Distribuição e abundância das ostras de areia (Pinctada capensis) e da rocha (Saccostrea cucullata) na Ilha de Inhaca, sul de Moçambique

Abstract

Oysters play a fundamental role in the subsistence of coastal communities, serving as a major source of food, income, protein and are responsible for improving the health of aquatic ecosystems. Knowing their distribution and abundance can serve as a foundation for the sustainable management of this resource. This study was carried out between July and September 2023, on Inhaca Island and focused on describing the distribution of the Pinctada capensis and Saccostrea cucullata oysters on Inhaca Island and determining their abundance. Transects parallel to the coastline were drawn for the Saccostrea cucullata oyster and perpendicular to the coastline for the Pinctada capensis oyster. For both species, 30 (0.5 x 0.5) meter squares were allocated, separated by a distance of 10 meters, and to determine abundance, the individuals in each square were counted. The results showed that sand oysters are distributed among the banks of Bángua, Sangala, Nolwe and Inguane and rock oysters in the substrates of Ponta Torres, Ponta Ponduine, Farol and EBMI, and that there are statistically significant differences (p<0.05) in the abundance of sand and rock oysters throughout the island. For rock oysters, the difference is evident in Ponta Torres and Farol (p=0.0008) and Ponta Torres and Ponta Ponduine (p=0.0001). For sand oysters, the difference is evident in Bángua and Sangala (p=0.0249). There was a low abundance of Pinctada capensis and Saccostrea cucullata oysters in areas close to the population and high in areas distant from the population. The highest density of Pinctada capensis oysters was found in Bángua, 7-9 individuals per km 2 , and the lowest in Sangala, with 2-3 individuals per km 2 . The highest density of Saccostrea cucullata oysters was found in Ponta Torres, 7-9 individuals per km 2 , and the lowest in Farol, with 2-3 individuals per km 2 . The results of this study could be crucial for the authorities managing fisheries resources, as they will help in the adoption of management and conservation measures for this resource, as well as in improving the level of exploitation of the same(TRADUÇÃO NOSSA)