The ‘fishy’ bonanza of Bakun

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The 205m-high Bakun hydroelectric dam, the second tallest concrete rock-filled dam in the world, generates more than 2,400MW of power – it also spawns several industries that have yet to be properly tapped.

Among the business spin-offs of the creation of the Bakun Lake is fish production which holds tremendous potential  both in capture fisheries and aquaculture.

The 700 sq km fresh water expanse of the scenic lake in the upper reaches of the Rejang teems with fish holding a potential production of 14,000,000 kg of fish per year through capture fishery.

This astounding figure was estimated by internationally known tropical aquaculture scientist Dr Jerome Lazard based on a comparative study of Lake Volta in Ghana which has similar environmental conditions and depth as Bakun.

Both lakes were formed through flooding of rainforest and studies of the fish population in Lake Volta over the years showed that its fisheries productivity has reached its full potential of 150-200kg per hectare per year.

“If we refer to other man-made lakes around the world in tropical forests, we can forecast the future productivity of the fisheries in Bakun Lake,” Lazard said.

As Bakun is a relatively new lake compared to Lake Volta, Lazard projected that Bakun would only reach its full fisheries potential between five to seven years after the lake has reached the upper level in 2011.

Lazard, who is a France Human Development and Dams (HUDDA) aquaculture scientific director, said after the maximum level has been reached, capture fisheries productivity will most probably remain at the same level for five to 10 years or start declining to reach a value somewhere between 50 and 200kg per hectare per year.

A section of Bakun Lake.

Bakun lake has huge potential for fishery industry

The level of productivity is determined by the management of the fishing industry.

The locals are already harvesting fish in the lake and selling their catches to middlemen coming from Bintulu, Sibu and other towns.

The present uncontrolled fishing in the lake and the rivers that feed into it worries Lazard as overfishing might prevent it from reaching its full production potential and might even cause some  species to be extinct.

Lazard likens capture fisheries to drawing interest from a deposit in the bank.

“The mature fish harvested is like the interest of your capital deposited in a bank – if you overfish, it is like overdrawing the interest and depleting the capital.”

Although Bakun Lake offers the local population excellent opportunities in developing capture fisheries, it is the huge potential in aquaculture of the lake that excites Lazard.

On the potential harvest of fish farm in Bakun Lazard said each 6m by 6m cage and 3m deep, can accommodate between 5000 and 10000 fish per cycle.

He estimated that a farmer could harvest about four tonnes of matured fish at the end of every cycle of eight months from each cage.

Lazard proposed tilapia as the main specie for aquaculture in Bakun Lake.

The ‘King of fish’ the Empurau is reputedly the most expensive fish in the state with prices ranging between RM800 and RM1000 per kilogramme.

This is because no other alien aquatic species or species group in the tropics has such a high production capacity as tilapias.

Lazard said tilapia has become an international commodity with an increasing demand from developed countries including United States, Europe and Japan.

“As such tilapias play an important role in food security and poverty alienation,” he added.

On potential threats to aquatic environment posed by the introduction of tilapia in Asia and the Pacific region Lazard said studies showed 22 per cent of the tilapia introduced to a new area disappeared without trace; 51 per cent had little or no effect on the ecosystems or depended on regular stocking for continued presence; 17 per cent established self-sustaining populations either with beneficial or neutral effects; seven per cent had harmful effects that could obviously be discerned; three per cent rapidly increased and then declined either through natural means or deliberate eradication.

“The balance of currently available evidence in Asia and the Pacific suggests that, as far as we are aware, tilapias have had no major negative impact on biodiversity per se.

“Aside from tilapia, projects focusing on domestication of indigenous species showing good aquaculture potential should also be encouraged,” he said.

But he cautions before any large scale aquaculture farming is carried out in the lake there must be an evolution assessment of the occurrence of the different indigenous fish species both in experimental and commercial landings.

He added a survey carried out in 2009-2010 by UPM-KL found the occurrence of 16 commercial fish species in Batang Balui which flows into the lake.

From these species, a number were found to be of aquaculture interest.

Lazard, who is the adviser to Wargana Consortium Sdn Bhd, contractor of a fish farming project in Bakun, said the results of a water quality monitoring programme carried out by Sarawak Hidro showed levels of the different physical and chemical parameters recorded revealed a fairly good potential of the lake for aquaculture.

He said the lake has very stable and pronounced thermocline located approximately six to eight metres deep.

“This means aquaculture structures (floating cages mainly) need to be implemented in the six superior metres of water and the risk of toxic substances (minerals and dissolved gases) migrating from the bottom towards the surface is very low,” he added.

Dr Lazard explaining the depth of Bakun Lake.

Taking into account the fact that most, if not all, commercial aquaculture development projects implemented under the umbrella of the public sector have failed in many parts of the world including Malaysia, Lazard proposed that the private sector be encouraged to develop aquaculture in Bakun Lake.

He supported Wargana’s initiative to work closely with small scale family operators (the affected local populace) to start a pilot aquaculture project in Bakun Lake.

He believed Wargana could be the driving force in developing the aquaculture industry in the lake by providing to the local people the technical support for facilities construction and implementation support in the lake.

Aside from that, Wargana would also provide the local operators with fry and feed as well as support to rear the fish.

“For these purposes and for reaching its own economic target, Wargana will implement close to the dam a hatchery for the needs of its own grow-up cages and of those of family farms.”

Wargana group general manager Stephen Sia said the pilot project with the local people would be implemented at the Belanum area.

He said 50 cages would be set up for the local people to work on it.

“For the start, we are looking at working with the local people for one and a half year for two cycles.

“Each cycle may last for eight months, which by then the fish will roughly be about 800g per tail,” he said.

Sia said the result from the two cycles may determine the future of the project.

“If it works well, we will continue, but if it fails we may stop it,” he added.

The result of the pilot project would be an important guide for any aquaculture venture in the lake.

Bakun Lake is an aquaculture goldmine but it is imperative the local population must be involved in any effort to tap this tremendous potential.

An aerial view of the bakun dam.