Conservation of Aquatic Ecosystems by Constraining Nitrogen Pollution through Aquaculture Effluents

Abstract

Recirculated aquaculture systems (RAS) have increased in preponderance in producing fish and shrimp protein. Yet, the economic sustainability of constraining RAS from negatively impacting aquatic ecosystems remains challenging. The future of RAS agriculture will eventually be settled by the relationship between water treatment costs and the impacts on downstream ecosystems. We present a user-friendly simulator of the costs of the treatment of water from RAS farms. This open-source freeware accounts for consumables and energy needed to protect the fish stock from ammonia and nitrite distress, as well as the cost of effluent treatments for specific nitrogen emission targets. This simulation platform uses information inflows about a RAS farm's layout, filters’ performance, toxicity limits, and operational costs. It monitors the budget of water, ammonium, ammonia, nitrite, and nitrate, as well as the cumulative costs of management decisions for controlling nitrogen inorganics. In combination with local environmental regulations, such an assessment is essential for making business projections that correspond with acceptable impacts on downstream ecosystems. This simulator helps determine whether a specific RAS farm is both financially sound and environmentally sustainable. Such analyses are key to constraining pollution in the surrounding ecosystems and contributing to the conservation of biodiversity.