A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resource & Development

Thesis (M.Sc.) - Asian Institute of Technology, 1997

Intensive cage and pen culture in Great Lake and Tonle Sap river have a great potential as the contribution from cage culture to total aquaculture production is estimated to be more than 70%. The most widely cultured species in cages in the Tonle Sap river is Pangasius spp. and Channa spp., whereas in the Great Lake Pangasius spp. is most common. There are two types of cages used in Great Lake and Tonle Sap river, namely small cages made from bamboo, which is cheap but less durable, and medium to large cages made from wood which is costly but more durable. Availability of wild seed of Pangasius spp. is becoming scarce and fish disease outbreak and low survival rate are main problem for farmers. Feed contributes over 70% of the production cost. Cage and pen culture utilizes poor quality small size species of third grade fish from capture fishery which may not be used for human food. Pangasius are fed small trash fish during the open fishing season as it is widely available. The fish are fed rice bran and aquatic vegetation during the closed fishing season. The study mainly focused on cage culture practice during the open fishing season when the price of third grade fish vary from 0.02 to 0.1 US$/kg. Food Conversion Ratio (FCR) on the dry weigh (dry weight feed : wet weight fish) varied between 1 to 2 depending on the management practices adopted. The culture period is commonly 2 years in Great Lake and 1 to 2 year in Tonle Sap river.