Abstract:
Water pollution is becoming a major global issue, as pollutants frequently transfer between
freshwater and marine ecosystems, directly impacting recreational water quality. This study
compared key water quality parameters including turbidity, temperature, oil and grease,
total suspended solids (TSS), electrical conductivity (EC), pH, dissolved oxygen (DO),
biochemical oxygen demand (BOD), chemical oxygen demand (COD), and Escherichia
coli (E. coli) in both freshwater and marine water around the Pasikuda beach site. The
objective was to determine whether the freshwater pollution has any significant effect on
marine water quality at that site. Water samples were collected from both marine water and
freshwater systems (streams), which are connected to the sea at specific locations over a
three-month period, and were analyzed using standard methods. The results were analyzed
statistically using SPSS and Minitab software. In freshwater, the average mean values of oil
and grease, TSS, DO, COD, and E. coli were not within the threshold limits set by EPA and
WHO guidelines. In marine water, the average mean values of oil and grease, TSS, DO,
and COD were not within the threshold levels. Oil and grease, TSS and COD were above
acceptable limits and DO was below the limit in both marine and freshwater systems. The E.
coli counts in freshwater were significantly high, indicating higher fecal contamination. The
presence of E. coli in the marine environment indicates potential contamination from
freshwater inflows. The results of two sample t-test indicate that there is no a significant
difference in the mean values of turbidity, temperature oil and grease, DO, BOD, COD, E.
coli between marine water and freshwater. However, there is a significant difference (p =
0.05) in the mean values of TSS, EC, pH between marine and freshwater. Overall, the
results suggest that marine water quality at Pasikuda beach is influenced by nearby
freshwater systems, highlighting the interconnected nature of aquatic pollution and the need
for integrated water management strategies.
