Effects of Microalgae Grown in Membrane Treated Distillery Wastewater as Diet on Growth and Survival Rate of Juvenile Pearl Oyster (Pinctada fucata martensii)

Abstract

Microalgae serve as feedstock for bivalves and larvae in aquaculture. The production of microalgae in large quantities is, however, characterized by the high cost of major nutrients and vitamins and scarcity of freshwater. Wastewater is a cheap alternative medium for microalgae cultivation. The wastewater provides essential nutrients for microalgae growth and biomass production. This study examined the biomass productivity, nutrient removal, and biochemical content of Chlorella vulgaris, Spiruna platensis, and Haematococcus pluvialis biomass cultivated in membrane treated distillery wastewater (MTDW). The study further examined the use of cultivated biomass as a diet to analyze the growth and survival rate of Pinctada fucata martensii. The results showed 79.61% and 82.89%, and 41.73% of Total Nitrogen (TN) and 74.95%, 78.21%, and 29.05% of Total Phosphorus (TP) removal efficiency for C. vulgaris, S. platensis, and H. pluvialis respectively. Biomass productivity of 0.069 g L−1, 0.086 g L−1, and 0.057 g L−1, 43.3%, 40.9%, and 34.9% (protein), 10.3%, 14.5%, and 13.8% (lipid), and 16.4%, 14.8%, and 20.8% (carbohydrate) for C. vulgaris, S. platensis, and H. pluvialis respectively. The specific growth rate and survival rate of pearl oysters were significantly (p < 0.05) higher (0.99 ± 0.12%, 87.3%) under C. vulgaris diet compared to S. platensis and H. pluvialis diets.