A rice paddy in Cambodia
Rice fields are temporary man-made aquatic habitats. In most parts of the world they are planted and harvested once or twice a year and cover a range of irrigated, rainfed lowland, flood-prone, and up-land ecosystems. As many edible aquatic and semi-aquatic organisms have always been part of these ecosystems, the capture of wild fish, frogs, shrimps, clams, and snails in rice fields and irrigation channels has been an ancient practice in most Asian countries.
Rice management and rice field habitats have changed remarkably these last hundred years. Farmers used to depend on tall, vigorously tillered traditional rice varieties. The introduction of high-yielding, semi-dwarf types, starting with the IR8 strain in 1962, and the following green revolution emphasized the intensive use of fertilizers and pesticides. Rice production increased substantially. For example, annual rice production in the Philippines increased from 3.7 to 7.7 million tonnes in two decades. However, this achievement was made at a cost to the environment. Fish and frog species, still abundant in Philippine rice fields in the 1960s, were hardly found anymore in the 1970s - mainly due to heavy pesticide use.
Drawing of a net used in Bangladesh to trap fish in a rice field
Fishing in rice fields
Catching fish from a rice field is done in different ways. In Bangladesh for instance, during the monsoon season flooded rice fields are fenced off with a net -- sometimes with a special net allowing fish to enter the rice field, preventing them from escaping. In the rice field there is a deeper area where the fish gather after the field itself dries completely, facilitating their capture.