The people of Fiji have launched an ambitious attempt to save their magnificent coral reefs from uncontrolled development.
By Alex Kirby
BBC News Online environment correspondent
The reefs attract thousands of tourists, yet the impact of tourism is one of the main threats they face.
Another is chemical run-off from intensive agriculture, which is making increasing inroads in Fiji.
The Fijians hope their approach will work for other islands facing similar problems.
The problems of Fiji's reefs are explored in Waibulabula, a film made by Television Trust for the Environment (TVE) for BBC World.
Waibulabula, the name of the project, means "living waters" in Fijian, but the water flowing off the island has for years been helping to kill the coral.
Only one destination
The island gets plenty of rain, which helps to carry fertilisers and chemicals off the sugar canefields and into the streams.
Suva, the capital with 80,000 people, is the largest urban centre in the South Pacific. Many of its rivers are contaminated with sewage, which also finds its way to the sea.
Crown-of-thorns starfish eat the coral
But the problem is especially acute on the southern coast of Viti Levu, the largest island of Fiji. Austin Bowden-Kerby is a scientist working on the Coral Gardens Initiative.
He tells TVE: "This was called the coral coast of Fiji - now it's called the dead coral coast... This is the inner reef, and it's in very bad shape.
"It's got a little film of mud from the agricultural run-off. In the near-shore area there were live corals up until very recently. These have all been killed by the run-off, and there are just algal mats all over what used to be beautiful corals."
Part of the problem is the local villages' sewerage systems, whose contents all end up on the reefs.
But tourism has a malign effect. Most resorts treat their sewage but then release the nutrient-rich water to find its way to the sea.
Removing the invaders
The fish which tourists can see from glass-bottomed boats are disappearing. So some hotels are upgrading their sewage treatment plants, and one has installed an artificial wetland, three linked lakes which purify the sewage.
In some cases the dried sludge is bagged up and taken for safe disposal elsewhere.
Cleaning the reef
To try to help the reefs to recover, volunteers removed an infestation of crown-of-thorns starfish from the coral.
They thrive in the nutrient-rich water, and left to themselves will eat the coral.
Austin Bowden-Kerby says the scheme is helping in another way: "What's happening is the herbivorous fish are coming in large numbers now.
"Parrot fish, surgeon fish, rabbit fish, they eat the algae. So even though there's fertilisations, it's keeping the algal cover down."
Wana Sivoi works for the Foundation for the Peoples of the South Pacific, which has developed the plan to save the reefs.
She says: "If you have a lot of money and you have no resources, you cannot eat money. So, to me, the resources are more important than anything, because if people are rich with their resources, they can survive in this world."
Starfish images courtesy of the US National Oceanic and Atmospheric Administration.