Questions have been growing for months about the coastal, and Bay, menhaden stocks as data have shown a conflicting picture of the population’s health.

Now, a first-ever review of Atlantic menhaden management has been ordered, and it could ultimately result in dramatic changes in how the species is managed.

Still, while ordering the review, the Atlantic States Marine Fisheries Commission decided at its June meeting not to reduce this year’s maximum catch, as some had requested.

In the Chesapeake, menhaden are important both as food for other fish and as a commercial fishery. Measured by weight, it is the largest commercial catch in the Bay. Some have claimed that the declining menhaden stock in the Bay is affecting the health of other fish, especially striped bass.

The ASMFC, which is responsible for managing migratory species along the coast, has not yet released the exact details of the upcoming review, but it was at a minimum to examine the methodology behind the stock assessment that annually determines the population’s health.

“Menhaden has never been taken out to an external peer review,” said Joe Desfosse, ASMFC fishery management plan coordinator. He did note, though, that the methodology used for the assessment has been examined. The new review is to be completed by October.

Recent stock assessments have shown dramatic declines in the number of young fish entering the population each year. As a result, the total population is declining, and the average fish is growing older.

At the same time, though, the assessment found that the spawning potential of the stock is high compared with the past three decades. Spawning potential is based on an estimate of the overall weight of the population, which is a predictor of spawning ability. That is happening even as the population shrinks because the remaining fish are growing older and larger.

Because the overall spawning potential remains high, the 1997 stock was deemed “healthy” by the National Marine Fisheries Service, which conducts the annual assessment, though it cautioned that problems could loom in the future unless reproduction improved.

Overall, the population has declined 58 percent since 1991, and that has caused some to question whether there are enough menhaden around for the larger fish that depend on them for food, such as striped bass, bluefish and weakfish.

“They say the stock is healthy, but it is not,” said Jim Price, president of the Chesapeake Bay Acid Rain Foundation, who has been raising concerns about the menhaden. “Back in the ’60s, when it was averaging 4.65 billion fish, they termed that ‘severely depressed.’ It’s 4.55 billion now. So you can’t say it’s severely depressed in the ’60s and say it’s healthy now when it’s the same level.”

To address those questions, the ASMFC-ordered review is expected to also look at whether its menhaden management plan adequately accounts for the role that the species plays as a food source for other fish. It will be the first time the ASMFC will have examined the role of a fish as prey.

The review could also examine such things as the makeup of the ASMFC’s advisory and management boards which oversee menhaden, Desfosse said. They are the only ASMFC boards that contain industry representatives.

In addition, the review may look at the regional impacts of the menhaden harvest. A disproportionate amount is caught in or near the Chesapeake, and some believe that could be the reason that fewer menhaden have been seen in the Bay the past few years.

Bill Goldsborough, senior scientist with the Chesapeake Bay Foundation, said the action was encouraging because, for the first time, the review will begin to account for interactions between species — in this case, the role menhaden play as food for larger fish.

“I’m happy with the outcome so far,” Goldsborough said. “I think it is taking us in the direction we need to go. Some might be impatient with the pace, but I think we’ve got significant movement in the right direction.”

But at the same time, the ASMFC decided not to reduce the amount of fish that can be caught this year, as some had sought.

ASMFC’s Menhaden Management Board accepted a recommendation from its technical committee that the harvest levels should not be changed from last year. In large part, that is because seven of the 22 ships used to harvest menhaden have been shifted from the Atlantic to the Gulf Coast — an action expected to reduce harvest by about 30 percent.

But there is concern among some that catches in and around the Chesapeake may not decline that much because all but two of the menhaden boats for the East Coast are based in the Bay.

“That’s one of our major concerns — 62 percent of the harvest is coming out of the Bay,” Price said. “That’s one of the reasons our fish in the Bay are showing up undernourished. There is too much pressure in the lower Bay.”

He said it’s possible that a lack of menhaden for food is adding stress to the Bay’s striped bass population, which has been at high levels in recent years. Last fall, Maryland Department of Natural Resources surveys found that 12 percent of the adult striped bass — which are most dependent on menhaden — had lesions.

Price said more of the same could be in store for this year. “I’ve examined a few fish in the past few days, and they are extremely undernourished.” He added that the approach of warm temperature will cause even more stress on the fish, which could lead to lesions. “I’ve talked to several people who have already seen some bad-looking fish,” he said.