During the period of 145 days, in 1974, an experiment with the European eel (Anguilla anguilla L.) culture into the net cages was carried into effect. The cages, 6 in number, were kept in warm water canal running out from the "Pomorzany II" power station in Szczecin. The water temperature in this canal evermore was above 20°C (21-32°C), and the oxygen content never fall down below 6.5 mg/litre throughout all 4 months of research. The eels were fed with minced freshwater fish at the first period of experiment, and hereafter with the mackerel flesh only. Growth of the fishes was unequal and very discriminating. Fish mortality amounts to 6.15 per cent.