Bait fish that were once plentiful in the waters around the Cape and Islands have grown scarce. And recreational fishermen want Congress to step in to help do something about it.

Menhaden, also called bunker, have all but disappeared. Atlantic mackerel had a weak showing this spring. Even squid are down; the commonwealth has extended the spring fishing season into June to help commercial draggers meet the state quota, but the bigger question is what happened to the squid?

The Cape Cod Salties, a commercial and recreational fishing organization that has 200 members, has mounted a campaign to have the federal government stop the overfishing of menhaden.

Louis M. MacKeil, vice president for environmental affairs for the Salties, said his organization is concerned about the state of fisheries in Cape Cod waters and has made the issue a top priority. Fishermen worry that the dramatic declines in menhaden will affect the striped bass fishery.

“Striped bass are migratory inshore fish. Without sufficient food along the coast they won’t come. There are two things we need. We need a good habitat and viable food. They need a good food source in order to sustain themselves,” Mr. MacKeil said, adding:

“We have the management to protect the striped bass and it is working. Now we have to look at the environment and their food source.”

The remaining school of menhaden can be found south of the Vineyard and off the Carolina coast. But they are the target of large fishing boats with fine mesh nets.

But it is not only menhaden that are in trouble. The numbers for alewives, or river herring, are also low. Though the state banned the harvesting of river herring in state waters for three years, and the first year of another three-year moratorium just began, the alewives seem to be recovering slowly. The greater concern is that while the moratorium is in effect, the herring are being caught far offshore, outside of Massachusetts state waters.

Buddy Vanderhoop, an Aquinnah charter fisherman, wrote a letter to the New England Fishery Management Council last month, urging the council to take action to protect bait fish. Fishermen on the Cape and Islands have initiated a letter campaign to lawmakers seeking help.

A form letter to Cong. William Delahunt is being circulated by the Cape Cod Salties. “Please help end the industrial fishing for Atlantic menhaden, and allow this keystone species to return to its former level of abundance throughout their range,” the letter reads in part.

Mark Forrest, chief of staff for Congressman Delahunt, said the letters are coming in.

“We’ve heard from a number of fishermen on the Cape and on the Island who are concerned about the overharvesting of menhaden and bait fish,” Mr. Forest said in a recent interview. “I think there is frustration with the Atlantic States Marine Fisheries Commission, that they haven’t acted aggressively enough.”

The commission is a regional management authority that brings state fisheries managers together to oversee the fish stocks that travel up and down the coast. The commission is well known for its efforts to restore striped bass in the 1980s, but its oversight of other species, especially menhaden, has been criticized.

Mr. Forrest said to date federal legislation to prohibit the commercial harvesting of menhaden has been unsuccessful. “In the last Congress there were a couple of measures that were introduced that were not successful,” he said. “So there is renewed interest in getting something through Congress now.”

The large fishing fleet that works out of Virginia has been effective at lobbying against government intervention to protect bait fish.

Meanwhile, Mr. Forest said menhaden are the subject of growing research. “There are 15 research projects on menhaden. Most of it is being done in the Chesapeake Bay. A lot of the research is being underwritten by the Atlantic States Marine Fisheries Commission,” he said, adding:

“The question that’s unclear is whether the species declines due to harvesting, predation or is it environmental degradation.

“We are looking closely at this. When there is concern out there, we are concerned.”

Mr. Forrest said his staff also are in talks with people at the National Oceanic and Atmospheric Administration about the problem. “We know the recreational guys are concerned and it also points to the larger issue, the ecosystem,” he said, adding:

“Our next step is to talk with Paul Diodati [director of the state Division of Marine Fisheries]. We need to look at where we can collaborate.”

He concluded: “Fishing issues are not just matters of concern to fishermen. You have a larger constituency that is interested in the affairs of the sea. People feel a connection to the saltwater.”