COMPOSITION, DISTRIBUTION, AND TAPHONOMY OF NEARSHORE BENTHIC FORAMINIFERA OF THE FARASAN ISLANDS, SOUTHERN RED SEA, SAUDI ARABIA RAMADAN H. ABU-ZIED 1,2,3 ,RASHAD A. BANTAN 1 ,ALI S. BASAHAM 1 ,MOHAMED H. EL MAMONEY 1 AND HAMAD A. AL-WASHMI 1 ABSTRACT Nearshore benthic foraminifera of the Farasan Islands (southern Red Sea) were investigated to highlight the faunal distributions and the controlling environmental factors. Forty-one sediment samples were collected in transects of four areas: Khor As Sailah, Ras Sheidah-Ras Abbrah, Jinabah Bay, and Ras Farasan. Cluster and canonical correspondence analyses were performed to determine if any groups of samples or species correlated with ambient environmental factors. Symbiont-bearing species (e.g., Pe- neroplis planatus, Sorites orbiculus, Neorotalia calcar, and Coscinospira hemprichii) dominate the hypersaline lagoon of Khor As Sailah, which is characterized by muddy sand, seagrasses, and green filamentous algae. Neorotalia calcar dominates the hard substrates with green filamentous algae in the nearshore area of Ras Sheidah-Ras Abbrah. Both Jinabah Bay and Ras Farasan have sandy substrates with assemblages dominated by Ammonia convexa, P. planatus, S. orbiculus, N. calcar, Varidentella neostriatula, Quinqueloculina sp., and Elphidium sp., and indications of shoreward transport. Overall, foraminiferal density was highest (210–3930 specimens/g) in the Khor As Sailah lagoon and lowest (8– 327 specimens/g) in the nearshore sediments of Jinabah Bay and Ras Farasan. Taphonomic effects were evident as dissolution and bioerosion in the calm waters of Khor As Sailah lagoon, and abrasion and breakage in the nearshore sediments of Jinabah Bay and Ras Farasan. INTRODUCTION Distributions and compositions of nearshore benthic foraminifera are mainly controlled by factors such as tides, currents, waves, substrates, salinity, temperature, food, light, dissolved oxygen, bioturbation, and predation (Bol- tovskoy and Wright, 1976; Murray, 1991; Sen Gupta, 1999; Murray, 2000, 2006). Due to interactions of these factors, foraminifers have unpredictable life-cycles and patchy distribution patterns (Ribes and others, 2000; Alve and Murray, 2001; Debenay and others, 2006; Wilson and Ramsook, 2007). Where there is seagrass or macroalgae, foraminiferal assemblages and abundances can vary from one part of the substrate to another (Steinker and Clem, 1984; Wilson, 1998; Ribes and others, 2000; Debenay and Payri, 2010). Detailed studies on the distributions of nearshore and intertidal benthic foraminifera (e.g., Buzas- Stephens and Buzas, 2005; Morvan and others, 2006; Vance and others, 2006; Wilson and Ramsook, 2007; Abu-Zied and others, 2007; Berkeley and others, 2008; Debenay and Payri, 2010) have shown how they are determined by particular environmental parameters. The nearshore benthic foraminifera of the southern Red Sea have received much less attention than those in the northern sector, which have been thoroughly investigated (Said, 1949, 1950; Reiss and others, 1977; Bahafzallah, 1979; Reiss and Hottinger, 1984; Abou-Ouf and others, 1988; Abou-Ouf and El-Shater, 1991; Hottinger and others, 1993; Haunold and others, 1997). The purpose of our study was to determine the composition and distribution of benthic foraminiferal assemblages, as well as their control- ling environmental factors, in nearshore sediments of the Farasan Islands. We sought this information in order to enhance the use of foraminifera as environmental proxies in regional paleoenvironment and sea-level reconstructions. Although the reliability of the proxies can be compromised by taphonomic processes, many studies, particularly those on the Holocene, have suggested that the basic composition and structure of fossil benthic foraminiferal assemblages, are retained (e.g., (Murray, 1986; Hippensteel and others, 2002; Buzas-Stephens and Buzas, 2005; Vance and others, 2006; Wilson and Ramsook, 2007). STUDY AREA The Farasan Islands are located in the southern Red Sea platform of Saudi Arabia between 16.5–17.2uN and 41.5– 42.3uE (Fig. 1). They are located approximately 40 km offshore Jizan City and 50 km away from the Red Sea axial trough. Within the tropical sector of the Red Sea, the Farasan Islands are the largest coral island group (c. 128 islands totalling 3000 km 2 of land). Its largest islands are Farasan Al-Kabir and Sajid (Bantan, 1999). The Farasan Islands have low topography (,15 m a.s.l) with maximum elevation of 75 m a.s.l. They are composed of reefal limestone that formed during the early to late Pleistocene sea-level rise (Dabbagh and others, 1984; Bantan, 1999). Bantan (1999) reported that the limestone is older toward the centers of the larger islands, suggesting that the Farasan Islands emerged by progressive uplift due to salt diapirism. Ages determined from strontium and carbon isotopes suggest that this uplift is still occurring (Bantan, 1999). The Farasan Islands are within a monsoon belt where the prevailing winds are northwesterly in summer and south- easterly in winter (Morcos, 1970; Bantan, 1999). This affects surface-water currents around the Farasan Islands, which flow southward in summer and northward in winter. Air temperatures at the Farasan Islands range 19–32uC in winter and 26.5–43uC in summer. Average annual rainfall is about 1 cm (El-Beheiry, 2009). Due to the hot, arid climate, surface-water salinity averages ,38 around the islands 3 Correspondence author. E-mail: rabuzied@kau.edu.sa 1 Marine Geology Department, Faculty of Marine Science, King Abdulaziz University, P.O. Box 80207, Jeddah 21589, Saudi Arabia 2 Geology Department, Faculty of Science, Mansoura University, El-Mansoura: 35516, Egypt Journal of Foraminiferal Research, v. 41, no. 4, p. 349–362, October 2011 349