Proceedings of the Third International Conference on Invasive ...

Chapter 4: Spartina Control and Management<strong>Proceedings</strong> <strong>of</strong> <strong>the</strong> <strong>Third</strong> <strong>International</strong> <strong>Conference</strong> on Invasive Spartinaon <strong>the</strong> North Arm. The concentrated port activity includes aconstant movement <strong>of</strong> barges and ships through <strong>the</strong> estuary.S. anglica is <strong>of</strong> particular concern in <strong>the</strong> Fraser estuarybecause <strong>of</strong> <strong>the</strong> known ecological impacts, includingconversion <strong>of</strong> mudflats to monoculture Spartina marshes(Gray et al. 1991; Huckle et al. 2000), displacement <strong>of</strong>waterbirds (Goss-Cutard and Moser 1988; Nairn 1986), fish(Sullivan 2001 cited in Anon. 2002; Dethier and Hacker2004), and invertebrates (Hedge and Kriwoken 2000;Jackson et al. 1985), accretion <strong>of</strong> sediment (Ranwell 1964;Gray 1991; Dethier and Hacker 2004), disruption <strong>of</strong> tidaldrainage patterns (Gray et al. 1991), and impacts on nativeintertidal marsh, eelgrass beds, and unvegetated habitats(Hedge and Kriwoken 2000; Hacker et al. 2001). Experiencein Washington State and elsewhere has shown that a quickresponse is required to avoid costly Spartina eradicationprograms. For example, $1.5 million was spent in 2003 totreat 6,000 ac <strong>of</strong> solid Spartina (70% <strong>of</strong> <strong>the</strong> infestation) inWillapa Bay and 694 solid ac (90% <strong>of</strong> <strong>the</strong> infestation) inPuget Sound (Murphy 2003). This paper summarizes <strong>the</strong>work undertaken in 2003 and 2004 in Roberts Bank andBoundary Bay and provides suggestions for fur<strong>the</strong>r work toeffectively control S. anglica in <strong>the</strong> Fraser River estuary.METHODS AND PROGRAM PLANNINGFig.1. Location <strong>of</strong> Fraser River estuary.The large tidal flats provide vast mudflat, eelgrass, andbrackish and salt marsh habitats for birds, fish and wildlife(Adams and Williams 2004; Harrison and Dunn 2004;Schaefer 2004). Over one million migratory birds use <strong>the</strong>outer delta for critical feeding and staging areas annually(Butler and Campbell 1987; Important Bird Area (IBA) SiteSummary, BC017, www.ibscanada.com; Pacific EstuaryConservation Program, www.ramsar.org). Numerous fishand invertebrate species utilize <strong>the</strong> flats, including Pacificsalmon and Dungeness crab that support importantcommercial, recreational, and First Nations fisheries (Hoosand Packmann 1974; Levings 2004). Much <strong>of</strong> <strong>the</strong> area isprotected within provincial Wildlife Management Areas, isrecognized as a nationally Important Bird Area, and exceeds<strong>the</strong> criteria for Ramsar and Western Hemisphere ShorebirdNetwork sites (Important Bird Area, IBA, Site Summary,BC017, www.ibacanada.com). The 586-hectare AlaskanNational Wildlife Area on Westham Island, adjacent toRoberts Bank, is a designated Ramsar site.Fraser River estuary is also a hub for domestic andinternational shipping with three port authorities: VPA’scontainer and bulk terminals at Roberts Bank, Fraser Port’scoastal and deep sea terminals on <strong>the</strong> Main Arm, and PortNorth Fraser’s coastal shipping and log booming facilities2003 VPA Spartina Control Program for Roberts BankFollowing discovery <strong>of</strong> S. anglica in Roberts Bank inAugust, GL Williams & Associates Ltd. was retained byVPA to establish a control program. Since <strong>the</strong> infestationwas limited in coverage and total area, <strong>the</strong> objective was tomanually remove <strong>the</strong> plants as quickly as possible without<strong>the</strong> use <strong>of</strong> herbicide. The VPA control program consisted <strong>of</strong>confirming identification <strong>of</strong> <strong>the</strong> Roberts Bank Spartina,researching scientific literature to guide managementoptions, conducting field GPS/GIS mapping and datacollection, and undertaking plant removal.Plant IdentificationPlant specimens were collected, digital images obtained,and a web search conducted for information about S.anglica. The field identification manual prepared by <strong>the</strong>California Coastal Conservancy (www.spartina.org) wasespecially useful for preliminary identification and providingdescriptions <strong>of</strong> <strong>the</strong> five Spartina species found along <strong>the</strong>Pacific Coast. Several wetland specialists in BritishColumbia and Washington State were contacted forappropriate keys and information. The indentification <strong>of</strong> <strong>the</strong>Roberts Bank specimens were confirmed using <strong>the</strong> Spartinakey developed by Barkworth (2003). Specimens were alsosubmitted to <strong>the</strong> Univeristy <strong>of</strong> British Columbia herbarium.Fresh S. anglica specimens from Roberts Bank andBoundary Bay were shipped to Dr. Debra Ayres, University<strong>of</strong> California at Davis, for DNA analysis (Ayres and Strong- 236 -