Cage Culture of Sea Urchins in La Union
Sea urchins are marine invertebrates locally known as “pana-pana” (Tagalog) or “kuden-kuden” (Ilocano) that thrive in the seagrass beds of our coastal waters. These are highly prized particularly to the Japanese who consider their gonads or “uni” a delicacy.
The breeding in captivity and cage culture of the sea urchin (Tripnuestes gratilla), was pioneered in the country by researchers of the University of the Philippines’ Marine Science Institute led by Dr. Marie Antonette Juinio-Menez in the `90s. Starting in Bolinao, Pangasinan, the culture of the sea urchin has spread to nearby La Union.
Through the assistance of the Bureau of Fisheries and Aquatic Resources of Region I and the local government of San Fernando City, small fisherfolk are now commercially growing sea urchins in cages in the coastal waters of La Union. There are now 80 cages being operated by 26 members of the Wallace-Poro Sea Urchin Cooperators’ Association. Treasurer Lourdes Galvez of the group imparted to us the know-how and benefits of sea urchin cage culture.
The cages measuring 1.5 x 1.2 x 0.5meter each are built of round iron bars for the frame and polyethylene screen as siding. A cage costs less than R500. Cages are placed near the shore with good water movement, no freshwater outflow, protection from storms, and abundant growth of the seaweed known locally as “aragan” (Sargassum). The cages should be at least 0.5 meter below the water surface during the lowest tide and their bottoms at least 0.3 meter above the sea floor.
Sea urchin juveniles (7.5-10 centimeters in diameter), which are purchased at P2.50 each from fishers who gather them from the wild, are initially stocked at 500 per cage. The cultured animals are fed with “aragan” once or twice a week. The number of juveniles in each cage is reduced in the succeeding months of culture (every 2-3 months) to allow their faster growth.
The market-size sea urchins (7-8 centimeters in diameter) are harvested after 4-5 months of culture with a survival of 80%-90%. They are sold whole at P60-P70 per kilo (6-7 pieces) in the fresh market.
When processed, fresh sea urchin gonads sell for more than P1,000 per kilo. The shells of sea urchins can also be made into decorative items for additional income.
According to a study conducted by Senior Aquaculturist A1manda Galang of BFAR Region 1, a farmer with six cages for sea urchin culture will need to invest P55,000 for the cages and working capital for two croppings. With the expected harvest of 550 kilos of the produce with a value of P38,556, the farmer can have an annual net income of P30,458 or P2,538 per month.
