Collaborative efforts for Elwha River freshwater mussel rescue

[display_podcast] PORT ANGELES (October 16, 2008) There was a sense of urgency when tribal, state and federal biologists recently snorkeled for 5,000 freshwater mussels along the bottom of a 300-foot-long shallow side channel of the Elwha River. A dredge was slated the next day to dig up the side channel as part of construction of the Elwha Water Treatment Facility.

This mussel rescue was part of larger efforts to prepare the Elwha River for the removal of its two fish-blocking dams; the 108-foot-tall Elwha Dam and the 210-foot-tall Glines Canyon Dam will be removed starting in 2012. The new treatment plant will help filter out river sediment that will be released after the dams are removed.

“Mussels are a legacy population, meaning they can live for more than 100 years,” said Larry Ward, the Lower Elwha Klallam Tribe’s hatchery manager. “They also naturally help protect the quality of the water because they are filter feeders. While they are able to move around a little bit to find better habitat, the high levels of sediment expected in the river after the dams come down means they’ll most likely get wiped out. We’re trying to make sure they’re preserved.”

The mussels are temporarily stored in one of the tribe’s hatchery raceways. Various strategies are being considered for releasing them back into the Elwha River.

Freshwater mussels are excellent indicators of water quality. While also a source of food for tribes, mussel shells are used for regalia and other traditional uses.

Mussels must depend on other species in the ecosystem in order to survive. Recently hatched larvae attach themselves to fish, such as chinook salmon, a common species in the Elwha River. After feeding off the gills of host fish for a few weeks, the larvae drop off into the streambed and continue their development.

“The lack of mussels above the dams could have something to do with the fact that there are no salmon above the dams either, because fish can’t get past the tall structures,” Ward said. “Once the chinook colonize upriver after the dams are removed, we hope to see a population boost in mussels and other species too.”

The project was supported by the Lower Elwha Klallam and Jamestown S’Klallam tribes, Washington Department of Fish and Wildlife, the National Park Service and U.S. Geological Survey.


For more information, contact: Larry Ward, Lower Elwha Klallam Tribe hatchery manager, at (360) 457-4012 or [email protected]; or Tiffany Royal, Northwest Indian Fisheries Commission information officer, at (360) 297-6546 or [email protected].