As head of the Brackish-water Aquaculture Centre on the northeast coast of Indonesia's Aceh province, Mr Raharjo was responsible for creating a model breeding ground for the production of giant prawns, softshell crabs and prized species such as grouper and milkfish.
The waves that thrashed into the Centre not only took the lives of seven of its staff and destroyed most of its buildings, they also swept away all the fish fry and shrimp larvae growing in surrounding tanks.
Now the FAO, backed by some 2 million euros from the Government of Italy, is working with Mr Raharjo's Indonesian team to restore the damaged site stretched between two small villages on the once-idyllic northeast coast.
Worst affected province
Aceh province was the worst affected of all the Indian Ocean areas hit by the December 26 earthquake and tsunami. The tsunami destroyed the earthen banks of the fishponds and filled the ponds with debris and often-toxic silt. More than half of Aceh's 44 000 hectares of fishponds were destroyed, according to an FAO survey. Fortunately the concrete fish tanks are intact.
About 27 000 people earned a living from the ponds (known by their Indonesian name, tambaks). Many of them, swept away with their families, are among the 235 000 people listed as missing or dead in Indonesia since the tsunami struck. Most of those who survived are living in makeshift tents and hastily-built government 'barracks'.
Rebuilding the aquaculture industry - one of Aceh's most lucrative activities - is not only a massive undertaking, but also a controversial one. Small local producers earning a steady living from a fishpond of one hectare or less compete with larger commercial concerns, often for the same waterlogged land.
Introducing more responsible practices
David James, part of the FAO team studying all aspects of the fishing industry in Aceh, says the commercial organizations can bring much-needed work to an area, "but they tend to overstock the ponds. When they run into problems like disease, the commercial firms close down and move on, leaving the local people without jobs."
Small-scale fish farmers are also guilty of poor aquaculture practices, but as one charity worker engaged in fishpond recovery put it, "their potential to do harm is much less."
Reviving the fishponds is not just a matter of rebuilding what was there before.
"Apart from the rehabilitation of the infrastructure, such as damaged ponds and water supply and drainage systems, there is a need for more responsible farming practices," says Mike Phillips, an FAO aquaculture expert working with Mr Raharjo's team.
"The Centre has a new and important role to play in introducing responsible farming practices in the province," says Phillips. "The challenge is how to make the centre more sustainable than it was before to respond to the present situation."
Mr Raharjo agrees that the Centre has to have a new focus, "We aim to raise production to 70 percent of our activity, compared to the previous 50 percent," he says. "The farmers will be coming to us for stocks of fish and shrimp."
But Mr Raharjo also wants to rebuild his research facilities, which relied heavily on sophisticated equipment now needing replacement. One small blessing is that the genetic testing apparatus, vital for protecting stock against disease, will be of a more modern design than the ones first installed when the Centre was established in 1985.
The Centre will need to decide where to build its new installations, and reconstruction work may take up to a year to complete.
Where to build new installations?
On a larger scale, the fish farmers may be restricted as to where they can rebuild ponds. In a bid to protect the coastal communities from any future tsunami threat, as well as protect the environment, the Indonesian authorities are studying the possible declaration of some coastal areas as zones for specific use - such as conservation, residential and commercial.
Fish farmer Sofian Ahmad squats on a damaged bank near the Aquaculture Centre as an FAO official explains how zoning might work to his advantage. Sofian says he can see merit in the scheme, "but we must have somewhere else to go."
He looks over his shoulder at the silt-filled ponds behind him, and then shifts his gaze to a less-damaged area that may have been protected by a clump of mangrove trees near the beach.
Mangrove trees provide a naturally brackish habitat for fish, but much of Aceh's mangroves have been cut down over the years, precisely to build fishponds.
Along the coast at Krung Jaya, clean-up gangs at a highly-specialized installation are working hard to revive another aspect of the fishing industry at the top end of the commercial scale.
The factory employed 400 people, mostly women, to strip the loins from tuna fish, a delicacy then sent fresh or frozen to Japan. The factory was one of the most sophisticated examples in Aceh of how fishing can turn a real commercial profit.
Many of the men who fished for those tuna out at sea are still waiting to hear if they will have new boats and replacement gear - and who will make the 60 tonnes of ice a day they need to preserve their catch.
Meanwhile the Brackish-water Aquaculture Centre aims to play its part in a process to revive Aceh as one of Southeast Asia's prestige breeding grounds for top-quality fish and shellfish.
Source: Food and Agriculture Organization of the United Nations (FAO) - 16th March 2005