The European Inland Fisheries Advisory Commission organized on 29-30 May 1980 a symposium on new developments in the utilization of heated effluents and of recirculation systems for intensive aquaculture, in Stavanger, Norway. There were six consecutive technical sessions during which the various topics were introduced and discussed. These topics referred to water quality, engineering/technology of equipment facilities, biology of cultured organisms, management/economics of rearing systems and socio-economics. A series of recommendations were made, six of them being later endorsed by the Commission at its Eleventh Session. These include (i) the establishment of a working party to analyze the problems related to fish farms effluents (ii) the activation of a correspondence group to propose terminology, format and units of measurement related to flow-through systems and to recirculation systems (iii) the preparation of a code of practice on the introduction of non-indigenous species.