Lands under estuarine agricultural system, called Khazan farming.
- low-lying floodplains of Goa, was characterised by an estuarine agricultural system called Khazan farming.
- This system is a carefully designed topo-hydro-engineered agro-aquacultural ecosystem mainly based on the regulation salinity and tides.
- Centuries ago, people in this region reclaimed low-lying brackish coastal floodplains and mangrove forests.
- They constructed bunds using locally available material to prevent the ingress of salt water, which killed the halophilic mangroves.
- To control the flow of tidal waters, they built openings in bunds fitted with sluice gates. These gates acted as one way valves, allowing water from the main backwaters to enter the specially dug channels (poiems) around the fields.
- These channels would fill in with the oncoming tide and bring with them fish, crab and shrimp, and the gates would automatically shut when the water level was equal on both sides.
- This prevented the water from overflowing into the fields used to grow paddy and which has a low tolerance to salt.
- When the tide receded, the sluice gates would open outwards automatically, allowing the water from the poiems to drain out. During this time, a bag net was set at the sluice gate to catch fish that had entered in earlier.
- Everything has a place in the system — while well-managed khazan lands would not have mangroves growing within them, they were allowed to continue to flourish along the outer banks of the bund and the banks of the backwater or the estuary, because their significance for artisanal fisheries as fish nurseries was well understood.
- Every bit of space was precious and used efficiently — the bunds were used to grow a variety of vegetables. The Khazan system allowed for the farmer and the fisher to harmoniously coexist and was the key to sustaining what is considered Goa’s staple — fish, curry and rice.