Performance of oysters in reciprocal transplants between two Ghanaian lagoons

Abstract

Oyster spat were reciprocally transplanted between Benya Lagoon at Elmina and Nakwa Lagoon at Nakwa and grown on cultches. Shell growth, dry meat weight, and survival of the transplants were monitored for at least six months and compared with their counterparts at their new locations as well as their places of origin. Temperature, dissolved oxygen concentration, pH, salinity and transparency of the water bodies were also monitored. In Benya Lagoon, growth in shell height of the transplants were higher than their counterparts in Nakwa but lower than resident indigenes in the first experiment. In the second trial, shell growth of the transplants and their two counterparts were comparable. Survival of oysters introduced into Benya Lagoons was significantly higher than both indigenous counterparts. In both experiments, oysters transplanted from Benya to Nakwa did not survive beyond the second month. These observations were attributed to differences in the salinity and transparency which were relatively unstable in the Nakwa Lagoon. It could be inferred from the results that transplantation of spat from a widely fluctuating environmental background to seed a more stable habitat would be a viable venture. Furthermore, better results are likely to be achieved during the main spatfall season.



JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 1 Number 2, January (1999) pp. 78-89