Marine-derived Streptomyces sp. isolated from the Persian Gulf as a novel source of melanin.

Polycyclic aromatic hydrocarbons in the surface sediments of China's Eastern Beibu gulf: Unveiling distribution patterns, tracing sources, and evaluating risks.

Tracing sources and ecological risks: seasonal-spatial variations of potentially toxic element (PTE) pollution in marine sediments of Beibu Gulf.

Diversity and Antibacterial Activity of Fungus–Bacterium Symbionts from Marine Sediments in the Beibu Gulf

Potential toxic elements (PTEs) in the surface sediments of the Beibu Gulf, South China Sea: Spatiotemporal variation, geochemical fractionation and ecological risk assessment.

ABSTRACT In numerous Middle Eastern carbonate reservoirs, peloidal wackestone, packstone, and grainstone facies deposited in shallow-marine environments are rock types with excellent pore storage potential in microporous and micritized grains. While the origin of microporosity has been studied extensively, the process of early marine micritization remains unclear. One hypothesis suggests that early marine micritization first alters carbonate microtextures, which then facilitates the formation of micro spar and micropores in the micritized sediments during later subsurface diagenesis. Therefore, a better understanding of the origin and spatial distribution of micritized sediments is essential for accurately predicting the distribution of microporosity in limestones. This study examines micritization products in shallow-marine carbonate sediments from four lagoons on the Arabian plate coast: the Red Sea, the Arabian Sea, and the Arabian/Persian Gulf. Micritized grains are identified and characterized using optical and backscattered scanning electron microscopy. Petrographic observations are compared and correlated with oceanographic and environmental parameters to identify micritization styles and environmental conditions at a regional scale. The findings present several key insights: i) cryptocrystalline micritic microtextures are heterogeneous, characterized by a combinations of microborings and various microborings infill materials, ii) Red Sea and Arabian Gulf sediments are primarily made up of micritized grains, with about 60% of the grains being micritized grains or peloids, whereas Arabian Sea coast sediments are mainly microbored with minimal infill of endolithic tunnels and rare cryptocrystalline microtextures, and iii) the arid climate and warm, restricted oligotrophic seawater of the Red Sea and Arabian Gulf promote micritization. Conversely, the cooler seawater of the Arabian Sea relative to Red Sea and Arabian Gulf, largely open to the Indian Ocean and influenced by the southeast Asian monsoon and associated upwelling currents, promotes intense endolithic activity but limited boring infilling (incomplete micritization). Hence, we show for the first time that the early marine and microbial diagenetic process of micritization relate to a well-defined set of parameters of a regional environmental and oceanographic settings, corresponding to those that also promote the tropical-biochemical carbonate factory.

Assessing pollution and ecological risks of potentially toxic elements in surface sediments of the north-central Persian Gulf

Proper geologic reservoir characterization is crucial for energy generation and climate change mitigation efforts. While conventional techniques like core analysis and well logs provide limited spatial reservoir information, seismic data can offer valuable 3D insights into fluid and rock properties away from the well. This research focuses on identifying important structural and stratigraphic variations at the Mississippi Canyon Block 118 (MC-118) field, located on the northern slope of the Gulf of Mexico, which is significantly influenced by complex salt tectonics and slope failure. Due to a lack of direct subsurface data like well logs and cores, this area poses challenges in delineating potential reservoirs for carbon storage. The study leveraged seismic multi-attribute analysis and machine learning on 3-D seismic data and well logs to improve reservoir characterization, which could inform field development strategies for hydrogen or carbon storage. Different combinations of geometric, instantaneous, amplitude-based, spectral frequency, and textural attributes were tested using Self-Organizing Maps (SOM) to identify distinct seismic facies. SOM Models 1 and 2, which combined geometric, spectral, and amplitude-based attributes, were shown to delineate potential storage reservoirs, gas hydrates, salt structures, associated radial faults, and areas with poor data quality due to the presence of the salt structures more than SOM Models 3 and 4. The SOM results presented evidence of potential carbon storage reservoirs and were validated by matching reservoir sands in well log information with identified seismic facies using SOM. By automating data integration and property prediction, the proposed workflow leads to a cost-effective and faster understanding of the subsurface than traditional interpretation methods. Additionally, this approach may apply to other locations with sparse direct subsurface information to identify potential reservoirs of interest.

Abstract This study provides a comprehensive assessment of environmental and human health risks associated with potentially toxic elements in the coastal sediments of the Gulf of Aqaba. A total of 33 sediment samples were analyzed using inductively coupled plasma mass spectrometry, revealing Fe (1,526–5,123 mg/kg), Zn (16.8–32.0 mg/kg), Pb (3.5–9.1 mg/kg), Co (2.2–6.4 mg/kg), and Cd (0.05–0.18 mg/kg). The concentrations detected were within acceptable limits and below the Interim Sediment Quality Guidelines, indicating minimal environmental risk. Environmental indices, including the pollution index, modified contamination degree, pollution load index, hazard index, and lifetime cancer risk indicate no contamination or health risks for adults or children through ingestion and dermal contact pathways. Principal component and correlation analysis suggest that Fe, Zn, and Co primarily originate from natural geological processes due to their strong association with elements typically derived from bedrock weathering, while minor anthropogenic contributions may arise from tourism and coastal activities. The findings confirm that the sediments pose no environmental or health risks, providing a baseline for future monitoring and pollution management in the Gulf of Aqaba.

Mangrove ecosystems play essential roles in coastal resilience, carbon sequestration, and biodiversity but are under increasing threat from anthropogenic pressures. This study explores the impact of hydrological variability on microbial communities in mangrove sediments of the southern Gulf of Mexico. We employed 16S rRNA sequencing to assess microbial diversity and function across different hydrological zones, seasons, and sediment depths at Estero Pargo. Our results show that microbial community composition is significantly influenced by hydrological conditions, with distinct microbial assemblages observed across the fringe, basin, and impaired zones. Seasonal variations were particularly pronounced, with higher microbial diversity during the flood season compared to the dry season. Depth also played a critical role, with surface layers (5 cm) predominantly featuring aerobic microbial communities, while deeper layers (20-40 cm) harbored anaerobic taxa such as Bathyarchaeota and Thermococcaceae. Notably, the impaired zone showed enrichment in genes related to denitrification and sulfur oxidation pathways, indicating strong microbial adaptation to reduced environments. These findings highlight the intricate interactions between microbial dynamics and environmental factors in mangrove ecosystems. Understanding these relationships is crucial for developing effective conservation and management strategies that enhance mangrove resilience in the face of global environmental changes.

Spatial characteristics of microbial communities and their functions in sediments of subtropical Beibu Gulf, China.

Ocean current modulation of the spatial distribution of microplastics in the surface sediments of the Beibu Gulf, China.

Integration of microplastics and heavy metals in the potential ecological risk index: Spatial pollution assessment of sediments in the inner Gulf of Thailand.

Polychlorinated biphenyls (PCBs) and organochloride pesticides (OCPs) in sediment from the Beibu Gulf, China: Occurrence, spatial-temporal distribution, source, historical variation and ecological risks.

The opening of the Qiongzhou Strait during the Holocene was a significant geological event in the Beibu Gulf, profoundly influencing sediment provenance and ocean circulation systems. Due to the scarcity of geological records documenting this event, the understanding of regional Holocene sedimentary evolution has been constrained. To investigate the impact of this event on sediment provenance and ocean currents in the Beibu Gulf, geochemical analyses were conducted on sediment core SO-31 retrieved from the South China Sea. The sediments in core SO-31 were stratigraphically divided into three units based on vertical geochemical profiles, reflecting changes in sea level and shifts in sediment provenance within the study area. The Th/Cr vs. Th/Sc scatter plot for core SO-31 indicate that sedimentary materials primarily originated from the Red River during 11,400–7700 a BP, and a significant change in provenance occurred in the study region around 7700 a BP, characterized by increased contributions from the Qiongzhou Strait and decreased contributions from the Red River. This suggests that the opening of the Qiongzhou Strait significantly influenced the sediment supply to the central Beibu Gulf around 7700 a BP. These findings provide critical geochemical evidence for studying the Qiongzhou Strait opening event and enhance our understanding of Holocene sedimentary evolution and “source–sink” transitions in the Beibu Gulf.

Application of novel background criteria for assessing metal contamination in sediments of the inner Gulf of Thailand.

Fate, source, and ecological risk of microplastic in the surface sediment of the Beibu Gulf, the Northern South China sea.

This study investigates uranium (U) and thorium (Th) levels in surface beach sediments from the Central Gulf of Gabes (SE Tunisia), aiming to identify concentration zones, geochemical behaviors, and enrichment factors. U concentrations ranged from 0.71 to 38.00 mg/kg, exceeding Th levels, which ranged from 1.00 to 10.60 mg/kg. A positive correlation between U and Th indicates a common source, which is most likely phosphogypsum wastes, and similar geochemical behaviors. The central sector near Gabes’ fertilizer factories showed the highest U and Th concentrations, with factors such as proximity to industrial discharge, port structures’ influence, organic matter enrichment, low seawater pH, and high phosphorus levels affecting the spatial distribution of these elements. Thermochemical analysis suggests that U and Th exhibit parallel chemical behaviors in low-pH, phosphate-rich conditions. This is the first study to document U and Th presence in phosphogypsum-contaminated beach sediments in Gabes, underlining potential risks to the environment and human health. The findings of this work contribute to the international database of U and Th contamination in coastal sediments, providing essential data to support sustainable strategies aimed at safeguarding human health and preserving local environments affected by phosphate fertilizer industry pollution.

Petrophysical and seismic evaluation of pre rift sediments of the southern Gulf of Suez basin, Egypt

Interplay of natural and anthropogenic factors in sediment dynamics and trace element distribution in Güllük Gulf, western Türkiye: A comprehensive geochemical and hydrodynamic analysis