National Management Plan for the Genus Caulerpa Photo by R. Woodfield, Merkel and Associates Submitted to the Aquatic Nuisance Species Task Force Prepared by the Caulerpa Working Group Draft - October, 2004 Executive Summary A variety of surveys have confirmed at least twenty-one species and varieties of Caulerpa with populations in different regions of the United States (U.S.). Three species of Caulerpa are thought to be invasive due to their historic and ongoing invasions of U.S. and Deleted: species have warranted special foreign waters; Caulerpa taxifolia (Aquarium or Mediterranean strain), Caulerpa brachypus and concern Caulerpa racemosa. Deleted: to which they are not native In June 2000 divers detected C. taxifolia (Mediterranean strain) in Agua Hedionda Lagoon located in Carlsbad, CA and a second population in Huntington Harbor, CA. Divers first discovered non-native C. brachypus off the coast of southern Florida in 1999. Concerns have Deleted: The spread of C. brachypus also been raised by scientists about C. racemosa, which has spread rapidly in the Mediterranean, has raised concerns because of its potential impact on the reef ecosystem off but has not yet produced any problematic populations in U.S. waters. the southeastern coast of Florida. The impact of Caulerpa on natural systems in U.S. waters is unknown. It is possible to Deleted: Introduction and spread of infer likely impacts based on documented impacts in similar ecosystems in other regions of the Caulerpa species into world, where non-native Caulerpa species have become established. Deleted: remain largely unstudied so Documented impacts of invasive Caulerpa species include competition with marine plants and the likely impacts on U.S. coastal marine macroalgae, direct and indirect impacts on marine invertebrates, direct and indirect impacts on ecosystems and the subsequent economic costs remain uncertain. marine vertebrates and economic impacts due to control costs and costs associated with ecosystem alteration. To date, eradication efforts for C. taxifolia in California have totaled over Deleted: Global d $3.7 million in direct control costs, and over $500,000 has been allocated to study the effects of Deleted: direct C. brachypus in Florida. Deleted: indirect The Aquatic Nuisance Species Task Force (ANSTF) asked the Caulerpa Working Group Deleted: ¶ (CWG) to draft a National Management Plan (NMP) that addresses the Caulerpa genus. This NMP was developed with the input of the CWG and other experts to guide the ANSTF and other Deleted: . interested parties in managing Caulerpa species in U.S. waters. Deleted: O The goals of this National Management Plan for the genus Caulerpa are: Deleted: to which they are not native 1) Prevent the introduction and spread of invasive Caulerpa species in U.S. waters where Deleted: to areas they are not native. 2) Early detection, rapid response to and monitoring of Caulerpa species in U.S. waters Deleted: ly where they are not native. Deleted: d 3) To eradicate Caulerpa populations, in waters to which they are not native, where feasible. 4) Provide long-term adaptive management and mitigate impacts of populations of Caulerpa species in U.S. waters where they are not native, and where eradication is not feasible. 5) Educate and inform the public, agencies and policymakers to advocate for preventing the introduction and spread of Caulerpa species. 6) Identify research needs and facilitate research to fill information gaps. 7) Assess progress, review and revise the management plan, and continue developing Deleted: Review, a information to meet national management plan goals. Many of the action items in this plan are included in the Prevention Program for the Formatted: Left Mediterranean Strain of Caulerpa taxifolia. It would be helpful to know what progress has been made since the adoption of the program and what components proved to be most effective along with any suggestions the Prevention Program team may have for improvements. Risk assessment – mentioned only briefly as goal 1-3 in the plan, should play a major role in the development of the plan itself. High risk species need to be identified early on, as do regions at high risk of successful introduction. i Table of Contents Executive Summary .............................................................................................................................i Figures............................................................................................................................................... iii Tables ................................................................................................................................................ iii Appendices........................................................................................................................................ iii 1. Purpose of this National Management Plan ..................................................................................1 2. Introduction to the Genus Caulerpa..............................................................................................3 2.1. Species of Caulerpa which are native to U.S. waters.............................................................5 2.2. Species of Caulerpa that may be introduced to U.S. waters to which they are not native....6 2.2.1. Caulerpa taxifolia.............................................................................................................7 2.2.2. Caulerpa brachypus .........................................................................................................9 2.2.3. Caulerpa racemosa.........................................................................................................10 2.2.4. Other species of Caulerpa..............................................................................................13 2.3. Assessment of historic Caulerpa introductions.....................................................................18 Deleted: 17 2.3.1. History of Caulerpa taxifolia introduction in California...............................................19 Deleted: 17 2.3.2. History of Caulerpa brachypus introduction in Florida................................................19 Deleted: 18 2.3.3. History of Caulerpa taxifolia introductions in other regions ........................................19 Deleted: 18 2.3.4 Eradication and control efforts for Caulerpa taxifolia ...................................................20 2.4. Regulation of Caulerpa species in the U.S............................................................................22 Deleted: 19 3. Impacts of Caulerpa Introductions..............................................................................................23 Deleted: 21 3.1. Ecological Impacts of Caulerpa Introductions .....................................................................23 Deleted: 22 3.1.1. Direct and indirect impacts on marine plants ................................................................23 Deleted: 22 3.1.2. Direct impacts on marine herbivores .............................................................................24 Deleted: 22 3.1.3. Indirect impacts on marine invertebrates.......................................................................25 3.1.4. Indirect impacts on marine vertebrates ..........................................................................26 Deleted: 23 3.2. Potential Economic Impacts of Caulerpa Infestations .........................................................26 Deleted: 24 3.3. Actual costs of Caulerpa control in the U.S. ........................................................................29 Deleted: 25 3.3.1. Costs of eradication treatment in California ..................................................................29 Deleted: 25 3.3.2. Costs of control and educational outreach in Florida ....................................................29 Deleted: 27 4. Implementation Action Items ......................................................................................................30 4.1. Primary Priorities for Implementation ..................................................................................31 Deleted: 27 4.2. Secondary Priorities for Implementation ..............................................................................42 Deleted: 28 4.3. Tertiary Priorities for Implementation ..................................................................................47 Deleted: 29 4.4. Implementation Table for Action Items................................................................................49 Deleted: 30 5. References Cited ..........................................................................................................................50 Deleted: 40 Deleted: 44 Deleted: 46 Deleted: 47 ii Figures Figure 1. Caulerpa taxifolia exhibits a habit typical of the genus: a creeping rhizome produces rhizoids downward and photosynthetic branches (in this case bearing leaf-like pinnules) upward.........................................................................................................................................3 Figure 2. On the Pacific coast of North America indigenous populations of Caulerpa only exist as far north as Guadalupe Island. ...............................................................................................5 Figure 3. Caulerpa taxifolia, prior to treatment in California. .........................................................7 Figure 4. Caulerpa brachypus growing on coral in FL. ...................................................................9