The device has a container containing an ecosystem of aquatic organisms (AO). The container is provided with a lid (CV) to cover an upper surface of the container. The container provides an entry and an exit (Oi) of water for receiving and delivering a water flow (FO) crossing the container, respectively. The water entry is arranged at a height more than or equal to that of the water exit. An Independent claim is also included for a process of conservation of organisms in an aquatic environment.
