Pacific Ocean

The pacific ocean is one of the largest regions of the world. It spans from roughly 120 degrees east longitude eastward to 90 degrees west longitude for a total span of 150 degrees of longitude, covering almost half the globe. The Pacific Ocean also comprises nearly half the surface area of the earth's oceans. As a geographic region, it spans the Pacific Islands from New Guinea (including both the independent state of Papua New Guinea and Indonesia's Irian Jaya) eastward to Easter Island and Hawaii. Midway Island marks the northernmost island in the region. New Zealand is sometimes considered to be part of the Pacific Region due to its cultural affiliation with Polynesia, but is normally grouped with the Austral Region. The rest of Indonesia and the Philippines are typically considered to be part of Southeast Asia.

With the exception of the continental island of New Guinea, the region is dominated by volcanic high islands and atolls. Despite its vast spatial expanse, the region only hosts a population of roughly 8.5 million people (about 0.1 percent of the world's population) by 2005 estimates. Nevertheless, the region comprises roughly one-fifth of the world's 200-mile coastal exclusive economic zones. The island nations of this region thus have strong claims to fisheries and mineral rights in the region. However, most of these island nations are less-developed nations with little means of enforcing their fishing laws and illegal fishing is common. The fisheries of the region are at risk from overfishing, largely in conjunction with tuna fisheries.

The vast expanse of oceans and predominance of islands has exerted a strong influence on the biodiversity of the realm. The oceans act as filters limiting the numbers of species that are able to disperse between islands, and the relative isolation of the islands gives rise to the evolution of unique biota. Prior to human colonization, the terrestrial species in the Pacific dispersed eastward across the region. In terms of flora, the Pacific's plants show greater similarity to those of Southeast Asia, and hence the region is considered to be part of the Paleotropical Realm.

There is only one genus of mammal native to the region, fruit bats (Pteropus), and the fauna of the region is dominated by birds deriving from the area around Papua New Guinea. The Pacific is therefore classed as part of the Austral Realm in terms of its fauna. Given that these are island ecosystems, many of which lacked predators, many bird species evolved out of their ability to fly, leaving them [Page 1324]vulnerable to extinction once humans and associated introduced species arrived.

The Pacific region was among the last areas of the globe to be colonized by humans. Although humans had settled into New Guinea and Australia by 40,000 years ago, and had settled into the nearby Solomon Islands by 28,000 years ago, eastern Melanesia (Vanuatu to Fiji), western Polynesia (Tonga and Samoa), and Micronesia were not colonized until roughly 3,500–3,000 years ago. Eastern Polynesia (Society Islands and the Marquesas) was settled roughly 2,200 years ago, and the outermost extremes of Polynesia (Hawaii, Easter Island and New Zealand) between 1,700 and 1,200 years ago.

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