Pollution of aquatic ecosystem poses a serious
threat to aquatic organisms and gradually the entire
ecosystem. The polluted water often makes its way into
the water tables and water systems, which means it is in
the drinking water we access. The physiochemical
characteristics of surface water in Okrika LGA. Rivers
State, Nigeria were assessed during the dry season
(February) and wet season (July, November), 2020.
Water samples were obtained randomly from six surface
waters in different communities in Okrika, namely,
Ogan-Ama, Kalio-Ama, George-Ama, Edeme-biri,
Okari-Ama, Isaka Town and analyzed according to
standard international methods to determine the
physicochemical parameters of collected samples.
Parameters analyzed include among others; pH, EC,
TDS, DO, BOD, TPH, PAH, Salinity and heavy metals.
The Surface waters contained high Electrical
Conductivity values which ranged from 30400us/cm to
65400us/cm with highest during the dry season. In
comparing values of Total Dissolved Solids (TDS )of
18645mg/l to 50200mg/l with World Health Organization
(WHO) limits, these values are above WHO limits of
600mg/l. This is not acceptable due to disruption of fish
spawning and rearing in the marine environment.
Salinity value of 15840mg/l was recorded in Isaka which
is higher than WHO's limit of 200mg/l and can cause
acute and chronic effects on aquatic organisms. Most
samples recorded low DO, of less than
6mg/l(WHO/National Environmental Standards
Regulations Enforcement Agency -NESREA), High
BOD above WHO limit of 0.002mg/l but within
NESREA limit of 3.0mg/l. There were traces of TPH,
PAHs, also, contamination with Cadmium, Lead and
Zinc metals. These can cause histopathological
alterations in tissues of aquatic organisms and threatens
survival of fishes. This calls for proper management of
the marine environment by appropriate authorities in
order to safe guard the ecosystem and human lives.
Keywords : Contaminant concentration, Assessment, Aquatic degradation, Endangered species, Okrika