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The knowledge of biogeochemical processes of recent sedimentation is a key to assess
the paleoenvironments. Suspended sediments are useful probes to understand such
environments as they are fine particles, which can adsorb many elements and are food
for several organisms. Hence this study attempted to evaluate the quality and quantity
of suspended sediments (SS) in the shallow peripheral environments of the Batticaloa
lagoon, Sri Lanka. A total of 34 water samples were collected from the lagoon and
physical parameters were recorded. Suspended sediments were extracted using 45 µm
quartz fiber filters and measured on dry weight basis. The composition of the collected
samples and SS were analyzed using X-ray fluorescence method. The peripheral
environment of the lagoon water was characterized with low oxygenated (range: 0.4-
21.3 mg/l, average: 2.4 mg/l) brackish water (salinity range: 0.1-28.8 ‰, average: 7.5 ‰)
with an average pH of 7.32. Results suggested that the concentration of suspended
sediments does not depend on the physical parameters of water in the lagoon
peripherals. Higher concentrations for Zn, Cu, Ni, MnO and P2O5 were observed in SS
with respect to the surface sediments. Principal component analysis indicated that the
inorganic fraction of SS was mainly composed of weathering products of the country
rocks. This implies that the micro-biological activities, especially planktons of tropical
shallow marine environments can change the chemical compositions of SS.
