Abstract:
The world's aquaculture industry has in recent times grown rapidly to
satisfu the demand for seafood, which cannot be met by wild fisheries
trariiesting. Uncontrolled expansion of aquaculture industries has fofsome
countries like Sri Lanka, resulted in adverse environmental impacts and
dbgradation of coastal environments. Prawn farms near the coabtal area
of Sri Lanka are one of the profit-oriented industries and those are
constrained by problems related to environmental degradation. This study
was undertaken in 2004 and examined the wastewater from the prawn
farms located at the Thiruperunthurai area of the Batticaloa district.
Quality parameters such as Chemical Oxygen Demand (COD), Turbidity,
Nitrate, Phosphate, Total Suspended Solids (TSS), pH, Temperature and
Salinity were monitored in the prawn farm wastewater. The wastewater
discharged from the prawn farms to the Batticaloa lagoon showed that
relatively higher concentrations ofTSS, Turbidity, COD and Salinity with
mean concentrations of 34833 mgll,94 FAU, 1451 mg/l and25%o"
respectively. Further, large volume of prawn farm wastewater was
discharged directly to the lagoon water without any treatment processes.
Therefore, lagoon water in Batticaloa showed high turbidity values and
found some algal growth near the prawn farms. It is proposed that
secondary treatment systems or wetlands to be introduced to improve
the quality of prawn farm effluents before discharged into the lagoon to
minimize the environmental impact ofthe prawn farm industry
