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Click here to go back Details of this species in San Francisco Bay (Estuary) Status: Alien Invasiveness: Invasive Occurrence: Established Source: Bortolus, 2006 Arrival Date: 1977 Introduction: Unintentional (accidentally) Species Notes for this Location: Spartina densiflora was introduced here due to accidental transplanting by a landscaper in Creekside Park (Bertolus, 2006). Management Notes for this Location: The San Francisco Estuary Invasive Spartina Project has developed a management and control program that includes both mechanical and chemical treatments to the invasive Spartina densiflora. The aquatic herbicides imazapyr and glyphosate are currently being used exclusively in conjunction with other non-chemical methods. Mechanical removal of S. densiflora can be costly and time consuming but has proven to be more effective than hand removal methods. The covering or blanketing method involves draping fabric that seals out sunlight and kills off the S. densiflora trapped underneath. This method is only effective when used on smaller populations of cordgrass that are limited in area (San Fransisco Estuary Invasive Spartina Project, undated). Location Notes: Impacts: Habitat alteration: The ability of Spartina densiflora to colonize mudflats causes a loss of foraging habitat for local waterfowl and shorebirds (San Fransisco Estuary Invasive Spartina Project, undated). Other: The buildup of dense patches of Spartina densiflora leads to a decrease in water flow, in turn leading to an increased rate of sedimentation (San Fransisco Estuary Invasive Spartina Project, undated). Reduction in native biodiversity: The negative interaction with native plants, such as pickleweed (Salicornia virginica) and California cordgrass (Spartina foliosa) may over time lead to a loss of local plant diversity (San Fransisco Estuary Invasive Spartina Project, undated). Other native species affected in California are Frankenia salina, Limonium californicum, and Jaumea carmosa (University of California, undated). Threat to endangered species: The invasion of Spartina densiflora affects the habitat of the 'Vulvnerable (VU)' salt marsh harvest mouse (see Reithrodontomys raviventris in IUCN Red List of Threatened Species), and the federally listed California clapper rail (see Rallus longirostris obsoletus for State and Federal status (San Fransisco Estuary Invasive Spartina Project, undated). Last Modified: 16/05/2008 3:55:13 p.m.