Abstract

In the present study, water samples were collected across the three observation stations (Stations 1, 2 and 3) while plankton samples were extracted from the water surface at the stations using net plankton. Identification and enumeration were carried out under a binocular compound microscope with model XSZ-701A(N). Statistical multivariate techniques were employed to assess the effect of sand dredging on the marine ecosystem. The study revealed a significant difference between the minimum and maximum values for total dissolved solids (TDS), temperature, dissolved oxygen (DO) and water conductivity. Although, zooplankton abundance showed inverse relationship with water salinity (r=-0.090), TDS (r=-0.108), and pH (r=-0.162) which is poorly negatively correlated while transparency (r=-0.497) is moderately negatively correlated. However, zooplankton showed direct relationship with water temperature (r=0.012), DO (r = 0.075), BOD (r=0.110), flowrate (r=0.450) and conductivity (r=0.484). Similarly, station 2 showed inverse and significant relationship with TDS (r= -0.821), salinity (r=-0.669) pH (r=-0.659). Meanwhile, the water physicochemical parameters like Conductivity (r=0.484) and flow rate (r=0.450) are moderately and positively correlated. Additionally, a significant impact was observed at station 3, which caused a temporal effect on station 2 from January to April because the river flows from station 3 through station 2 to station 1. Thus, the deleterious effects on the creek as a result of dredged-material deposition need to be reduced to meet the recommended environmental guidelines, and consequently avert heavy remedial costs

Keywords

multivariate technique, zooplankton, surface water characteristics, creek, ecological disturbances, endangered habitats, flora and fauna, topographic