A concise study on essential parameters for the sustainability of Lagoon waters in terms of scientific literature

Abstract

Agriculture encompasses both plant growing (agronomy, horticulture, and forestry) and animal husbandry. Aquaculture is the aquatic embodiment of agriculture. Lagoons are the main sources of aquaculture in various countries around the world which especially yield shrimp, finfish, macrophytes, and mollusk. Agricultural effluents are highly affecting the lagoon water quality parameters in Sri Lanka since most of the agricultural farmlands in the country are on coastal landmasses. It leads to the increased risks of lagoon water contamination. Therefore, it is essential to identify the water quality parameters affected by anthropogenic agricultural activities and establish their threshold limits for ensuring the sustainability of lagoons. This study has identified the influential lagoon water quality parameters associated with agricultural effluents using bibliographic references, tested the existing values of the most influential parameters in five Sri Lankan lagoons, and briefly discussed their fate and transport. The lagoon water quality was classified into biological, physical, and chemical parameters and studied for their importance in enhancing the water quality. The overall experimental findings on temperature, turbidity, pH, salinity, DO, BOD, COD, phosphates, nitrates, ammonia content, and faecal coliforms in water specimens suggest that the selected Sri Lankan lagoons are heavily polluted because of the accumulation over the decades from the agricultural lands which worsens even more with this salinity from the seawater when the tide comes in. This paper concludes that there is a growing need for mechanisms that can be used to monitor and apply control measures to effectively manage lagoon water quality not only for the integrity of the lagoon itself but also for the dependent ecosystems both in and out of the lagoon.