Oyster Culture Using Raft Method

Steamed Oysters

Commonly called “talaba” in tagalog or “tirem” In Ilocano, oyster can be cultured in bays, coves, tidal streams, mouth of rivers, marshland and shore areas.

Buguey, Cagayan is the traditional area for oyster farming in region 2. However, techno-demos conducted by BFAR R02 have shown that it can also be cultured at new areas like Sta. Ana, Gonzaga and C’laveria. all in Cagayan.

Oyster farming does not require skilled manpower. Anybody can prepare the spat collectors and can do the harvesting. It is a well-liked sea delicacy of high nutritive value and a good source of protein and calcium like any other edible sea shell.

Four Local Species of Oyster

• a. Talabang Tsinelas ( Crassostrea iredalie) or the slipper-shaped oyster.
• b. Kukong Kabayo (Saccostrea maiabonenesis) or subtrigional oblong oyster.
• c. Pulid-Pulid (Saccostrea culcullata)
• d. Kulot (Saccostrea palmipes)

Talabang tsinelas and Kukong kabayo are the most commonly cultivated species while puiid-pulid grows wild on rocky bottoms in many coastal areas in the country.

Feeding

Oysters are filter feeders. Through the opening and closing movement of the valves and the beating action of the gills, water entering the shells is strained and nutrients are obtained. No artificial or commercial feed input is needed as they depend mainly on natural food. Oyster feed on phytoplankton which are microscopic plants floating on water.

Site Selection

A potential oyster farm should have the following characteristics:

1. Indigenous spawners should be present to ensure adequate seed supply.
2. Should have clean brackish water whole year round, with green to blue-green in color which indicates presence of natural food. Salinity should be between 17-25 ppt and temperature between 27-32 °C.
3. The area should be free from excessive flooding which result to very low salinity (0-10 ppt) and heavy siltation, which can result to mass mortality.
4. Water depth should be 1.5-2.5 meter for traditional and 5 meters for eon-traditional culture methods.
5. The area must be protected by a natural barrier or a breakwater to prevent damages to farm structure specially during typhoons.
6. There should be sufficient tidal current for good water exchange and to prevent build-up of decaying matter.
7. The bottom should be either hard and non-shifting or soft and muddy to minimize siltation. The type soil determines the method of cultivation.
8. Occurrence of predators like crabs, borers, starfish, barnacles should be minimal to lessen predation. and competition for food and space. If endemic seeds are not present in the area but the other criteria are met, transplantation/seeding of oyster can be undertaken.

Common Methods Used In Oyster Culture

• a. Broadcast – makes use of stone, empty oyster shells and other media collectors. These are positioned in hard bottom areas while natural population of oyster is known to occur.
• b. Stake – bamboo poles either whole or halves are driven in the bottom where the water is not less than a meter deep during the lowest tide. These are aligned and spaced at 1 to 2 feet. Installation of additional bamboos for support against flash flood, tidal currents and other disturbances is a common practice among local farmers.
• c. Plot hanging – is an off-bottom type suitable in relatively deeper water of at least 2.5 meters deep during the lowest tide. It uses several types and sizes of indigenous materials as collectors such as oyster shells, old rubber tires, plastic packaging straps and bamboo.

For plots that require staking of bamboos such as the tulos and bitin the substratum should be muddy or soft enough so that the post will be easily planted at a minimum depth of 0.5 meter.