Full Cycle Mariculture Solution to Declining Grouper Stocks

MAY 14 (WWF) — “Don’t fall into that fish pen,” warns Daryl Dandal, an offshore cage warden. “It has two giant groupers. Both are larger than you.”

I nod and tiptoe through a network of planks above the glittering waters of Taytay in Palawan, Philippines. Here lie about 2000 fish cages, where various species of grouper are grown to feed a ballooning export trade. For the Philippines, this is the center of the LRFFT: the live reef food fish trade.

What began in the 1980s as an experiment in Samar now employs over 100,000 people in Palawan alone. Palawan’s annual grouper exports exceed PHP1.7 billion – but the fish are slowly disappearing.

Leopard Coral Trout

Chinese restaurants usually have a bubbling tank of grouper. Locally called lapu-lapu, señorita or suno, the lethargic predators are among Asia’s most sought-after reef fish, prized for taste and texture. Across the Philippines, millions of juveniles are caught before they reproduce, raising serious concerns about the LRFFT’s sustainability.

Although there are 161 grouper species, the apple of traders’ eyes is the leopard coral trout, an orange fish that fetches up to PHP7200 per kilogram in Hong Kong and PHP13,500 per kilogram in China.

“When the trade started in the 1980s, most wild-caught groupers were market-sized, each around a foot long,” recounts Dr. Geoffrey Muldoon, Worl Wide Fund for Nature (WWF’s) LRFFT strategy leader. “After 30 years, most of the large ones have been fished out. Today just one in five wild-caught groupers is market-sized. Since there aren’t enough adults to go around, the trade turned to grouper ranching, a system where juveniles are caught and grown in guarded offshore cages.”

Within submerged cages and pens, groupers must endure temperature fluctuations, overcrowding and diseases. Many die in the process. Those that survive around 10 months in captivity are sold as market-sized fish – each around a foot long and weighing from 500 to 700 grams. At this stage in the supply chain, a single suno, as the leopard coral trout is locally known, retails for about PHP2500.

It’s a lucrative livelihood. Fishers earn up to 50 times more selling a kilogram of suno than other types of fish. Federico and Nida Ellut from northern Palawan sent their three children to school from their income as grouper collectors. “From a simple straw hut, we now have a two-bedroom concrete home. We’re saving to buy our third boat,” says Nida. Money talks – but extraction has hidden costs.

Stocks Depleted?

The current system of LRFFT collection is untenable: WWF surveys have shown that over half the groupers taken from Palawan’s reefs are juveniles, a clear sign of dangerous stock depletion.

“Overharvesting has been a huge problem. Fishers were catching five times more than what could be sustained. Spawning aggregations were targeted, depleting brood-stock. Fortunately local governments and fishing communities have embraced conservation efforts,” says WWF-Philippines Project Manager Mavic Matillano. WWF is now leading efforts to facilitate the recovery of suno stocks by establishing marine protected areas, plus enhanced enforcement, licensing and education. Alternative solutions may also exist.

“Given the fishery’s dependence on wild juveniles, a way forward is through full-cycle mariculture, potentially freeing suppliers from having to catch wild fish,” explains Muldoon.

First mastered by the Taiwanese in the 1970s, full-cycle or closed loop mariculture entails breeding and rearing fish in complete captivity and is meant to eliminate the need to draw from wild stocks. Hardier but lower-value species such as green grouper and tiger grouper have been successfully bred and reared in captivity since the year 2000. Few have met success with finicky leopard coral trout, but the Palawan Aquaculture Corporation claims to have successfully bred them – a vital first step for the road to full-cycle mariculture.

Farmed suno might soon be a commercial reality, but the clock is ticking. “Just a few years ago, the panther grouper was at the top of the LRFFT heap,” says Matillano. “It was caught and exported by the millions, but stocks crashed and the government imposed a total ban on the panther grouper. The suno was next in line, becoming LRFFT’s top-traded fish.”

As I jump and dive around the floating leopard farms of Taytay, I notice how leopard coral trout comprise just half the fish in the cages. Whereas a few years ago cages would brim with bright red suno, each fish cage now hosts an eclectic blend of strawberry, saddle, harlequin and other types of grouper – now pressed into the trade to take the declining suno’s place.

I ponder how long before the suno population crashes. If and when it does, the market will likely move on to other fish, continuing the pattern of over-consumption. It’s clear that full-cycle mariculture of suno and other grouper species is the LRFFT’s best way forward.  (A featured news from Gregg Yan of WWF)


Taytay Grouper Cages (Jun Lao)

Floating offshore cages house dozens of juvenile groupers in the municipality of Taytay in Northern Palawan. (Jun Lao)





Plectropomus leopardus by Gregg Yan & WWFCherished in China for their ‘lucky’ red color, leopard coral trout (Plectropomus leopardus) await their fate inside a floating cage in Palawan. Some die of stress and disease – but enough survive to make the trade lucrative. (Gregg Yan / WWF)





Grow-out Facility Topside by Gregg Yan & WWFA typical grow-out facility in Southern Palawan. Operators must feed and protect the fish, which are held in submerged cages beneath and around the central hut for around 10 months. There is no electricity. Food and water are supplied exclusively by boat. (Gregg Yan / WWF)




Cromileptes_altivelisOnce at the top of the LRFFT head, the panther grouper (Cromileptes altivelis) was harvested to the point where government intervention was required to save wild stocks. It is now illegal to capture these fish. Will the suno fall into a similar fate? (Steve Childs / Wikipedia Commons)




The end of the line for all LRFFT fish. Two red groupers, Plectropomus areolatus and Cephalopholis miniata, await the grill at a seafood restaurant. Once second-tier fish, these alternatives are starting to take the place of suno. Already there aren’t enough leopard coral trout to go around. WWF works to steer the LRFFT to sustainability. (Gregg Yan / WWF)