8.2 Research Needs
The oysters Crassostrea rhizophorae and C. virginica are cultivated commercially in Mexico, as is Ostrea chilensis in Chile. Studies on these and other species of oysters have been carried out in Brazil, Colombia, Cuba, Mexico and Venezuela (FAO/UNDP, 1976). Studies in Brazil also indicate that the production of C. braziliana in coastal lagoons holds considerable potential for the future. However, few of the culture systems are intensive and products are seldom marketed in a systematic and structured way. Sanitation is also often uncertain.
The cultivation of mussels is important to several countries. Higher production of Mytilus chilensis in Chile is largely limited by a scarcity of seed which is often transported over long distances. Chile also cultures Aulacomya ater and Choromytilus chorus on an experimental or small-scale basis, whereas Perna perna is produced commercially, though only on a limited scale, in Venezuela. Other species of molluscs which are being investigated include abalones (Haliotis spp.) in Mexico, mother-of-pearl shells in Mexico and Venezuela, and the mussel Mytilus platensis in Argentina.
The Task Force had considerable reservations on attempting to culture both oysters and mussels on the same site, and recommended that the programme at Cananeia be confined to the strains of oysters (C. brasiliana) already on site. Studies on mussel culture may be undertaken at a later stage, but before that investigations should be carried out on the existing and potential markets for mussels in the countries of the region.
Oyster production trials should be conducted using off-bottom rearing techniques with the prime focus on determining the economic dimensions of the system. Hatchery production of spat is another area of research that needs early attention. This would enable genetic studies to be initiated for the purpose of developing strains with the desired qualities for commercial farming under Latin American conditions. The common pests and predators of oysters have to be identified and methods devised for their control. On the engineering side, construction material and the design of rafts required, with special reference to cost and durability, should receive attention.
Studies aimed at quality control, including depuration of oysters grown in polluted areas, are of major importance and should be given priority.