Concerned about a precipitous decline in herring, the state has banned their harvest in Massachusetts for the next three years.

Also known as alewives, herring is the most valued bait fish in Vineyard waters.

The closure, which affects at least 100 herring runs along the Massachusetts coast, ironically comes at a time when Vineyard towns are taking steps to revive and improve their runs.

Still in flux is what the moratorium will mean at the Gay Head run, whose custodian is the Wampanoag Tribe of Gay Head (Aquinnah). The state has recognized the tribe's rights to harvest wild resources such as herring.

Alewives are a critical food source in the ecology of coastal waterways. Striped bass, bluefish and just about every other recreational fish feeds on herring. Ospreys and eagles feed on herring. Now cormorants are consuming large amounts of the fish.

The alewives spend their winters in the open ocean. Every spring, like clockwork, the fish return to climb up the herring runs to freshwater ponds, where they spawn.

But in recent years, fewer herring have been returning from the sea.

"There was a catastrophic collapse in many runs," said Mike Armstrong, a program manager for recreational and anadromous fish at the state Division of Marine Fisheries.

"We were watching the stocks going down last spring," Mr. Armstrong said. "We know that alewives go through cycles and we had actually proposed to drop the bag limit to take a little pressure off. But last spring the stocks didn't just drop - they dropped a whole lot in many runs."

On Nov. 9, the matter was brought before the state Marine Fisheries Commission, which enacted the moratorium.

"This is the most dramatic fisheries actions we've taken," Mr. Armstrong said. "This is a little more daunting because it is coastwide."

Connecticut fisheries managers have had a closure on the taking of alewives for two years. Rhode Island could follow right behind Massachusetts with a ban, Mr. Armstrong said.

The Vineyard has four herring runs. The Gay Head run is the oldest continuously operated herring run on the Island. The Richard F. Madeiras herring run at the head of the Lagoon Pond is the most popular run and attracts fishermen from all over the Island. Tisbury has a new herring run at the head of Lake Tashmoo, which is just showing signs of becoming effective. Edgartown is in the midst of completing a five-year program to revitalize the old herring run at Mattakesett, Crackatuxet and Edgartown Great Pond.

The Richard F. Madeiras herring run has been a success story in the restoration of herring runs. In the year 2000, the towns of Oak Bluffs and Tisbury issued 200 herring family permits for those interested in catching herring.

But last year, the numbers of herring were so low that Tisbury shellfish constable Derek Cimeno said the joint town herring committee which oversees the run even considered having its own moratorium.

Of the statewide closure, Mr. Cimeno said: "This is a good thing. It was coming to that. This gives us a three-year window to get some counts up and better knowledge on what is going on. We will step up enforcement. Poaching is a big issue. We will be vigilant."

The fish have been in decline at the herring run in Aquinnah.

Brian Vanderhoop, Aquinnah shellfish constable, has held the lease to fish the Gay Head herring run for the last three years. His brother, William (Buddy) Vanderhoop, has fished the herring run for 30 years before that. Both have noticed the decline.

Brian Vanderhoop believes the cormorants have had a big impact on the fishery. "We watch them eat herring for breakfast, lunch and dinner. They eat everything. They decimated the perch in Squibnocket Pond," he said, adding:

"We are not the ones doing the damage. During the fishing season we will let the herring run free for four days out of the week."

Last year, Mr. Vanderhoop harvested 10,000 fish, according to the tribal records. He harvested 10,000 fish in 2004 and 6,000 fish in 2003. Mr. Vanderhoop sells the herring to lobstermen for bait and to recreational fishermen.

Meanwhile, Edgartown is in the midst of a five-year plan to revive the herring run that connects Katama Bay to Edgartown Great Pond. With the help of grants, private funds and local tax dollars, the town has spent over $300,000 to revitalize the run, through permitting and construction costs.

Shellfish constable Paul Bagnall said he saw herring coming up the old run for the first time last spring.

"I hope they are coming back," Mr. Bagnall said. In the 20 years he has been a shellfish constable, he sees the return of the herring as an important step.

Some say blame for the decline in the fishery lies offshore rather than in harvesting at the runs.

"It ain't the guy at the end of Lagoon Pond with a scoop net that wants 20 fish, it ain't him," Mr. Bagnall said.

"What fascinates me is that there has been a mistake and the people who will suffer are the people who aren't responsible for the decline," agreed Cooper A. Gilkes 3rd of Edgartown, who runs a recreational tackle shop.

"For hundreds of years there has been herring," Mr. Gilkes said. "My feeling is that this problem didn't arise until we opened the outside Atlantic herring fishery. It was quick and too sudden. I think our herring are being taken along with the Atlantic herring that are being fished."

In the Gulf of Maine, the New England Fishery Management Council took action to cut the fishing effort of boats using purse seine nets from June through September in the pursuit of Atlantic herring.

Council spokesman Pat Fiorelli said new federal regulations are being written to further limit the number of fishermen pursuing Atlantic herring because of concerns about declines in forage fish.

Mr. Vanderhoop said he and his brother Buddy wrote a letter to the state last October suggesting that a prohibition on the sale of herring in Massachusetts was a better idea, because it would curb the alewives coming into New Bedford harbor through the Atlantic herring fishery. But Lori Steele, an Atlantic herring fisheries analyst for the New England Fishery Management Council, questions whether that fishery is responsible for the alewife decline.

Atlantic herring, which spend their whole lives in the ocean, are a distant cousin of alewives. Hundreds of tons of Atlantic herring can be harvested by a single fishing boat in one trip in the waters south of the Vineyard.

"The data we have isn't indicating it is a result of the Atlantic herring bycatch," Ms. Steele said.

She said there is intermingling between alewives and Atlantic herring but not many alewives are being caught in the nets. "It is an important issue and we are certainly looking at it," she said.

Mr. Gilkes said another culprit in the decline of herring could be the cormorant.

"I think the impact of cormorants is huge, as far as I am concerned. There are so many cormorants on Sarson's Island, you can smell them from the bridge," Mr. Gilkes said. Sarson's Island in Sengekontacket Pond was originally built up to help the tern populations during the summer. In recent years the little island has become overrun with cormorants.

"Just watch the birds. They just sweep all the fish. The cormorants have decimated the winter flounder fishery. Those birds decimate those fish and we sit back and do nothing," Mr. Gilkes said.

Efforts have been growing in Massachusetts to increase the number of herring runs in the state, Mr. Armstrong said. Fishermen recognize the importance of the fish in the ecosystem.

Last month, Mr. Armstrong went before the November meeting of the Massachusetts Striped Bass Association to talk about the fish closure.

"I spoke to them thinking that I was going to get slammed for the closure," he said. "But you know, they agreed with me. These are the guys who go out and live line for striped bass with herring in Cape Cod Canal. Instead of slamming me they voted to support the ban."

The Wampanoag Tribe has asked tribal members to comment on what degree the Aquinnah herring run should be shut down. One option may be allowing only tribal members to take herring for sustenance, and closing the run for commercial use. Spencer Booker, a ranger for the tribe, said herring are an essential part of the culture and lifestyle of the Wampanoag people.

"It is a cultural resource, a spiritual resource. We take our role very seriously as benefactor and protector of the creek. The history goes back thousands of years. Herring to the Wampanoag tribe is as important as electricity is to the 21st century," he said.