Density and diversity of larval fish in some coastal bays in Sharm El-Sheikh, northern Red Sea, Egypt

Abstract

This study was carried out to investigate the composition and the spatial and temporal distribution of coral reef fish larvae in Port Bay, Sharm El- Maya Bay and Naama bay located in Sharm El-Sheikh area on the Egyptian Red Sea coast. Ichthyoplankton samples were collected monthly for one year mostly in the morning just before and at sunrise. A net of 100 cm, and 0.5 mm mesh size was towed horizontally parallel to the reef for 5–10 min. Throughout the period of study, a total of 205 plankton samples resulted in a collection of 3678 larvae representing 46 taxa and 32 fish families. Although larvae occurred all the year round, the general pattern showed two peaks in summer and winter with their maximum density in August with 1030 individuals/1000 m3. The lowest density of fish larvae was observed in September with 12 individuals/1000 m3. Regarding the distribution in bays, Port Bay (PRT) recorded the highest larval density where 1476 individuals/1000 m3 were collected. On the other hand, the lowest density was recorded in Sharm El-Maya Bay (SMB) with an average density of 908 larvae/1000 m3. The highest density of fish larvae occurred in any sample was recorded in Naama bay in August with a density of 1824 individuals/1000 m3. In several cases the spawning seasons of these taxa as determined from the present work based on the seasonal occurrence of larvae coincides mostly with that obtained from the literature based on the reproductive biological studies. Results obtained during this work reflected the importance of fish eggs and larvae survey in the management and conservation of reef fish in the Red Sea.