A comparison of the growth performance of rainbow trout ( Salmo gairdneri) in fresh and brackish water in Yugoslavia

Abstract

Rainbow trout of two year-classes (0 +, 1 +) and four different initial average weights (84, 118, 197 and 301 g) were grown-on in floating cages moored on the Adriatic coast of Yugoslavia, while two control groups (84 and 301 g) were kept in fresh water at a conventional fish farm. All fish were fed the same commercial diet at 2% of body weight per day and were reared for 8 months from October 1982 to June 1983. Physiochemical characteristics of water at the brackish and fresh-water sites were monitored, and all fish were weighed every month. Growth of fish in all groups held in brackish water was greatly superior (3 to 4 times) to that of their contemporaries at the fresh-water unit. The results point the way to a new type of trout farming in Yugoslavia, and possibly in other countries of the Adriatic and Mediterranean region, using conventional fresh-water farms to produce fingerlings which are then grown-on in sea water either using floating cages or pumped sea water. By comparison with the papers written so far, this work demonstrates the feasibility of rainbow trout culture in warm seas, opening up the possibility for developing a new technology of aquaculture.