Invasion
Invasion Description
1st record- Carlsbad/CA/Aqua Hedionda Lagoon (Kaiser 2000; Williams et al. 2002; Williams et al. 2004 Anderson 2005) In 2000, colonies were discovered in Aqua Hedionda Lagoon, Carlsbad, and in Huntington Harbor, southern CA (Jousson et al. 2000, Kaiser 2000). An mulit-agency eradication program (Southern California Caulerpa Action Team, SCCAT) was started almost immediately, with the first control programs beginning with 17 days after the first discovery in Agua Hedionda Lagoon, using chlorine bleach, injected under PVC plastic sheets spread out over the bottom (Williams et al. 2004) . Laboratory tests indicated that bleach was effective at killing Caulerpa at the doses used in the field. Although the program was initally subject to some controversy (Dalton 2000), the method proved effective, and no plants were found after November 2002. In late 2005, SCCAT declared that eradication was successful (Anderson 2005).
Geographic Extent
Carlsbad/CA/Aqua Hedionda Lagoon (Kaiser 2000; Williams et al. 2005; Williams et al. 2004; Anderson 2005); CA/Huntington Harbor (Kaiser 2000; Williams et al. 2005; Williams et al. 2004; Anderson 2005).
Vectors
| Level | Vector |
|---|---|
| Probable | Aquatic Plant Shipments |
Regional Impacts
| Economic Impact | Aesthetic | |
| The eradication of Caulerpa taxifolia in southern California, using plastic sheets and chlorine bleach cost US$ 7.6 million for eradication (Anderson 2005; Anderson 2007). Motivations for the eradication program included biotic integrity of native seaweed and seagrass, recreational value (diving, boating, fishing), and coastal property values. The affected lagoons do not support commercial fisheries, and the probability of an extensive spread on the open coast is unlikely. | ||
| Ecological Impact | Competition | |
| Before its eradication, Caulerpa taxifolia greatly reduced the abundance of Widgeon Grass Ruppia maritima in Huntington Harbor and Eelgrass (Zostera marina) in Agua Hedionda Lagoon (Williams and Grosholz 2002). | ||
| Ecological Impact | Habitat Change | |
| The Caulerpa taxifolia adversely affected seagrass beds (Widgeongrass Ruppia maritima) in Huntington Harbor and Eelgrass (Zostera marina) in Agua Hedionda Lagoon, nursery areas for fishes and invertebrates (Williams and Grosholz 2002). The eradication program had an even larger, but temporary effect, killing much of the benthic biota. However, some benthic invertebrates and eelgrass seeds survived the chlorine treatment (Anderson 2005). | ||