Divers gauge size of clam infestation

SANDPOINT — Nearly 5 acres of Lake Pend Oreille shoreline at Hope are infested with Asian clams, according to a preliminary estimate from the Idaho State Department of Agriculture.

Dive teams from Bonner and Boundary counties descended on Elliott Bay’s Hope Marine Services and Pend Oreille Shores Resort on Monday to gauge the size of the infestation.

“There was definitely a concentration of them right by the boat ramp and they were kind of scattered in some sandy areas and silty areas,” said Tom Woolf, program manager for the Idaho State Department of Agriculture’s invasive species division.

Woolf said the population estimate will be refined through computer mapping and further analysis.

The good news is the clam population might be small enough to wipe out, perhaps using impermeable rubber mats that would smother them in the sediment.

“To me, it actually appears to be an opportunity to actually catch it before the horse leaves the barn,” said Woolf.

The bad news? There are Asian clams in Lake Pend Oreille.

The clams have been known to disrupt aquatic food chains and spawn algae blooms. The clams, which can be found in 38 states, are known to be present in Idaho’s Snake River, but it’s the first time the bivalves have been detected in North Idaho.

“This is a listed invasive species, although on the threat matrix it’s not that extreme,” said Woolf.

 Zebra and quagga mussels present a much greater threat, although Idaho’s aggressive boat-inspection program has kept them from taking hold.

It’s unclear if or how the Asian clam infestation will be addressed. Woolf said ISDA will consult with the Bonner County Aquatic Invasive Species Task Force and the U.S. Fish & Wildlife Service due to bull trout considerations.