A Review on Mariculture Effluent: Characterization and Management Tools

While marine aquaculture, or mariculture, has been growing rapidly and globally in recent decades, many environmental concerns remain to be fully addressed to achieve its long-term goal of sustainable development. This paper aims to provide a synthesized perspective on these issues by reviewing and discussing the characterization, transport, and current modelling and management tools associated with effluents released from mariculture sites. Specifically, we examined the effluent characteristics and behavior from source-to-sink, including the composition and load of effluent discharge, its transport and transformation processes in the water column and at the seabed, and its impacts on the pelagic and benthic environments. We then focused on management-related issues, including the setting of the regulatory mixing zone, the establishment of environmental standards, monitoring measures, and modelling techniques to depict the current state-of-the-art modes in a global context. Our study shows that while substantial progress has been made in understanding the nature of the mariculture effluent, as well as in monitoring and modelling its transport and fate, the regulatory framework still lags behind in many countries where the mariculture industry is relevant. This is particularly evident in the lack of consistent criteria for the definition of regulatory mixing zones and the associated environmental standards for water quality and benthic impacts. Besides, as new predictive models are emerging quickly, their proper evaluation and validation are imperative in view of their increasing application in regulatory practices. This review is intended to provide references for advancing regulatory management of mariculture effluents, as well as for promoting sustainable mariculture development.