Oyster Cultivation Marine Biology Station Puntarenas National University
Mollusks in general are one of the most important and constantly growing economic resources in the world. Among these, oyster cultivation stands out, with the global oyster cultivation reaching 7.53 million metric tons in 2025.
Most species cultivated worldwide belong to the genus Crassostrea, including Crassostrea gigas, Crassostrea rivularis and Crassostrea eradelie (endemic to Asia), Crassostrea angulata (from Spain and Portugal), Crassostrea commercialis (from Australia and New Zealand), Crassostrea virginica (from the East Coast of North America), and Crassostrea rhizophorae (from Central and South America).
When oysters are found naturally, their harvesting is essentially a fishing operation. However, when wild oysters and those too small for the market are returned to the sea to continue their growth, it marks the first step toward aquaculture or a production system.
In areas where this species is not found, the way to obtain young oysters (seed) is through an “artificial” process, inducing adult (spawning) oysters to release their gametes, followed by fertilization. Subsequently, the seed can be obtained during the larval phase within an average period of fifteen days.
The next step consists of collecting or producing the seed and raising it under controlled conditions until it reaches a marketable maturity through a method or a combination of various cultivation techniques.
Among the cultivation methods, we can mention the following:
Bottom Culture (Bottom Farming): This method is used when oysters are cultivated directly on the bottom, either in the intertidal or subtidal zone. Suspended Culture (Off-bottom/Off-bottom Culture): With this method, growing oysters are kept away from the bottom by various means. It is used when the bottom conditions are not appropriate due to their softness, exposure to wave action, tidal level, or other factors. Suspended oysters not only grow faster than those on the bottom, but they also have a better condition.
The growth rate of oysters is dependent on the species being cultivated and the geographical area where they are grown. For example, high water temperatures in the tropics can promote rapid oyster growth if there is an adequate food supply. Crassostrea paraibanensis can reach a height of 15 cm in one year; while, on the other hand, Crassostrea rhizophorae can reach commercial size of 6 cm in less than 6 months. In temperate climate areas, commercial sizes are generally reached much later than one year.
Gerardo Zúñiga C. Marine Biologist