Spatfall varied significantly by depth as the more frequently exposed top collectors harvested much less spat than submerged collectors. Narkwa, a relatively small lagoon with reef oysters had the highest annual mean spatfall, which was 1.3, 2.5, and 9.8 folds the spatfall in Densu Delta, Benya Lagoon and Whin Estuary, respectively. Locations with reef oysters had superior spatfall to mangrove root-adapted-oyster areas. Spatfall regimes were unique in each ecosystem albeit with an overall preponderance of dry season availability of spat. By monthly deployment of artificial substrates affixed to bamboo racks over 12 months, we find significant differences in spatfall among and within the brackish systems, and across months and seasons. In contribution to addressing this challenge, we proffer clarity on the spatiotemporal variations in spatfall (number of spat/m 2) of the mangrove oyster Crassostrea tulipa (Lamarck, 1819) in four estuaries along the Gulf of Guinea coast. Uncertainties associated with wild harvests of seed and adult oysters due to unknown oceanographic oscillations are a major challenge in oyster fisheries and aquaculture development. 3Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia.2Department of Fisheries and Aquatic Sciences, University of Cape Coast, Cape Coast, Ghana.1Centre for Coastal Management – Africa Centre of Excellence in Coastal Resilience, University of Cape Coast, Cape Coast, Ghana. ![]() Ernest Obeng Chuku 1,2,3*, Kobina Yankson 1,2†, Edward Adzesiwor Obodai 2, Emmanuel Acheampong 2 and Denis Worlanyo Aheto 1,2
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