Marine aquaponics for arid and coastal resilience: Closing loops in saline food systems

Marine aquaponics—also referred to as maraponics—integrates land-based marine aquaculture with the hydroponic cultivation of halophytes and salt-tolerant crops, enabling food production in saline environments with minimal freshwater input. This circular system presents a sustainable alternative to conventional aquaculture and agriculture, particularly in arid and coastal regions where freshwater scarcity and soil salinization challenge traditional farming. By recirculating water and nutrients between fish and plants, marine aquaponics reduces waste discharge, enhances resource efficiency, and minimizes environmental impact. This review synthesizes the current state of research on marine aquaponic systems, with a focus on system design, water quality management, nutrient dynamics, species selection, and operational parameters. We explore enabling technologies such as recirculating aquaculture systems (RAS), biofloc systems, and probiotics, alongside the functional role of halophytes in nutrient removal and biomass production. Case studies from diverse climatic zones highlight emerging applications and challenges. Despite growing interest, marine aquaponics faces unresolved issues, including salinity management, economic viability, and knowledge gaps in plant–microbe–fish interactions. We identify critical research priorities and propose future directions to support scalable, commercially viable models. Given its potential to reduce freshwater use and support food production in fragile ecosystems, marine aquaponics offers a promising contribution to climate-resilient and circular food systems.