Kandungan Nitrat, Fosfat Dan Pertumbuhan Biomassa Basah Kiambang (Salvinia molesta) Di Perairan Danau Buyan, Buleleng, Bali

Abstract

The objective of this research was to determined the relationship between nitrate and phosphate content on the growth of wet biomass Salvinia molesta in Buyan Lake, and also to know the difference of growth of Salvinia molesta in each station with different treatment. The research was conducted from February to March 2017 at Buyan Lake. Biomass measurements and water sampling were carried out at 4 stations with a plot of each treatment. The measurement of wet-biomass were carried out in situ by measuring at each treatment and for measuring the nitrate and phosphate content performed in the laboratory. The result showed that nitrate correlated with biomass growth of Salvinia molesta at the lowest treatment with R2 value of 0,105 and the highest at quarter treatment with value R2 of 0,889. The phosphate relationship with the lowest wet biomass growth was at full treatment with the R2 value of 0.042 and the highest in the quarter treatment with the R2 value of 0.936. The highest growth was found in station 1 and the lowest growth at station 4. For each treatment, the highest growth treatment was in a quarter treatment.

Physical, Chemical, and Biological Water Quality Characteristics of Buyan Lake and Tamblingan Lake

“…In this study, the levels of nitrite in water of Buyan Lake and Tamblingan Lake were low (<10 mg/l), which were 0.14 ± 0.04 mg/l dan 0.43 ± 0.10 mg/l, respectively. This similar finding was described by Purnamawati, et al (2018) in her study of nitrate and phosphate level in Buyan Lake and its relation to watermoss growth. Of four time measurements, Purnamawati, et al (2018) found that nitrate level was significantly lower compared to its quality standard class 1 (<10 mg/dl) where the lowest nitrate level was (0.086 mg/dl) and the highest level was 4.89 mg/dl.…”

“…This similar finding was described by Purnamawati, et al (2018) in her study of nitrate and phosphate level in Buyan Lake and its relation to watermoss growth. Of four time measurements, Purnamawati, et al (2018) found that nitrate level was significantly lower compared to its quality standard class 1 (<10 mg/dl) where the lowest nitrate level was (0.086 mg/dl) and the highest level was 4.89 mg/dl. In spite of that, Tatangindatu (2013) explains that nitrate level more than 0.2 mg/liter is enough to cause eutrofication and later invoke blooming.…”

“…Phosphate level in Buyan Lake was found exactly on the maximum threshold of standard quality class 1 (2.0 g/l), while the phosphate level of Tamblingan lake was slightly higher than the maximum level (2.3 mg/l). Higher level of phosphate compared to environmental standard was also found by Purnamawati, et al (2018) and the study suggested that the aquaculture was responsible for the contamination. Phosphate is a common component of fertilizer and organic waste from industry and households.…”