Abstract: The invention provides a process for the production of seafood in a closed-loop multitrophic aquaculture system comprising the steps of: (A) culturing phytoplankton in a medium, wherein said medium is irradiated with light; (B) transferring such cultured phytoplankton to a medium for culturing zooplankton; (C) transferring such cultured zooplankton to a medium for culturing seafood; and (D) transferring a part of the medium of step (C) as nutritient to the medium of step (A), thereby creating a closed loop, wherein steps (A) to (D) are carried out in a closed system, in which free gas exchange with the environment is prevented. The invention further provides an apparatus for carrying out this process.