Assessment of the Ecology of Diatoms in Relation to Environmental Variables in Landzu River Bida Niger State Nigeria

Abstract

Diatoms are widely utilised as excellent environmental indicators due to their ability to react to a wide range of physical, chemical, and  biological changes that take place in the aquatic environment. This study was carried out to investigate some aspects of the ecology of  diatoms in relation to environmental variables in Landzu River Bida, Niger state Nigeria. Samples were collected from five (5) sampling station and analysed using standard methods and procedures. The results show water temperature (23.63±2.18-25.75±0.25°C), Water  depth (23.76±4.87-36.32±3.21cm), Flow velocity ranged (0.011±0.00-0.182±0.01), Water pH (7.28±0.37-7.48±0.35), Transparency  (20.50±0.15- 22.01±0.31cm), Electrical conductivity (118.95±0.21-144.6±0.23 µS/cm). Dissolved oxygen concentration (6.4±0.50-7.70±0.19  mg/l), the Biochemical oxygen demand (2.14±0.23-2.55±0.26mg/l), total hardness (30.5±3.19-31.26±2.8.33mg/l), alkalinity  (13.83±0.74-14.00±0.71mg/l), Nitrate (0.014±0.00-0.035±0.00mg/l), Phosphate (0.028±0.01 to 0.03±0.00mg/l) the total dissolved solids (111.86±1.49 to 131.18±1.90), Magnesium (0.018±0.01-0.053±0.00mg/l), Zinc (12.02±9.00-23.45±3.00 mg/l), Nickel (4.90±0.45-5.51±0.52mg/ l), Lead (0.44±0.07-1.84±0.04mg/l) and Manganese (12.58±1.30-19.43±2.70 mg/l). All the physicochemical variables measured show no  significant (p>0.05) difference between the sampling stations except depth, flow velocity, dissolved oxygen, phosphate and total dissolved  solids which differ significantly (p<0.05) among the sampling stations while all the heavy metal differs significantly (p<0.05)  between the sampling stations except magnesium and nickel. A total of 2499 individual organisms from 25 species were identified.  Station 2 had the highest number of individuals with 561 organisms, followed by station 5 with 511 organisms while station 4 had 505  organisms. Station 1 had 481 organisms, while station 3 had the lowest with 441 organisms. The study shows diatom assemblage is  influenced by human activities.