Miners give salmon a break
Monday, March 15, 2004
Gold prospectors uncovered a different sort of mother lode Sunday, just a few yards into the Columbia River in east Vancouver.
They were dredging in this region's gold mine for chum salmon. The stretch of shallow-water gravel just east of the Interstate 205 Bridge is only 600 feet long. But Wood's Landing is a crucial chum spawning ground and part of only three major chum nurseries on the entire Columbia River.
Part of that nesting area was smothered recently by a plume of sand, killing at least 20,000 baby fish.
Members of the Northwest Mineral Prospectors literally jumped right in up to their waists in the chilly Columbia River to help save the inch-long chum emerging from their parents' gravel nests, or redds.
Instead of flashes of gold, Bob Elskamp was rewarded with streaks of silver as a few shiny chum wiggled free of the sand.
"I saw a few pop up, and that was encouraging," the wet-suited prospector said after wading onto shore for a break.
Chum deposit their eggs in December, and the babies emerge in March, so the sand plume arrived "at the worst possible time," said Mary Wood, whose family owns the riverfront property where the weekend dredging operation took place.
The gold miners launched six dredges into the water to suck up the sand plume, about 100 feet long by 30 feet wide. The sand was up to 18 inches deep in some areas, way too thick for the young chum.
"They can get through 2 or 3 inches of sand," said Carl Dugger, a biologist with the Washington Department of Fish and Wildlife.
The trick for the prospectors was to dredge most of the sand while leaving that 2-inch cushion, so the redds were not sucked up.
"If you just walk on the redds, you can destroy them," Dugger said.
When offered the chance to aid the baby fish, Elskamp had little trouble finding volunteers among fellow prospectors. The group wants to counter the stereotype that miners are not concerned about the welfare of the environment.
The miners have used their sand-sucking dredges to help Columbia River chum once before near Astoria, Ore.
"But that was just cleaning up" habitat, said Elskamp. "There were no fish around, not like this."
This weekend's operation focused on a section of river near Wood's Seeps, a network of springs. By chum standards, Wood's Seeps is particularly homey. The ground water that trickles into the Columbia is about 50 degrees about eight degrees warmer than river water, so eggs warmed by water from the seeps will incubate faster, said biologist Joe Hymer.
"They want to get as close to the seeps as possible," said Hymer, with the Pacific States Marine Fisheries Commission.
By hatching quickly, the young chum can get out into the river before predators make their way down the Columbia.
"They've got some survivor skills," Hymer said.
But not against the smothering sand. Hymer said biologists don't know its toll on the Wood's Landing chum hatch: maybe 2 percent mortality, or maybe as much as 10 or even 20 percent.
In addition to suffocating the baby chum, the sand probably reduced the hatch rate. If the sand caused eggs to clump up, that could have led to an egg-destroying fungus, Hymer said.
The chum was declared a threatened species in 1999, Hymer said, "So every fish matters."
Members of the Wood family own three parcels of Columbia River shoreline, and the Columbia Land Trust is raising money to buy an adjoining site, Columbia Grove, so it can be preserved instead of developed.
"It would be a real shame if these fish that have been saved through the heroic efforts of the gold miners came back in three years to find part of their native home destroyed by development," said Mary Wood.
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