Amelioration and Management of Shrimp Ponds in Acid Sulfate Soils: Key Researchable Issues

TLA!rapid expansion of shrimp farming has resulted in extensive excavation of coastal sediments that contain pyrite (FeS2). When oxidised, pyritic sediments develop into acid sulfate soils (ASS), which are characterised by high acidity and elevated concentrations of sulfate and toxic metals (Golez 1995). ASS reduce water quality in shrimp ponds, groundwater and nearby creeks and estuaries. Consequently, ASS adversely affect shrimp production (Simpson and Pedini 1985; Singh 1985) and reduce the conservation, recreational and commercial value of estuaries (Sammut et al. 1995). Acidified shrimp ponds are often abandoned, leading to ‘shifting aquaculture’ and increasing pressure on land and water resources. Under current practices, the production of shrimp in ponds which are impacted by ASS cannot be sustainable. Unless ameliorated and managed, acidified shrimp ponds also become a long-term source of pollution to off-site areas. The role of ASS in shrimp production is often overlooked and the associated socioeconomic and environmental impacts are not widely recognised. This paper briefly discusses the impacts of ASS, some of the methods that have been used to ameliorate and manage affected ponds, and identifies key researchable areas.