139736eo.pdf (20MB) - Japan Oceanographic Data Center

wind reef margins, are required. The possible use of algae as environmental indicators, at bothsmall-scale and broad-scale levels also needs to be investigated.THE FAUNA OF THE RED SEADuring the last decades investigations conducted on the different fauna in the Red Sea haveresulted in numerous publications. Particular mention should be made of reports on fish. SMITH(1950), CLARK and GOHAR (1953), BUDKER and FOURMANOIR (1954), MARSHALL (1964),ROUX et al. (1955), ROUX-ESTEVE (1956), RANDALL et al. (1978) and GOHAR (1954)discussed the distribution of the different biota and environmental controls for these distributions.TIRMIZI and KAZMI (1983) presented an overview of the marine crustacea of Pakistan with remarkson species in the Red Sea and the Mediterranean.In his review of the shark fauna of the Red Sea, COMPAGNO (1983) noted the absence ofendemiE shark species, the lack of members of the orders Squaliformes, Hexanchiformes,Pristiophoriforrnes, Heterodontiformes and possibly squatiniformes, and the virtual absence ofdeepwater benthic or bathypelagic species except Iago omanensis (a triakid specialized forenvironments with low oxygen levels). No members of the family Scyliorhinidae occur, a shark thatis particularly abundant in the western Indian Ocean. All of the Red Sea shark species also are foundin the western Indian Ocean. The limited deepwater shark fauna in the Red Sea is attributed to the highsalinity, high temperature and low oxygen levels, plus the shallow sill at Bab el-Mandab. Campagnoconcluded that the Red Sea shark fauna probably originated by direct dispersal from the western IndianOcean.FRAZIER (1983) mentioned that marine turtles are poorly documented in the Red Sea. Thereare five recorded species of marine turtle, all pantropical in distribution, but only Chelonia mydus andEremchelys imbricata have been documented to nest there.The Red Sea has an exceptionally rich in molluscs, but few data are present on the differencesin fauna from various parts of the Red Sea. In this connection several questions arise: Whatecological processes allow more species to co-exist in some parts of the Red Sea than in other parts?Are important resources (such as food and habitat) more finely partitioned? Do physical and/orbiological disturbances (i.e. predation) keep species populations reduced in size?FISH RESOURCES IN THE RED SEAEight hundred species of fish are present in the Red Sea as compared to 2000 species in theIndian Ocean. The fish can be characterized more by their diversity in forms and colours rather than inwealth of fish stock. Nevertheless, the marine life of the Red Sea is remarkably rich, and many of thefishes are able to tolerate wide extremes of temperature and salinity. The richness of marine life isapparent in the relatively large number of species seen in commercial catches.Nevertheless, the Red Sea is considered a particularly unexplored area in terms of commercialfisheries. One of the reasons for this lack of data is the poor development of the fishing industry incoastal countries, and as a result, incomplete and fragmentary statistics of fish landings. Analysis ofliterature and data shows that the western Indian Ocean and the Red Sea are rather difficult forcommercial utilization, especially for development of trawl fishing. The difficulties lie in the nature ofatmospheric circulation and complicated weather conditions as well the narrow and rocky shelvesalong most part of the coast. The difficulties in commercial utilization in this region are aggravated bythe great variety of fish species, which makes sorting and treatment of catches more difficult.Therefore, increased oceanographic and biological research could help us understandvariations in yields and their relationship to changing oceanic conditions. Knowledge of oceanic eventsduring the early life stages (ichthyoplankton) of many commercial fishes can be used to predictpopulation size two or three years hence and thus to determine changes in management strategies.362