Salt Marsh Project

Spartina Removal Project

Completed: Ongoing


  • Efforts to control and eradicate invasive spartina and re-colonization of native salt marsh plants.
  • Ongoing monitoring is performed on a yearly basis as funding allows, until project goals are obtained

Restoration Enhancements

Spartina eradication within the City of Arcata has taken place at two salt marsh locations in the Arcata Marsh and Wildlife Sanctuary near South I Street and South G Street and are part of the Humboldt Bay Regional Spartina Eradication Plan (HBRSEP), which included efforts to control and eradicate invasive spartina within the city limits. Efforts have occurred in several spartina infested areas within the Arcata Marsh and Wildlife Sanctuary (AMWS) since 2009. Monitoring plots have been established within treatment areas to survey the effectiveness of eradication efforts and re-colonization of native salt marsh plants. Goals of the monitoring are to help evaluate the effectiveness of treatment methods and to corroborate if the current eradication efforts are accomplishing the desired salt marsh enhancement. Monitoring is performed on a yearly basis as funding allows, until project goals are obtained. Eradication of spartina at the salt marshes has initially proven successful in reducing spartina and the marshes are now being populated by both rare and common salt marsh plants native to the area including: Humboldt Bay owl's clover (Castilleja ambigua ssp. humboldtiensis) and Point Reyes bird's beak (Chloropyron maritimum ssp. palustre), gum plant (Grindelia stricta), marsh jaumea (Jaumea carnosa), pickleweed (Salicornia pacifica), Point Reyes bird’s beak (Cordylanthus maritimus ssp. paulstris), seaside arrow-grass (Triglochin maritima), sea lavender (Limonium californicum), and spear saltbrush (Atriplex patula).

Partnership and Funding

City of Arcata.



Since the 1850s, Humboldt Bay has lost over 90% of its 9,000 acres of salt marsh habitat due to diking, draining, and agricultural conversion. More recently, the remaining marshlands have become dominated by non-native invasive dense-flowered cordgrass (Spartina densiflora), referred to as spartina. Salt marshes play a vital role in providing food, refuge and/or nursery habitat for a rich diversity of invertebrates, mammals, fish, and avian species inhabiting Humboldt Bay. Salt marshes also provide vital benefits known as ‘ecosystem services’ by serving as natural buffers against coastal erosion caused by storms, capturing sediments, reducing flooding, and preserving water quality through the filtration and processing of runoff nutrients.

Spartina, believed to have arrived via ballast water in lumber ships from Chile, has had detrimental effects on Humboldt Bay's native flora and fauna by altering and diminishing their habitats and food chains. A concerted effort to restore Humboldt Bay's salt marsh habitat is underway, with nearly half of the marshlands currently undergoing restoration or secured funding for restoration, thanks to a collaborative effort involving state, federal, and local agencies.  The eradication of spartina in Humboldt Bay is just one of the numerous projects underway along the entire west coast. Spartina removal involves a mechanical process, which includes cutting, disking, or grinding the rhizomes using brush cutters or a rototiller towed by an amphibious tractor. Given the reemergence of seedlings, multiple treatments are often necessary.