Fish Assemblages and Water Quality at Downstream of Batang Ai Hydroelectric Dam, Lubok Antu, Sarawak

• Main Author: Noor Azha, Noor Iskandar
• Format: Final Year Project Report
• Language: English; English
• Published: Universiti Malaysia Sarawak, (UNIMAS) 2015
• Subjects: SH Aquaculture. Fisheries. Angling
• Online Access: http://ir.unimas.my/id/eprint/11246/1/Noor%20Iskandar.pdf; http://ir.unimas.my/id/eprint/11246/2/Noor%20Iskandar%20full.pdf; http://ir.unimas.my/id/eprint/11246/

The stretch of river below Batang Ai Hydroelectric Dam is susceptible to frequent fluctuations, primarily due to the discharge of water from the dam in order to generate electrical power. However, information on fish assemblages in this area is scarce in literature and how this event affected the fish assemblages within the area is still unknown. Therefore, the objective of this study was to document the assemblages of fish fauna and water quality parameter in the stretch of river below the dam. Fish samples were collected using gill net of various mesh sizes. A total of 14 species from 7 families of fish was documented in the study area. The most dominant species occurred in the area are Cyclocheilichthys apogon (N=103), Hemibagrus planiceps (N=37) and Hampala macrolepidota (N=32). Based on stomach content analysis, Cyclocheilichthys apogon and Hemibagrus planiceps showed omnivorous feeding habit, meanwhile Hemibagrus planiceps showed carnivorous feeding habit. Hepato-somatic index values for Cyclocheilichthys apogon (N=31) ranged from 1.46 ± 0.44 and Hemibagrus planiceps (N=30) was 1.16 ± 0.64. Water quality results show that pH values ranged from 6.52 to 7.13, temperature ranged from 26.2 to 30.7 ºC, conductivity ranged from 16.73 to 27.6 µS/cm, turbidity ranged from 2.79 to 61 NTU, transparency ranged from 0.34 to 4.10 m, chlorophyll-a content ranged from 1.30 to 6.00 µg/L, BOD5 ranged from 0.64 to 3.67 mg/L, TSS ranged from 0.0040 to 00.0277 mg/L, ammonia ranged from 0.03 to 0.49 mg/L and nitrate ranged from 0.006 to 0.483 mg/L.