地理ジャーナルと自然災害
オープンアクセス

概要

Studies on the Physicochemical Properties of Ebonyi River in Ebonyi State, Nigeria and on the Abundance of Benthic Fauna during the Rainy Season

Okwuonu Elijah S*, Odo Gregory E, Eme SO and Okoye Charles O

The study of physicochemical parameters have been documented, however little may still be known on how those parameters determine the abundance and composition of benthic fauna. We investigated, from May to August, 2018 the relationship between physicochemical parameters and the abundance of some benthic fauna found in Ebonyi River. Using a scoop-net, we collected samples ranging from vertebrates and invertebrates. Four sampling stations were chosen so as to encompass as a wide range of physical conditions. The mean values of dissolved oxygen (10.56 ± 0.6 mg/L), alkalinity (25.5 ± 0.3 mg/L) and hardness (15.3 ± 0.4 mg/L) were determined. We found out that the abundance of benthos was influenced by physicochemical quality of the water, habitat, and immediate substrate of occupation, tropic condition, resource partitioning and predation. Six classes of both vertebrates and invertebrates were recorded of which the class Insecta was dominant. The genera of Coenagrion nymph, Sympetrum, and Chironomus negatively correlated to the depth and velocity of water. However, we found a positive relationship between the water temperature and Belostoma genus. The negative relationships may be as a result of pollutants acquired through anthropogenic activities. However, the positive relationship between temperature and Belostoma genus may be as a result of essential resources e.g. food and mating season.