<str<strong>on</strong>g>Proceedings</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> <str<strong>on</strong>g>Third</str<strong>on</strong>g> <str<strong>on</strong>g>Internati<strong>on</strong>al</str<strong>on</strong>g> <str<strong>on</strong>g>C<strong>on</strong>ference</str<strong>on</strong>g> <strong>on</strong> <strong>Invasive</strong> SpartinaChapter 4: Spartina C<strong>on</strong>trol and Managementto address aquatic herbicides. The revisi<strong>on</strong>s were adopted inJune <str<strong>on</strong>g>of</str<strong>on</strong>g> 2004, enabling ISP partners to issue Notices <str<strong>on</strong>g>of</str<strong>on</strong>g> Intent(NOIs) to be covered under <str<strong>on</strong>g>the</str<strong>on</strong>g> Statewide GeneralNPDES Permit for Aquatic Weed C<strong>on</strong>trol.The NPDES permit also requires developing an AquaticPesticide Applicati<strong>on</strong> Plan (APAP) identifying <str<strong>on</strong>g>the</str<strong>on</strong>g> proceduresfor applying herbicides, <str<strong>on</strong>g>the</str<strong>on</strong>g> chemicals to be used, <str<strong>on</strong>g>the</str<strong>on</strong>g>species targeted for treatment, a descripti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> waterbodysystem, and o<str<strong>on</strong>g>the</str<strong>on</strong>g>r related informati<strong>on</strong>. Within <str<strong>on</strong>g>the</str<strong>on</strong>g> APAP is aWater Quality M<strong>on</strong>itoring Plan (WQMP), which defines <str<strong>on</strong>g>the</str<strong>on</strong>g>protocols for water quality sampling <str<strong>on</strong>g>of</str<strong>on</strong>g> treatment areaswhere herbicide is used. While <str<strong>on</strong>g>the</str<strong>on</strong>g> ISP developed <str<strong>on</strong>g>the</str<strong>on</strong>g> APAP<strong>on</strong> behalf <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ISP partners, <str<strong>on</strong>g>the</str<strong>on</strong>g>y c<strong>on</strong>tracted <str<strong>on</strong>g>the</str<strong>on</strong>g> services <str<strong>on</strong>g>of</str<strong>on</strong>g><str<strong>on</strong>g>the</str<strong>on</strong>g> San Francisco Estuary Institute (SFEI) to fur<str<strong>on</strong>g>the</str<strong>on</strong>g>r developand implement <str<strong>on</strong>g>the</str<strong>on</strong>g> WQMP for <str<strong>on</strong>g>the</str<strong>on</strong>g> work proposed by <str<strong>on</strong>g>the</str<strong>on</strong>g> ISPand its partners, and to report <strong>on</strong> its findings following <str<strong>on</strong>g>the</str<strong>on</strong>g>2004 treatment seas<strong>on</strong> (California Coastal C<strong>on</strong>servancy2004(c)).In additi<strong>on</strong>, access permits from regi<strong>on</strong>al and localagencies were necessary for treatment <strong>on</strong> many <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> 16sites slated for Spartina c<strong>on</strong>trol and <str<strong>on</strong>g>the</str<strong>on</strong>g> ISP coordinated <str<strong>on</strong>g>the</str<strong>on</strong>g>irprocurement.TREATMENT METHODSA variety <str<strong>on</strong>g>of</str<strong>on</strong>g> methods can be used to treat n<strong>on</strong>-nativeSpartina populati<strong>on</strong>s in <str<strong>on</strong>g>the</str<strong>on</strong>g> estuary. However, very rarely isany particular treatment method appropriate for all situati<strong>on</strong>s.In <str<strong>on</strong>g>the</str<strong>on</strong>g> FEIS/R, <str<strong>on</strong>g>the</str<strong>on</strong>g> ISP proposed a suite <str<strong>on</strong>g>of</str<strong>on</strong>g> c<strong>on</strong>trolmethods and approaches based <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> cumulative expertise<str<strong>on</strong>g>of</str<strong>on</strong>g> Spartina c<strong>on</strong>trol operati<strong>on</strong>s worldwide, especially <str<strong>on</strong>g>the</str<strong>on</strong>g>work being d<strong>on</strong>e to c<strong>on</strong>trol S. alterniflora in Willapa Bay,Washingt<strong>on</strong> State, USA. In 2004, <str<strong>on</strong>g>the</str<strong>on</strong>g> ISP tested several possiblec<strong>on</strong>trol techniques to determine <str<strong>on</strong>g>the</str<strong>on</strong>g> relative benefits <str<strong>on</strong>g>of</str<strong>on</strong>g>each.Chemical C<strong>on</strong>trolGlyphosate herbicide (Aquamaster® or Rodeo®) wasused in most <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> area <str<strong>on</strong>g>of</str<strong>on</strong>g> Spartina infestati<strong>on</strong> that waschemically treated in 2004. The applicati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> herbicidescomprised <str<strong>on</strong>g>the</str<strong>on</strong>g> largest part <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> C<strong>on</strong>trol Program for a host<str<strong>on</strong>g>of</str<strong>on</strong>g> reas<strong>on</strong>s, not least <str<strong>on</strong>g>of</str<strong>on</strong>g> which was <str<strong>on</strong>g>the</str<strong>on</strong>g> need to c<strong>on</strong>trol largeacreage at low cost to stay ahead <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> rapid expansi<strong>on</strong> rate<str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> invader. Moreover, this method has a relatively lowimpact <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> treated marshlands in c<strong>on</strong>trast to o<str<strong>on</strong>g>the</str<strong>on</strong>g>r treatmentopti<strong>on</strong>s. Drawbacks to herbicide use include <str<strong>on</strong>g>the</str<strong>on</strong>g> potentialfor herbicide or fuel spills, negative public percepti<strong>on</strong>,timing restricti<strong>on</strong>s, and potential water quality impacts. Glyphosateherbicide was applied via tracked amphibious vehicles(Hydrotraxx or Argo) fitted with spray apparatus, truckmountedspray equipment, backpack sprayers, shallowbottomedboats with outboard motors and broadcast aerialapplicati<strong>on</strong>s via helicopter with a 30-foot boom fitted with anozzle array.Manual C<strong>on</strong>trolFor those sites not yet fully established—where <str<strong>on</strong>g>the</str<strong>on</strong>g>rewere very small, pi<strong>on</strong>eering infestati<strong>on</strong>s to be treated—manual c<strong>on</strong>trol techniques were used. These methods were<str<strong>on</strong>g>of</str<strong>on</strong>g>ten incorporated into public outreach efforts, involvingvolunteer groups that worked <strong>on</strong> marshland restorati<strong>on</strong>projects. For smaller sites, digging <str<strong>on</strong>g>the</str<strong>on</strong>g> plants resulted ingood c<strong>on</strong>trol, but swiftly exhausted worker enthusiasm andresulted in heavy impacts to <str<strong>on</strong>g>the</str<strong>on</strong>g> marsh. Digging plants ininfestati<strong>on</strong>s much larger than 25 square meters is prohibitivelyexpensive and has <str<strong>on</strong>g>the</str<strong>on</strong>g> potential to leave lasting damageto <str<strong>on</strong>g>the</str<strong>on</strong>g> treated marsh in <str<strong>on</strong>g>the</str<strong>on</strong>g> form <str<strong>on</strong>g>of</str<strong>on</strong>g> deep holes ortrenches. In such cases, tarping or covering <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> plants wasused to good effect. Heavy syn<str<strong>on</strong>g>the</str<strong>on</strong>g>tic tarps were staked inplace over trampled stands <str<strong>on</strong>g>of</str<strong>on</strong>g> n<strong>on</strong>-native Spartina in severallocati<strong>on</strong>s in <str<strong>on</strong>g>the</str<strong>on</strong>g> estuary, as well as at Point Reyes Nati<strong>on</strong>alSeashore <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> outer coast north <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Golden Gate. Tarpswere left in place for at least eight m<strong>on</strong>ths and required regularm<strong>on</strong>itoring to assure that <str<strong>on</strong>g>the</str<strong>on</strong>g> covering remained in placeduring tidal fluctuati<strong>on</strong>, especially storms. Removal <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g>covering following successful c<strong>on</strong>trol <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Spartina was<str<strong>on</strong>g>of</str<strong>on</strong>g>ten difficult because <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> heavy accumulati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> mud <strong>on</strong>top <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> tarps, requiring laborious excavati<strong>on</strong>s to unearth<str<strong>on</strong>g>the</str<strong>on</strong>g> covering. Drawbacks to covering include <str<strong>on</strong>g>the</str<strong>on</strong>g> high cost <str<strong>on</strong>g>of</str<strong>on</strong>g>installati<strong>on</strong>, maintenance and removal and <str<strong>on</strong>g>the</str<strong>on</strong>g> attendantdamage to <str<strong>on</strong>g>the</str<strong>on</strong>g> marsh, as well as <str<strong>on</strong>g>the</str<strong>on</strong>g> negative envir<strong>on</strong>mentalimpacts <str<strong>on</strong>g>of</str<strong>on</strong>g> petrochemical producti<strong>on</strong> associated with <str<strong>on</strong>g>the</str<strong>on</strong>g>manufacture <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> heavy syn<str<strong>on</strong>g>the</str<strong>on</strong>g>tic fabric used in this treatmentmethod. Two <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> sub-areas identified for Spartinac<strong>on</strong>trol in 2004 used small-scale mowing <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> infestati<strong>on</strong>.Gas-powered hand mowers fitted with a tri-blade were ableto make quick work <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> standing material which was ei<str<strong>on</strong>g>the</str<strong>on</strong>g>rleft in place in <str<strong>on</strong>g>the</str<strong>on</strong>g> marsh (early seas<strong>on</strong>, pre-seed set) orremoved from <str<strong>on</strong>g>the</str<strong>on</strong>g> marsh and disposed <str<strong>on</strong>g>of</str<strong>on</strong>g> at a landfill (lateseas<strong>on</strong>, post seed-set). Mowing in this way serves to c<strong>on</strong>trolseed and pollen spread and may slow <str<strong>on</strong>g>the</str<strong>on</strong>g> vegetative expansi<strong>on</strong><str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Spartina cl<strong>on</strong>e by usurping root reserves. Mowingal<strong>on</strong>e does not kill <str<strong>on</strong>g>the</str<strong>on</strong>g> plants, however. Unless coupledwith o<str<strong>on</strong>g>the</str<strong>on</strong>g>r c<strong>on</strong>trol methods, mowing would need to be implementedseveral times each year in perpetuity and yetwould still allow some vegetative expansi<strong>on</strong>.O<str<strong>on</strong>g>the</str<strong>on</strong>g>r methods <str<strong>on</strong>g>of</str<strong>on</strong>g> Spartina c<strong>on</strong>trol tried elsewhere werenot attempted in <str<strong>on</strong>g>the</str<strong>on</strong>g> 2004 c<strong>on</strong>trol seas<strong>on</strong> for various reas<strong>on</strong>s.Macerating or tilling was not used because <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> c<strong>on</strong>cerns<str<strong>on</strong>g>of</str<strong>on</strong>g> land managers that <str<strong>on</strong>g>the</str<strong>on</strong>g> high amount <str<strong>on</strong>g>of</str<strong>on</strong>g> urban refuse presentin estuary marshes (tires, shopping carts, blocks <str<strong>on</strong>g>of</str<strong>on</strong>g> c<strong>on</strong>crete,pieces <str<strong>on</strong>g>of</str<strong>on</strong>g> metal, wood debris embedded with bolts ornails) and natural wrack (driftwood logs), would result inhigh maintenance costs or operator injury. The extremelys<str<strong>on</strong>g>of</str<strong>on</strong>g>t nature <str<strong>on</strong>g>of</str<strong>on</strong>g> most <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> estuary mud where c<strong>on</strong>trol wouldtake place was also taken into c<strong>on</strong>siderati<strong>on</strong>, as <str<strong>on</strong>g>the</str<strong>on</strong>g> machineryinvolved in <str<strong>on</strong>g>the</str<strong>on</strong>g>se methods is heavy and very likely to getstuck in place. Crushing <str<strong>on</strong>g>the</str<strong>on</strong>g> plants, where machinery is used- 219 -
Chapter 4: Spartina C<strong>on</strong>trol and Management<str<strong>on</strong>g>Proceedings</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> <str<strong>on</strong>g>Third</str<strong>on</strong>g> <str<strong>on</strong>g>Internati<strong>on</strong>al</str<strong>on</strong>g> <str<strong>on</strong>g>C<strong>on</strong>ference</str<strong>on</strong>g> <strong>on</strong> <strong>Invasive</strong> SpartinaFig. 1. 2004 Spartina treatment sites in <str<strong>on</strong>g>the</str<strong>on</strong>g> San Francisco Estuary, CA.to press <str<strong>on</strong>g>the</str<strong>on</strong>g> plants into <str<strong>on</strong>g>the</str<strong>on</strong>g> mud, was tried <strong>on</strong> a very smallscale, but <str<strong>on</strong>g>the</str<strong>on</strong>g> visual impacts <str<strong>on</strong>g>of</str<strong>on</strong>g> such a treatment method aswell as potential impacts to endangered species made thisopti<strong>on</strong> unsuitable for large-scale use.TIMINGSpartina c<strong>on</strong>trol work in <str<strong>on</strong>g>the</str<strong>on</strong>g> estuary is limited by morethan just <str<strong>on</strong>g>the</str<strong>on</strong>g> daunting amount <str<strong>on</strong>g>of</str<strong>on</strong>g> paperwork necessary toinitiate treatment. The estuary is a highly dynamic system,and <str<strong>on</strong>g>the</str<strong>on</strong>g> areas typically infested with n<strong>on</strong>-native Spartinabear <str<strong>on</strong>g>the</str<strong>on</strong>g> brunt <str<strong>on</strong>g>of</str<strong>on</strong>g> much <str<strong>on</strong>g>of</str<strong>on</strong>g> this dynamism. Occupying manyhabitats, including <str<strong>on</strong>g>the</str<strong>on</strong>g> bayfr<strong>on</strong>t edge as well as more shelteredmarshlands, n<strong>on</strong>-native Spartina infestati<strong>on</strong>s are subjectto daily tidal inundati<strong>on</strong>, storms, wrack deposits, urbanrun<str<strong>on</strong>g>of</str<strong>on</strong>g>f and polluti<strong>on</strong>, and sediment depositi<strong>on</strong>. Treatmentmethods selected for <str<strong>on</strong>g>the</str<strong>on</strong>g>se areas must account for all <str<strong>on</strong>g>of</str<strong>on</strong>g><str<strong>on</strong>g>the</str<strong>on</strong>g>se factors. Since large-scale treatment in 2004 reliedheavily <strong>on</strong> herbicide use, <str<strong>on</strong>g>the</str<strong>on</strong>g> treatment parameters <str<strong>on</strong>g>of</str<strong>on</strong>g> glyphosatefur<str<strong>on</strong>g>the</str<strong>on</strong>g>r dictated <str<strong>on</strong>g>the</str<strong>on</strong>g> available treatment window in<str<strong>on</strong>g>the</str<strong>on</strong>g> estuary.Glyphosate herbicide has specific requirements thatmust be satisfied in order to achieve high treatment efficacies.For Spartina c<strong>on</strong>trol <str<strong>on</strong>g>the</str<strong>on</strong>g>se are: l<strong>on</strong>g dry times (12-24- 220 -
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