Australian Nuclear Science and Technology Organisation (ANSTO)
Title: Isotopic applications for ecologically sound cost effective aquaculture production
Biography: Debashish Mazumder
Aquaculture is the fastest growing food producing sector globally. Future growth of aquaculture depends on a more ecologically sound management practice. The dietary effects on nutrient assimilation, isotopic turnover rates and discrimination factors were assessed using exponential models to determine the influence of microalgal diets on the growth and survival of hatchery-reared Pacific oyster larvae. Of the four dietary treatments used, larvae fed Chaetoceros calcitrans and a mixed diet had the best growth and high survival. Isotopic analysis of tilapia muscle tissue and all potential dietary sources from daily and weekly fed tilapia ponds suggests that natural feed such as detritus, algae and zooplankton appear to be favored more by tilapia than formulated feed. After 90 days of cultivation, the average final body weight of tilapia receiving daily feed inputs was 134 g while in weekly feed it was 92 g. The feed conversion ratio (FCR) was very high in the daily fed tilapia compared to a small FCR in the weekly fed ponds. Feed input cost for the weekly feeding treatment was much less than the daily feeding treatment. Isotopic techniques have the potential to develop cost-effective environment friendly aquaculture.