Growth of Chaetoceros calcitrans in sediment extracts from Artemia franciscana culture ponds points to phosphorus limitation

Abstract

Chaetoceros calcitrans is one of the most suitable algal strains to feed Artemia because of its appropriate size, digestibility, absence of toxins, and nutritional value. Apart from light and temperature, the growth of C. calcitrans in Artemia ponds in the Mekong Delta of Vietnam depends on the supply of nutrients, especially nitrogen (N) and phosphorus (P) released from the pond bottom sediments. This study was carried out to investigate the growth of C. calcitrans in relation to the availability and proportions of N and P present in the extracts of Artemia pond bottom sediments. The results show that the sediments are depleted in dissolved reactive P (DRP) and highly unbalanced in terms of the ratio of dissolved inorganic N (DIN) to DRP. Algal density and biomass were significantly higher in the extracts with DRP concentrations above 0.1 mg P/L and DIN/DRP ratios below 100. © Copyright by the World Aquaculture Society 2009.