Herring are back and the numbers are stronger compared with a year ago. Also known as alewives, herring are one of the true coastal signs of spring and considered essential bait fish in the food chain.

While the reports of numbers this spring are improved over last year, they are at best cautiously optimistic. A state moratorium prohibiting the catching of herring has been in place since 2005. The ban was a response to a dramatic drop in the numbers of fish returning in the spring of 2004 and before. Recovery has been slow, if at all, until this spring.

Buddy Vanderhoop of Aquinnah said he has seen an improvement at the Aquinnah herring run this year. The run is owned and managed by the Wampanoag Tribe of Gay Head (Aquinnah) and is the longest continuously operating run on the Island. Mr. Vanderhoop is a charter fisherman.

David Grunden, Oak Bluffs shellfish constable, concurred with Mr. Vanderhoop’s report. Mr. Grunden said he has seen more herring at the fish ladder at the head of Lagoon Pond this year. But he said his observations are limited; as there is no counting method, making comparisons to past years difficult.

Prior to 2005, fishermen were allowed to harvest herring either for personal use or for sale. Fish markets once sold the much-desired roe, and lobster fishermen filled their bait barrels with herring. Sport and commercial rod and reel fishermen used herring as bait to catch bigger fish, especially striped bass.

Bret Stearns, director of natural resources with the Wampanoag Tribe of Gay Head (Aquinnah), said they saw the first signs of herring early this year in late March.

Alewives are anadromous fish, which means they spawn in fresh water but spend most of their life in the sea.

Mr. Stearns cited two possible reasons why the Aquinnah run experienced an improvement this spring. “The striped bass were late to arrive this spring. That to me meant that the fish were able to move toward the run without the pressure [of being pursued by their prey],” he said. “The other reason is tied to those big rainfall events we’ve had. All that freshwater entering into the pond — I think there was a big surge of fish heading toward the runs.”

Mr. Vanderhoop has his own theory. Herring have been less of a target for commercial fishing draggers in deep water in recent years, and the reduced pressure from the midwater trawlers south of the Vineyard has given the herring a chance to return to inshore waters, Mr. Vanderhoop thinks. A number of fishermen, including Mr. Vanderhoop, believe additional restrictions on large-scale harvesting of bait fish in waters south of the Vineyard and in Cape Cod Bay has helped the fish recover. While fishermen are prohibited from targeting river herring, it is understood that the herring have been caught as a bycatch. Fisheries managers at the state and federal level continue to claim there is not enough evidence to prove that midwater trawlers are responsible.

Mike Armstrong, a herring specialist with the state Division of Marine Fisheries, said he is getting mixed positive and few negative signs around the state. “There is a run in West Bridgewater, which is far upstream from the Taunton system. They believe they are seeing the most fish they’ve ever seen,” Mr. Armstrong said. “Back River, in Weymouth, has good news. They were very excited,” he also said. But other places didn’t do well. “I think we are up since the moratorium,” Mr. Armstrong said, “. . . I think we are headed in the right direction. At least we’ve heard a lack of negativity. Which is good news.”

In Edgartown, shellfish constable Paul Bagnall said osprey have been spotted feeding on herring in Crackatuxet Pond, another positive sign of recovery. And he said there are raccoons feeding on herring in the creek that runs parallel to Atlantic Drive by South Beach. The run was once known as the Mattakesett herring run.

Last March, the town used machinery to dig and remove vegetation that had grown up in the century-old manmade creek that runs from the Right Fork bridge to Crackatuxet. In addition, there was hand digging with a shovel along the creek to the east. The restoration work gave the fish a better chance to survive as they swim from Katama Bay to Crackatuxet Pond.

In late May a group of AmeriCorps volunteers from the Farm Institute worked on the sluiceway that connects the creek to the Edgartown Great Pond. Thanks to these efforts, Mr. Bagnall said: “The water is flowing.”

The Mattakesett herring creek was once the Vineyard’s biggest and most productive herring run. A century ago, the run provided spring employment, and alewives were shipped off-Island by the barrel. For a time then, herring were harvested and used locally to manufacture Priscilla Pearls.

The ban on harvesting herring has allowed attention to turn to restoring the waterways where the fish once prevailed. Mr. Armstrong heads up programs across the state to revitalize old herring runs. Each year they trap and transfer 40,000 fish by truck from working herring runs to places in need. The adults will spawn juveniles which will possess the necessary internal marker that allows them to return as adults to where they were spawned.

In recent years, Mr. Armstrong said the emphasis is now toward stocking waterways far upstream. A recent project included restocking Three Mile River in Bristol County.

For three years, starting in 2003, crews trucked fish caught in the Lagoon Pond to Crackatuxet Pond. Mr. Bagnall said he believes some of the fish in Crackatuxet Pond are a sign of the stocking program’s success.