Pages: (1-8 )
Abstract
Seven chemical parameters (pH, conductivity, dissolved oxygen, salinity, calcium, nitrate-N, phosphate-p) were analyzed for the tidal zone of the Benin River water samples at fortnightly intervals. Three (I, III, V) of the five study stations were situated along the main river channel while two (II, IV) were located on creeks entering the main river. The ranges of the chemical characteristic at the study stretch throughout the study period are as follows: pH (6.70 – 2.80); conductivity (2000.00 – 10.00 μScm-1); dissolved oxygen (16.4 – 2.3 mgL-1); salinity (6.17 – 0.01 ‰); calcium (252.0 – 17.0 mgL-1 x 10-1); NO3-N (6.90 – 0.15 mgL-1); PO4-P (5.70 – 0.0 mgL-1). However, fluctuations in dissolved oxygen, salinity and phosphorus only were significantly different (P <0.05) at the study stations in the two years. Generally, the chemical characteristics of the creek stations were similar and different from those of the main river stations. The chemical heterogeneity of the study stretch as reflected by the variations of the chemical conditions at the creeks and the main river sites seem to have influenced the distribution and abundance of prawns at the study area.
Keywords: Chemical constituents, brackish water, prawn habitat, creeks, Nigeria,