Australian scientists are warning of an environmental disaster in Micronesia as World War II wrecks start to leak fuel into the region's pristine lagoons.
The wrecks attract tourists from all over the world but now appear to be a serious pollution threat.
Thousands of Japanese and US vessels are scattered on the sea beds in the area and have become home to an abundance of marine life.
Micronesia is in the western Pacific Ocean and consists of 600 islands.
Diving and fishing are the region's main sources of revenue, but both could be severely damaged by a toxic threat that lurks in the tropical waters.
Scientists have said that an oil slick from a submerged ship is already contaminating the Chuuk lagoon, where dozens of Japanese vessels were sunk by American bombers.
"We saw quite a long slick from one of the oil tankers, the Hoyo Maru," Dr Bill Jeffery, from Australia's James Cook University, told the BBC.
Mr Jeffery, who has been recruited by the Micronesian government to assess the likely environmental impact of these corroding wartime remains, said that about 32 million litres of oil could potentially come out of the three tankers in Chuuk lagoon.
The oil "could come out quite massively if a typhoon comes", he said. "With the corrosion that's going on, these things fall apart... quite quickly."
This fragile situation could also be destabilised by the local practice of detonating explosives over the wrecks to catch fish.
Draining the oil would be an expensive business but it can be done safely.
In 2003 the US navy extracted fuel from a sunken World War II tanker in another part of Micronesia, and managed to recoup some of the costs by reselling the salvaged oil.