Efforts to snuff out spartina yield mixed results
Monday, March 29, 2004 7:47 AM PST
By Eric Apalategui
Printable version
E-mail this articleOn some of Willapa Bay's vast tidal flats, thousands of green tufts of spartina sprout from tidal flats in bold defiance of last summer's massive herbicidal assault on the nonnative saltmarsh grass that threatens to overrun the bay.
In other areas, few sprigs of green spartina emerge amid the tan stubble left over from last year's attack on lush meadows of the plant invader.
Willapa National Wildlife Refuge staff and partners from other agencies surveyed the bay twice by airboat in recent weeks. Those partners say the lessons they are starting to learn will help them refine this year's spraying program, which again has $1 million in federal funding.
This year the refuge's goal is to mop up surviving plants on the 5,000 acres treated last year and to spray another 1,000 acres. The area to be treated is so vast it could hold 50 parks the size of Longview's Lake Sacajawea.
"By and large, there's some areas that look very, very good," said Charlie Stenvall, project leader for local refuges. For example, spraying nearly wiped out a spartina infestation at the northern end of Long Island on the refuge.
But spartina on the lower two-thirds of the 1,000 acres treated near Nemah is resprouting with unwelcome vigor, after incoming tides washed away the herbicide after about four hours, Stenvall said.
"It's kind of a mixed bag," agreed Washington State University researcher Dr. Kim Patten. "Nevertheless, I think we are amassing the strategies and the tools ... to pretty much eliminate 6,000 acres of spartina from the bay this year."
Spartina, which at its peak last year would have covered 12,000 or more acres if clumped together, already has made its mark at Willapa. The meadows collect silt and raise the bay floor, turning open mudflats into upper tidal grasslands and eliminating habitat for shorebirds, young salmon and farmed oysters.
In past years, spartina crews sprayed spartina with glyphosate, the active ingredient in common herbicides such as Roundup and Rodeo. Workers will continue to use glyphosate this summer but also will try imazapyr, an herbicide Patten's research found to be more effective with shorter drying times or when mixed with impurities such as dirt. However, imazapyr is more expensive.
Besides the mop-up work on the big meadows treated in 2003, refuge crews will penetrate narrow ditches that Stenvall called "tidal guts" where spartina lurks but where most equipment can't navigate. Some areas can only be reached on foot or on a new amphibious vehicle that is smaller than the tank-like models already in use.
"This is really going to be some arduous, tedious, monotonous work," Stenvall said.
The state Department of Agriculture, oyster growers, state universities and other partners also will continue their control work when the spraying season starts in June. They will focus on areas in the Nemah, Palix and other tidal flats in the middle and northern sections of the bay, said Kyle Murphy, who coordinates the Department of Agriculture's spartina control program.
"It's going to be a big test to see what we can do," Murphy said.
WSU researcher will stay in Long Beach
Washington State University will keep Kim Patten on the shores of Willapa Bay, where the researcher is one of the area's experts on growing cranberries and controlling pests such as burrowing shrimp and invasive spartina grass.
Last year, WSU officials facing budget cuts in research considered reassigning Patten to Mount Vernon, Wash. If he had moved, Patten would have spent more time working with other small fruits and less on the southern coast's agricultural and environmental problems.
Industry and political leaders in Southwest Washington urged the university to reconsider, and WSU recently agreed to keep Patten stationed in Long Beach. He will divide most of his time between research on cranberry farming and finding new ways to control overpopulated shrimp that are ruining the bay's fertile commercial oyster grounds. Most of Patten's experimental work on controlling spartina is done, but he still will spend part of his time finishing that project and targeting other invasive plants, he said.
"WSU worked hard to make this a win-win," Patten said last week. "I can work on the issues that are most critical to this region."
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