Floating Farms

Rising sea levels are increasing the salinity of water sources near the coastline of Bangladesh making it harder for farmers to grow their crops.  Growing conditions are already challenging as the clay soil becomes hard during the dry season (November to March) while prolonged rain during the monsoon (June to October) causes flooding.  The region has many polders, large ponds created when building coastal embankments in the 1960s. These are using for fish farming and support the livelihoods of around 8 million people. They are suitable for a technology, known as aqua-geoponics, which offers an alternative means of production for people who cannot grow vegetables in fields because of salinity, water logging or lack of land.  Aqua-geoponics combines two existing technologies hydroponics (floating farms) and aquaculture (fish farming). These offer farmers an innovative way to generate income and provide enough food for their families. Vegetables are planted in a floating tub attached to the top of a cage and fish are then farmed within the cage itself. The vegetable cultivation process purifies the water and waste provided by the fish supplies much-needed nutrients for the growth of the crops.  Both the crops and the fish selected are fast growing, meaning that up to three cycles of production can be completed each year. When the water rises, the cage rises too.