The Senegalese National Aquaculture Agency (ANA) has completed a mapping of the country's oyster potential in its mangroves and lagoons. This mapping, which took the form of a harmonized database, aims to boost the industrialization of the oyster sector. According to ANA Director General Samba Ka, the study seeks to transform wild oyster harvesting into planned, rational, and scientific farming. The project was presented during a workshop that reported on the results of studies on the oyster potential of Senegal's mangroves and lagoons.
The study was conducted over a year and involved teams from ANA, regional fisheries services, and local communities. They applied a unique protocol to 20 pilot sites across five coastal regions: Saint-Louis, Thiès, Fatick, Kaolack, and Ziguinchor. The protocol included monthly monitoring of growth, mortality, flesh yield, and salinity levels. This rigorous follow-up has provided Senegal with a harmonized database and a comprehensive cartographic atlas for the first time.
The scientific study reveals that each coastal area in Senegal has its own vocation. The north, particularly Saint-Louis, records the fastest growth in the country. For example, in the Tassinière site, oysters reach a record weight of 130 grams. This opens up the possibility of short breeding cycles, with oysters being put into the water in December and harvested just before the rainy season.
The study also highlights that the central oceanic sites, such as Somone, Joal, or Falia, are the national quality pole, offering very rich oysters in terms of flesh and stable yields throughout the year. According to Samba Ka, the southern zone appears to be the privileged and highly strategic sector for oyster spat collection. The study also emphasizes the need for a rigorous rotation of production structures.
The research shows that a good spat collection site does not necessarily make a good site for oyster fattening. For example, the Mbassis site in Fatick recorded a high number of spat, but suffered a mortality rate of nearly 85% during the breeding phase. In contrast, the Niayam site in Potou commune saw a significant increase in spat, from a dozen in May to 172 in September.
Based on these findings, ANA recommends a transhumance strategy, similar to European models, which involves setting up collectors in August-September and then transferring young oysters to the most performant fattening sites in December. The study also highlights that controlling mortality remains the main constraint to the profitability of the oyster sector. Massive losses of livestock occur mainly at the end of the dry season in the center, due to high salinity, and during the rainy season in the north.
The results of this study provide valuable insights for the development of Senegal's oyster sector. By implementing these recommendations, the sector could become more productive and profitable, contributing to the country's economic growth. Key stakeholders will need to work together to ensure the successful implementation of these strategies and to address the challenges facing the sector.
Key points
- The study provides a comprehensive database and cartographic atlas of Senegal's oyster potential.
- The southern zone is identified as a strategic sector for oyster spat collection.
- Controlling mortality is crucial to improving the profitability of the oyster sector.
