Vanuatu represents the main bulk of an island chain which continues into the Santa Cruz Islands of the eastern Solomon Islands. Lying on the western margins of the Pacific plate, the islands are all of volcanic origin, and there is ongoing volcanic activity in a number of locations, including the Banks Islands in the northeast, Lopevi and Ambryn in the central islands, and Tanna in the south. Submarine volcanoes are also active, notably off Épi and Erromango. About 100 kilometers south of Anatom the Gemini Seamounts are another area of volcanic activity – explosions were observed from the eastern seamount in 1996. However the western Gemini Seamount, which rises to about 30 meters below the surface, was reported to have considerable marine life. The Matthew and Hunter Islands, in the far south of the island chain, are disputed between Vanuatu and New Caledonia. All of the islands are volcanic rock or uplifted carbonate structures, or some combination of these. The northern islands form a double chain. Current volcanic activity is generally restricted to the eastern islands and reef development is greatest in the western ones. Fringing reefs predominate, though Cook Reef, north of Efaté, is a small atoll-like structure with no associated islands. The Reef Islands north of Vanua Lava are also part of a carbonate structure which has undergone a slight uplift. The islands lie in an area particularly prone to tropical cyclones, which cause damage to at least part of the archipelago annually. Cyclone Uma in 1987 was one of the most devastating, causing considerable harm to Efaté and its reefs. Southeast trade winds predominate between May and October.

Vanuatu has a rapidly growing population. While a large number live in the two main towns, over 70 percent live on their traditional lands and remain heavily reliant on subsistence from the land and ocean. Catch methods include gill netting, capture by hand and spear gun and, in more remote areas, traditional techniques including bow and arrow, spears, traps and traditional poisons. Subsistence capture is largely of fish, but also includes substantial amounts of shellfish (34 percent) and lobster (20 percent). Cash income is also provided at the local level through collection of sea cucumbers, trochus, green snails, crustaceans and aquarium fish.