AQUACULTURE CARRYING CAPACITY OF STUNG CHINIT RESERVOIR, CAMBODIA: A PILOT PROJECT

David A. Bengtson*, Chheng Phen, Tith Puthearath, Touch Bunthang, and So
 Nam
 
Department of Fisheries, Animal and Veterinary Sciences
University of Rhode Island
Kingston, Rhode Island  02881, USA
dbengtson@uri.edu

The objective of the study was to plan for sustainable aquaculture development in Cambodia by training Cambodian scientists in the use of models to estimate the amount of aquaculture waste. Staff of the Inland Fisheries Research and Development Institute were trained in the uses of modeling to estimate Aquaculture Carrying Capacity (ACC). Stung Chinit Reservoir, located in Kampong Thom province, was selected as the pilot study site. We used mass-balance modeling of phosphorus (P) to calculate ACC under different scenarios of feed conversion ratio (FCR) and acceptable [P] levels, and we modeled wet seasons and dry seasons separately. The results showed that in the best scenario with acceptable phosphorus concentration ([P]) at 200 mg/m3 and FCR at 1.8, farmers could produce 895 tons of snakehead in dry season or 467 tons in wet season. Setting acceptable [P] at 200 mg/m3 and just varying FCR demonstrates that an FCR of 2.0 allows only 790 tons of snakehead production during the dry season and 412 tons during the wet season, whereas lowering the FCR to 1.0 will allow 1918 tons of snakehead production during the dry season and 1000 tons during the wet season (Fig. 1).  Holding FCR constant at 1.8, setting acceptable [P] at 150 mg/cubic meter means that aquaculture will not be allowed in Stung Chinit; however, setting acceptable [P] at 350 mg/m3 means that 2138 tons will allowed during the dry season and 14,448 tons during the wet season (Fig. 2). Because snakehead production takes longer than one season, we recommend using the lower of the dry season and wet season values to determine annual production levels. Using P mass-balance modeling to project acceptable snakehead production levels in Stung Chinit Reservoir provides government officials, and especially farmers (lowering FCR means more allowable fish production), to see the impacts of different scenarios on potential snakehead production in Cambodian reservoirs.