Precious coral reefs and mangrove areas would have been crushed by the huge tsunami waves that have devastated southern Asia, an environmental and economic setback that could take years to reverse, experts say.
Deep sea creatures are likely to have escaped unscathed but coastal ecologies were exposed to the full force of the crushing wall of water.
"Some of the reefs around Sri Lanka and Phuket would likely be pretty severely damaged because big waves hit them pretty close into shore.
"It's going to depend on the size of the waves that hit," said Prof Michael Keogh, professor of marine ecology at the University of Melbourne.
"The big forces from these waves come when they get close to shore and into shallow water and they build up, they start to break, and that's where the really severe energy is," he added.
Diving resorts popular with tourists were flattened by the force of the waves.
"If you lose some of the coral reefs then you lose the appeal to tourists and they'll go elsewhere," said Prof Keogh.
The worst marine damage was likely to have been concentrated 100 metres to a kilometre from shore. However, the feeding, breeding and other activities of large sea mammals such as whales and dolphins probably suffered little impact.
"Dolphins can feel things like that happening in the water and they would probably head for deep water where they could be safe," said Mr John Michel, communications manager at the government marine research department of Australia's Commonwealth Scientific and Industrial Research Organisation.
Reuters