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TASK 3: CORDGRASS MANAGEMENT AND MONITORING <br />Problem Statement <br />Over the previous five years, the spread of non-native smooth cordgrass (Spartina <br />alterniflora) has been identified as a major management concern in the Bay Area and <br />throughout SLSM and Citation Marsh. Introduced to the Bay Area in the mid-1970s, <br />smooth cordgrass is threatening to take over marshlands throughout the East Bay. It <br />has spread by purposeful introduction of rooted plants and dispersal of seeds on the <br />tides. Smooth cordgrass is rapidly spreading at all constituent marshes at <br />SLSM/Citation Marsh and is well established at the entrance to San Leandro and San <br />Lorenzo Creeks. <br />The spread of smooth cordgrass is hastened by fully tidal hydrologic systems like those <br />in Bunker Marsh and Citation Marsh. The greater distribution potential in these <br />marshes also provides a greater opportunity for cordgrass establishment and subsequent <br />habitat modification. Smooth cordgrass readily hybridizes with Pacific cordgrass and is <br />rapidly reducing genetically "pure" native cordgrass stands. The proliferation of <br />hybrids could result in local extinction of the native cordgrass species. What is more, <br />smooth cordgrass has the ability to greatly modify estuarine ecosystems to the <br />detriment of other native species. If left unchecked, the proliferation of smooth <br />cordgrass has the potential to completely displace Pacific pickleweed (Salicornia <br />virginica), and eliminate habitat for the federally endangered salt marsh harvest mouse <br />and many other native species in the process. The proliferation of smooth cordgrass <br />anal. hybrids is expected to grossly alter the character of the San Francisco Bay. <br />Genetic patterns observed by the Spartina Lab at Bodega Marine Laboratory and U.C. <br />Davis provide general guidelines to curb the spread of smooth cordgrass and its hybrids <br />in California, anal form. the basis for the scope of work for this task. Recent research <br />suggests that control efforts should focus on the complete extirpation of populations <br />that contain few pure native plants since these populations export large numbers of <br />hybrid seed (e.g., Coyote Hills Slough, Cogswell marsh, San Bruno marsh). In <br />addition, smooth cordgrass and hybrids should be selectively removed from native <br />marshes that have not been heavily invaded. Also, uninvaded marshes should be <br />regularly monitored to prevent invasion. SLSM and Citation Marsh have an even mix <br />of smooth cordgrass and. hybrids. Based on the above guidelines, SLSM should be <br />considered a high management priority with complete extirpation as an overall <br />management goal. <br />Scope of Work <br />The current management strategy, annual herbicide-application, has successfully <br />stopped the spread of smooth cordgrass in North Marsh. ESA's 1997-2000 cordgrass <br />monitoring results found. that hand application of herbicides to be more than 70% <br />effective in killing new clumps, but the management of large clumps and newly <br />introduced clumps remains an ongoing management Head. More than 400 stands of <br />San Lcanch•o Shoreline Marshlands 2 ENVIRONMENTAL SCIENCE ASSOClATFS <br />Ongoing Biological Assesxmenl And Managemonf Sciviccs Submittal Dale: December 12, 200(1 <br />