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
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 species have warranted special concern are thought to be invasive due to their historic and ongoing invasions of U.S. and foreign waters to which they are not native; Caulerpa taxifolia (Aquarium or Mediterranean strain), Caulerpa brachypus and Caulerpa racemosa.
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. The spread of C. brachypus has raised concerns because of its potential impact on the reef ecosystem off the southeastern coast of Florida. Concerns have also been raised by scientists about C. racemosa, which has spread rapidly in the Mediterranean, but has not yet produced any problematic populations in U.S. waters.
Introduction and spread of Caulerpa species into The impact of Caulerpa on natural systems in U.S. waters remain largely unstudied so the likely impacts on U.S. coastal marine ecosystems and the subsequent economic costs remain uncertain. is unknown. It is possible to infer likely impacts based on documented impacts in similar ecosystems in other regions of the world, where non-native Caulerpa species have become established.
Global dDocumented impacts of invasive Caulerpa species include competition with marine plants and macroalgae, direct and indirect impacts on marine invertebrates, direct and indirect impacts on marine vertebrates and economic impacts due to direct control costs and indirect costs associated with ecosystem alteration.
To date, eradication efforts for C. taxifolia in California have totaled over $3.7 million in direct control costs. , and O over $500,000 has been allocated to study the effects of C. brachypus in Florida.
The Aquatic Nuisance Species Task Force (ANSTF) asked the Caulerpa Working Group (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 interested parties in managing Caulerpa species in U.S. waters to which they are not native.
The goals of this National Management Plan for the genus Caulerpa are:
Prevent the introduction and spread of invasive Caulerpa species to areas in U.S. waters where they are not native.
Early detection, rapidly respondse to and monitoring of Caulerpa species in U.S. waters where they are not native.
To eradicate Caulerpa populations, in waters to which they are not native, where feasible.
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.
Educate and inform the public, agencies and policymakers to advocate for preventing the introduction and spread of Caulerpa species.
Identify research needs and facilitate research to fill information gaps.
Review, aAssess progress, review and revise the management plan, and continue developing information to meet national management plan goals.
Many of the action items in this plan are included in the Prevention Program for the 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.
Table of Contents
Executive Summary i
1. Purpose of this National Management Plan 1
2. Introduction to the Genus Caulerpa 2
2.1. Species of Caulerpa which are native to U.S. waters 4
2.2. Species of Caulerpa that may be introduced to U.S. waters to which they are not native 5
2.2.1. Caulerpa taxifolia 6
2.2.2. Caulerpa brachypus 8
2.2.3. Caulerpa racemosa 10
2.3. Assessment of historic Caulerpa introductions 19
2.3.1. History of Caulerpa taxifolia introduction in California 20
2.3.2. History of Caulerpa brachypus introduction in Florida 20
2.3.3. History of Caulerpa taxifolia introductions in other regions 20
2.3.4 Eradication and control efforts for Caulerpa taxifolia 22
2.4. Regulation of Caulerpa species in the U.S. 23
3. Impacts of Caulerpa Introductions 25
3.1. Ecological Impacts of Caulerpa Introductions 25
3.1.1. Direct and indirect impacts on marine plants 25
3.1.2. Direct impacts on marine herbivores 26
3.1.3. Indirect impacts on marine invertebrates 27
3.1.4. Indirect impacts on marine vertebrates 28
3.2. Potential Economic Impacts of Caulerpa Infestations 28
3.3. Actual costs of Caulerpa control in the U.S. 32
3.3.1. Costs of eradication treatment in California 32
3.3.2. Costs of control and educational outreach in Florida 32
4. Implementation Action Items 33
4.1. Primary Priorities for Implementation 35
How will this plan be implemented? How will the plan be managed? Since it is a National Plan will the Task Force be the managing entity, or is the intent to have the Working Group manage the plan? 47
4.2. Secondary Priorities for Implementation 48
4.4. Implementation Table for Action Items 55
5. References Cited 56
Appendix A. 1A Prevention Program for the Mediterranean Strain of Caulerpa taxifolia 64
Appendix B. Contributors to the draft National Management Plan for the Genus Caulerpa, 2004. 20
Appendix C. Literature Review of the Aquarium Strain of Caulerpa taxifolia 22