PENGAMATAN POLA STRATIFIKASI DI DANAU MANINJAU SEBAGAI POTENSI TUBO BELERANG

Abstract

“Tubo belerang”, is a term that characterized by the
presence of the mass death of fish in cage aquaculture Lake Maninjau. Lake Maninjau is
known to have a intensive cage aquaculture and the of fish mass death phenomenon in
these waters often occur. To recognize the “tubo belerang” indication in Lake
Maninjau, has done observation on stratification patterns of some water quality
parameters, include temperature, dissolved oxygen (DO) and the levels of total organic
matter (TOM). Observations were conducted in August 2011, October 2011, December
2011 and March 2012 at five different stations,on the strata 0, 25, 50, 75, 100, 125 and
150 m, which is parallel to the depth of each stations. In December 2011 and March
2012, DO and temperature parameters were also measured at a depths of 5, 10, 15 and 20
m. As supporting parameters, chlorophyll a content was measured at depths 0, 1.5, 3.0
and 4.5 m, Secchi depth, also total phosphor (TP) and total nitrogen (TN) on surface
layer. Based chlorophyll levels,Sechi depth, and TP and TN content, Lake Maninjau waters
are characterized eutrophic conditions. Water temperature relative stabil after 25 meters
water depth, and anoxic conditions indicating lift up to 15 m water depth.Content of TOM
levels ranged from 5.9 to 24.9 mg/L, and no specific pattern of TOM distribution vertically.