One of the smallest fish in the Chesapeake Bay is also one of the most critical. Atlantic menhaden have been called “the most important fish in the sea” because of the vital ecological and economic roles they play in the bay and along the Atlantic Coast.

Filter feeders, the silvery fish form massive schools that sweep through the water eating microscopic plants, animals and detritus. Young menhaden are sardine-size, but they can grow into foot-long fish that are bony, oily and considered quite unpalatable by human tastes.

Other critters love them, however. Menhaden are a major food source for striped bass, bluefish, summer flounder, weakfish, dolphin, whales and iconic Chesapeake birds such as ospreys, loons and pelicans. Seventy percent of an adult rockfish’s diet typically has been menhaden. If you love angling for stripers or dining on rockfish fillets, you have to love menhaden, the little fish that makes it all possible.

But all is not well. And in Virginia, one peculiar legislative oddity could stand in the way of badly needed action.

For many years, menhaden numbers have been declining dramatically in the Chesapeake Bay and along the Atlantic Coast. Today, they’re at their lowest levels on record, or about 8 percent of unfished numbers. The Atlantic States Marine Fisheries Commission, which manages the coast-wide menhaden population, has concluded that menhaden have been experiencing overfishing for at least 32 of the past 54 years.

Equally disturbing are scientific reports that osprey in the lower bay are suffering malnourishment linked to fewer menhaden; similar concerns have been raised about striped bass.

Help for menhaden could be on the way. But two things need to happen first.

First, the Atlantic States Marine Fisheries Commission, which is considering steps to address the menhaden decline, must produce an aggressive action plan. Reducing annual harvests by 25 percent or more, for example, is an essential first step for allowing the population to recover. The commission will release a new conservation plan this month.

Second, East Coast states must implement the plan — including Virginia. If Virginia fails to adopt meaningful catch restrictions, menhaden simply will not recover.

That's because menhaden are the target of an intense, industrial-scale fishery operating in the Chesapeake Bay and off the mid-Atlantic coast by Omega Protein Corp. This “reduction fishery” uses spotter airplanes, mother ships, small boats and giant nets to catch vast quantities of menhaden and bring them ashore to Reedville, Va. There, they are processed into fish meal and oil for vitamin supplements, cosmetics and animal feed. Eighty percent of all menhaden caught on the East Coast come back to Reedville, making the tiny town one of the nation’s largest fish landing ports (by weight) and providing several hundred local jobs. Any conservation plan that doesn’t apply to Virginia and the Omega Protein plant will have little effect.

But there’s a problem. In Virginia, fisheries decisions are made by the state’s Marine Resources Commission — except when they relate to one species. Yes, you guessed it: menhaden, which is instead managed by the 140 members of the General Assembly. This odd arrangement puts politicians, lobbyists and money, rather than scientists, in charge of menhaden. This, it goes without saying, does not bode well for making the tough choices needed now.

To overcome this, it is vital that Gov. Robert F. McDonnell (R) take a leadership role in support of legislation that implements meaningful menhaden conservation. Powerful and successful precedents argue that he do so. Virginia took strong steps in the past to successfully rebuild the striped bass population and to spur the rebound of blue crabs in the bay. The recovery of these species, and of menhaden, will benefit everyone, including Omega Protein, watermen, anglers and wildlife.

The fate of the “most important fish in the sea” may well depend upon it.

The writer is a senior scientist for the Chesapeake Bay Foundation.