Aside from its vibrant fish cage industry, the community within the Pata and Namuac River on the boundaries of the towns of Sanchez Mira and Claveria in northwestern Cagayan has found another profitable fishery project to support its constituents.

By Max Prudencio, BFAR R02

For three years now, the 4P group in Brgy. Minanga, led by 51 year-old Ofelia Agag, regularly collects oysters in eight oyster rafts previously awarded to them by the Bureau of Fisheries and Aquatic Resources (BFAR) – Region 02. The group are among the beneficiaries of the poverty alleviation program implemented by the Department of Social Welfare and Development (DSWD).

The soft-spoken but firm leader of the group narrates that the project serves as a vital source of income to support their daily needs. Each member can harvest, on the average, 7 bottles of shucked oysters in a day, which they sell for Php50 to Php70 per bottle. The oysters are so big and succulent, Agag said that sometimes, these can hardly fit into the mouth of the gin bottles they use for packaging.

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The 4P group led by Ofelia Agag (center, with eyeglasses) with LGU and BFAR RO2 personnel during the Harvest Field Day last March 2015. Inset shows shelled oysters.

The members are required to remit 40% of their sales to the group; this then accrues to the funds of the group. But Agag said she usually brings this figure down to 20% out of consideration for her group members.

As a management measure and to ensure the sustainability of the project, Agag said that she makes sure that there is ample time between harvests and the members ask permission first before gathering oysters. “My groupmates come to me to ask permission to gather oysters, especially in times of bad weather, when their spouses cannot go fishing,” Agag narrates.

Oyster Culture

Oyster culture is very easy and is done with very minimal inputs. The species does not require artificial feeds, unlike, for example, tilapia. Like other popular bivalves like mussels (tahong), freshwater clams, and shells, oysters are filter feeders, drawing water in over their gills. Plankton are then trapped in the mucus of the gill then transported to its mouth where the plankton and other particles are eaten and digested.

The location for the oyster cultivation of Agag’s group is an ideal site since it is sheltered from waves coming from the sea, but near enough that the salinity level is within the ideal 17 to 25 parts per thousand (ppt) and water exchange is frequent.

Each oyster raft, measuring 5 meters (m) by 5 m, is seeded with ten hangs of breeders and fitted with 360 empty hangs (made of empty oyster shells) to which new and young oysters cling. Its placement is ideally where oysters naturally occur in the area.

Oysters are prolific breeders. The species reproduces through external fertilization. A female releases eggs and males release sperm. Both then fuse in water. After six months, the empty hangs can all be filled with oysters and harvest can take place. So long as the fruits of the project are not harvested all at one time, the harvest can be continuous.

“The offspring breed and thus contribute towards the propagation of the species in the area,” BFAR RO2 Oyster project leader Quirino Pascua said.

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A sample of an oyster raft in Namuac River.

Recognizing the feasibility of culturing oysters within the Namuac river, BFAR RO2 Regional Director Dr. Jovita Ayson granted Agag’s group’s request for 10 more units to be distributed to them, the local out-of-school youth, and village leaders in the area. Two units will also be established in neighboring Pata, to add to the eight units existing in the area.

Pretty soon, the Pata and Namuac rivers will be known not only for their prime saline tilapia cultured in cages, but also for succulent oysters.

This appeared in Agriculture Monthly’s July 2015 issue.