The Israeli Journal of Aquaculture - Bamidgeh 51(1), 1999, 17-25.


Temel Sahin

Su Ürünleri Arastirma Enstitütü, PK 129 , Trabzon, Turkey

lbrahim Okumus and M. Salih Çelikkale

KTÜ Deniz Bilimleri Fakültesi, TP-6I530 Camburnu-Trabzon, Turkey,
tel.: 90-462-752 2805 - 09, fax: 90-462-752 2158

(Received 1.7.98, Accepted 19.2.99)

Rainbow trout (Oncorhynchus mykiss) of nine months (trial I) and 1.5 years (trial II) were reared in cages in the southern Black Sea to assess growth performance. The effects of stocking density and size of fish at transfer to sea water on growth were also examined. Initial mean weights were around 30 and 200 g and stocking densities were 660, 990, 1320 and 800, 1000, 1500 and 2000 fish per cages of 56 m³ in trials I and II, respectively.
Final mean weights at the end of 180 days were 589.4 (15.2) -633.9 (10.4) g in trial I and 1038.3 (22.5) - 1227.5 (28.1) g in trial II at water temperatures ranging 6.7-17.5C. Biomass at harvest ranged from 7.4 to 40.2 kg per m³ depending on the initial stocking density. Growth was affected when density reached over 25 kg m³ and, according to growth rates, the optimum stocking density at harvest was estimated as 20-25 kg ma. Specific growth rates and food conversion ratios varied 0.46-3.26% and 1.54-2.13, respectively. Mortality ranged from 3.1% to 4,6%. It has been concluded that mariculture of rainbow trout on the southern coast of the Black Sea can be carried out approximately eight months of the year. It is possible to produce portion size fish (200-250 g) by stocking small fish of around 15-30 g and conducting multiple harvests in one culture season. However, production of large or salmon trout (2-3 kg) needs development of more suitable technology and culture strategies.