Feed input is required in this system. The fish-in-fish-out ratio is low, meaning that low volumes of fish feed are used to produce one kilogram of giant tiger prawn. Feed traceability policies are strong and verifiable with most sources of feed ingredients certified environmentally responsible by reliable standards. There is transgenic (GM) plant material in the feed component.
Frequent water exchange and effluent is discharged into the open water under this production method. Most of the fish farms in Vietnam are located on land formerly used for agricultural purposes, causing moderate habitat impact. The escape risk is high, with escapes occurring during water exchanges, harvests and flooding. Since the species is native to Vietnam, the environmental impact is low. Diseases are a problem in shrimp farming. There is moderate environmental risk and chemical impact especially for intensive aquaculture systems.
Vietnam has extensive environmental legislation but in general strict enforcement is lacking. The overall management is marginally effective.