Changes in water quality and trophic status associated with cage aquaculture in Lake Maninjau, Indonesia

Workshop and International Seminar on Science of Complex Natural Systems

Henny, C.^1 ; Nomosatryo, S.^1

Research Center for Limnology, Indonesian Institute of Sciences, Cibinong Science Center, Jl. Raya Bogor km 46, Cibinong

16911, Indonesia^1

关键词: Critical level;    Lake water quality;    Long-term monitoring datum;    Oxygen depletion;    Phosphate release;    Temporal change;    Trophic conditions;    Water transparency;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/31/1/012027/pdf
DOI  :  10.1088/1755-1315/31/1/012027

来源: IOP

【 摘 要 】

The cage aquaculture unquestionably has been degrading lake water quality by increasing nutrients and organic carbon in lake water and sediments. The question is to what extend this condition affects other key indictors such as the temporal changes in trophic status and the thickness of anoxic hypolimnion layer where the anoxic water column is moving upward pushing up the oxic epilimnion layer. The condition in Lake Maninjau could be worse since the lake is steadily producing sulfide which can cause not only oxygen depletion in the water column but also the phosphate release from the sediments. The study is based on the long term monitoring data from on going research for about 8 years observation. The results indeed show the anoxic water column is moving upward increasing the thickness of anoxic hypolimnion layer and decreasing epilimnion layer from 30 m to 10 m depth. The trophic status of the lake also has changed from mesotrophic to eutrophic decreasing the water transparency to even a critical level