State health officials will today conduct an inspection of the Aquinnah laboratory whose fluctuating test results have led to a series of recent beach closures on Martha’s Vineyard.

Late yesterday a spokeswoman for the state Department of Public Health, Jennifer Manley, confirmed the audit of the Wampanoag tribe lab, but said it was routine and not related to recent results of water sampling.

She said, in an e-mail response to questions about the visit, that such audits sought to ensure “that all protocols, methods and quality assessments are followed.”

Questions continue to be raised about the numerous beach closures over recent weeks, all prompted by water quality tests carried out by the Aquinnah lab, which found high levels of enterococcus bacteria.

Yesterday the Martha’s Vineyard superintendent for The Trustees of Reservations, Chris Kennedy, said he found the results “not believable.”

“What I’ve heard about the staff at the Aquinnah lab is that they’re very professional and take their job very seriously. But there is something happening here,” Mr. Kennedy said. “I’m not saying it’s the lab. Maybe it’s all the samplers in all the various towns and the Trustees doing it wrong. Maybe it’s dirty bottles. Who knows?

“But when you look at all of the evidence you have to ask yourself if this makes any sense. And it doesn’t make any sense.”

Mr. Kennedy said on one day a couple of weeks ago, the DPH Web site which lists the status of all the state’s beaches showed that of 107 beaches, public and private, from the Cape to the south shore, including Nantucket, 106 were open.

“The only one that had been closed was in Fairhaven, right outside of the New Bedford harbor. And yet 10 beaches on the Vineyard had been closed that same week because of [high] bacterial readings,” Mr. Kennedy said.

“This is not believable. How can all those other beaches pass the health standards, yet 10 on Martha’s Vineyard were considered too dirty to allow people to swim?”

Mr. Kennedy said he found the situation very frustrating.

“It’s frustrating not only from the point of view of the visitors who come here to relax and spend some time with their families and friends and enjoy the beaches. It’s also very frustrating for the beach managers and all of us who live on the Island and understand what the economy of this place is built on. It’s built around the beaches,” he said.

The accuracy of the tests was called into question in part by the fact that Tisbury, the one Island town which does not use the Aquinnah lab, but does its own testing, had no closures.

Subsequently, Edgartown health agent Matt Poole sent water samples from South Beach in Edgartown to both the Wampanoag Tribe lab and the Tisbury town lab. The samples sent to Tisbury came back clean, while the samples sent to Aquinnah showed unacceptable levels of enterococcus bacteria, the same bacteria that forced a series of state-mandated beach closures in West Tisbury, Oak Bluffs and Chilmark. Mr. Poole also sent samples of Poland Spring bottled water to each lab.

The sample sent to Tisbury tested clean, while that sent to Aquinnah again was found to contain unacceptable levels of the bacteria.

Yesterday Bret Stearns, natural resource director for the tribe, insisted there was no problem with the lab.

“I can’t elaborate too much. I know that a long time ago the Department of Public Health made an appointment with the Island health agents to go around and meet with them. And they usually come out and meet with us when they meet with the agents. But that has nothing to do with results; it has to do with an annual check in.

“I think they are just checking in to say hi. I don’t think they are going to be going over any data. If they have an issue with data, they take care of it when it happens,” he said.

“I know they don’t have any problems with any of the results that we’ve provided,” he said.

Chilmark health agent Marina Lent cautioned against any rush to judgment about where the problem lies. It could have been with the collection of the samples or the handling of them before they reached the lab, or could be due to chance, she said.

“The sampling technique is very important,” she said.

“Any direct contact by a finger can contaminate [a sample]. People don’t realize how dirty our hands are.”

The [people collecting the samples from the ocean also had to be extremely careful how they did it, Ms. Lent said.

“You have to use the correct technique in plunging the vessel face down. If you put it in right side up, when the rim of the vessel hits the water surface, it sucks in the water faster from the surface than from a little bit below.

“You have to wade out about hip deep and plunge the bottle in and put it down a certain distance below the surface, so it fills from the middle of the water column.

“So sampling technique does leave a fair possibility of error.”

Nor was the fact that bottled water tested positive necessarily indicate poor lab practice, she said.

“Bottled water is not guaranteed sterile. You would be better using medically sterile sealed samples,” she said.

Ms. Lent said it was characteristic of the type of bacteria to cluster together, making it possible for one sample to come up with high levels and another to read low.

“There’s always a degree of chance — where you dip your bottle in. You can’t see if there is a bit of fecal matter that’s just broken up into pieces too small to see,” she said.