Seattle Press on Line - Spartina Alterniflora in Willapa Bay

Spartina Alterniflora in Willapa Bay

By Larry Warnberg

May 31, 2000 -- Willapa Bay in Southwest Washington State has been used and abused severely in the past 150 years. The succulent native Olympia oysters were overharvested within 30 years after white settlement. By 1895 there were so few oysters remaining that it was necessary for entrepreneurs to import seed from the Chesapeake Bay, shipped by rail in barrels packed with Spartina grass. The oysters did not do well because massive erosion and sedimentation caused the crops to sink and suffocate. Spartina, however, began colonizing the upper tideland around the perimeter of the Bay, trapping silt, stabilizing shorelines, and absorbing excess nutrients from forestry, agriculture and sewage systems. The natural evolution of an estuary is usually to become shallower, with gradual conversion of tidelands to upper saltmarsh. Willapa Bay has aged prematurely due to clear-cut forestry, extensive diking for farmland, careless roadbuilding and increasing use of pesticides in the watershed.

In 1928 Japanese oyster seed was imported by ship from Japan, including dozens of non-native species. The fast-growing large variety Pacific oyster, Crossostrea gigas, was able to cope with the excessive sedimentation and quickly became a commercial success. Spartina steadily colonized the upper tideland, while the Japanese oysters gradually spread under cultivation to much of the lower tidelands. Few paid attention to the healthy green meadows of grass fringing the Bay until 1988, when Monsanto Chemical Company launched a national advertising campaign targeting aquatic nuisance plants for eradication with its popular herbicide glyphosate (Round-Up for terrestrial use, Rodeo for aquatic). The Nature Conservancy conducted an extensive propaganda program to generate public and government support for a Spartina eradication plan in Willapa Bay, largely based on a hypothetical threat to important food sources that sustain migrating waterfowl on the Pacific flyway. There is no solid evidence that Spartina has negative impacts on birds, or oysters, clams, fish, or humans. On the East coast where Spartina ranges from Nova Scotia to Mexico, it is considered a valuable part of estuaries. Polluted overdeveloped areas on the Chesapeake Bay are being actively revegetated with Spartina to buffer shorelines from storm waves and to improve water quality by reducing sediment transport and absorbing harmful excessive nutrients. On Willapa Bay, Spartina thrives, water quality is famously good, while oysters, clams and fish benefit from the many positive functions it performs. The campaign to sell Rodeo created controversy and opposition at the start.

A group of organic oyster farmers and gardeners formed the Ad Hoc Coalition for Willapa Bay to protest pesticide use and to find non-chemical means of controlling Spartina. Hand-pulling seedlings was found to be effective at stopping formation of new meadows. Eventually, state and federal agencies also adopted hand-pulling as the top priority front-line strategy. Millions of tax dollars were spent testing Rodeo, with generally poor results. Drying-penetration time is inadequate due to the 12-hour tidal cycle which washed the chemical off the grass. The Ad Hoc Coalition has demonstrated effective control by repeated mowing. The incoming tide floats the cut grass, which is easily gathered for harvest and use in gardening, mushroom culture or papermaking. The cost of mowing is offset by marketing Spartina for beneficial uses.

Eleven years after The Nature Conservancy alarmed people with loud cries of "Spartina is devouring the Bay," new studies show this humble grass is helping to heal this ravaged estuary. Monsanto is still trying to find a way to make Rodeo kill Spartina, testing small experimental plots with double-strength glyphosate, using more tax dollars. The Ad Hoc Coalition still practices and promotes non-chemical Spartina control. Purchasing Spartina art and craft work supports grassroots efforts to keep pesticides out of Willapa Bay.

Larry Warnberg, POB 43, Nahcotta, WA. 98637
E-mail to: Warnberg@pacifier.com

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