Saudi Arabia was the first Arab country to claim offshore jurisdiction and the first Middle Eastern state to define its offshore waters. This study examines the principal geographical factors which have resulted in the present Saudi maritime boundary. The semi-enclosed sea, islands, reefs, natural resources of the continental shelf, exclusive economic zone and coastline, can all be considered principal geographical factors that have influenced Saudi territorial waters policy. Islands, for example, play an effective role in increasing the area of Saudi internal waters, increasing the breadth of the territorial sea, straight baseline and the delimitation of maritime boundary in the Red Sea and the Arabian Gulf with opposite and adjacent states. Natural resources demanded the swift implementation of unique agreements, used later as an example worldwide. The author has drawn the 1958 Saudi straight baseline and a theoretical straight baseline based on the 1982 Convention and states practice. The territorial sea which is drawn on this basis along the Red Sea and the Arabian Gulf coasts, is affected by the presence of islands and reefs. The Saudi Exclusive Fishing Zone claimed by the 1974 decree gave the Kingdom the same right as the 1982 Exclusive Economic Zone (EEZ), but the Kingdom had to adapt the latter in order to gain more control over its resources and non-mineral activities. The importance of the 1949 Saudi decree can be found in the contribution made by Saudi Arabia to the development of the law of the sea, and to safeguarding the national hydrocarbon resources (natural gas and oil) on and below its seabed. Saudi Arabia engaged in several agreements, mainly in the Gulf, in order to define its boundary. This study has highlighted these agreements as a model which can be used in different parts of the world to solve similar disputes, and can be adopted as methods of maritime delimitation between opposite and adjacent states. The importance of the economic factor has been shown, along with security, as the main factor influencing the successful conclusion of such agreements, but where there is no such importance, the boundary may become less significant and by the absence of such motivation the boundary may not be defined. Saudi waters are a rich and highly important maritime area. This is based on the facts that Saudi Arabia has 30 per cent of the world seawater desalination plants; that the sea represents food, fuel and wealth to Saudi Arabia; and that the existence of huge deserts emphasises the importance of the sea.

Th. doct.--Métallogénie--Toulouse 3, 1989. / Bibliogr. p. 263-274. Résumé en français et anglais.

There has been an increased interest in Romeʼs connections with the Far East over the course of the last 20 years. This has resulted in the publication of many articles and monographs about the Roman involvement in the Red Sea which was the key maritime region linking the Far East with the West. This thesis synthesizes the recent scholarship on the Red Sea trade in Late Antiquity by merging all of the most up to date information into a concise narrative. In order to accomplish this, three major sources of information have been analyzed. Firstly, the historical time frame of all of the major regions of the Red Sea including Egypt, Aksum, and Himyar have been laid out in a straight forward narrative. This offers the most pertinent background information for the development of Red Sea trade. Secondly, the most up to date archaeological evidence has been incorporated into a description of the ancient maritime trade infrastructure of the Red Sea and Indian Ocean. The archaeological evidence broadens our knowledge of the roads through the Eastern Desert of Egypt, the ports of the Red Sea, and the development of the Indian subcontinent more generally. Thirdly, this thesis builds on all of the historical as well as archaeological data and attempts to quantify the impact of Red Sea trade on the Late Antique Roman Empire both economically and culturally. This synthesis helps to elucidate the growing conception among Late Antique scholars that the Roman Empire was far more interconnected with its eastern neighbours. This further nuances the role which outside forces had on the evolution of the Late Antique world.

As anthropogenically-forced ocean temperatures continue to rise, the physiological response of marine macrophytes becomes exceedingly relevant. The Red Sea is a semi-isolated sea- the warmest in the world (SST up to 34°C) - already exhibiting signs of rapid warming rates exceeding those of other tropical oceans. This will have profound effects on the physiology of marine organisms, specifically marine macrophytes, which have direct influence on the dynamic carbonate system of the Red Sea. The aim of this paper is to define the physiological capability and thermal optima and limits of six ecologically important Red Sea macrophytes- ranging from seagrasses to calcifying and non-calcifying algae- and to describe the effects of increasing thermal stress on the performance and limits of each macrophyte in terms of activation energy. Of the species considered, Halophila stipulacae, Halimeda optunia, Halimeda monile and Padina pavonica thrive in thermal extremes and may be more successful in future Red Sea warming scenarios. Specifically, Halimeda opuntia increased productivity and calcification rates up to 38°C, making it the most thermally resilient macrophyte. Halophila stipulacae is the most productive seagrass, and hence has the greatest positive effect on Omega saturation state and offers chemical buffer capacity to future ocean acidification.

Prokaryotes are the main actors in biogeochemical cycles that are fundamental in global nutrient cycling. The characterization of microbial communities and isolates can enhance the comprehension of such cycles. Potentially novel biochemical processes can be discovered in particular environments with unique characteristics. The Red Sea can be considered as a unique natural laboratory due to its peculiar hydrology and physical features including temperature, salinity and water circulation. Moreover the Red Sea is subjected to hydrocarbon pollution by both anthropogenic and natural sources that select hydrocarbon degrading prokaryotes. Due to its unique features the Red Sea has the potential to host uncharacterized novel microorganisms with hydrocarbondegrading pathways. The focus of this thesis is on the characterization at the metagenomic level of the water column of the Red Sea and on the isolation and characterization of novel hydrocarbon-degrading species and genomes adapted to the unique environmental characteristics of the basin. The presence of metabolic genes responsible of both linear and aromatic hydrocarbon degradation has been evaluated from a metagenomic survey and a meta-analysis of already available datasets. In parallel, water column-based microcosms have been established with crude oil as the sole carbon source, with aim to isolate potential novel bacterial species and provide new genome-based insights on the hydrocarbon degradation potential available in the Red Sea.

Eddies are one of the key features of the Red Sea circulation. They are not only crucial for energy conversion among dynamics at different scales, but also for materials transport across the basin. This thesis focuses on studying the characteristics of Red Sea eddies, including their temporal and spatial properties, their energy budget, the mechanisms of their evolution, and their predictability. Remote sensing data, in-situ observations, the oceanic general circulation model, and data assimilation techniques were employed in this thesis. The eddies in the Red Sea were first identified using altimeter data by applying an improved winding-angle method, based on which the statistical properties of those eddies were derived. The results suggested that eddies occur more frequently in the central basin of the Red Sea and exhibit a significant seasonal variation. The mechanisms of the eddies’ evolution, particularly the eddy kinetic energy budget, were then investigated based on the outputs of a long-term eddy resolving numerical model configured for the Red Sea with realistic forcing. Examination of the energy budget revealed that the eddies acquire the vast majority of kinetic energy through conversion of eddy available potential energy via baroclinic instability, which is intensified during winter. The possible factors modulating the behavior of the several observed eddies in the Red Sea were then revealed by conducting a sensitivity analysis using the adjoint model. These eddies were found to exhibit different sensitivities to external forcings, suggesting different mechanisms for their evolution. This is the first known adjoint sensitivity study on specific eddy events in the Red Sea and was hitherto not previously appreciated. The last chapter examines the predictability of Red Sea eddies using an ensemble-based forecasting and assimilation system. The forecast sea surface height was used to evaluate the overall performance of the short-term eddy predictability. Different ensemble sampling schemes were implemented, and the investigation among different schemes is followed by a discussion of performance and challenges based on the results of a case study. The thesis not only enhances understanding of the Red Sea dynamics, but also deepens knowledge of the physical-biological and air-sea interactions within the basin. Further, it is a stepping stone to building a robust regional operational system with refined forecasting skills.

The genus Albula includes marine fish species, commonly called bonefish, that occur in tropical coastal ecosystems worldwide. Their association to nearshore marine environments makes bonefish especially vulnerable to habitat loss and overharvest. Artisanal fisheries often harvest bonefish, although, in certain areas, bonefish support lucrative catch-and-release recreational fisheries. Bonefish are largely understudied compared to other economically significant fish species, and the presence of cryptic species within the Albula genus has further complicated the establishment of conservation measures. In particular, there is no detailed biological information available on bonefish from the Red Sea despite the unregulated harvest of bonefish that occurs there. To facilitate the establishment of management and contribute to the overall knowledge of Albula biology, I assessed the genetic diversity, growth, and seasonal reproduction of bonefish in Saudi Arabia. Based on samples collected from local fish markets and coastal waters, my findings provide the first genetically verified records of A. glossodonta in the Red Sea and A. oligolepis in the northwest Indian Ocean. Moreover, my results indicate a genetically distinct Red Sea population of A. glossodonta that reaches smaller sizes than documented for the species in the Pacific Ocean and exhibits distinct seasonal spawning activity over the winter months. This information enables fishery managers to make informed decisions regarding bonefish size limits and seasonal colures around peak spawning activity. My results may become increasingly relevant as the potential for lucrative recreational fisheries for Albula glossodonta will likely increase with the ambitious Red Sea tourism development plans.

Picoeukaryotes are protist 3 µm belonging to a wide diversity of taxonomic groups, and they are an important constituent of the ocean microbiota, performing essential ecological roles in marine trophic chains and in nutrient and carbon budgets. Despite this, the true extent of their diversity is currently unknown, and in the last decade molecular surveys have uncovered a substantial number of previously unknown groups from all taxonomic levels. No studies on this group have been done so far on the Red Sea, a unique marine environment characterized by oligotrophic conditions and high irradiance, salinity and water temperature. We sampled the surface waters of a site near the northern Red Sea coast, and analyzed the picoeukaryotic diversity through the construction of PCR clone libraries using the 18S ribosomal gene. The community captured by our library is dominated by three main groups, the alveolates (32%), chlorophytes (32%) and Stramenopiles (20.55%). Members of Radiolaria, Cercozoans and Haptophyta were also found, although in low abundances. Photosynthetic organisms are especially diverse and abundant in the sample, with heterotrophic organism mostly composed by the mostly parasitic novel alveolates and bacterivorous stramenopiles. Novel clades were detected among the Novel Alveolates- II and the photosynthetic stramenopiles taxa, which suggests that they may be part of a number of groups unique to the basin and adapted to the high salinity and temperature conditions. This is the first study done on the Red Sea focusing on the diversity of the complete picoeukaryotic fraction, and provides a stepping stone in the characterization of the picoeukaryotic component of the microbial diversity of the basin.

The demand for novel and robust microbial biocatalysts for industrial and pharmaceutical applications continue to grow at a fast pace.This warrants a continuous need for advanced tools and technologies to exploit the vast metabolic potential of microorganisms in different environments. Unlike culture-based studies that can only reveal the metabolic potential of cultivable microorganisms, functional metagenomics charts the enzymatic potential of the entire microbial communities in a given environment. This method has substantially contributed to the effective discovery of unique microbial genes for industrial and medical applications. Functional metagenomics involves the extraction of microbial DNA directly from environmental samples,construction of an expression library containing the entire microbial genome, and screening the libraries for the presence of desired phenotypes. Therefore, development of a pipeline for analyzing and screening metagenomic libraries is essential for rapid detection of the desired features from thousands of clones of a single library. Here, we developed a pipeline for high-throughput screening of the lipolytic genes from the Red Sea.Further, a high-throughput single cell microfluidics platform combined with a laser-based fluorescent screening bioassay was deployed to discover new lipolytic genes. Our analysis led to the identification of 24 microbial genes for lipases and esterase from a metagenomic library of the Red Sea water. The results further showed that the constructed pipeline is robust in conducting functional metagenomics and for the discovery of new genes. It also implies that the Red Sea is a rich under- investigated source of natural resources of new genes and gene products.

Cellulolytic microorganisms are considered to be key players in biorefinery, especially for the utilization of plant biomass. These organisms have been isolated from various environments. The Red Sea is one of the seas with high biodiversity and a unique environment, characterized by high water temperature and high salinity . However, there is little information regarding cellulases in Red Sea environments. The aim of the present study is to evaluate the Red Sea as a gene resource for microbial cellulase. I first surveyed microbial cellulases in the Red Sea using a method called metagenomes, and then investigated their abundance and diversity. My survey revealed that the Red Sea biome has a substantial abundance and a wide range of cellulase enzymes with substantial abundance, when compared with those in other environments. Next, I tried to isolate cellulase-active microorganisms from the Red Sea and I successfully obtained seven strains of four different taxonomic groups. These strains showed a similarity of 99% identity to Aspergillus ustus, 99% to Staphylococcus pasteuri, 99% to Bacillus aerius and 99% to Bacillus subtilis. The enzyme assay I conducted, revealed that these strains actually secreted active cellulases. These results suggest that the Red Sea environment can be, indeed, an excellent gene resource of microbial cellulases.