CP Foods eyes Thai shrimp farmer’s green methods : March 22, 2016
Thailand’s Charoen Pokphand Foods has apparently sent more than 1,000 people to Thongchai shrimp farm in the east of the country, to see how a closed-loop shrimp farm incorporating tilapia and barramundi can combat early mortality syndrome (EMS).
Chaiwairuth Arunsopha, the owner of Thongchai, started designing a new way to farm shrimp when it became clear farmers would have to live with EMS, reports Hakai Magazine.
He transformed his ponds, which used to solely grow shrimp, into an experimental closed system featuring four different types of pond, all of which work together.
The first type of pond has aerators to keep the water oxygenated, shrimp moving, and sediment concentrated in the center of the pond. The dirty water from the first type of pond is suctioned into the second type, which contains tilapia.
The tilapia feed on the waste from the first pond and filter the water. Tilapia flow from their reservoir into a third pond — which contains barramundi, or sea bass, to control the tilapia population — by gravity. Finally, in the fourth pond, minerals and nutrients are added to the clean, filtered water before it is returned to the first pond.
On Arunsopha’s farm, this closed-loop system apparently improved shrimp survival rates from a baseline of between 30 to 50% all the way up to 90%.