Size distribution of bilih (Mystacoleucus padangensis Blkr.) as an endemic fish spatially and temporally using dipp nets in Lake Singkarak, West Sumatra, Indonesia

Abstract

Lake Singkarak has endemic fish resources of only one species in the world that has economic value, namely Bilih (Mystacoleucus padangensis, Blkr.). The rapid rate of catching using dipp nets fishing gear in this lake is expected to result in a decline in the Bilih population. Dipp nets is a fishing gear that is not environmentally friendly. Bilih fish samples were obtained using dipp nets fishing gear at two locations, namely Intake PLTA (hydropower intake) and Batu Taba for seven (7) months from June to December 2021. The number and size distribution of Bilih were calculated spatially and temporally. The abundance of fish in the Intake PLTA and Batu Taba locations were 472 fish and 716 fish, respectively. As spatially the size range of fish in Intake PLTA is 45-104 mm and in Batu Taba 40-130 mm. The highest fish size is in the 65-72 mm class range, both spatially and temporally (June). Average water quality at Intake PLTA location (temperature 27.87 °C; pH 8.6; DO 4.68 mg/L; Conductivity 0.143 mS/cm; TDS 0.092 mg/L) at a depth of 14.15 m and at Batu Taba location (temperature 28.14 °C, pH 9.24; DO 4.68 mg/L; Conductivity 0.231 mS/cm; TDS 0.092 mg/L) at a depth of 14.15 m.