dc.description.abstract |
The study was conducted in the Zarima River between March and July 2023. The objectives of the study were to assess the ecological health of Zarima River using macroinvertebrates, fish community, and physicochemical parameters and determine the length-weight relationship the most dominant fish species. Physicochemical sampling were collected using in situ multi parameter probe. Macroinvertebrate specimens were collected using a D-shaped sweep net with a mesh size of 500 µm. Gillnets with different mesh sizes 6, 8 and 10 cm and monofilament nets of various mesh sizes(4 and 6 cm) were used to collect fish specimens in both dry and wet seasons. Immediately after capture, the total length(TL), forked length and total weight(TW)of each individual were measured in centimeters and grams, respectively, and their relationship was determined using the power function. A one-way ANOVA and independent t-test were used to describe the mean difference and statistical difference in physicochemical parameters across the sampling sites and seasons respectively. Moreover, canonical correspondence analysis(CCA)was used to visually display patterns in macroinvertebrate and fish distribution in relation to their environmental variables. Also, a principal component analysis was run to ordinate sampling sites in relation to the distribution of macroinvertebrate and fish communities. A total of 292 macroinvertebrate and 253 individual fishes were collected. While Gomphidae was the most dominant(67.47%) taxon among the macroinvertebrates, Cyprinidae was the best-represented family of fishes. Zarima River had higher diversity(H'=1.22) of fish in dry season but lower in wet season which was(H'=0.97). Likewise, L. intermedius was the top(88.1%) in Index of Relative Importance value, indicating its influence in terms of number, weight, and frequency of occurrence in Zarima River. Furthermore, the length-weight relationship for the most abundant species showed that the relationship was strong by discussing the b-value for Garra species(b=3.1015)attain positive allometric growth. However Labeobarbus intermedius and Labeo forskalii attain negative allometric growth. The Zarima River’s diverse aquatic ecosystem, influenced by seasonal and environmental factors, to recommend it need regularly monitor the river's water quality macroinvertebrates and fish populations across different seasons to track changes and respond to potential stressors. |
en_US |