The Secrets of the Gei Wai
Recipe: how to make a gei wai
Dredge water channels around mangrove stands. Use the dredged mud to build a bund which encloses the water and mangroves. Construct a sluice gate on the seaward side. Use the gate to control the water flow and set water levels. Result: one perfect environment for aquatic and airborne creatures!
How they function?
When the sluice gates are opened during the winter high tides, young shrimp are flushed from Deep Bay into the gei wai. The shrimp feed on dead mangrove leaves which have fallen into the ponds.
The shrimp harvest takes place from the end of April until August or September and is usually carried out at night, when shrimp are most active. Fishermen set up a net at the sluice gate to collect the shrimp as the water flows out to the Bay at low tide. A gei wai can be harvested up to 80 times annually. In addition to shrimp, fish of commercial importance like the Grey mullet also live in the ponds. After the harvest season ends, the gei wai are drained down and the remaining fish inside are harvested.
High ecological value
Gei wai not only support vast numbers of aquatic and marine invertebrates and fish, they are also a food source for other wildlife including waterbirds, mammals and reptiles. Non-commercial fish and shrimp are left in draineddown gei wai and become food for waterbirds. A single gei wai can attract up to 1,600 individual birds from many species, including the globally endangered Black-faced spoonbill. These traditional shrimp ponds are a good example of how coastal wetlands can be managed sustainably in a way that benefits both local communities and wildlife while minimizing impacts on the natural environment.