By Rex Delsar Dianala
While oysters are naturally clingy, a scientist has found that they grow best with no attachments and when given healthy boundaries.
Seafood lovers are acquainted with prying their way through clumps of steamed oyster shells. The shells – sizeable, petite and everything in between – reveal random morsels of meat that go well with fish sauce and spiced vinegar. These oysters sell for as little as P50 per kilogram, roughly a dozen to two dozen shells, in small seafood restaurants.
However, diligent traders may opt to carefully separate, sort, and clean larger shells to enter the lucrative market of premium unclustered oysters served in hotels and high-end restaurants, where a dozen can fetch for P500.
To help oyster producers capture the premium market, a mollusk scientist devised a simple method of growing oysters that are not only single, but are also young and meaty.
“Oysters are traditionally grown on bamboo stakes, worn tires, or old shells installed at river mouths,” said Dr. Ma. Junemie Hazel Lebata-Ramos, a scientist at the Southeast Asian Fisheries Development Center, Aquaculture Department (SEAFDEC/AQD) based in Iloilo.
Dr. Lebata-Ramos found that by giving oysters (Crassostrea iredalei) their own private space to grow, in pouches or trays, they can grow unclustered, yield up to 59 percent more meat, and in 50 percent less time.
As detailed in her recently-published study, her team placed wild-collected baby oyster “spat” and individually stocked them in prototype net pouches and plastic trays suspended from floating bamboo rafts at their study site in Batan Bay in Aklan.
Each hanging pouch contained 25 compartment pockets that each contained one oyster. Meanwhile, the plastic trays were stacked on top of each other, with each tray also containing 25 oysters.
After six months, the oysters grown in pouches and trays grew the most, to an average of 8.9 and 8.3 centimeters shell length, respectively. Those produced traditionally on old shells and tires were of an average of 7.6 and 7.2 centimeters shell length.
The body weight followed the same trend, with pouch-grown (87.7 grams average) and tray-grown oysters (87.1 grams) proving to be heavier than those grown clustered on old shells (67.4 grams) and tires (55.1 grams).
“Growing them individually in a space without overcrowding may have caused these oysters to grow larger and meatier compared with those reared using traditional methods,” Dr. Lebata-Ramos said.
“More importantly, the oysters in pouches and trays grew individually and achieved almost uniform sizes, which is what the premium market requires.”
SEAFDEC/AQD Chief Dan Baliao said that while the pouch technique is yet to be tested on a commercial scale, its simplicity makes it a potential springboard for small-scale farmers to improve their income.
“Oyster farmers should embrace innovation to expand their market and elevate the common oyster to a true seafood delicacy,” he added.