The staple diet of Khmer is fresh water fish.  With the abundant supply of fish (said to be 600 different species in the Tonle Sap lake), it is not surprising that the Khmer love to eat fish!  The majority of Khmer families would have fresh fish at least twice per day except in areas where there are no permanent streams, rivers or lakes.  Here during the dry season they may have to catch frogs, crabs, snails, insects and in some places rats from the field!  Khmer, like their Thai neighbours will often eat any type of moving animal or insect to ensure a protein intake
Unlike westerners, fishing is not fun for most Khmer.  It is a daily chore performed mostly by men and boys who must find fish to feed the family each day.  The Khmer have many different techniques to catch fish but it often depends on the season and from where they catch the fish e.g. lake, river or field
Mostly they do not use a fishing line although you may see some children trying to catch fish this way.  They use a bamboo pole with a fixed length of fishing line which in this case gets dunked in the water.