Catch per Unit Effort, Density and Size Distribution of the Oysters Pinctada capensis and Saccostrea cucullata (Class Bivalvea) on Inhaca Island, Southern Mozambique

Abstract

Oysters are important resources for the daily diet, a source of economic income for many coastal communities and a delicacy for the tourism industry. In this study, the oysters (Pinctada capensis and Saccostrea cucullata) were investigated with the aim to assess the catch per unit effort, density and size composition. The study was conducted over a three-year period on Inhaca Island, Southern Mozambique. For both species, perception of fishery trends from collectors was carried out through habitat censuses and interviews. Transects, quadrats and daily fisheries catches approaches were used. Results show that P. capensis is the most exploited on the island. A total of 72.1% of respondents pointed that the oyster P. capensis is decreasing, due to excessive catching (75.4%) followed by natural death (24.6%), while 20.9% affirmed that the resource is stable and 7.0% are unaware about the resource trend. Oyster densities, sizes and catches per unit effort were higher in less accessible areas only for P. capensis. The present study provides valuable baseline information to recommend best practices to improve the exploitation, and access the need for introduction of aquaculture, towards the sustainable management and conservation of oysters, and ultimately to ameliorate people’s livelihoods.