Tuesday, August 7, 2007

PS 33-161: The effect of salinity on filtration rates of the West African mangrove oyster

Alexandra E. Sutton, Howard University and Kobina Yankson, University of Cape Coast, Ghana.

 The potential for developing a fisheries industry based on the West African Mangrove Oyster is high in Ghana. The oyster, Crassostrea tulipa, is a euryhaline organism that thrives in the coastal lagoons of the Ghanaian shoreline. The organism is commonly known, yet further research should be done in preparation for a fishery development. Subsequently, this experiment focused on exploring the precise relationship between salinity and filtration rates of the oyster. Oysters gathered from two types of coastal lagoons (closed and open) were exposed to salinity varying from 0 ppt to 35 ppt and filtration rates were measured at one-hour intervals. Data showed that salinity had no significant effect on filtration rate of a given oyster type (p value = 0.91265, open lagoon; p value = 0.9965, closed lagoon). However, significant difference did exist between the filtration rates of oysters collected from the two different types of lagoon (p value = 0.0002). Oysters collected from the closed lagoon had a significantly greater mean filtration rate across all salinity levels than oysters collected from the open lagoon (0.3485 ppm/min, open lagoon; 0.6567 ppm/min, closed lagoon). These differences in filtration rates may relate to adaptation for greater salinity variation in closed lagoons. Alexandra Sutton is supported by NSF Grant # 040515, Environmental Biology Scholars Program, Biology Dept, Howard University, Dr Mary A McKenna, PI, and by the NSF REU program, Department of Biology, James Madison University, Harrisonburg, VA.