Method and apparatus for concentration of trace material from large water volumes

Method of and apparatus for concentration of trace material from large volumes of water is claimed. Carrier bodies having a lower density than that of water are introduced into a water layer, especially a natural sea current or stream; these carrier bodies are collected again after an automatic traversal of the sea flow or water layer under conditions determined by density differing from that of water. The carrier bodies are loaded and charged by depositing or accumulation of trace material, e.g. uranium concentration, on the carrier bodies. The carrier bodies are then conveyed to a further treatment location for isolating the accumulated and concentrated trace material. The carrier bodies are then again discharged into the flow or stream after being depleted