This hot-spot includes all the islands of Micronesia and Polynesia, plus Fiji, scattered across 40 million km² of the Pacific Ocean. Included in this enormous expanse are at least 4,500 islands, representing 11 countries, eight territories, and Hawaii. Twenty-five bird species have gone extinct here since the arrival of the Europeans 200 years ago, victims of introduced invasive species and over-hunting. The spectacular endemic honey-creepers and other forest birds of the Hawaiian Islands are among those that are seriously threatened but still surviving in this hot-spot.
Hotspot Original Extent (km²) 47,239
Hotspot Vegetation Remaining (km²) 10,015
Endemic Plant Species 3,074
Endemic Threatened Birds 90
Endemic Threatened Mammals 8
Endemic Threatened Amphibians 1
Extinct Species† 43
Human Population Density (people/km²) 59
Area Protected (km²) 2,436
Area Protected (km²) in Categories I-IV* 2,088
There are roughly 5,330 species of vascular plants native to Polynesia-Micronesia, of which more than 3,070 (58 percent) are endemic.The only terrestrial mammals native to Polynesia-Micronesia are 15 species of bats, of which 11 are endemic. Two other endemic bat species have gone extinct. Most bat species are restricted to the high islands (Mariana Islands, Palau, Chuuk (or Truk), Kosrae, Pohnpei, Yap, Samoa, Fiji, and the Hawaiian Islands). The Fijian monkey-faced flying fox (Pteralopex acrodonta, CR), one of the most primitive species of fruit bats in the world, is the only mammal endemic to Fiji.There are more than 60 species of native terrestrial reptiles in Polynesia-Micronesia, including seven snakes, the saltwater crocodile (Crocodylus porosus) and more than 50 lizards. Over 30 reptile species are endemic.
A fascinating phenomenon among reptiles has been the spread of Lepidodactylus geckos across the region. These geckos are parthenogenic, meaning that they do not need males to reproduce, and can colonize new islands more easily than other geckos that rely on finding other individuals to reproduce sexually.
As a result of their isolation and small size, the island ecosystems of the Polynesia-Micronesia hotspot are exceedingly vulnerable to habitat degradation and the introduction of invasive species. Due mainly to these threats, species in this hotspot are some of the most endangered in the world. Species extinction rates are among the highest in the world, especially for birds and reptiles.
Human activities have threatened the unique biodiversity in Polynesia-Micronesia for at least 3,000 years, since the first Polynesian people began to migrate east from Southeast Asia and New Guinea. Micronesians are linguistically different from the Polynesians and show a clear migration from the Philippines, both prehistorically and contemporarily. These earliest settlers introduced several plants and animals, which they used for food, medicine, building materials, and ornamentation. They converted land for agriculture and hunted many birds and reptiles to extinction. The fossil record for the Pacific Islands reveals that as many as 2,000 bird species may have disappeared since humans colonized the islands.
At least 356 protected areas exist in the Polynesia-Micronesia hotspot, covering 18,722 km² of land and sea. Almost one-third of these are found in Hawai'i. Excluding Hawai'i, about 154, or 60 percent, of these protected areas are terrestrial, accounting for about 6.7 percent of the land area of the hotspot. However, figures relating to coverage must be taken as approximates for two reasons. The first is that many protected areas have no recorded size, partly because boundaries have not been defined or updated. Also, communities are sometimes hesitant about publicizing information about locally managed areas. There are many temporary and permanent closures that constitute protected areas, but which are not recognized by national governments. An analysis using the World Database on Protected Areas gives a lower number of protected areas in the hotspot.
Even after taking into account traditionally managed areas, many more protected areas are needed to conserve the varied and unique biodiversity of this region. One way of ensuring that the network of protected areas adequately conserves biodiversity is through the identification and conservation of Key Biodiversity Areas (KBAs), globally important sites for biodiversity conservation. For Polynesia-Micronesia, KBAs this process was led by CI's Melanesia program in partnership with the Secretariat for the Pacific Regional Environment Programme (SPREP), WCS-Pacific Islands, TNC-Micronesia, the Societé d'Ornithologie de la Polynésie, the Délégation à la Recherche de la Polynésie française, Te Ora Fenua (Tahiti Conservation Society) and the Bishop Museum. Of the 162 sites, only roughly one-third are within existing or planned protected areas.
Most current conservation investment in the region occurs in the form of relatively small grants. Multilateral donors include the Asian Development Bank (ADB) and United Nations agencies, mainly through GEF enabling activities and mid-size projects. Bilateral donors include mainly the governments of New Zealand, Australia, Japan, France and the United States. Except in the most developed nations, a lack of capacity and technical infrastructure impedes the ability of governments to implement conservation projects. Nevertheless, it is important to highlight successes such as the Takitumu Conservation Area in the Cook Islands.
During the past several thousand years, the Pacific has arguably lost more species to extinction than any other region on Earth. Thus, coordinated regional efforts above and beyond the establishment of protected areas are needed to share information and address common threats, such as invasive alien species, are showing great promise and offer the best hope for preserving what remains of the extraordinary biota of the Polynesia-Micronesia Hotspot. One example is the technique of translocating threatened species to nearby islands and eradicating invasive species. For example, the Rarotongan monarch or Kakerori (Pomarea dimidiata, EN) was downlisted from Critically Endangered to Endangered status in the Cook Islands, following 15 years of intensive management involving predator control and translocation to the nearby rat-free island of Atiu. An important Pacific-wide effort was funded in 2004 by the New Zealand Government: the Pacific Islands Cooperative Initiative on Invasive Species, which aims to control and eradicate alien invasive species. The main partners in this initiative are the IUCN Invasive Species Specialist Group, Cl, SPREP and SPC.
Because so much of the biota of Polynesia-Micronesia remains unknown, there is a crucial need for a comprehensive biological survey to guide conservation in the region. Plants, land snails, and flying foxes are particularly understudied. The Pacific Science Association, the Bishop Museum, SPREP, the U.S. Geological Survey (USGS), and others are working on major initiatives such as the Pacific Biological Survey and the Pacific Basin Information Facility. More localized biodiversity surveys are also underway, initiative by Fiji, French Polynesia and other nations.
Using a $10 million grant from the Global Environment Facility (GEF), through UNDP, SPREP executed the South Pacific Biodiversity Conservation Programme (SPBCP) to establish and manage a series of large, diverse Conservation Areas throughout the region between 1993 and 2001. The Roundtable for Nature Conservation, facilitated by SPREP, is working with national governments to determine regional priorities and develop and implement the resulting action plans for combating invasive species and conservation whales and dolphins, marine turtles, dugongs and avifauna.