Islands, Small

High Islands

One approach to classifying small islands is based on their formation. High islands such as the Hawaiian Islands, Bora Bora, and Pohnpei are created by volcanic action, often through tectonic plates moving over fixed hot spots of pressurized magma in the upper mantle. This often results in a dominant conical form with basaltic geology and high relief (see high island photo).

High-island topography causes orographic lifting of moisture-laden clouds fed by the surrounding ocean, producing remarkable amounts [Page 1635]of rainfall. Some of the wettest places on Earth are found on small high islands (e.g., approximately 1,200 millimeters per year on Kauai in Hawaii). This high-island relief, together with being spread about large spaces and in great isolation, also results in a tremendous degree of habitat diversity. In the tropical small islands, streams, terrestrial forests, mangrove forests, grasslands, and fringing coral reefs produce habitat for a large number of endangered or endemic species. Charles Darwin's theory of evolution and E. O. Wilson's theory of island biogeography are two scientific cornerstones relating to understanding island biodiversity.

The high island of Tonowas in Chuuk Lagoon, Chuuk State, Federated States of Micronesia

Source: Dr. William James Smith Jr.

Taking the Micronesia region of the Pacific Ocean as an example, which includes the Republic of the Marshall Islands, Territory of Guam, Commonwealth of the Northern Mariana Islands, Republic of Palau, and Federated States of Micronesia (FSM), all the nations have taken the “Micronesia Challenge” (MC), a commitment to biodiversity conservation, launched in Curitiba, Brazil, in 2006, during the eighth meeting of the Conference of the Parties to the Convention on Biological Diversity. The jurisdictions involved in the MC have committed at least 30% of their marine areas and 20% of their terrestrial areas to be under effective management by 2020. It is estimated that 30% of the world's coral reefs are significantly damaged and the extent of the damage will double by the year 2030 if no conservation measures are undertaken. Notably, approximately half of the world's plant and animal species that have become extinct are island species. The jurisdictional area associated with the MC represents 10% of the Pacific Ocean, and when implemented, the MC will protect 10% of the world's reef area and 462 coral species, which represent 58% of all known corals. The then-FSM vice-president, Killion, described the initiative as a regional framework that is aimed at poising the Micronesian island governments toward achieving the targets and objectives set forth in the Convention on Biological Diversity and the Millennium Development Goals. Micronesia is a biodiversity “hot spot.”

...