Integrated multi-trophic aquaculture (IMTA) is a type of polyculture in which two or more species are grown together. IMTA is the practice of growing multiple aquactic species of different trophic levels together in an integrated fashion to improve efficiency, reduce waste, and provide ecosystem support, such as bio-remediation. This system is regarded as one of the most environmentally friendly aquaculture systems. During IMTA production, uneaten feed and waste produced by one species, generally a fish, are converted into feed, fertilizers, and energy for another species. Thorough nutrient cycling, increased production efficiency creating increased economic resilience, product diversification, and the potential for premium prices, IMTA promotes aquaculture sustainability with economic, social, and environmental advantages. 

​

There are many ways to configure an IMTA system. Depending on the species chosen and water flow, the integration of production can change. Fed aquatic species, such as fish or shrimp, are always paired with an extractive species which takes organic or inorganic nutrients out of the water column. Species that extract organic matter could be filter feeders such as oysters, mussels, and clams, or deposit feeders such as polychaetes or sea urchins. The organic matter they feed on includes organic waste from the fed species, such as excess feed and feces produced. Species that extract inorganic nutrients include macroalgae like seaweeds. This combination of species creates a more efficient use of resources while diversifying the economic benefits for the farmer. 

​

The two images below give examples of how IMTA systems can be arranged.