Sunday, August 15, 1999 Published at 19:00 GMT 20:00 UK
Fish tank weed threatens PNG river
One of the world's mightiest rivers is under threat from a weed which started life in a missionary's fish tank, conservationists have warned.
The World Wide Fund for Nature (WWF) says the rampant growth of aquatic weeds is wreaking havoc in Papua New Guinea's Sepik River.
Unfortunately for the Sepik, the water contained a small strand of salvinia molesta, which is capable of doubling in size every two days.
The weed is one of several species clogging up stretches of the river that runs more than 1,000 kilometres from the mountains to the sea. A report by the WWF report says it is one of the worlds most significant river systems and one of the few to remain in a near pristine state.
The Sepik, which has hundreds of lakes and dozens of tributaries, is also the key to local transport and a source of food.
The WWF warned of ''catastrophic'' results if the weeds invaded large areas of the Sepik flood plains. A beetle has been successfully introduced to combat salvinia molesta, but conservationists say it will now always be a component of the Sepik.
However, the WWF says there are no known means of controlling another weed, known as the Giant Sensitive Plant, which is encroaching near the river.
The WWF report also highlighted other threats to the ecology of the island. Monkeys from Irian Jaya which steal bird eggs pose a major problem - reports say they may already have wiped out some species.
And water buffalo introduced from Australia should be eradicated because they are damaging the wetlands.
The WWF also warned that mining could be the next big environmental issue for the island.
One of the Sepik's tributaries is already targeted by an American firm that is planning a copper and gold mine with a 2002 start-up date.
"If this mine is operated in the same way as all the other large mining projects, it probably will have major impacts on the region," the report said.