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 Spartinabe a more efficient removal method for larger clones. It isunlikely that S. anglica will grow from a depth <strong>of</strong> 2–3 m.Total plant material disposed <strong>of</strong> in 2004 was about8,000 kilograms (kg) and it is estimated that approximatelyfive times that amount was removed using in situ burial. Thetotal weight included plants and some sediment.Hovercraft Survey <strong>of</strong> <strong>the</strong> Outer Fraser EstuaryA hovercraft provides an efficient survey method forcovering large areas <strong>of</strong> tidal flats, especially where mudsubstrates make walking difficult. Seedlings are easilyobserved from ei<strong>the</strong>r inside or from <strong>the</strong> foredeck. The onboarddigital charts and GPS provide accurate locating. Thecraft can travel ei<strong>the</strong>r rapidly or at a very low speed, and iscapable <strong>of</strong> stopping if <strong>the</strong>re is a need to obtain plantspecimens.Outreach and EducationThe outreach component <strong>of</strong> <strong>the</strong> VPA Roberts Bankprogram included PowerPoint presentations, localnewspaper and radio, and printed/electronic publications.The PowerPoint presentations were well received and <strong>of</strong>tenled to invitations from o<strong>the</strong>r groups. The newspaper articlesprovided broad local coverage, which appeared to reach alarger audience than radio. The Vancouver Natural HistorySociety (VNHS) newsletter article led to a request to preparea more detailed article for <strong>the</strong> VNHS journal, Discovery.The electronic publication in Botantical Electronic News(BEN), being available on <strong>the</strong> web, led to communicationsand exchange <strong>of</strong> information with scientists in France andOregon.As well as increasing awareness <strong>of</strong> <strong>the</strong> S. anglica threat,<strong>the</strong> outreach was effective in recruiting volunteers. Duringconversations with removal volunteers, many said <strong>the</strong>y weremotivated to provide assistance after seeing <strong>the</strong> PowerPointpresentation or attending local World Oceans Day eventswhere information about <strong>the</strong> problem was presented.Program CostsThe 2003 VPA S. anglica management program wasdeveloped and coordinated by <strong>the</strong> author (GW), andvolunteers conducted <strong>the</strong> actual removal. The total budgetwas approximately $15,000, covering consultant fees,disposal trucking, incineration, and supplies (e.g. plasticbags, gloves, etc.). The hovercraft survey cost about $1500,including reporting and mapping. There were also in-kindcontributions <strong>of</strong> hovercraft fuel (provided by Fisheries andOceans Canada) and staff salaries.The 2004 program costs were over $50,000 plus amatching amount in-kind from many agencies involved in<strong>the</strong> Spartina removal program.DISCUSSION AND RECOMMENDATIONSThe management efforts in 2003 and 2004 were usefulin developing strategeies to effectively control S. anglica inFig. 7. Fraser Spartina Busters on Roberts Bank in October 2003.<strong>the</strong> Fraser estuary. Spartina. anglica was fully controlled atRoberts Bank by <strong>the</strong> end <strong>of</strong> October 2004, althoughcontinued management will be required to address newrecuitment from existing seedbank and new invasions. Thedistribution <strong>of</strong> S. anglica in Boundary Bay has been greatlyreduced, but <strong>the</strong>re is still a substantial amount remaining east<strong>of</strong> 112 th St., and scattered new seedlings were observedthroughout Boundary Bay in November 2004. The Fraserestuary program shows that control is possible without <strong>the</strong>use <strong>of</strong> herbicides, provided that <strong>the</strong> infestation is caughtearly and aggressive removal programs implemented(Daehler and Strong 1996; Anon 2002).Manual effort was effective in removing S. anglica in<strong>the</strong> Fraser estuary, but in situ burial is more effective forlarge clones exceeding 1 m. Digging and bagging plants isefficient for seedlings and tussocks, but <strong>the</strong> use <strong>of</strong> all-terrainvehicles for collection and transport to shore for disposal isrequired for large scale programs. Firmer substrates permit<strong>the</strong> use <strong>of</strong> mechanized equipment and are generally easier towork on than muddy sediments.The Fraser estuary Spartina programs depended onvolunteer manpower, but dedicated work crews arerecommended for Boundary Bay. Boundary Bay will requirea greater effort than 107 person-days <strong>of</strong> removal to reach <strong>the</strong>status <strong>of</strong> Roberts Bank. However, much <strong>of</strong> <strong>the</strong> S. anglica inBoundary Bay consists <strong>of</strong> seedlings, which can be easilyremoved. Denser coverage occurs in localized areas, such as<strong>the</strong> six, 3 m-diameter clones west <strong>of</strong> 104 th Street or mixedwithin native marsh west <strong>of</strong> 112 th Street.Mapping was a critical component <strong>of</strong> <strong>the</strong> 2003 and 2004programs. Handheld GPS units provide sufficient accuracyfor mapping S. anglica, and classification <strong>of</strong> <strong>the</strong> growth asseedling, tussock (0.1–0.3 m), small clone (0.3–1m) or largeclone (>1 m) provides sufficient detail for planning manual- 240 -