BELLINGHAM - Asian clams have been found in Lake Whatcom, and their discovery has raised concerns that the non-native species could harm water quality, clog water-intake pipes, and stink up beaches as they accumulate and die off.
City and county officials are surveying the lake to determine the extent of the infestation, and to figure out what to do about the invasive clams.
That includes plans to send divers into the lake next week, and requests for lake residents to look for Asian clams in the shallow water and on beaches along their shoreline.
"We're hoping to get better informed as we go through this process," said Clare Fogelsong, environmental resources manager for the city of Bellingham.
It is hoped that the Asian clams found so far are "isolated infestations in Lake Whatcom that we caught early," said Laurel Baldwin, coordinator for the Whatcom County Noxious Weed Board.
First discovered in the U.S. in the Columbia River near Knappton in Washington state in 1938, Asian clams have since spread to 38 states and the District of Columbia.
Lake Whatcom is the first body of water in Whatcom County where the freshwater clams have been reported.
The clams live in sediment in the water. The ones found so far were less than an inch in diameter and with shells that were yellowish-brown to black in color.
Their presence was discovered when a resident collected them from his beach and showed them to state and local officials at a Sept. 17 demonstration boat inspection at Bloedel Donovan Park.
The event was put on by officials trying to battle the spread of aquatic invasives by educating boaters about the importance of inspecting and decontaminating their boats and trailers before putting them into water.
Since then, officials have been searching for the clams, Corbicula fluminea, in all three basins of Lake Whatcom, which provides drinking water to 95,000 residents in Whatcom County. The lake is about 10 miles long and a little over one mile wide at its widest point.
As of Sept. 30, local officials have found well-established colonies of Asian clams in the swimming area at Bloedel Donovan Park and at Western Washington University's Lakewood recreational facility. They may have been in those locations at least two to four years.
Those colonies are near recreational areas with boat access, and Lakewood also is near a floatplane facility called Floathaven Seaplane Base, according to a report from the Lake Whatcom Management Program.
That proximity might indicate how the clams ended up in Lake Whatcom although it's not certain, according to Fogelsong.
Those two areas were part of four hotspots along the shores of Lake Whatcom. The other two sites were at a North Shore Drive residence and a beach at Britton Road/North Shore Drive.
And Asian clam shells, but no live clams, were found at the Sudden Valley Marina.
The good news would be if some of the clams washed across shallower beaches across the lake, which means the presence of a series of small infestations.
The bad news would be one large colony responsible for all four of the hotspots, Fogelsong explained.
Asian clams might have entered the U.S. as food used by Chinese immigrants, with the importation of the Giant Pacific oyster from Asia, introduced as live bait, or brought to the U.S. in ship ballast water.
The clams are native to southern Asia, Australia and the eastern Mediterranean. Thousands of them can crowd into a square meter as they compete with native mussels for food and space.
"The more of them there are, the less oxygen there is in the water," Fogelsong said, and that's an issue for other native species.
While officials are more concerned about keeping invasive zebra and quagga mussels out of Lake Whatcom - Fogelsong said they could wreak havoc throughout the lake - he said Asian clams create hotspots of increased calcium levels in the water and, ultimately, make the lake a welcoming habitat for those mussels.
"On that level, it's a high priority for us," he said.
Local officials hope to have a better understanding of the extent of the infestation by the end of next week, and have been talking to federal aquatic invasive species experts on how to get rid of the clams.
In other places, combating them has entailed sucking out the clams and the sediment they're in; drawing down reservoirs so they die in the cold during winter; and covering them in plastic mats to cut off their supply of oxygen.
ASIAN CLAMS
Learn more about this invasive bivalve and efforts to fight its presence in Lake Whatcom by going to lakewhatcom.whatcomcounty.org.
Lake Whatcom residents are being asked to look for Asian clams in the shallows and on beaches along their shoreline. Or they can request a site visit. Do so by calling or emailing Clare Fogelsong, environmental resources manager for the city of Bellingham, at 360-778-7965 or cfogelsong@cob.org.
The clams are among the invasives discussed in the Aquatic Invasive Species Action Plan for Lake Whatcom, which is being considered by the Bellingham City Council and the Whatcom County Council.
