Patterns of genetic connectivity can help answer key questions about the evolutionary ecology of fishes. This knowledge is particularly useful when considering the management and conservation of species that are impacted by fisheries. Population connectivity in ocean habitats is heavily influenced by environmental and oceanographic factors. These factors can lead to strong genetic differences within populations, causing fragmentation into smaller subpopulations. The Red Sea exhibits pronounced oceanographic gradients in temperature, chlorophyll, and salinity, which have been assessed in various species’ populations and which have been found to have potential impacts on gene flow. The Red Sea also features strong cyclonic and anticyclonic eddies that may facilitate, or possibly inhibit, the transport of larvae throughout the Red Sea, potentially influencing gene flow themselves. The ability of oceanographic factors like eddies to structure wild fisheries populations in this region has yet to be fully determined. To address this, the genetic composition of two of the most highly fished species, (Plectropomus areolatus and Plectropomus pessuliferus marisrubri), in the Red Sea were evaluated utilizing genetic markers (polymorphic microsatellite loci). Samples from three geographically separate regions along the Saudi Arabian Red Sea coastline, as well as from Sudan, were analyzed to address latitudinal and cross-sea connectivity. I was able to determine that little genetic differentiation exists within Plectropomus species across all regions of the Red Sea, indicating high gene flow for these species throughout. These findings highlight the ability of currents and eddies to transport larvae along and across the Red Sea. The results from this study also indicate that a single population of P. areolatus and a single population of P. pessuliferus marisrubri occurs in the Red Sea. The high degree of genetic flow suggests that each species should be managed as individual units. This study presents a plausible avenue for buffering the effects of overfishing currently occurring in Saudi Arabia; Saudi Arabian fish subpopulations may be reseeded by the Sudanese subpopulations.

Thesis (Ph.D.) - James Cook University, 2007. / Typescript (photocopy) Bibliography: leaves 154-165.