HARPSWELL, Maine — David Wilson thought clam harvesting was bad last year.
But the clam digger of 20 years and chairman of the town’s Marine Resources Committee this week said 2012 marks a new low.
In some of his good years, he said, he could make up to six figures in income. Now he’s thinking about getting a second job.
“This year I haven’t harvested a quarter of what I harvested last year, and I thought last year was the worst year I’ve seen digging,” Wilson said. “In the past we’ve had clams everywhere in town, and now we don’t.”
State biologist Denis Knault said recent surveys found that three areas in Harpswell have high percentages of clams with stage-four neoplasia, a stress-induced disease that will kill the clams at a young age.
Orrs Island was found to have 23 percent of clams with stage-four neoplasia, Gurnet Landing with 30 percent and Beals Cove with 18 percent, the state biologist said.
But despite these new figures, Knault said this is only one piece of the puzzle in diagnosing the town’s clam decline. Other possible causes include the increase of predators such as green crabs and milk ribbon worms.
“There are many factors that can cause a decline in that area,” Knault said. “Can we change that? I am confident, yes, we can.”
The surveys were coordinated by Wilson, Knault, marine resource officers, harvesters and a biology professor at West Chester University in Pennsylvania who studies clam populations from New England to Maryland.
There were three other areas, the state biologist said, that had no signs of clams with advanced neoplasia.
Knault said the presence of the disease itself is not alarming, because it has naturally occurred for years. But the higher rates of clams at the deadly stage of neoplasia indicates that something has changed.
Why that’s the case is not known, he said. But he does know the disease happens as a result of stress, and there can be multiple causes of that.
Bloodworm harvesting is partially to blame, said Wilson, who helped survey Skofield Cove on Oct. 6.
“When you have worms in a clam bed, these guys are coming in over and over again,” the chairman of the Marine Resources Committee said. “The third time they do that, it stresses the clam to a point.”
Nineteen other harvesters were present that day, Marine Patrol Officer Kyle Neugebauer said, because two days of conservation work is required for them to keep their license.
In the past, he said, they used to only pick up trash. This year is different.
“This is the first year we’re using them to dig,” Neugebauer said. “Why collect trash when we can kind of help your resource here?”
Echoing the remarks of Wilson and other harvesters, the marine patrol officer said clam populations have been in decline for the area.
“There are two or three coves that just keep producing, which is nice, but these other ones are dead,” Neugebauer said, adding that the town is still trying to figure out the scope of the problem.
Knault said he cannot draw any conclusions about the cause of stage-four neoplasia in clams, because not all of the data has been collected, nor has there been enough time to analyze it.
But responding to Wilson’s claims about bloodworm harvesting, he said there might be some substance to the argument.
“We’re seeing some greater evidence of the intensity of bloodworm harvesting,” Knault said.
Since the worms are mobile, harvesters will dig up more mud to catch them, the state biologist said, and that can cause clams to be turned upside down and stressed.
After the harvesters finished their survey last weekend, Wilson and others huddled in the woods next to the cove to discuss their frustrations with the decline in the past few years.
Gordon Austin, who has been harvesting clams for most of his life, said efforts to reseed clams in other areas and grow the population in the past have failed.
“No, it’s never worked. Every time we’ve [taken] seed from one area and put it into another, it never takes,” Austin said. “And I’m talking from the ’80s, when they first started it — in Brunswick, in Harpswell, in all of it. It’s never worked. It’s never worked to re-seed flats.”
Austin and Wilson said they don’t always see eye-to-eye with the biologists, and they doubt that conservation and research efforts will help if a growing clam population depends on colder water temperatures, especially during the winter.
“I argue and argue with them, like that was eight years ago when I was seeing them on Harpswell Cove, first hand,” said Wilson, who then imitated one of the biologist’s responses. “‘No, you don’t know what you’re talking about. They spawn when the water reaches a certain temperature.’ Then why am I seeing them when the ice leaves?”
Knault said there is some anecdotal evidence to support their claim that clams reseed better in colder climates. But he pointed out that the clam population is growing in other areas, including the mid-Atlantic, which generally has a warmer climate.
In response to Austin’s response about failed reseeding efforts, Knault said there may be other factors causing the failures that the harvesters haven’t considered. Other towns, such as West Bath, have had “tremendous success with reseeding,” he said.
Knault said he and two other biologists will continue to work on conservation issues like this to figure out the best way to approach the problem.
Despite Wilson’s doubts about the situation, he said the Marine Resources Committee is pushing for a conservation closure of Quahog Bay, which will have a public hearing the Board of Selectmen meeting on Oct. 18.
The action would close Quahog Bay four days a week, Wilson said, but he’s not sure it will do much good.
“That was an attempt from the committee just to try and make people happy,” he said, “because in the past, [people have said] ‘oh, you guys don’t do no management. You don’t want to shut down nothing.’ We shut down Quahog Bay four days out of the week. That’s still not going to solve nothing if you ask me. These clams are going to continue dying, whether we’re digging them or not.”