15 MARCH 1999
HATCHERY CULTIVATION OF PACIFIC OYSTER JUVENILES USING ALGAE PRODUCED IN OUTDOOR BLOOM-TANKS
I. Laing, R.W. Chang-1998
Aquaculture Internatinal, 6 (4) : 303-315 (Current Contents)
Abstract:
Algae were bloomed as batch cultures by adding fertilizers to natural seawater in 500 outdoor tanks, from mid-June to mid-August, over a period of 2 y. In the first year of experiments the bloomed algae were fed to Pacific oyster (Crassostrea gigas Thunberg) juveniles at a range of rations from 0.06 to 1.63 g (organic weight of algae)/g live weight of spat)/week. At rations of 0.5 g/g/week or higher, growth rates of juveniles were similar (mean, 97%) to those fed a control diet of intensively cultured algae (Tetraselmis suecica Kylin) Butch and Chaetoceros calcitrans (Paulsen) Takano at a ration of 0.3 g/g/week). In the second year, the bloomed algae were fed at a ration of 0.5 g/g/week throughout all the experiments, and gave growth rates of 70-98% (mean, 85.6%), compared with the control diet. The proportion (by weight) of the diet consumed by the juveniles was about 70% for the control diet and 78% for the bloomed algae. Total lipid and essential fatty acid content of the bloomed algae were similar and total carbohydrate content was lower, when compared with typical published values for intensively cultured algae food species.
(Conwy Lab, Ctr Environm Fisheries & Aquaculture Sci, Benarth Rd, Conwy LL32 8UB, Wales, UK, e-mail: i.liang@cefas.co.uk)