Quaternary corals (Scleractinia: Merulinidae) from the Egyptian and Saudi Arabian Red Sea Coast

Coral reef terraces are investigated in five localities around Marsa Alam on the Egyptian Red Sea Coast. The reefal limestones and the alternating terrigenous clastics are assigned to the Pleistocene Samadai Formation. Sixty-one scleractinian coral species belonging to 25 genera and 10 families were identified. Thirteen scleractinian species, for the first time recorded from the Egyptian Red Sea coastal plain, are systematically studied. The stratigraphic distribution of these fossils is illustrated and discussed. Six species are extended to the Miocene and five other species are recorded from the Pliocene and still living in the present Red Sea and the Indo-Pacific. The geographic distributions of the identified coral species are illustrated on maps. These maps show that, all the identified coral species are distributed only throughout the Indo-Pacific realm, increasing from the central part westwards across the Indian Ocean to the Red Sea. There are four species that are restricted to the Red Sea, Arabian region and West Indian Ocean.

The recent agglutinated small benthic foraminiferal species Clavulina pseudoparisensis Anan are common in the five coastal areas around the Arabian Peninsula: the Egyptian Red Sea coast between Qusseir-Marsa Alam, the Saudi Arabian Red Sea coast in Jeddah, the north Socotra Island of Yemen, the Abu Dhabi coast of the United Arab Emirates (UAE), and the east coast of Qatar of the Arabian Gulf. The taxonomy is presented and discussed. The warmer environment of the Red Sea, and also the other studied areas, favor precipitation of organic binding material for the sand grains of the arenaceous tests, which favor the forms thriving in shallow and warm environment. The recorded C. pseudoparisensis in wide geographic distribution in the Red Sea, Arabian Sea, and Arabian Gulf around the Arabian Peninsula indicates an open marine environment between these localities.

The present study revised taxonomy and occurrence of the ghost crabs (genus Ocypode) and fiddler crabs (genus Uca), belonging to family Ocypodidae collected from different localities of the Egyptian Red Sea and Mediterranean Sea coasts. A total of six species were collected, comprised three species of ghost crabs, represented by Ocypode cordimanus, O. cursor, and O. saratan and three species of fiddler crabs, including Uca albimana, U. inversa, and U. tetragonon. With the exception of Ocypode cursor which was only recorded from the Mediterranean Sea, all other five species were collected from the Red Sea. All species of Ocypode construct permanent burrows in the supralittoral sandy shores, while Uca species live in permanent burrows in the upper intertidal zone of mud-flats and sandy mud areas around and within mangrove swamps only. The present results showed also that, the fiddler crab, Uca albimana, was recorded for the first time from South Sinai mangroves at Nabq (Gulf of Aqaba) and Ras Mohammed (northern Red Sea), increased ocypodid fauna at the most northern portions of the Red Sea and Gulf of Aqaba. These results denote to the northward distribution of this species and recommend re-investigating all Uca species collected previously from South Sinai, particularly U. inversa, deposited in all National Museum of Natural History of the world. Notes on habitats, color, size and geographical distribution, in addition to keys for identification were also given.

The present study introduce an overview on the cladal structure of Symbiodinium population associated with some species of scleractinean corals and fire coral in the Egyptian Red Sea coast and discuss the possible consequences of recent climate changes on coral reefs. Cladal structure of Symbiodinium populations associated with eight keystone species of scleractinean corals and one species of fire coral that collected along Egyptian Red Sea coast, during 2012-2013, had been resolved based on 18S nrDNA and ITS2 genetic markers. Only Symbiodinium subclades C1 and A1 were identified from all examined species. Symbiodinium C1 was the dominant subclade that associated with 61% of coral samples. Results revealed that the studied pocilloporid corals were associated with Symbiodinium C1 and/or A1 while acroporids were only associated with Symbiodinium C1. The present data also indicated that Symbiodinium C1 occurred at high densities than A1 or A1+C1 combination. Because of the relative thermal susceptibility of clades C and A, the current study addresses that the recent climate changes may derive dramatic changes on community structure of coral reefs at the Red Sea.

Safaga and Qusseir are two important harbours on the Egyptian Proper Red Sea coast. To the best of the authors’ knowledge, this is the first work to describe the sea level characteristics at these two ports. The study is based on hourly sea level records over 3 years (2012–2014). There are no missed data at Qusseir site, but Safaga dataset missed 25% of records (April–December 2014). The hourly water level ranged between 0.02 m and 1.70 m at Safaga and between 0.04 m and 1.03 m at Qusseir, with a mean sea level (MSL) of 0.56 m and 0.50 m at the two Harbours, respectively. The T_TIDE package was used to produce astronomical and residual elevations at the two Harbours. Results revealed that the two Harbours examine explicit semidiurnal tidal cycle, with a bit higher astronomical amplitudes in Safaga. Moreover, the two sites exhibit almost the same seasonal sea level trend with very slight differences. The monthly mean levels at the two Harbours are always below their averages except during the summer months. The principal features of the semidiurnal tides indicated a ratio of 1.3 and 1.5 between spring and neap ranges at Safaga and Qusseir, respectively. The most pronounced sea level range at Safaga Harbour was 0.50 m, while it was 0.60 m at Qusseir Harbour. The astronomical elevations fluctuated between − 0.55 m and + 0.71 m and between − 0.47 m and + 0.53 m in Safaga and Qusseir Harbours, respectively.

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Environmental implications and spatial distribution of natural radionuclides and heavy metals in sediments from four harbours in the Egyptian Red Sea coast