Sustained high yields of Gracilaria (Rhodophyta) grown in intensive large-scale culture

摘要

G. ferox was grown continuously in large, outdoor tanks under a pulse-fed nutrient regime for 4 years in Florida, USA. Productivity was in the range 21.4-59.2 g/m2 per day (dry weight) with a mean of 39.7 g/m2 per day over the entire study period. Cultures were maintained under non-nutrient limiting conditions, so productivity was regulated primarily by seasonal changes in light and temperature, which accounted for 75% of the variability in growth and algal yields. Variations in salinity had insignificant effects on growth. The original vegetative strain was maintained over the entire study without the need for additional supplementation from field-collected stock. Nutrients were supplied using a pulse system, so epiphytic growth on G. ferox was negligible (<3% total biomass). The yields obtained in this study were high, and demonstrate the feasibility of growing red macroalgae like Gracilaria at a sustained high yield in a large-scale, land-based culture system.