An 800 square-foot colony of Spartina was found this summer in Young’s Bay, not far from the mouth of the Skipanon River. While the Oregon Department of Agriculture, the PSU Center for Lakes and Reservoirs, and Oregon Department of Fish and Wildlife responded quickly to detect and treat the colony, the plant’s appearance in the Columbia River Estuary is potentially a bad omen of more to come.
Cordgrass or Spartina is a serious, aggressive invader of brackish or salty water. On the U.S. west coast, four species of these plants have transformed open estuaries into meadows which dramatically alters the local hydrology and habitat for native plants and animals. By trapping sediment that normally ebbs and flows with the tide, Spartina colonies actually raise the height of these flooded landscapes. In Spartina-dominated systems, estuaries go from productive mudflats to saltmarshes with only a few open channels for water flow. Native biodiversity suffers when this happens. Boating and shellfish harvest become more difficult as well.
Willapa Bay in Washington State is just one example of an ecosystem that was completely transformed by the invader in a few years. Humboldt Bay in Northern California is another. Spartina has appeared in Coos Bay where eradication efforts have drastically limited its spread.
It spreads by seeds and vegetative propagation. Boats, aquaculture operations, and possibly even ocean currents can move Spartina from place to place. If you boat, fish or hunt in the Willapa Bay area (our closest source), then please clean your trailer, boat and gear before departing the area and certainly before you put in into a new water body. Other areas with Spartina investations are the Puget Sound and Gray’s Harbor. Find out how and where to clean your boat by visiting the BoatUS Foundation website.