The Regional Security Complex Theory (RSCT) recently marked its 20th anniversary since its introduction by Barry Buzan and Ole Wæver. Coincidentally, the Saada wars and broader civil strife in Yemen have persisted for two decades, rendering it one of the most overlooked yet protracted conflicts of the modern era. Historically, Yemen has played a pivotal though ambiguous role in the Middle East – emerging as the region’s first democratic republic while also serving as a hotspot for extremist activity and proxy competition. Despite its internal fragmentation and recurring wars, Yemen continues to influence regional security dynamics, reinforcing the ‘conflict formation’ character of the Middle Eastern Security Complex (MESC). The article introduces the concept of the ‘Yemen complex’ – defined through five interlinked factors: enduring civil strife and Houthi resistance, proxy warfare, terrorism, economic collapse, and maritime security. Using RSCT as the main analytical framework, it examines the Yemen complex’s boundaries, polarity, and amity–enmity structure. The analysis draws on qualitative examination of conflict timelines, military interventions (2015, 2023), and a visual actors–threats–referent objects mapping to track continuity and change in securitisation patterns. The findings show that earlier securitisations centred on Yemen’s homegrown and foreign terrorism have declined in prominence, replaced by heightened concerns over Houthi military empowerment and threats to Red Sea shipping lanes – both contributing to the ‘economisation’ of the Yemen complex. The conflict has also reinforced the multipolar nature of the MESC, partly as a result of the counterproductive consequences of the Saudi-led intervention. In the past two decades, the Yemen complex has evolved into a substructure within the MESC, influencing both regional alignments and global maritime security considerations. Although prospects for peaceful conflict resolution have emerged, external actors remain divided in their strategic objectives. This ongoing fragmentation continues to complicate conflict management and obstructs straightforward policy solutions

The depth distribution of marine species is essential ecological information, especially within hotspots of biological invasions and given the increasing evidence of climate-driven depth shifts. Due to the scarcity of systematic surveys across depths, most studies rely on coarse-scale compilations of opportunistic data. High-quality depth estimates are particularly lacking in the eastern Mediterranean, a global hotspot of climate change and biological invasions, and the adjacent Red Sea, which serves as the source for most species introductions. Using baited remote underwater stereo-video systems to depths of 150 m, we report new depth records for fish species in the northern Red Sea and eastern Mediterranean Sea, and model their abundance patterns across depths. We found that 96 of the 230 studied species (42%) were found at novel depths compared to their previously known records, with 84 species showing deeper distributions. The mean deep border extension across these species was 22.4 m. Our results highlight the importance of in-situ observations across depths. We offer a comprehensive dataset including species’ depth ranges, modeled central depth niches, abundance, body size, and associated habitat types. This dataset is useful for understanding the role of depth shifts in response to climate change and species introductions into the Mediterranean Sea.

Flash-Flood Hazard Mapping and Risk Management Using Morphometric Analysis and HEC-RAS Simulation: Case study from Ras Bakr and Safaga along the Red Sea Coast of Egypt

Interactive effects of black sand and heat stress on coral reefs at Red Sea, Egypt.

The Red Sea, a biologically rich marine ecosystem, is a promising source of novel bioactive compounds with significant therapeutic potential. This review analyzes a decade of research on the isolation, characterization, and biological activities of compounds obtained from sponges, corals, microalgae, seaweeds, marine fish, and microorganisms. These bioactive molecules, including alkaloids, glycosides, terpenes, and peptides, exhibit antimicrobial, anticancer, anti-inflammatory, and neuroprotective properties. Various extraction techniques, ranging from traditional solvent extraction to advanced methods such as supercritical fluid and ultrasound-assisted extraction, aid in their isolation. Meanwhile, chromatographic purification and bioassay-guided fractionation enhance their identification. However, challenges such as limited availability, complex extraction processes, and regulatory constraints hinder the clinical translation of these technologies. Addressing these barriers requires innovative extraction strategies, advanced characterization techniques, and interdisciplinary approaches that integrate marine biology with emerging technologies, such as deep learning. Future research should focus on exploring molecular interactions within coral reef ecosystems, unraveling marine bacterial diversity, and implementing conservation strategies to protect the Red Sea's unique biodiversity while accelerating drug discovery.

Validating shipping noise simulations for the Red Sea using field measurements.

Tectono-sedimentary evolution of early syn-rift deposits in a hangingwall dip-slope setting, northern Duwi half-graben, Red Sea, Egypt

Seafloor marine litter density and distribution in the Jordanian Gulf of Aqaba, northern Red Sea.

Ecosystem function: Trait diversity, bioturbation, and bio-irrigation potentials of macrobenthic invertebrate communities in the Red Sea

Using multivariate models to link seasonality and biodiesel efficiency in red sea brown algae

A review of the 1968 Afar Magnetic Survey data and integration with vintage Red Sea and Gulf of Aden data

Geochemical evidence for fluid provenance and hydrothermal alteration processes in sub-salt units of the Northern Red Sea

Meta-analysis of last interglacial (MIS 5e) sea-level proxies along the Egyptian Red Sea

Trophic transfer of nanoplastics reduces larval survival of marine fish more than waterborne exposure.

Decadal changes in California's temperate mesophotic reef invertebrate community through the 2014-2016 northeast Pacific marine heatwave.

A multi-method assessment of elasmobranch diversity and abundance in the southern Red Sea

Structural inheritance as a control on oblique rift fault segmentation and relay ramp evolution: El Nakheil Master Fault, NW Red Sea margin, Egypt

Shark Reef’s untapped seaweed resources: Chemical characterization and bioactive potentials of Digenea simplex and Padina pavonica from the Egyptian Red Sea

Freshness is a key quality attribute in seafood, yet it is rarely labeled explicitly in the marketplace. This study examined how disclosing objective freshness information influences sensory evaluations and willingness to pay for red sea bream (Pagrus major) sashimi. Using a bioimpedance-based indicator that provides accurate, real-time freshness measurements, we conducted a within-subject tasting experiment structured in three sequential rounds (experimental conditions). In the first round, only basic product information was provided. In the second, participants were introduced to the freshness-measuring device and shown market-level freshness distributions. In the third round, the actual freshness level of each sashimi sample was disclosed. In the first two rounds, participants preferred and were willing to pay more for the less fresh sashimi, presumably due to more umami components. This trend reversed in the third round after disclosure. To interpret this reversal, we introduce two innovations. First, we used a revealed-preference approach by comparing evaluations of samples in the same objective freshness category before and after freshness prompts, identifying assimilation effects without relying on stated expectations. Second, we examined heterogeneity in treatment effects based on participants' connoisseurship-their ability to identify the fresher sample without labeling. Our findings suggest that, within the freshness range used in our experiment, freshness functions as an unperceived intrinsic cue: an objectively measurable attribute that does not influence consumer evaluation unless explicitly disclosed. These findings highlight the value of freshness labeling and the broader role of information in activating hidden quality perceptions, offering insights for improving consumer trust and choices in seafood markets.

Talc mineralization in the SW Fodikwan area, Red Sea Hills, NE Sudan: Geological and geochemical constraints