Divers have been helping restore Indonesia's coral reefs
Scientists have reported a rapid recovery in some of the coral reefs that were damaged by the Indian Ocean tsunami four years ago.
It had been feared that some of the reefs off the coast of Indonesia could take a decade to recover.
The New York-based Wildlife Conservation Society (WCS) found evidence of rapid growth of young corals in badly-hit areas.
A spokesman said reefs damaged before the tsunami were also recovering.
Some communities were abandoning destructive fishing techniques and even transplanting corals into damaged areas, the WCS said.
"This is a great story of ecosystem resilience and recovery," said Stuart Campbell, co-ordinator of the WCS's Indonesia Marine Program.
"These findings provide new insights into coral recovery processes that can help us manage coral reefs in the face of climate change."
Ove Hoegh-Guldberg, a reef expert from the University of Queensland in Australia who did not take part in the study, said the findings were not surprising since corals typically recovered if not affected by fishing and coastal development.
"We are seeing similar things around the southern Great Barrier Reef where reefs that experience major catastrophe can bounce back quite quickly," the scientist told the Associated Press.
Countries across the Indian Ocean have been remembering the 2004 disaster, which claimed some 230,000 lives.
Prayers were said in Indonesia, Thailand and India on Friday, while Sri Lanka declared a two-minute silence in memory of the dead.