Use of saline ground water for intensive rearing of Ruditapes philippinarum juveniles in a nursery system.
Saline ground water was used as a thermal source for intensive rearing of juveniles of the Manila clam Ruditapes philippinarum and as a source of nutrients for phytoplankton production. In experiments investigating growth at different seasons, controlled factors were density of juveniles, flow of water, phytoplankton concentration, temperature and frequency of feeding. Their effects on growth and mortality were classified through correspondence analysis, analysis of multiway contigency tables and analysis of variance. An optimal strategy for summer and winter rearing was then defined. The different strategies are discussed in biological terms, with reference to the literature. Growth rates in this intensive culture were compared with available data for artificially fed and naturally reared populations.