BAR TODAY || Official Quarterly Publication of the Bureau of Agricultural Research

Archives (2003)

Sinarapan swims home
by Ma. Lizbeth J. Baroña

April-June 2003
Volume 5 No. 2

They are extremely small , fragile, and delicious: the very reasons why they are headed for possible extinction.

Sinarapan - scientifically known as Mistichthys luzonensis Smith - is the world's smallest commercial fish.

LakeBuhi
Inset: Sinarapan

It is about 9-14 millimeters long or to be graphic, at least a thousand can be cradled in a single tablespoon. It is transparent with only its relatively large black eyes to indicate it's a fish. The tiny goby lives in Lake Buhi of Camarines Sur, where the water is about 10-20 meters deep. The goby likes to gather in swarms, a habit that makes their capture easier.

People within the goby's habitat have been catching this fish in enormous quantities in the 1940's to the 1960's, because aside from being world class in size, it is also exotic at the table. They are usually fried in oil or boiled with vegetables. Being a delicacy that it is, it was soon in demand in the markets of the neighboring towns in Albay and Camarines Sur. The commercialization of the Sinarapan contributed to its decline in number.

Becoming extinct?
Not so, say experts from the Bicol University led by Professor Victor Soliman. Preventing the goby's extinction is the key objective of their research.

Decades of catching in huge quantities has taken its toll on the tiny goby. It is now threatened with extinction, a possibility that compelled scientists in the area to take steps in salvaging the remaining Sinarapan in the Lake Manapao Sanctuary of Buhi, the only natural abode for this minute fish, until 1998. From the Sinarapan's heyday in 1979, over-fishing using a motorized sarap, - a triangular net made of a material from abaca fibers called sinamay, destroyed the breeding and feeding areas of the goby leading to critical decline in population.

This near total stock collapse of the species was unforeseen during the species' prime years in the 1940's. Mismanagement caused by complacency, coupled with the species' inherent annual high mortality rate, led the species to a significant near total mortality rate.

According to a study made by Soliman and group in 1996, aside from being caught in huge numbers, the goby's threatened existence is caused by predation of Nile tilapia that are illegally stocked in net cages in the lake sanctuary. The natural coexistence of the Nile tilapia and Sinarapan has been altered in favor of the predator causing ecological imbalance. Fortunately, this threat was eliminated from the sanctuary when the Sinarapan Conservation Team of Bicol University, headed by Prof. Soliman, reported the sanctuary violation during an assembly of the Buhi Municipal Government.

Helping hands
Experts saved the species through the Sinarapan Repopulation Strategy (SRS), a bid to revive the Sinarapan stock through live fish transfer. Some 120,000 live Sinarapan were transferred to Lakes Makuwaw and Katugday in 1999 to 2001 from their natural home of Lake Manapao in Buhi. Prof. Soliman came up with the strategy after a careful study and assessment of the biology of the fish and the suitability of the receiving lakes.

He has been studying the species for years, and was the one who warned the Local Government of Buhi of the species' dire condition in 1996, a move that eventually brought the Sinarapan's plight to the limelight.

By virtue of the Sinarapan Conservation and Management Ordinance (Municipal Order No. 97-017), the Sinarapan Conservation and Management Council was formed in April last year. Studies on the ecology and biology of the fish by Soliman in 1994 and 1998 were the basis for putting together management schemes and legal mechanisms.

The SRS consists of integral steps to revive the stock: a) assessment of the suitability of the receiving habitat; b) analysis of the fish population and how the lakes will be able to contain the fish' population behavior; c) evaluation of fish stocking schemes; and d) encouraging involvement of local residents.

Repopulation
The transfer of a number of live fish from one lake to another is what experts' term as "repopulation". Whether or not the receiving lakes are suitable habitats for the live fish was first determined, aquaculture activities, human settlement, and socio-economic factors considered. Out of four lakes, Makuwaw and Katugday were chosen.

Since the fish is small and fragile, collecting the Sinarapan from the source lake was done carefully. They were collected using a manually operated sarap. The fish were then put in polyethylene bags cushioned by "buri" bags. Each bag containing 3000-5000 fish, were transported to the receiving lakes. Death among the fish was high during transport. As high as 70% of the fish die during transport. Stocking was done at the rate of 15,000 Sinarapan per month from late 1999 to early 2001.

Upon arrival at Makuwaw and Katugday, the bags containing the fish were floated on the water while they were carefully untied. This is to acclimatize the fish to the new environment. After
20-25 minutes, the fish were released and they swam to the shady part of the lake where hyacinth and kangkong grow. Some 60,000 Sinarapan were transferred to Lake Makuwaw until May 2001, and another 60,000 to Lake Katugday in December 1999.

They are reproducing!
Observations done in July 2001 found female Sinarapans carrying eggs. It was concluded that the females could not have been carrying the same eggs during the transfer because the eggs would have been spawned or hatched which would take about a month at most.

This means only one thing: that the transferred stock has been reproducing, evidence that the strategy is effective. This finding was further supported by observations done in September 2002. The success factors identified were: following the minimum number of fish to be transported per trip, and a consistent and sustained coordination with stakeholders and the local government.

"From our experiences in Bicol Region, biodiversity conservation has been truly effective when the local community becomes a true partner in protective management, which is essentially the agreeable marriage of biology and social science." concludes Prof. Soliman.

Sources: Successful Repopulation of Mountain Lakes Makuwaw and Katugdat with Sinarapan Mistichthys luzonensis , the "World's Smallest Commercial Fish", and the Implications for Sinarapan Stock Revival in Bicol Lakes by: Victor S. Soliman, Bicol University, Tabaco Campus Tabaco City 4511 Contact through: vss@digitelone.com and 052-830-0012
Sinarapan Conservation Project at http://www.geocities.com/RainForest/5520/sinarapan.htm
Lake Buhi: Home to World's Smallest Fish at www.naga.gov.ph/tourism/BuhiLake
Sinarapan, World's Smallest Fish at http://www.aenet.org/mayon/sinarap.htm