Clammers will hit Holmes Harbor for the first time in eight years this spring.

The digging will be short lived, however.

State fishery officials announced that the area will reopen from April 1 to May 15, pending formal approval by the Washington Fish and WildLife Commission.

The narrow window is largely the result of an unexpected and unwelcome development — the expanded presence and domination of varnish clams.

According to Camille Speck, a state Department of Fish and Wildlife biologist based out of Port Townsend, the non-native species moved in while the fishery was closed and is pushing out native clams, particularly Manilla and butter clams.

“It was a little bit of a rude shock,” Speck said during a telephone interview.

WHIDBEY ISLAND has few good public beaches to dig clams, and Holmes Harbor was one of the best, she said. Having lain untouched for nearly a decade, she was expecting to find a stable and healthy fishery.

Instead, survey digs in 2008 and again this year showed the once prevalent Manilla and butter clams to have declined from four individuals per square foot to under one and a half.

During the same period, varnish clam numbers jumped from about seven- and-a-half per square foot to nearly 11.5 per square foot.

For clammers who eagerly anticipated the reopening of the once popular South Whidbey hotspot, which used to be open year-round, news of the six-week season is disappointing.

“That’s a shame,” said Eugene Thrasher, Whidbey’s widely recognized clamming guru.

A BEACH WATCHER with Washington State University Extension, Island County, Thrasher has taught clam digging classes on South and Central Whidbey for years.

“This particular beach was loaded with steamers … You could show up and in 20 minutes have your limit,” he said.

Holmes Harbor was closed to shellfish harvesting in March 2007 with the formation of the Holmes Harbor Shellfish Protection District. Required under state law, it was created by county commissioners due to the presence of fecal coliform bacteria in water samples.

County workers and the community worked to clean up the watershed, identify problem septic systems and launched initiatives such as a campaign to pick up dog waste at Freeland Park.

No smoking gun was ever discovered, but water quality from fresh water outlets has improved significantly, according to state Department of Health officials.

IN A recent letter to local regulators, the agency said Island County’s long efforts paid off, but additional monitoring of the shoreline revealed the presence of Enterococcus bacteria, a genus of lactic acid bacteria, during peak summer months. It was especially present in wrack, the often smelly carpet of seaweed/organic material that collects on the beach at Freeland Park.

The results were enough to warrant a “conditional” reopening of the beach for nine months of the year.

Island County Public Health Director Keith Higman said the reopening, though limited, is welcome news and a testament to the county’s long efforts.

THE DECISION to reopen the fishery and set harvest dates is up to Fish and Wildlife, not the Department of Health, however, and the two agencies have left the county facing legal and scientific questions.

For one, it’s unclear what a limited “condition” reopening by the department means in terms of the existing protection district and whether the commissioners have the green light to dissolve it.

“We’ve posed that question to DOH and we haven’t gotten an answer yet,” Higman said.

There are only a handful of protection districts in Washington and there isn’t a lot of precedent for removing them.

Higman said the agency may research the question with its legal department about just when it can give the county the OK.

ALSO UNCLEAR is from where the Enterococcus bacteria orignated, Higman said.

Enterococcus is part of the normal intestinal flora of humans and animals, which means the contributor could be nothing more than wildlife.

“If it’s seabird poop — does that constitute a health risk?,” Higman said.

Experts are also baffled by the seeming take over of varnish clams. Appearing in the 1980s, they are native to Asia.

While they are all over Puget Sound, they haven’t been known to outcompete regional species.

Speck said she wants to know why.

“This presents a pretty exciting opportunity,” she said.

BIOLOGISTS SAID they hope to discover what’s happening through studies and testing. Part of that will include removing the offending varnish clams in small areas and reseeding it with Manilla and butter clams. They will be small, however, and crops take from two to four years to cultivate.

“I’m talking a one-fourth acre or less of the seven acres of productive habitat,” she said.

Depending on the results, future transplants may occur.

A limited fishery will likely be the case for many years to come, Speck said. There is some discussion with local tribes to harvest varnish clams as crab bait, but it’s unclear whether that will materialize or expedite the return of local species.

Varnish clams are OK to eat, though they aren’t as tasty as steamers or Washington little necks, Thrasher said.

Also, they are known to carry paralytic shellfish poisoning, or PSP, for longer periods of time.

HARVESTED VARNISH clams, invasive species or not, will be applied to a clammer’s catch quota, Speck said.

Despite the development and setback to returning to year-round harvest, Speck said she’s optimistic.

“It’s not without hope,” she said. “The water quality story is a huge success.

“We can improve the fishery with time.”