CARIBBEAN FOOD CORPS SOCIETY

SERVING THE CARIBBEAN SINCE 1963

CARIBBEAN FOOD

CROPS SOCIETY

39 Thirty Ninth

Annual Meeting 2003

Grenada

Vol. XXXIX Number 1

Proceedings of the Caribbean Food Crops Society. 39(1):102-118. 2003

THE NATURE CONSERVANCY'S CONSERVATION ACCOMPLISHMENTS AT RISK: ABATING THE THREAT OF INVASIVE SPECIES

Elizabeth A. Sklad1, Ann M. Bartuska, John M. Randall2, Barry A. Rice2, Mandy Tu, and Doria R. Gordon4. 1The Nature Conservancy, Invasive Species Initiative, 4245 Fairfax Drive, Suite 100, Arlington, VA 22203. 2The Nature Conservancy, Wildland Invasive Species Team, Weed Science Program, 124 Robbins Hall, University of California, Davis, CA 95616. 3The Nature Conservancy, Oregon Field Office, 821 SE 14'h Avenue, Portland, OR 97214. 4The Nature Conservancy, Florida Field Office, 220 Bartram Hall, Department of Botany, University of Florida, Gainesville, FL, 32611

ABSTRACT: Whether in the coral reefs of the South Pacific, in native grasslands of the western U.S., in Brazil's Pantanal wetlands, in the hardwood hammocks of the Florida Keys, in coastal and tropical forests in the Caribbean, or across Mexican deserts, invasive species have been identified as one of the most serious and pervasive threats across all of The Nature Conservancy's Conservation Areas, threatening all our conservation accomplishments to date. Invasive species have been identified as one of the top two threats to global biodiversity, and this threat has economic consequences -estimated at $137 billion annually in the U.S. alone. In the long term, conservation success will depend greatly on the ability to prevent new invasions, and to manage "invaded" native systems for maximum benefit to native biodiversity and intact, functioning ecosystems. The prevention and early detection of new invasive species is not only important to natural systems, but can also save millions of dollars in control measures for agricultural systems. The Conservancy is actively promoting the implementation and scientific improvement of new prevention programs and methods, through capacity building and through the influence on policy. The steps for a comprehensive strategy include assessment and risk analysis, prevention, early detection, rapid response and eradication, control and management, restoration, and public education and awareness. The foundation for all these steps is science -but much more is needed and our ability to incorporate new information into management decisions in a timely fashion continues to be limited.

KEY WORDS: The Nature Conservancy; invasive species; threat; prevention; early detection; strategy

INTRODUCTION

The invasion of native ecosystems by non-native or alien organisms - animals, plants, insects, and pathogens - is now widely regarded as a top threat to biological diversity worldwide. In the United States, invasion negatively affects some 52% of all imperiled species (Wilcove et al., 1998). The scientific study of invasion is in its infancy. We know enough, however, to be confident that aggressive action is warranted to slow the flow of new invaders and to reduce the impact of established, habitat-altering species.

Some invasive species disrupt ecosystem processes, such as fire regimes, hydrology, and soil chemistry. Other invasive species have economic and social impact, costing millions of dollars to agricultural systems, the tourism industry, and utilities and highway maintenance, to name a few.

No habitat type or region of the globe is immune to biological invasion. From continental systems to oceanic islands, from the poles to the tropics, from evolutionarily ancient to youthful

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systems, and in marine, aquatic, and terrestrial habitats, all are experiencing important invasion impacts. Island ecosystems are especially vulnerable to invasions given that island species have evolved in relative isolation and often are not able to respond adequately to intense inter-specific competition.

Global trade and travel, climate change, habitat degradation and fragmentation, and the natural propensity of most species to disperse into available habitats will continue to drive invasion and threaten native species and ecosystems. Furthermore, many non-native species, particularly plants, exhibit a pronounced "lag effect" between their introduction in a new landscape and their first invasive expansion in that landscape. Even if all new introductions were stopped immediately, the existing pool of introduced species in most landscapes would still pose a threat requiring full attention.

POLICY CONSIDERATIONS IN THE PREVENTION AND CONTROL OF BIOLOGICAL INVASIONS

Within countries, farmers, health agencies, foresters, and conservation interests are understandably far more aware of the threat of invasive species than the general citizenry. Society-wide awareness and political action typically occur only where invasive species threaten public safety, health, or economic security in a dramatic way (e.g., the brown tree snake in Hawaii, or the Mediterranean fruit flies in California, Japan, or New Zealand). Some communities have utilized these high-profile pests to build political support for significant growth in invasive species management systems.

Awareness and engagement vary widely among countries. Australia, New Zealand, Great Britain, South Africa, and the U.S. stand out as leaders in invasive species management and public awareness. Most developing nations lack the personnel and technical capacity to carry out strong quarantine and mitigation work, even though many have basic quarantine laws in place.

Numerous international instruments, binding and non-binding, have been developed to deal with certain aspects of the invasive species threat. The most comprehensive is the 1992 Convention on Biological Diversity (CBD), which calls on its parties —178 governments as of 2000— to "prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats, or species" (Article 8h). The 1952 International Plant Protection Convention binds 111 governments in a shared strategy to prevent the spread and reduce the impacts of plant pests. Other instruments deal with invasive alien species in specific regions (e.g., Antarctica), sectors (e.g., fishing in the Danube), or vectors (e.g., in ballast water, through the International Maritime Organization). Over 40 such instruments or programs are already in force, and many more are awaiting finalization and ratification.

The U.S. Federal government has begun showing stronger leadership on this issue, forming the National Invasive Species Council (NISC) in 1998 to prepare the first U.S. National Invasive Species Management Plan. Forty-three senators from both political parties issued a joint call in 1999 for stronger action against invasive species. The National Governors' Association has named invasive species a top policy concern, and several states are engaged in cross-sectoral strategies to reduce this threat. Some states and local governments have developed invasive species management programs that are more protective and pro-active than those overseen by higher levels of government, giving rise in some instances to jurisdictional disputes.

All of this action is dwarfed, however, by forces promoting free trade. The General Agreement on Tariffs and Trade (GATT), the North American Free Trade Agreement (NAFTA) and the World Trade Organization work explicitly to remove unnecessary trade restrictions, and have identified unjustified invasive species quarantines as a major focus for reform. All quarantines must be grounded in science, and the country restricting the import must demonstrate

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that it is actively controlling the pests that it seeks to prevent from entering. These rules put pressure on all trading countries to strengthen the technical aspects of their prevention systems, but few are currently capable of doing so.

THE NATURE CONSERVANCY'S INVASIVE SPECIES INITIATIVE

Whether in the coral reefs of the South Pacific, in native grasslands of the western U.S., in Brazil's Pantanal wetlands, in the hardwood hammocks of the Florida Keys, in coastal and tropical forests in the Caribbean, or across Mexican deserts, invasive species were identified as one of the most serious and pervasive threats across all of The Nature Conservancy's Conservation Areas, threatening all of our conservation accomplishments to date. The Nature Conservancy (TNC) is a non-profit organization dedicated to preserving the plants, animals and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need in order to survive. The Conservancy has more than 1.1 million individual members and over 1,900 corporate sponsors, and currently has programs in all 50 states and in 27 other nations, including the Bahamas, Jamaica, Dominica, the Dominican Republic, and the U.S. Virgin Islands. To date, the Conservancy has protected more than 12 million acres worldwide, and has helped local partner organizations preserve millions of acres in other nations. The Conservancy itself owns more than 1,340 preserves in the United States -the largest private system of nature sanctuaries in the world. Its conservation work is grounded on sound science, strong partnerships with other landowners, and tangible results at local scale.

The Nature Conservancy determines where and how to do its work through a planning process that identifies areas in the country containing the most viable and important examples of plant and animal populations and communities. This process further identifies the principal threats to the integrity of the sites such as land conversion, non-point source runoff, or repression of natural fire regimes. And, in a bottom-up priority setting assessment in mid-2001, an overwhelming 94% of TNC sites identified invasive species as a significant threat to the native species and communities that we are working to protect.

In response to the pervasive threat of invasive species to the Conservancy's conservation achievements, TNC created an Invasive Species Initiative (ISI). The ISI's overarching goal is to reduce and manage the threat to worldwide biological diversity, and the concomitant social costs, caused by non-native organisms invading ecosystems. To achieve this goal, the Invasive Species Initiative developed a set of seven steps, which, when carried out in concert, will build a solid and adaptable foundation for any effective invasive species strategy. The steps for this comprehensive strategy include: 1. Adoption of governmental policies (on all scales) to prevent harmful new invasive species

and control significant existing invasive species in a manner equivalent to the cutting-edge policies in New Zealand;

2. Availability of and use of tools, techniques, and information on invasive species prevention and management;

3. An accurate, all-taxa, baseline assessment of threats from invasive species; 4. Prevention of harmful new introductions on continental and local scales; 5. Early detection of, and subsequent rapid response to, newly established invaders; 6. Identification and control of all established invasions, including restoration of native

ecosystems; 7. Awareness of the urgency and seriousness of the issue by the general public.

Although a comprehensive strategy includes all of these steps, the most effective invasive species efforts will focus priority attention on prevention and early detection, as once an invasive

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species becomes established, the time and money requirements needed for control of that species increase dramatically. The establishment of a new invader takes a similar toll on the ecosystem (Figure 1). In the absence of effective prevention and early detection systems, we are limited to the last remaining option for invasive species management, control. Below, we outline examples of the Conservancy's work on assessment, early detection and rapid response, and control strategies.

Before an early detection system can detect a new invasive species, it is necessary to have an all-taxa baseline assessment of invasive species threats already in place. The Nature Conservancy's Invasive Species Initiative and Northeast/Caribbean Division, in cooperation with CAB International, completed the first Caribbean Invasive Species Assessment in April 2003. This assessment has led to the creation of a database containing a list of contact information for invasive species experts in the Caribbean. In addition, the assessment discovered that invasive species policies and invasive species management techniques throughout the Caribbean are piecemeal in nature. This important baseline information will focus attention on the direction of future efforts in the Caribbean region; the region must develop comprehensive regional policies, control action plans, information exchange methods, and an early detection system.

No prevention system can be completely foolproof in keeping invasive species out of an area. This fact underscores the importance of maintaining an early detection and rapid response system to quickly eradicate new invasions. The following case studies illustrate The Nature Conservancy's commitment to abating invasive threats on local regional scales.

INTRODUCTION OF RACCOONS ON ABACO ISLAND, BAHAMAS

In 1992, raccoons were accidentally introduced to the Bahamian island of Abaco. This introduction threatens a number of species, in particular, an endemic, ground-nesting subspecies of the Cuban parrot (Amazona leucocephala bahamensis), the only significant remaining population being restricted to Abaco. In order to help the Abaconian community better respond to new invasive species, The Nature Conservancy's Bahamas Office is supporting and partnering with a local conservation organization called Friends of the Environment. Effective management of biological invasions requires consensus among all entities and decision makers, as well as affected parties. The Nature Conservancy is assisting this group in establishing a governing board to represent a diverse group of interests from the community, including a representative from the local Department of Agriculture. With help from The Nature Conservancy, the group is also developing a plan to control newly-detected invasive species, like the raccoon, and raising public awareness about the importance of preventing new invasive species from becoming established and threatening the island's biodiversity.

SPREAD OF CACTUS MOTH THROUGH THE CARIBBEAN AND FLORIDA

In 1988, officials in South Florida were alerted that the cactus moth (Cactoblastis cactorum) had been detected in Cuba. In the intervening fourteen years, the moth made its way to the Florida Keys and continued spreading northward at the rate of approximately 50 km per year, where it can now be found as far north as Charleston, South Carolina, on the East Coast and the panhandle of Florida on the Gulf Coast. Without a prevention or early detection plan, officials in Florida, as well as Conservancy staff, are now forced to try to control C. cactorum and stop it from spreading further.

The moth's larvae feed predominately on species of Opuntia cacti. The genus Opuntia is a diverse group in North America, with many endemic species. There are 31 likely host Opuntia across the United States (9 endemic), 56 in Mexico (38 endemic), and additional native and

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endemic species found throughout the Caribbean and Central America. Additionally, C. cactorum has been documented on one species of Cereus in Argentina, and may threaten some species of this group as well.

The establishment of C. cactorum seriously affects not only biodiversity in natural areas, but is a significant threat to agriculture across the Americas. Opuntia cacti are the seventh largest agricultural species in Mexico, with 215,000 ha planted commercially, as well as 3 million ha in the wild (Soberon et al., 2001). The threat to Opuntia affects other economic and social sectors as well. Opuntia serve as the third largest staple food for Mexico's rural poor (Soberon et al., 2001), and in 2001, the horticultural industry in Arizona sold $9.5 million worth of Opuntia cacti for landscaping purposes (Irish, 2001). With the inclusion of consequences to biodiversity across the region, the moth has the potential to dramatically change the landscape across the Americas.

When C. cactorum was discovered to have killed one out of a population of fourteen remaining individuals of the rare Opuntia corallicola on a Conservancy preserve, The Nature Conservancy began research on control methods for C. cactorum. Research methods currently include outplanting of O. corallicola, covering at-risk cacti with cages to exclude moths, and collaboration with the U.S. Department of Agriculture's Animal and Plant Health Inspection Agency on the possible use of pheromone traps and a sterile male release program. The Conservancy participated in an International Atomic Energy Agency workshop to develop a proposal and funding for mitigating the threat from C. cactorum in 2002. Additionally, the Conservancy raised the issue to the intra-governmental level at the April 2003 Annua] Meeting of the Trilateral Committee for Wildlife and Ecosystem Conservation and Management, which includes the Governments of Canada, the United States, and Mexico. TNC participated in the invasive species working group, which asked the Executive Committee to initiate a project under the Trilateral Committee that would address the threat of the spread of the cactus moth, using modeling, surveillance, and public education.

CONCLUSION

Fundamentally, managing the threat of invasive species is not just about ecological intervention; it is about social change. The public's behavior must change because it is unacceptable to our quality of life to enable the free movement and establishment of invasive species, whether in natural areas and biodiversity hot spots, in agricultural systems and forests, or in our own backyards. To this end, The Nature Conservancy's approach is built foremost upon partnerships, locally and globally. Without the support of partnerships between the Conservancy and local conservation groups, university researchers, and Federal agencies, the early detection system and invasive species control research described above would be severely hampered. Additionally, a significant ramping up of efforts and partnerships outside of North America will be critical to the overall success of The Nature Conservancy's Invasive Species Initiative, as international travel and trade continue to spread new invasive species around the world at an unprecedented pace. Putting The Nature Conservancy's seven-step strategy into action, along with an emphasis on creating partnerships with a variety of stakeholders and on a number of scales, will reduce the threat of invasive species, not only to the Conservancy's preserves, but to others as well.

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REFERENCES

Irish, M. 2001. The ornamental prickly pear industry in the southwestern United States. Florida Entomologist 84: 484-485.

Pimentel, D., L. Lach, R. Zuniga, and D. Morrison. 2000. Environmental and Economic Costs of Nonindigenous Species in the United States. Bioscience. 50 (1): 53-65.

Soberon, J., J. Golubov, and J. Sarukhan. 2001. The importance of Opuntia in Mexico and routes of invasion and impact of Cactoblastis cactorum (Lepidoptera: Pyralidae). Florida Entomologist 84: 486-492.

Wilcove, D.S., D. Rothstein, J. Dubow, A. Philips, and E. Losos. 1998. Quantifying Threats to Imperiled Species in the United States - assessing the relative importance of habitat destruction, alien species, pollution, overexploitation, and disease. Bioscience 48 (8): 607-615.

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Prevention E a r l V Large-Scale Eradication Control

Figure 1. Direct and ecosystem services costs attributed to invasive species at different stages of invasion.

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