The Importance of Islands Throughout the World
While the very thought of islands conjures up romantic images, island ecosystems are very fragile and very much endangered for the following reasons:
Because of their isolation, islands have a disproportionately high number of endemic species (naturally occuring species found nowhere else on earth). For example, the island of Madagascar has 8,000 endemic plant species - twice the number in the entire United States.
Due to the high rate of endemism, islands have a disproportionately large number of endangered species. The Hawaiian islands are a case in point. Dubbed "the endangered species capital of the world," seventy two percent of all plant and animal extinctions ever recorded in the U.S. have occurred in Hawaii, a state that makes up less than two tenths of one percent of the nation's land area. Today Hawaii is home to forty percent of the nation's endangered plants and bird species.
Due to the self-contained nature of island environments their ecosystems are extremely vulnerable to damage caused by introduced species. The devastating impact of introduced foxes and rats on the seabird colonies of Alaska and the destruction caused by feral pigs in Hawaii are but two examples.
Due to their low sea levels, islands are particularly susceptible to the ill effects of global warming. While global warming may wreak havoc on continental landmasses, the ensuing rise in sea level may wipe some Micronesian islands and the Maldives Islands of the Indian Ocean off the face of the earth.
Many tropical islands are surrounded by coral reefs, often referred to as the "rainforests of the ocean" because of their astonishing diversity. Coral reefs are so endangered that it is estimated that 70 percent will cease to function as healthy ecosystems in the next 50 years unless remedial action is taken immediately.
Mangrove forests are often found on tropical islands. They act as a buffer to coastline and as important nurseries for diverse species of fish. Fifty percent of the world's mangrove forests have already been destroyed by commercial development including industrial aquaculture.
Even small islands have exclusive economic zones with huge territorial claims to surrounding oceans. One nation, the Cook Islands, has a total land mass of 90 square miles (one tenth the size of Rhode Island) spread out over 850,000 square miles (one quarter the size of the United States). Another island nation, Kiribati, has a total landmass of 300 square miles but an exclusive economic zone in the Pacific Ocean of 1,020,000 square miles. All told, the exclusive economic zones of islands cover one sixth of the Earth's surface and harbor one half of the world's marine biodiversity.
Due to their typically small populations and small economies, most islands are not able to resist pressures from outside development nor can they afford appropriate environmental remediation procedures. As well, many islands do not have environmental NGOs or other types of advocacy available in the face of such outside pressures.
Due to their small and isolated ecosystems, islands are ideal venues for scientific studies of the Earth's environment. They serve as scientific "canaries in the coal mine" as the effects of habitat destruction and unsustainable development are all the more apparent.
