The treatment season for the continued eradication of spartina, or cordgrass — categorized by the Washington Sate Department of Agriculture as a noxious weed that can harm shellfish — begins June 1 and will continue through October.
The agency has been trying to eliminate the weed, which is considered by many as a threat to the ecosystems of native saltwater estuaries because of its ability to take-over native vegetation, since 1995 and specifically since since federal funding for the project was first secured in 2003. The weed is said to alter ecologically productive mudflats, to destroy migratory shorebird and waterfowl habitat and to increase the threat of flooding by filling waterways.
Possibly of most importance to the areas the WSDA plans to focus on (Grays Harbor, Hood Canal, Willapa Bay, Puget Sound and the north and west sides of the Olympic Peninsula as well as the mouth of the Columbia River) is the harm the weed is said to cause local shellfish industry.
The agency considers its efforts to eliminate the weed throughout the past nine years as “extremely effective,” and says the areas considered infested have dropped from more than 9,000 acres in 2003 to an estimated five acres this year. However, to ensure the weed does not return, they say they nearly 30,000 sites around the region will need to be visited twice in the coming year.
“We have seen great success in combating this invasive species thanks to the cooperative effort of many partners,” said Jim Marra, manager for WSDA’s Pest Program. “But our efforts must continue if we are able to protect our state’s critical shoreline habitat.
Though Enivronmental Protection Agency studies have shown them to be safe at low levels for animals and humans, there has been some backlash from individuals or shellfish farmers who fear for the safety of their ecosystems or personal health because of the type and the amount of chemical sprayed to eradicate spartina.
Glyphosate, a chemical first produced by Monsanto in the 1970s, was the first chemical used to try and eradicate the weed. Imazapyr, a salt that kills plants by inhibiting the amino acid synthesis which is needed for cell growth, was introduced afterwards and seemed to have much better results, said Keeley O’Connell, a senior project manager for Earthcorps, a non-profit organization with an expertise in community-based environmental restoration, who admitted she— as seems to be the case with many organizations who previously studied the spartina eradication efforts — has not worked on the issue in a few years.
“What we saw in field trials was that it (Imazapyr) was much more effective (than Glyphosate), there was actually the potential for eradication, where as with the Glyphosate it wasn’t even really part of the plan, we were just working on containment,” she said, adding that the vast majority of oyster farmers have been supportive of the state’s efforts.
“And it puts less herbicide into the environment overall,” she said. ” There’s a better kill rate with a much lower concentration.”
This year, the WSDA and its partners expect to survey more than 80,000 acres of saltwater estuaries and 1,000 miles of shoreline in 14 countries in determining the current extent of spartina presence or threat. They will dig out small infestations and treat larger sites with both glyphosate and imazapyr with a goal of discovering new infestations and preventing the weed from returning to where it has previously been eradicated.