Assessments of Biological Water Quality and Condition Factor of Clarias gariepinus in Lake Alau, North - Eastern Nigeria

摘要

This study was conducted on the assessments of biological water quality and condition factor of Catfish (Clarias gariepinus) of Lake Alau, Nigeria. Water was sampled biweekly for the period of seven months from five sampling stations and was determined according to the method described by Boyd (1990). The assemblage of planktons in the Lake, it revealed that 3 genera and 10 species of zooplankton were identified; five Rotifera (66.2%), 3 Cladocera (18.2%) and 2 Copepod species (15.6%) making 100% abundance with Rotifers dominating the fauna. 4 genera and 9 species of phytoplankton were identified; 5 Chlorophyceae (60%), 2 Myxophyceae (21%), 1 Denoflugelae (10%) and 1 Bacillariophyceae species (9%) making 100% in abundance with Chlorophyceae is the most dominant taxa. Indicated that, there are adequate biological water quality parameters, within the range recommended for fish production. The Mean condition factor (K) for male's Clarias gariepinus (raining season; 2.20 ± 0.06, dry season; 2.08 ± 0.03) and female's (raining season; 1.90 ± 0.01, dry season; 2.2 ± 0.06). The male K was significantly higher in rainy season than in dry season, while the female K was lower in rainy season than in dry season. Clarias gariepinus in Lake Alau were in good condition in all the season. Biological water quality parameters were within the observed composition in unpolluted water bodies and found to be within the limit range for aquatic life, domestic use and for high yield for fish production. Lake Alau is maintaining its productive status and has high potential for fisheries development based on the values obtained which were in conformity with recommended values for freshwater fish production. A community based monitoring program should be developed to capture valuable data and increase awareness within the local population on water quality and shoreline issues should be encouraged.