ROQUE BLUFFS – For the past week, residents living next to Sanford Cove have been beset by an increasingly overpowering stench of rotting fish that have washed up on the shore.

It forces people to keep their doors and windows shut and to dry their laundry inside. One family whose house overlooks the cove has had to erect plastic owls on the roof to prevent hordes of gulls from perching there between bites of decaying fish flesh. The gulls stay off the roof now, but the splotches that remain prove they were there.

It is hard to tell how many dead herrings stretch for hundreds of yards along the shore, but to say it numbers in the thousands is an understatement.

“We’re not used to this,” Vicki Kelley, whose parents own the golf course across the road from the cove, said Monday. “It makes you want to move.”

Lucille Sinford, Kelley’s mother, said the stink has affected their business. The dead fish started washing up about a week ago, but the smell has been getting steadily worse.

“Yesterday, our golfers started leaving,” Sinford said Monday. “We never have an odor off the clam flats. It’s always been so clean.”

The cause of the mass fish death is being investigated by the Maine Marine Patrol, but residents believe they know how it happened. Seine fishermen, whom they did not mention by name, closed off the cove at high tide on July 14 but trapped too many herrings in the cove and couldn’t handle the catch. Thousands upon thousands of fish died in the nets, suffocating under their own weight as the retreating tide pushed them tighter and tighter into the mesh, they said. The fish that died later were washed back to shore, where they lay rotting in the sun.

Birds descended upon the mud flats, pecking at the corpses. Lobstermen, who use herring as bait, showed up to load handfuls of the free lobster feed into buckets.

Darrell Richards, who lives on the cove just east of the Sinfords, said he has a fisherman friend who showed up at the cove the next day.

“He went down there and picked up 45 buckets Sunday afternoon,” Richards said. Bait prices have increased so that it costs about $10 for a 5-gallon bucket of bait, he said, which means his friend saved $450.

“When the wind is [directed toward] shore and the tide is out, it can gag you,” he said. “I know guys are trying to make a living, but there’s no need for that.”

Gordon Faulkingham, a Marine Patrol officer, appeared at the cove Monday afternoon to take stock of the situation. Without commenting on the fish kill in Sanford Cove, he said that in the late 1950s, seine fishermen caused a mass fish death in Faulkingham Cove on Great Wass Island, near where he grew up.

The rotting fish poisoned the clam flat there, the officer said, and only within the past few years has the cove been reopened for digging.

Skirting the edge of Sanford Cove on Monday, Faulkingham noted that most of the fish in the cove seem to be piled around the edge rather than lying out on the mud in the cove where clammers dig. He said more dead fish were piled up on a stretch of shoreline nearby, out of sight around a nearby point of land. But most of the fish seemed to be at the northern end of the cove.

“This is bad right here,” he said.

Matt Young, who works for the Maine Department of Environmental Protection in Bangor, said Monday he was contacted about the fish kill at the end of last week. He said that, as far as he knows, DEP is not involved in the investigation because the kill was not caused by poor air or water quality. It would be different, he said, if the fish were killed by some sort of substance in the water.

“It’s a fishing issue,” he said. “There’s little to nothing I can do.”

Young did say that he was trying to contact commercial composters to see whether they might be interested in cleaning up the dead fish and selling it for their business.

Leon Sinford, however, doesn’t think that’s about to happen. He said the local residents would just have to put up with the smell until it fades away naturally.

“That’s a dream,” he said, standing by a golf course green and looking out toward the cove. “How could they possibly? It would be like cleaning up an oil spill.”

If there is anything that happens, he said, he hopes it’s educational.

“I hope whoever’s done it can learn something from this,” Sinford said. “They couldn’t handle what they had.”