Dampak Kegiatan Budidaya Keramba Jaring Apung terhadap Kualitas Air Danau Toba di Kecamatan Haranggaol Horison Kabupaten Simalungun Sumatera Utara

Abstract

Aquaculture of floating net cages system at Lake Toba in particular Haranggaol developed rapidly, As uncontrolled development unit of culture can cause experienced water quality in Haranggaol, Toba Lake so that it can pass through water quality standart. This research aim to know the level of water pollution in Lake Toba Haranggaol using the STORET Methods and compares with the controls. This research was done in May- July 2013. Station used for research that was Station 1 at environment of floating net cages and Station 2 at controls. Average value of each parameter water quality in each station was varied among other such as range of temperature: 26-28 0C, brightness: 2,8-5,35 meter, turbidity: 0,16-7.13 NTU, TSS: 12.36 -19.36 mg/l, pH: 7,1 - 8,3, DO: 4,3–6,3 mg/l, BOD: 0,4-1,7 mg/l, COD: 4,42 -6,63 mg/l, NH3: 0,115–0,293 mg/l, NO3: 0,306–0,814 mg/l, NO2: 0,001–0,015 mg/l, PO4: 0,038–0,188mg/l and fecal coliform: 8,6–22,2 MPN/100 ml. Results of research showed the average value of organic matter at environment of floating net cages was 0,217 mg/l of NH3, 0,578 mg/l of NO3 and 0,134 mg/l of PO4, while on the controls was 0,144 mg/l of NH3, 0,401 mg/l of NO3 and 0,056 mg/l of PO4. Therefore, that can be concluded that value of average organic matter as NH3, NO3 and PO4 at environment of floating net cages Haranggaol higher than at controls. and has passed water quality parameter with defined standart according to PP No. 82 Year 2001 Class III. Based on STORET methods, Haranggaol Lake Toba categorized into the class C that is in middle polluted.