LONG BEACH — Shellfish farmers who sprayed clam beds last spring say the herbicide they used was effective and that they’re prepared to defend the practice against environmental opposition.
“You can’t describe the feeling you have when you walk out and see that the weed that’s been destroying your farm is gone,” Willapa Bay shellfish farmer Brian Sheldon said. “Uplifting would be one word. It’s worked tremendously. Beyond my expectations.”
The farmers received a permit from the Washington Department of Ecology to spray imazamox, marketed as Clearcast, to kill Japanese eelgrass, a non-native species classified by the state as a noxious weed.
An environmental group, the Coalition to Protect Puget Sound Habitat, says Japanese eelgrass benefits fish and migratory wildfowl, and farmers shouldn’t be allowed to spray chemicals in the bay. The group hopes to convince the state Pollution Control Hearings Board to yank the permit at a hearing in March.
“We hope to provide good science and enlightenment to the Pollution Control Hearings Board,” said Lacey resident Robert Kavanaugh, one of the plaintiffs challenging the permit. “We don’t dispute the Willapa Bay shellfish industry is an important asset. We just think they can operate without putting chemicals on Japanese eelgrass.”
Washington State University research scientist Kim Patten, stationed at Long Beach, said Japanese eelgrass, also known as Zastera japonica, has been on the Long Beach Peninsula for decades. Over the last decade, it crept toward the bay and onto clam beds, he said.
“Once it reached critical mass, then it sort of went ‘boom,'” he said.
Patten worked with farmers to build a case for spraying. The Japanese eelgrass turns sandy tidelands into meadows, stunting the growth of clams by blocking food washed in by the tide. Also, the grass shields clam predators and slows down ocean currents, allowing smothering sediment to build.
Sheldon estimated Japanese eelgrass has cut production of Manila clams by half. Patten said the industry was heading toward becoming unprofitable.
Sheldon and Patten said it’s too early to say exactly how much gain farmers will see in production. But both expected large increases.
Patten said the herbicide produced results that were “next to extraordinary.”
“Growers were very pleased with the results,” he said. “It’s night and day in terms of production for them.”
Initially, the growers sought a statewide permit, which would have allowed spraying in Grays Harbor and Puget Sound. The proposal drew opposition, and the ecology department limited permission to Willapa Bay, where Japanese eelgrass was most prevalent.
The herbicide was applied between April 15 to June 30 on about 400 acres at low tide. Aerial spraying was prohibited, and no applications were allowed within 10 meters of property lines.
The work was hard, said Sheldon, who said he treated 136 acres in eight or days. Sheldon said spaying from a helicopter would have been easier, but that’s a battle the shellfish growers aren’t taking on now, he said.
The ecology department issued a five-year permit. It could be withdrawn after three years if farms can’t prove the spaying hasn’t harmed native eelgrass on neighboring properties, ecology department aquatics plant specialist Nathan Lubliner said.
The growers also will have to report this year how many acres were treated and the amount of herbicide used. Lubliner said imazamox is “considered practically non-toxic to animals” and that the department won’t do field research into how the spraying effects Willapa Bay.
The Coalition to Protect Puget Sound Habitat made a last-ditch motion to stop last spring’s spaying. The pollution control board declined to intervene.
A representative of the coalition, Laura Hendricks, said the group plans to lay out its case at a full hearing in March.
She said the group was organized to prevent the application of chemicals in Puget Sound and expanded its attention to Willapa Bay.
“People view these as public treasures,” Hendricks said. “We’re totally opposed to spraying.”
Sheldon said shellfish growers need to continue spraying or the industry will “tank.”
“We’re going to take it to the mat,” he said. “This is a huge thing for our industry.”
Patten said he will study the effects of applying imazamox, including whether birds and fish avoid clam beds sprayed with the herbicide.
