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Eradicating Pacific rats (Rattus exulans) from Nu'utele and Nu'ulua Islands, Samoa - some of the challenges of operating in the tropcial Pacific

Available Online

Butler, D.J.

Tipamaa, F.T.

Tye, A.

Wylie, M.

The restoration of the small offshore islands of Nuutele (108ha) and Nuulua (25ha) has long been identified as a priority for biodiversity conservation in Samoa. The first step towards restoration was the aerial spreading of brodifacoum to eradicate Pacific rats (Rattus exulans) in August 2009. Procedures for the eradication followed those used in New Zealand and involved technical experts from that country. Particular challenges included a tight operational time-frame (two months), technical problems magnified by the remote location, variable reliability of weather forecasting,working with the local community, and mitigating rodenticide exposure risks for the friendly ground-dove (Gallicolumba stairi) (IUCN: vulnerable). Solutions to these challenges are discussed as guidance for similar projects in remote island locations. Follow-up monitoring between August 2009 and March 2010 indicated that the eradication had been successful, but Pacific rats were detected on Nuutele in May 2011. Nuulua has yet to be rechecked in 2011. DNA analyses are being organised to determine if these rats are survivors or re-invaders.

Seabirds enhance coral reef productivity and functioning in the absence of invasive rats

Available Online

Carr, Peter.

Graham, Nicholas A. J.

Hoey, Andrew S.

Jennings, Simon.

MacNeil, M. Aaron

Wilson, Shaun K.

Biotic connectivity between ecosystems can provide major transport of organic matter and nutrients, influencing ecosystem structure and productivity, yet the implications are poorly understood owing to human disruptions of natural flows. When abundant, seabirds feeding in the open ocean transport large quantities of nutrients onto islands, enhancing the productivity of island fauna and flora. Whether leaching of these nutrients back into the sea influences the productivity, structure and functioning of adjacent coral reef ecosystems is not known. Here we address this question using a rare natural experiment in the Chagos Archipelago, in which some islands are rat-infested and others are rat-free. We found that seabird densities and nitrogen deposition rates are 760 and 251 times higher, respectively, on islands where humans have not introduced rats. Consequently, rat-free islands had substantially higher nitrogen stable isotope (?15N) values in soils and shrubs, reflecting pelagic nutrient sources. These higher values of ?15N were also apparent in macroalgae, filter-feeding sponges, turf algae and fish on adjacent coral reefs. Herbivorous damselfish on reefs adjacent to the rat-free islands grew faster, and fish communities had higher biomass across trophic feeding groups, with 48% greater overall biomass. Rates of two critical ecosystem functions, grazing and bioerosion, were 3.2 and 3.8 times higher, respectively, adjacent to rat-free islands. Collectively, these results reveal how rat introductions disrupt nutrient flows among pelagic, island and coral reef ecosystems. Thus, rat eradication on oceanic islands should be a high conservation priority as it is likely to benefit terrestrial ecosystems and enhance coral reef productivity and functioning by restoring seabird-derived nutrient subsidies from large areas of ocean.

Guidelines for invasive species planning and management on islands

Island and Ocean Ecosystems, BRB

Available Online

Tye, Alan

The purpose of this document is to assist anyone planning and programming the management of invasive species on islands, with the aim of reducing the negative impacts of invasive on islands' rich and fragile natural heritage communities and livelihoods

Marine and Coastal Biodiversity in the Tropical Island Pacifc Region

Maragos J E, Peterson M N... [et al]

The first of two workshops on Marine and Coastal Biodiversity in the Tropical Island Pacific Region was held at the East-West Center in Honolulu on 2 - 4 November 1994. The goal of the first workshop was to review the status of species systematics and database management studies and develop an action plan for marine and coastal biodiversity information management for the region. The workshop was divided into three parts...

Report of the Western South Pacific regionally workshop to facilitate the description of ecologically or biologically significant marine areas : subsidiary body on scientific, technical and technological advice sixth meeting, Montreal, 30 April - 5 May 2012

At its tenth meeting, the Conference of the Parties to the Convention on Biological Diversity (COP 10) requested the Executive Secretary to work with Parties and other Government as well as competent organisations and regional initiatives, such as the Food and Agriculture Organisation of the United Nations (FAo), regional seas conventions and action plans, and where appropriate, regional fisheries management organisations (RFMOs), with regards to fisheries management, to organise, including the setting of terms of reference, a series of regional workshop, with a primary objective to facilitate the description of ecologically or biologically significant marine areas through the application of scientific criteria in annex 1 to decision IX/20 as well as other relevant compatible and complementary nationally and intergovernmentally agreed scientific criteria, as well as the scientific guidance on the identification of marine areas beyond national jurisdiction, which meet the scientific criteria in annex 1 to decision IX/20.

New Caledonia's Strategy for Invasive Alien Species that threaten natural ecosystems

Available Online

This is a summary of New Caledonia's Strategy for Invasive Alien Species that threaten natural ecosystems which was endorsed by the governing board of the Conservatoire d'espaces naturels (CEN) at the end of 2016. This summary was produced to raise awareness amongst New Calendonians and visitors of the priority actions that have been developed at the territory level and the urgent need for cooperative action to address this major threat to the country.

Globally threatened vertebrates on islands with invasive species.

Available Online

Butchart, Stuart H M

Ceballos, Gerardo

Croll Donald A.

Genovesi, Piero Genovesi

Holmes, Nick D.

Spatz, Dena

Tershy, Bernie R

Zilliacus, Kelly M.

Global biodiversity loss is disproportionately rapid on islands, where invasive species are a major driver of extinctions. To inform conservation planning aimed at preventing extinctions, we identify the distribution and biogeographic patterns of highly threatened terrestrial vertebrates (classified by the International Union for Conservation of Nature) and invasive vertebrates on ~465,000 islands worldwide by conducting a comprehensive literature review and interviews with more than 500 experts. We found that 1189 highly threatened vertebrate species (319 amphibians, 282 reptiles, 296 birds, and 292 mammals) breed on 1288 islands. These taxa represent only 5% of Earth's terrestrial vertebrates and 41% of all highly threatened terrestrial vertebrates, which occur in

Preliminary Analysis of Vector Routes and Selected Invasive Species for Pacific Island Countries and Territories

Available Online

Green, Wren

Understanding vector routes for invasive species (i.e. the routes by which pest plants and animals move from place to place via human assistance) is a key element in global and national efforts to reduce risks and limit the further spread of invasive species. This report is divided into two main sections. The first section provides a quantitative analysis of air and sea movements between the countries and territories of the Pacific. The second section summarises information on eighty existing or potential invasive plants and animals to Pacific islands. While the GEF project with which this report is linked is limited to SPREP countries, the analysis also includes the territories of the region (with the exception of Pitcairn Island). This is essential since some territories are pivotal to understanding vector routes and transport hubs in the region. For the same reason, flights from Pacific islands to Hawaii are included, as well as including Hawaii in the analysis of the selected invasive species. There is significant variability in the volume and patterns of ship movements and aircraft flights between the countries and territories of the Pacific, which is consistent with their diverse sizes, economies, exports, and political linkages. A few countries emerged as significant hubs for sea and air transport within the region. (Refer to Tables 1 and 2 for summaries.) In the northern Pacific, Guam emerges as the high risk country, given its high levels of total merchant ship and oceanic fishing vessels as well as the largest number of weekly flights to other Pacific island countries (139) and to Asian destinations (148). In the central southern Pacific, Fiji is the major transport centre with a large volume of merchant shipping, cruise liners and itinerant yachts (585 yearly visits) and relatively high numbers of weekly flights both within and outside the region. To the east, French Polynesia has a smaller annual number of merchant ship visits, but when other shipping activity is included, as well as 26 weekly flights to the USA (including Hawaii) and more within the region, it emerges as an important vector route. (It already has a significant number of invasive species). Papua New Guinea and New Caledonia are important countries in the western Pacific for shipping volumes; New Caledonia also for visits by yachts (500/yr). Papua New Guinea has extensive air links with Australia, another source of tropical invasives, but very few within the Pacific. New Caledonia has a larger number of weekly flights than Papua New Guinea spread within the region, as well as to Asian, Australian and New Zealand destinations. The information in the second section on eighty invasive species provides evidence for the links between trade, travel and the distribution of invasives. Vector routes and methods of spread are identified. It also highlights the importance of early detection and eradication if Pacific countries are to be more effective at limiting the arrival and spread of invasive species.

invasive species

Hurricane disturbance accelerates invasion by alien tree Pittosporum undulatum in Jamaican montane rain forests

Island and Ocean Ecosystems, BRB

Available Online

Bellingham, Peter J.

Excurra, E.

Healey, John R.

Tanner, Edmund V. J.

Questions: Do past disturbance, soil nutrients, or species diversity predict the invasion success of the alien tree Pittosporum undulatum in an island montane rain forest? What are the consequences of its invasion for forest composition and species diversity? Location: Blue Mountains, Jamaica. Methods: Censuses of trees ? 3 cm DBH in permanent plots in four sites within ca. 7 ha; 19742004 (intensive sites) and in 16 plots within 250 ha; 19902004 (extensive plots). Results: Pittosporum was unrecorded in the intensive sites before a severe hurricane in 1988: by 2004 all four sites were invaded. Pittosporum had invaded 25% of the extensive plots in 1990 and 69% in 2004, where its basal area increased from 0.5 ± 0.4 (SEM) m2.ha?1 in 1990 to 2.8 ± 1.3 m2.ha?1 in 2004. It had zero stem mortality and diameter growth rate exceeded that of native species fourfold. Pittosporum's basal area in the extensive plots in 2004 was positively related to the stand basal area damaged in the 1988 hurricane and negatively related to soil N concentrations. Pittosporum invasion was unrelated to stand-level tree species diversity in the extensive plots but as its basal area increased over time the basal area of native species and stand-level diversity declined. Conclusions: There are no obvious functional attributes of Pittosporum unrepresented in the native tree flora although it has high photosynthetic efficiency compared with native trees. More widespread invasion of these forests by Pittosporum seems inevitable since hurricanes, which accelerated the invasion, affect these forests frequently.

Funtional Roles of Invasive Non-indigenous Plants in Hurricane-Affected Subtropical Hardwood Forests

Available Online

Freedman, Andrea.

Hoffstetter, Ronald H.

Horvitz, Carol. C.

McMann, Stephen.

Pascarella, John B.

Native forest species exhibit a well-known range of ecological roles with respect to natural disturbance regimes, from pioneer phase to mature phase, and they regenerate from a range of sources, including dormant seeds, seed rain, pre-established juveniles, and resprouts from damaged adults. In contrast, the ecological roles of invasive, non-indigenous species in forest communities after natural disturbances are not well understood. Some previous studies of invasive species have emphasized their weedy nature and their ability to colonize anthropogenic disturbances. Tropical hardwood hammock forest in southern Florida experience frequent disturbance by hurricanes. Our studies of forest regneration during two years following a recent severe hurricane suggest that invasive non-indigenous forest species exhibit the same range of ecological roles as native forest regeneration during two years following a recent severe hurricane suggest that invasive non-indigenous forest species exhibit the same range of ecological roles as native forest species and compete with native species for particular kinds of regeneration opportunities. To study ecological roles of non-indegenous species in regenerating forests after Hurricane Andrew, we set up four large study areas at each of three study sites that had differing amounts of hurricane-caused canopy disturbance. There were two pairs of 30 X 60 m research plots per site, and in each pair there was one control plot and one restoration plot; restoration areas were subject to an aggressive management program, focused on reducing non-indigenous vine cover. Within these study areas we subsampled vegetation in small study plots that were regularly spaced, and conducted vegetation censuses in April (the end of the dry season) and October (the end of the rainy season) for 2 yr, beginning in April 1993. We found that the source of regeneration for forest species was dependent upon the amount of canopy disturbance, the time since disturbance, and the autecology of the constituent species. Overall, 28% of the 90 species were non-indigenous: 34% of the vines (N=32) and 24% of other life-forms (N=58). Non-indigenous vines seemed to have a special role; not only could they compete with native vines, but they could also negatively affect the regeneration of other natives from a diverse array of sources including pre-established juveniles and resprouts from damaged adults. Both native and non-indigenous vine cover in unmanipulated study areas increased following the hurricane. Non-indigenous vine species had higher cover than native vine species, and many species formed dense "blankets." Non-indigenous species in general (not just vines) did not differ significantly from native species in seed mass, nor were they restricted to the pioneer type of life history. Many non-indigneous species had invaded forests prior to hurricane disturbance and had their own banks of pre-established juveniles; others recruited from dormant seeds, and seed rain, and/or respouts from pre-established adults. Based on information on source of regeneration and impact on native species, we propose a classification scheme for functional roles of non-indigenous invasive species in forests. To investigate whether non-indigenous taxa had roles in other geographic regions similar to those they had in Florida, we reviewed literature for 50 taxa belonging to genera that have species known to be invasive in southern Florida. We found that these taxa were invsive or had cogeners that were invsive in other geographic regions (Western Australis, the Mariana Islands, Hawaii, the rMascarene Islands, and South Africa). We propose that taxa predominantly retain their invasive, functional-role type across regions. Thus, studies of ecological roles of invasive species with respect to natural disturbance regimes in one region may help us predict invasive roles in other regions.

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