The South Sea, or southern Pacific Ocean, from Galapagos to Antarctic, comprises a quart of the world's water. Yet is's barely known, being so vast and scarcely populated with humans, yet immensely with wildlife, largely in seasonal migrations, as with breeding birds etc. and their predators. In reality, the weather and currents are varied, not just tropical heat, and crucial, as even storms were for propagating species, which may then mutate, often bizarrely, resulting in extraordinary variety on over 20,000, often quite isolated islands. Man too evolved uniquely, ...
The propagation of species and people over the fast southern Pacific combined with evolution to create its diversity. It was largely operated by natural forces, such as currents and storms, but in the few milennia since men moved in by boats from present Indonesia also deliberately and/or accidentally trough human travels.
Due to its extreme size and depth, the South Pacific has an equivalent variety of marine life. Some species are unique and most adapted to the various requirements of its conditions, such as great distances to travel in seasonal migrations, as whales, sharks and even turtles do.
Many if the countless island in the South Pacific are neither broken off continental shells nor made by corals, but created by spectacular volcanic activity in the ocean. These often young, fertile grounds developed varied wildlife on and around them.
Wildlife on the isolated South Sea islands largely evolved separately, creating unique, often bizarre species. However exposure to immigrant species, especially since the arrival of humans, can wipe and increasingly does them out, even completely. Human overexploitation and competition with domesticated species, like pigs, can be as detrimental to the ecosystem. Easter Island's Rapa Nui culture proves how quickly a fragile paradise can become a wasteland.
Almost all of the great and largely unique variety of South Pacific wildlife is under threat from excessive and destructive fishing, hunting, harvesting and pollution. Worst of all are ecological threats, notably global warming, which causes rising sea levels as well as climatic changes including storms and floods. Conservational measures, such as reserves and replanting coral reefs, can make a difference.