Carrying Capacity Based on Chlorophyll-ain The Betung Lake Betung Village PangkalanKuras Sub-districtPelalawan District Riau Province

Abstract

Abstract

Carrying capacity is defined as the ability of aquatic environment to support the life of organism in that area. A study aimed to assess the aquatic carrying capacity for extensive fishing in the Betung lake, Betung Village, Pangkalan Kuras Sub-district Pelalawan District, Riau Province. The carrying capacity was determined based on primary productivity using chlorophyll-aconcentration.This research was conducted July-August 2019. There were 3 stations, namely Station 1 (inlet area), Station 2 (in the middle of the lake) and Station 3 (in the end of the lake). In each stations, there were 2 sampling point, in the surface (15 cm) and 2 Secchi (160 cm) depth. Sampling was done three times, once a week. Water quality parameters measured werechlorophyll-a, transparency, temperature, pH, dissolved oxygen, CO₂, nitrate and phosphate concentration. Results shown that chlorophyll-a:17.81-26.73 µg/L, transparency : 81.3-84 cm, temperature : 28.3-29.7ºC, pH: 5, dissolved oxygen : 3.87-6.12 mg/L, CO₂ : 6.27-15.42 mg/L,nitrate : 0.02-0.05 mg/L, and phosphate : 0.02-0.04 mg/L. Based on chlorophyll-a concentration, the carrying capacity in Betung Lake was 1.61 tons/fish/year.

Keyword: Oxbow lake, Primary Productivity, and Water quality