The American oyster Crassostrea virginica is a mollusk that is naturally distributed along the Atlantic coast, from Canada to the state of Campeche, Mexico; it plays an important biological role and has excellent nutritional properties for human consumption. It has been pointed out that excessive extraction and anthropogenic activities have decreased mollusk production in different regions of the world and aquaculture represents an alternative to reduce these impacts. The present study determined the survival and growth rates of oyster seed in floating bags at 6 sites of the Soto La Marina river (SLM), associated with environmental parameters.
Seeds of C. virginica of 2 cm in length (Lt) collected in the SLM river were sown in floating plastic mesh bags (8 x 16 mm mesh size, 48 cm wide x 53 cm long), at a density of 30 seeds per bag, placing 3 replicates in 6 stations, from the beach to the most distant area upriver where the presence of the species was observed. Every 3 weeks, the bags were cleaned; the length, height, width (cm), and individual weight (g) of oysters were measured for 12 weeks. At the end of the study, the average survival and growth of the organisms were determined; turbidity, salinity (‰) (Fig 1), oxygen (mg/l), temperature (°C), and pH were measured at each station.
The highest survival was found at the Cortadura station with 85%; Vista H had 78%, La Pesca and Contadero 72%, and the lowest survival occurred in La Playa and Carricitos with 51%. The growth in total Lt (Mean ± SD) was higher at the Vista H station with 2.2 ± 0.3 cm, with an average salinity of 16 ‰; the lowest growth was observed at La Playa with 0.6 ± 0.3, and a salinity of 35 ‰ (Fig 2).