Growth of the oyster, Ostrea puelchana (D'Orbigny), at two sites of potential cultivation in Argentina

Abstract

Individual growth of the oyster, Ostrea puelchana, was monitored for 2 years, in two potential sites differing in their average temperature: an open bay, and a closed, coastal lagoon which, however, benefits from sea water exchange through a coastal sandhill. The hydrobiological parameters did not differ significantly between the two areas, except for the water temperatures for which extensive data were obtained and adjusted to sinusoidal models. The annual growth increments (shell height) varied between 10 and 45 mm. Marked seasonal variations in growth rate were observed, for two age groups. An off-bottom technique was used, as well as a suspended culture technique at two different depths. For every experimental condition, growth was faster in the coastal lagoon. Analysis of variance on the daily height-specific growth rates confirmed that these growth rates were significantly higher in the coastal lagoon for the off-bottom technique. For the two age groups, no differences were found between the different depths for the suspended culture technique. However, faster growth was observed in the coastal lagoon for the older individuals. Seasonal variations in growth during the experiments were described by a time-series approach, which included a linear trend and sinusoidal fluctuations. Since growth rates were correlated with the water temperature, this parameter was used to describe the seasonal fluctuations by means of a temperature model. The correlation coefficients between these mocels with two parameters and the original data varied from 0.862 to 0.929.