Carrying Capacity of Total Phosphate from Aquaculture Cage in Maninjau Lake


  • PutriSri Komala, Zulkarnaini, R I Kurniati*


The purpose of this study was to determine the total carrying capacity of total
phosphate (TP) in Maninjau Lake using the Beveridge Model. Pollutant sources taken into
account in this model are residents, hotels, agriculture, and livestock. Sampling was carried
out in 10 locations around Maninjau Lake that refer to SNI 6989.57: 2008 guideline. It was
located in the inlet, outlet, and middle of the lake, beside of hydropower plant and
aquaculture cages. The trophic state of the Maninjau Lake was hypertrophic, with an index of
72.49. Two scenarios were proposed for controlling the TP of the lake. The first scenario, the
mesotrophic state, the phosphorus limitations were needed to reduce the number of
aquaculture cages by up to 69%. The TP capacity of this condition is 220,063,878 kg/yr, fish
production 9,019 tons/yr, feed production 16,955.74 tons/yr with the number of aquaculture
cages of 5398.92 units. The second scenario is the oligotrophic state. Under this condition,
the TP capacity is 73,320.13 kg/yr, fish production 3,004.92 tons/yr, fish feed 5,649.25
tons/yr, and the number of aquaculture cage units is 1,799.64 units, which means an 89%
reduction is required