Baird and his fellow researchers said the exposed reefs are largely lost and will become coastal forests.
Those just beneath the water's surface, however, are likely to grow back as long as local communities protect the small, fragile marine animals.
"The news from Simeulue is not all bad," Stuart Campbell, coordinator of the Wildlife Conservation Society's Indonesia Marine Program, said in a statement.
At many sites, the species most affected by the die-off are beginning to re-colonize reefs in shallow water.
"The reefs appear to be returning to what they looked like before the earthquake, although the process may take many years."
Baird said their findings should give hope to communities in the Solomon Islands, where concerns have been raised that an April 2 earthquake and tsunami might have damaged its reefs and in turn its diving industry.
"They shouldn't be worried about losing their dive industry. The fish they target to eat will still be there," Baird said.
"Everything still in the water will still be fine," he said. "Reefs can respond to these massive mortality events. They can power on through it as long as there is enough good reef out there."
