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The “Invasive Species Battler” series has been developed to share what we have learned about common invasive species issues in the region. They are not intended to cover each issue in depth but to provide information and case-studies that can assist you to make a decision about what to do next or where to go for further information.

Invasive alien species represent an insidious and pervasive threat to the environmental, economic and human well-being of the Pacific islands. Pacific island ecosystems make up one of the world’s important biodiversity hotspots, with high numbers of endemic species that are particularly vulnerable to extinction due to their limited habitat and isolation.|This book is intended to serve as a practical guide, calling attention to the need to link emergencies, disasters and development, not only in policy statements, but in practical ways. The book identifies physical and social factors and processes determining disaster vulnerability and offers the reader a range of vulnerability-reduction options in development and disaster mitigation. The book covers the main relief and response technologies for a range of natural and technological disasters, and deals with community participation, health education, training and other social aspects relevant to the protection of health and the environment in emergencies and disasters.|The UNEP/GEF Prevention, Control and Management of Invasive Alien Species in the Pacific Islands project also known as the IAS project, commenced on 12 September 2012 and was due for completion on 30 September 2016, following an extension of one year. The project was designed to provide support to Pacific Island countries in their national efforts to implement the Guidelines for Invasive Species Management in the Pacific – a Pacific Strategy for managing pest, weeds and other invasive species (Tye 2009) which were developed and adopted as the regional strategic framework for invasive species management in 2009. Ten Pacific Island countries originally participated in the IAS project, these being the Cook Islands, Federated States of Micronesia, Kiribati, Marshall Islands, Niue, Palau, Papua New Guinea, Samoa, Tonga and Vanuatu. These were reduced to nine countries with the withdrawal of Papua New Guinea following the Mid-Term Review due to issues related to the country’s readiness to engage with the project. The project was therefore, responsible for delivering of support to a culturally, geographically and economic diverse set of Small Island Developing States (SIDS) spread across the vast geographical scope of the Pacific Ocean. The project was implemented by the UN Environment as the Implementing Agency (IA) and Executed by the Secretariat of the Pacific Regional Environment Programme (SPREP) as the Executing Agency (EA). In-country sub projects and activities were facilitated by National Project Coordinators and overseen by national Invasive Species Coordinating Committees. Its goal "to conserve ecosystems, species and genetic diversity in the Pacific region" is broad and aspirational and is backed by the Objective "to reduce the environmental economic and human health impacts of invasive alien species in both terrestrial and marine habitats in the Pacific region". The Project consisted of 5 core components: Building foundations for sustainable Invasive Alien Species (IAS) management by generating awareness and support, building institution and human capacity and strengthening legislation, policy and protocols. Defining problems, prioritisation and decision making by improving baseline information on IAS distribution and status, establishing systems to assess risk and prioritise action and developing or utilising effective management techniques. Taking management action through improved bio-security and border protection, direct management action through eradication and application of best practice methods and restoring ecosystems after IAS management. Undertaking effective monitoring and evaluation of the project.| Establishing effective and efficient project management and governance. This Terminal Project Evaluation is undertaken by the Evaluation Office of the UN Environment in order to assess the effectiveness of the project and its likely future impact on the state of IAS management in the region and its likely impact on invasive species and the environmental health of the participating countries. Further, the report aims to discern lessons and offers recommendations which may help improve the development and implementation of similar multi-country projects in the future both in the Pacific region and globally.

The first and second editions of the Handbook, on which this Pacific version is substantially based, were prepared as a practical introduction to negotiating or working on Mulitlateral Environmental Agreements (MEAs). They were prepared for people with little or no technical background in negotiations.They were also intended to function as a key reference tool for experienced negotiators. As a result the subject matter is developed at a relatively broad level. However, technical information and language was retained and used in context, with understanding facilitated by a comprehensive glossary prepared by UNEP. This new handbook preserves these key aspects but has enhanced the accessiblity of information and, were appropriate, used examples and material of particular relevance to the Pacific Region

Successful invasion is often due to a combination of species characteristics (or invasiveness) and habitat suitability (or invasibility). Our objective was to identify preferred habitats and suitable environmental conditions for the African tulip tree Spathodea campanulata (Bignoniaceae), one of the most invasive alien trees on the tropical island of French Polynesia (South Pacific Ocean), in relation to its distribution and photosynthesis capacity. Spathodea abundance and leaf chlorophyll fluorescence

Early Detection and Rapid Response (EDRR) systems are the first line of defence against invasive species once they have penetrated national or inter-island biosecurity systems. For these systems to be effective, a plan is required to coordinate the responsible agencies and ensure both the systems and equipment to address the detected species are in place prior to the response. Several countries have developed these plans recently, which are available on the Battler Resource Base. SPREP thanks James Stanford, who drafted the text for this guide.

To enhance their conservation value, several hundred islands worldwide have been cleared of invasive alien rats, Rattus spp. One of the largest projects yet undertaken was on 43 km2 Henderson Island in the Pitcairn group, South Pacific, in August 2011. Following massive immediate mortality, a single R. exulans was observed in March 2012 and, subsequently, rat numbers have recovered. The survivors show no sign of resistance to the toxicant used, brodifacoum. Using pre and post-operation rat tissue samples from Henderson, plus samples from around the Pacific, we exclude re-introduction as the source of continued rat presence. Microsatellite analysis of 18 loci enabled comparison of genetic diversity of Henderson rats before and after the bait drop. The fall in diversity measured by allele frequency change indicated that the bottleneck through which the breeding population passed was probably around 50 individuals, representing a census population of about 60-80 animals. This is the first failed project that has estimated how close it was to success.

The use of rodenticides to control or eradicate invasive rats (Rattus spp.) for conservation purposes has rapidly grown in the past decades, especially on islands. The non-target consequences and the fate of toxicant residue from such rodent eradication operations have not been well explored. In a cooperative effort, we monitored the application of a rodenticide, ‘Brodifacoum 25W: Conservation’, during an attempt to eradicate Rattus rattus from Palmyra Atoll. In 2011, Brodifacoum 25W: Conservation was aerially broadcasted twice over the entire atoll (2.5 km2) at rates of 80 kg/ha and 75 kg/ha and a supplemental hand broadcast application (71.6 kg/ha) occurred three weeks after the second aerial application over a 10 ha area. We documented brodifacoum residues in soil, water, and biota, and documented mortality of non-target organisms. Some bait (14–19% of the target application rate) entered the marine environment to distances 7 m from the shore. After the application commenced, carcasses of 84 animals representing 15 species of birds, fish, reptiles and invertebrates were collected opportunistically as potential non-target mortalities. In addition, fish, reptiles, and invertebrates were systematically collected for residue analysis. Brodifacoum residues were detected in most (84.3%) of the animal samples analyzed. Although detection of residues in samples was anticipated, the extent and concentrations in many parts of the food web were greater than expected. Risk assessments should carefully consider application rates and entire food webs prior to operations using rodenticides.

Invasive vertebrates are a leading cause of the extinction on islands and rats (Rattus spp.) are one of the most damaging to island ecosystems. Methods to eradicate rates from islands are well established and there have been over 580 successful eradications to date. Increasingly, rat eradications are being implemented on tropical islands, a reflection of the need to protect the threatened biodiversity in the tropics. Yet rat eradications on tropical islands fail more frequently than those in temperate climates. In an effort to identify the main reasons for the lower success rate on tropical islands and possible solutions, a workshop was convened with the 34 experts in rat eradication, tropical rodent and island ecology and toxicology. The workshop focused on projects using aerial broadcast of brodifacoum, a 2nd generation anticoagulant, because this approach had provided the highest success rate for eradicating rodents from islands. The workshop participants reviewed previously identified challenges to successful rat eradications on tropical islands including increased insect and crab densities resulting in competition for bait, year round or unpredictable timing of breeding rats and increased or unpredictable availability of alternative, natural foods. They also identified a number of new, likely reasons for the lower success rate on tropical islands and provided recommendations for how to address these risks in the planning and implementation of rat eradications. While the success rate of aerial broadcast rat eradications in tropical environments is quite high at 89%, it is hoped that by following the recommended best practices provided in this paper, future success rates will be closer to the 96.5% demonstrated for aerial broadcast rat eradication on temperate islands.

Poster or infographic on invasive plants in the Cook Islands.

Invasive species in the cook islands - poster/infographic