Photo credit: Ahmed Shaheen (Egypt)
Technical review: Abdel Rahman El Gamal (Founder of the website)
This photo was taken in Vietnam.
There are several mussel species in Vietnam especially green mussels (Perna viridis). As in many places in the world, the farming methods for oysters and mussels are well established.
Being an off-bottom method in the culture of mussels, this method is used in relatively deep waters (2-4 m at low tide and 5-8 m at high tide).
The stakes (poles) used in this method could be made of bamboo, coconut fronds or other suitable and available materials while keeping in mind the weather conditions. For example, bamboo stakes could be at risk during the monsoon season in which storm could cause great damage to the culture facilities.
The poles are staked at about ½ meter depth and one meter apart in soft, muddy bottoms. The poles are spaced 1 m apart and arranged in rows with about 3 m distance between rows. It is a good practice to wrap the bottom 30 cm of the exposed portion of poles with smooth plastic to minimize possible predation by starfish and crabs.
Mussels settle on the submerged poles at a rate of 2,000–3,000 seeds per meter. The mussels grow rapidly and fill the poles to several layers thick. During the grow-out season, poles are regularly inspected to monitor growth as well as to eliminate predators like starfish and crabs.
Depending on the availability of natural food, the mussels are harvested 6–10 months after settlement or when animals reach 5–10 cm in length. The selective harvesting could be performed whereas bigger mussels are picked while the small ones left for the next cropping season.
Even though the pole method is a simple and a low-cost method for the culture of mussels, this method leads to siltation which makes bays and estuaries too shallow.