chesapeake Bay Foundation proposed a study last fall that would probe the impact that the massive menhaden catch may have on the Bay's food chain.

The group took its proposal to the Virginia Marine Resources Commission's Recreational Fishing Advisory Board, which expressed support for the idea and recommended that VMRC support the study with money from the Saltwater Fishing License Fund.

That action, though, brought opposition from the two Virginia companies that catch menhaden and their trade group which contended that the study was both scientifically flawed and biased against the industry.

Caught in the middle, the full commission ended up rejecting the advisory board's recommendation when it came to them in October, saying it supported the study but that the money should come from another source.

"They just did not want to tie up that money for fear that it would be another element that polarizes the commercial and recreational fishermen," said Jack Travelstead, chief of VMRC's Fisheries Management Division." They never really said anything about whether they thought the study was good or bad or should be done or shouldn't be done, but they just didn't believe that the recreational license money would be appropriate to spend on the study."

Ironically, the controversy involves a fishery that - unlike many in the Bay and along the East Coast - is in good shape. Menhaden populations have been stable for years. Rather, the worry is about multi-species interactions - how actions affecting one species may impact another. It is an area of increased concern for fisheries managers, but also an area that is more poorly understood than many single-species management issues.

Menhaden, a valuable commercial species, are one of the most abundant species in the Chesapeake. They feed primarily on algae and, in turn, become a food source for predatory fish, including such popular sport species as striped bass and bluefish.

The annual catch of Atlantic menhaden is about 400,000 tons a year - making it the third largest fishery, by weight, in the United States. The top two are Alaskan pollock and gulf menhaden.

About 200 million pounds of the fish are taken annually from Virginia Bay waters - more than 20 times the catch of all other finfish species combined. Menhaden are used for fish oils and meal for livestock feed.

But some scientists and recreational fishermen have questioned whether the intensive pressure in and near the Bay is affecting the food supply - and therefore the number - of other fish species.

"All we're saying is, this is an area where there is insufficient information and this is a first step to providing more information in that area," said Bill Goldsborough, a fisheries scientist with CBF. "What this study attempts to give us is a relatively inexpensive first look at these questions that might indicate whether it is justified to go through the expense of a long-term, integrated study."

Last year, a bill backed by many recreational fishermen was introduced in the General Assembly to ban menhaden fishing within a mile of shore. That bill did not pass, but the possibility of such restrictions has raised concern among the two Virginia-based companies that catch menhaden, AMPRO Fisheries and Zapata Protein. Both are located in Reedville, where they employ more than 500 workers, and they account for about 70 percent of the coastal menhaden catch.

"The menhaden fishery on the Atlantic Coast cannot survive without the harvest of menhaden from the Chesapeake Bay as a part of the overall harvest,"said Richard Gutting Jr., of the National Fish Meal and Oil Association, an industry trade group.

The companies fear that information from the proposed study - which proponents have described as a "first step" toward understanding the ecological impact of the menhaden fishery - would be misused to impose new restrictions.

That concern was backed by a peer-review of the proposal by the National Marine Fisheries Service's Beaufort Laboratory, which is responsible for monitoring the coastal menhaden population. "Because there is a very high potential for this study to be misused, a high degree of caution must be used in presentation of findings," the NMFS reviewers said.

NMFS said the study would not provide information with "any degree of precision" that would be useful for management. At the same time, NMFS reviewers said the study would be "a useful exercise that may produce some insights into the complex dynamics within the Chesapeake Bay."

The $58,000 proposal called for constructing a computer model of the "trophic system" - or food chain connections - related to the menhaden in the Bay. The modeling work was to be done by two former researchers from the University of Maryland's Chesapeake Biological Laboratory, Kyle Hartman and Stephen Brandt.

Both scientists have since moved to the Great Lakes Center of the State University of New York's College at Buffalo, but remain interested in the study if new funding is found. Hartman said the study was useful because it would shed light on how the management of one species may affect others in unexpected ways. "The bottom line is, there is no better way to get that kind of information," Hartman said.

NMFS reviewers and industry representatives expressed doubt that there was enough information about the interactions to develop such a model with "sufficient precision" to be of use to managers.

Hartman said the model would be tested by trying to simulate known interactions in the food web. If it cannot do that with reasonable accuracy, it would help identify what new information research efforts should concentrate on gathering.

But industry representatives are concerned about pushing ahead with a model while questions remain about the quality of information going into it. In a letter to the VMRC, the industry trade group contended the study was primarily intended to "provide the necessary information for a successful passage of similar legislation" as was proposed last year. As a result, the association stated, "one must conclude the proposal is biased and the results predetermined."

"The industry takes any effort that might impede the likelihood of its survival very seriously," Gutting said.

The industry has said it would support "a long-term, integrated monitoring approach to examine geographic and seasonal complexities in the Chesapeake Bay [that] would generate worthwhile information." Officials say they will never support the study proposed by CBF.

Goldsborough, meanwhile, said a better understanding of the Bay's food web would ultimately benefit all species, including menhaden. He said CBF would seek funding from other sources. "I'm quite confident," he said. "It's part of a substantial mo vement within science toward multi-species research and better understanding of interspecies relationships. A lot of work had been done along these lines already in the Bay by these researchers and others."

No one disputes that menhaden play an important ecological role in the Bay and that more information about that role should be sought. One recent Bay Program report called it an "ecologically critical species," while a NMFS report said that the role of menhaden as prey for other species "needs consideration with respect to multi-species resource management."

The Bay serves as a major nursery for young menhaden, and in the spring their numbers in many tidal rivers overwhelm those of other fish.

The main concern has been "growth overfishing," in which many fish are caught before they reach their full size. While growth overfishing is not a concern to the overall health of the stock, it can raise some ecological concerns. Some have sugges ted, for example, that harvesting menhaden before their full size reduces the amount of phytoplankton they consume.

The more algae consumed before they are harvested, the less that is left to sink to the bottom of the Bay where it decomposes and depletes the water of oxygen. Scientists at the University of Maryland's Chesapeake Biological Laboratory have estimated that about 9 percent of the Bay's nitrogen is removed by "grazing" menhaden - a number that could hypothetically be maximized by allowing fish to grow larger before harvest.