Menu favourite is prone to stress and so is difficult to breed commercially.
Farmers try to keep the emperor on his throne
UMM AL QAIWAIN // The spangled emperor fish, a menu staple, has been successfully farmed in floating cages in Umm Al Qaiwain - a first for the country.
In time, it may provide a new source of income for the emirate's fishermen, while helping to preserve and replenish the Gulf's dwindling stocks of the fish.
The fish is notoriously hard to farm, because it becomes stressed easily. "Hatching and collecting their eggs is very difficult," said Dr Ebrahim Abdulla Al Jamali, director of the Marine Resources Research Centre in Umm Al Qaiwain. "They find it hard to cope with a closed environment."
Alongside hammour, the emperor fish is one of the most widely eaten in the UAE. Between them the two species account for up to half the fish caught here - and both have suffered steep declines in population as a result.
The spangled emperor has blue lines on its cheeks and blue spots on its scales. With moist, firm flesh, it can grow up to 41cm long, and weigh up to 6.5kg. It is typically rubbed with spices before being baked and served with rice.
"The emperor fish is commercially popular here in the UAE," said Ahmad Al Zabi, head of the aquaculture development section at the centre. "But the problem is we catch too much of it, which means the stock goes bad."
Although usually cheap - Dh20 to Dh40 a kilo depending on the season - the spangled emperor fish remains hard to find on the market.
"The best time to get it is from February until June," said Dr Al Jamali. "Most fish in the UAE come out during the winter time but it's still hard to find the emperor because it's become so rare."
To set up the farm, a broodstock of the spangled emperor fish was taken from the sea and released into a large pond to acclimatise.
"If they don't, some of them get too stressed and catch a disease," Dr Al Jamali said. "Many of them can even die of stress."
They are kept in round cages, which allow them to swim without hitting the net. The size of cages is designed according to the type and size of fish.
It has taken time to work out what kind of feed works best. Different fish species require different feed, from sardines to scallops or artificial fish pellets.
"Right now, the emperor fish is getting a combination of fish feed in the form of powder," said Dr Al Jamali. "This is the critical stage and if you can master that, you can become successful in keeping your survival rate above 70 per cent."
Although the centre has not released any of its emperor fish out to sea, it hopes to do so before the end of the year.
"They're now about five to six centimetres long but we need to keep them as broodstock because we are still testing them," Dr Al Jamali said. "Our goal is to produce more fish for the people, for now and the future".