Problem Definition-Research

This report contributes to the GEF PAS project "Prevention, eradication and control of invasive alien species in the Pacific islands". It is funded by the Global Environment Facility (GEF), implemented by the United Nations Environment Programme (UNEP) and executed by Secretariat of the Pacific Regional Environment Programme (SPREP) in partnership with the Department of Environment Protection & Conservation, Vanuatu.

The Aleipata islands are considered to be of great regional conservation significance because they are uninhabited (with the exception of Namua), relatively pristine as forest ecosystems, hosting many species threatened throughout the greater Samoa, and still not invaded by most invasive alien species (IAS) present within Upolu main island. Due to this reason they were included in the list of the 7 key biodiversity areas of Samoa (Conservation International et al. 2010).

Lack of biological knowledge of invasive species is recognised as a major factor contributing to eradication failure. Management needs to be informed by a site-specific understanding of the invasion system. Here, we describe targeted research designed to inform the potential eradication of the invasive yellow crazy ant Anoplolepis gracilipes on Nu'utele island, Samoa. First, we assessed the ant's impacts on invertebrate biodiversity by comparing invertebrate communities between infested and uninfested sites. Second, we investigated whether an association existed between A.

Many ant species that have been accidentally spread throughout the world have significant economic, environmental and social impacts in areas that they now infest. One of the most notable invasive ants is the Yellow crazy ant, A. gracilipes, and this species is present in Samoa, including on the Aleipata islands. The Aleipata islands are considered to be of great regional conservation significance because they are uninhabited, relatively pristine, contain many species threatened throughout greater Samoa, and lack many exotic species present within greater Samoa. The presence of A.

The Samoan islands of Nuutele and Nuulua from part of the Aleipata Marine Protected Area, in recognition of their contribution to biological diversity in Samoa. In a 1986 review of 226 islands in the South Pacific region, these islands together rated 30th in importance for biological diversity. The islands provide essential habitat for a reange of sea birds, bats and land birds such as the rare friendly ground dove, sea turtles, shell fish and other marine life.

Merremia peltata is a species with uncertain status in the island nations of the Pacific region. It has been designated introduced and invasive in some countries whereas it is considered native in others. Recent increase in its abundance across some island landscapes have led to calls for its designation as an invasive

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.

Seabirds drastically transform the environmental conditions of the sites where they establish their breeding colonies via soil, sediment, and water eutrophication (hereafter termed ornitheutrophication).