The herring industry says the often repeated charge is baseless, and there's no reliable evidence their boats are threatening either the fishing industry or the ecosystem.
On Wednesday, the New England Fishery Management Council voted to require independent monitors on every trip for the Northeast's largest herring vessels. Both the industry and its critics backed the requirement Wednesday, confident they'll be vindicated when the observers report what the trawlers do and don't pull up.
"We need to clear the air of all the lies that's been spoken over the last five years," said herring fisherman Peter Mullen during the council meeting in Portland, Maine.
But recreational fishing advocate Patrick Paquette said the sheer scale of the boats and gear used means they can have profound, if unintended, negative effects. "This fishery needs intense monitoring," he said.
The measure isn't expected to go into effect until at least spring 2013, as the industry and managers figure out how pay for it.
The tiny herring — no more than a foot long — are eaten pickled, but are more often sold as bait for more valuable species, such as lobster. They're seen as crucial by environmentalists and fishermen as food for numerous important species, from striped bass to whales.
Herring, a schooling fish, gather in masses that can extend miles. The largest herring boats, called midwater trawlers for the part of the water column they work, sometimes tow 100-yard long nets between them and can pull up hundreds of thousands of pounds of herring at once. About 46 boats, accounting for about 98 per cent of the catch, would be affected by Wednesday's vote.
Critics say these large trawlers aren't just depleting herring stocks, they're also inadvertently sweeping up struggling species such as cod, preventing their populations from rebounding.
They also say trawlers are snaring the river herring that mix with Atlantic herring, hurting the local ecology and thinning out cherished "herring runs" that occur each spring, when residents watch the fish return to upstream birthplaces to spawn.
Anecdotal stories abound about rich fishing areas going dead once the trawlers pass through.
"I've heard these claims of a clean fishery, not much dumping," Darren Saletta of the Massachusetts Commercial Striped Bass Association, told the council. "Then you see these boats come through with nets the size of football fields and just clean the place out."
But trawler operators say herring are abundant, and all the evidence shows they aren't pulling up large amount of unwanted fish.
They say people look at the hulking boats, which can be as long as 165 feet, and make faulty assumptions about the damage they do.
Jeff Kaelin, of Lund's Fisheries on Cape May, N.J., which fishes for herring, said he was looking forward to absolution from the observers.
"I'm pleased today that this long process of innuendo and accusation and class warfare ... may actually be coming to an end," he said.
The cost of the observers emerged as a key topic after the vote. Earlier this month, the National Marine Fisheries Service told the council it had no money to fund additional herring observers. The industry says it's willing to pay $325 for each observer, each trip, but that's well below a projected cost of $750 per day for about 375 additional trips annually.
Council members eventually voted to delay their measure a year, until the industry and regulators figure out how to pay for the monitors. The status quo includes monitors on some, not all, herring trawler trips.
"I don't see any other way forward here," said council member David Goethel, a New Hampshire fisherman.
The council also voted to set a cap as soon as possible on how much river herring the Atlantic herring fleet can catch accidentally.