Journal of Marine Biology

A substantial proportion of aquaculture farms worldwide are based on earthen ponds. The application of fertilizers to enhance primary production, or intensive feeding associated with higher stocking densities in such ponds, has generated numerous challenges in the management of bottom sediments and in maintaining stable water quality. With the continuing expansion of aquaculture, these problems have intensified exponentially and, in many cases, have contributed to the emergence and spread of disease outbreaks as well as to economic crises within the industry. Moreover, effluents discharged from these farms as well as from other aquaculture systems require treatment prior to release into the environment. Biochar, as an accessible, low-cost, and environmentally compatible biosorbent, can help mitigate these issues within ponds, recirculating waters, and discharged effluents, while also offering additional applications. Several established or potential areas of use are highlighted in this study, including regulation of nitrogenous compounds in aquaculture systems; incorporation into feed formulations; application as a fertilizer to promote pond fertilization; provision of microbial retention/colonization capacity; adsorption of environmental contaminants such as heavy metals; carbon sequestration; and modulation of nutrient bioavailability in primary-production-based ponds, among others. Given the diversity of techniques and materials available for developing these applications, biochar appears to merit consideration as a prospective solution for aquaculture, and further research across its various dimensions is warranted.