Aquaculture Effluent: Impacts and Remedies for Protecting the Environment and Human Health

Aquaculture industry is growing rapidly since the captured seafood alone could not meet the increasing demand. Although this trend is excellent for the economy of the aquaculture industry, it also brings several adverse effects to the environment. Both fresh- and saline water aquaculture require large amount of water with good quality. They also require large land area. When the freshwater is supplied from surface water sources, it directly competes with other demands such as drinking and other industrial water supplies; when it is supplied from groundwater aquifers, it is associated with land subsidence. The water that is used in the aquaculture systems accumulates suspended solids, dissolved organic substances, compounds of nitrogen and phosphorus, and other chemicals that are used to prevent diseases of aquatic species and require freshwater exchange. The aquaculture effluent that is being exchanged with freshwater requires appropriate treatment to remove the above-mentioned pollutants before being discharged into watercourses. Further, stringent effluent discharge standards imposed by regulatory authorities and the scarcity of freshwater force the aquaculture industry to look for novel treatment systems that could increase the reuse of aquaculture effluent. This will not only reduce the freshwater demand but also increase the productivity as the land used for treatment will be reduced significantly. This article discusses the treatment systems used to remove nutrients in order to encourage water recycling in aquaculture systems. Also, this article describes the fish diseases in aquaculture systems and how to incorporate appropriate mechanisms in aquaculture to safeguard the quality of the yield.