Search Results (106)

The genus Pavona includes massive to submassive hermatypic corals and represents one of the main reef builders of the coral reefs in the Eastern Tropical Pacific (ETP). However, its development and specific ecological role, particularly on offshore reefs (e.g., oceanic Atolls), remain poorly understood. This study aims to determine the sclerochronological characteristics of the four Pavona species (Pavona duerdeni, Pavona clavus, Pavona maldivensis, and Pavona varians) in Clipperton Atoll, and their contributions to reef maintenance. Using the optical densitometry technique, Pavona annual growth parameters were obtained, showing that skeletal density (1.26 ± 0.23 g cm⁻³), extension rate (0.94 ± 0.31 cm year⁻¹), and calcification rate (1.17 ± 0.36 g cm⁻² year⁻¹) were consistent with previous data from the ETP. However, differences at the species level showed that P. duerdeni, P. varians, and P. maldivensis invested their calcification resources into building denser skeletons, demonstrating the morphological plasticity of the genus, likely driven by local factors, such as strong hydrodynamics and depth, rather than regional conditions (e.g., El Niño-Southern Oscillation events). Pavona’s growth strategies contribute to the preservation potential on a geological timescale of Clipperton Atoll, highlighting their importance as one of the main reef builders at a massive coral-dominated reef. Full article

Coral reefs are crucial ecosystems for marine biodiversity but are increasingly threatened by anthropogenic pressures and climate anomalies. The 2016 global bleaching event resulted in widespread coral mortality, altering reef structure and benthic communities. Here, we examine the evolution of Maldivian reefs from 2015 to 2023 using long-term monitoring data to assess post-disturbance dynamics. Analyses of 26 benthic descriptors revealed severe impacts from thermal stress, with heterogeneous recovery patterns. Reef-building capacity, which reflects the reef’s accretion potential and is mainly sustained by primary (e.g., Acropora branching corals) and secondary constructors (e.g., Tridacna spp.), rebounded substantially, while binders (e.g., coralline algae) and bafflers (e.g., erect sponges) remained depleted. Among growth forms, fast-growing branching and digitate corals, despite substantial declines, drove rapid recovery. Massive corals were less affected and continued growing, while encrusting corals declined steadily over the period. Post-bleaching community composition shifted markedly toward increased abiotic cover and reduced coral dominance, with partial reversion by 2023. Despite the 2016 collapse in constructional capacity, most reefs exhibited notable recovery within seven years. These findings underscore the moderate yet promising resilience of Maldivian reefs, exceeding previous bleaching events, and emphasize the importance of long-term monitoring to understand ecosystem responses under accelerating climate stress. Full article

Italy represents one of the most prominent European countries in artificial reefs (ARs) research, with over 50 years of history and the construction of the second artificial reef in Europe designed according to scientific criteria. A review of 560 documents on Italian artificial reefs (ARs) from 1970s to 2025—including 404 scientific papers and 156 gray literature sources—together with an in-depth web-search allowed the identification of 118 artificial reefs deployed in the Italian seas. Concrete represents the most used material for AR construction, due to its durability over time, and ductility to build modules of different shapes and dimensions. More than 70% of the Italian ARs are made of concrete utilized alone or with other associated materials. Habitat protection and finfish enhancement have been the main scopes for AR deployment. Most scientific papers on Italian artificial reefs refer to the zoobenthic communities settled on the manmade substrates or living in the surrounding soft bottom, finfish assemblage, ecology, and general themes, such as history and management of the reefs. Recommendations include the need for a multidisciplinary panel of experts to comprehensively assess the environmental, biological, and socio-economic characteristics of an area selected for a new AR, and for development of eco-designed structures. Full article

Fears regarding the future of coral reefs are reflected in a growing scientific effort, worldwide, to help corals survive and adapt to the impacts of climate change through new management strategies. To be viable, these strategies must not only be ecologically beneficial and technically feasible; they must be developed in partnership with Indigenous peoples and sensitive to the needs and aspirations of local communities, stakeholders and broader publics. This paper synthesizes insights from a comprehensive program of qualitative and quantitative social research, conducted through Australia’s Reef Restoration and Adaptation Program, exploring local community and public perspectives on the Great Barrier Reef (GBR) and the prospect of assisted adaptation. While the results of this research indicate strong support for prospective interventions to help the GBR, they also demonstrate that local communities and the broader Australian public hold multiple visions for the GBR’s future and engage in careful processes to imagine and evaluate assisted adaptation. We discuss the implications of this complexity for the development of technically robust and socially responsible adaptation intervention in the GBR, emphasizing the opportunities it presents for robust and inclusive dialogue, knowledge building, and governance around these strategies. Community and public support, we conclude, is contingent on moving beyond the seemingly straightforward question of whether or not people support intervention and towards forms of engagement that allow space for social and cultural diversity and the co-creation of ethically grounded adaptation pathways. Full article

It is known that the giant barrel sponge (GBS) Xestospongia spp. may provide shelter or a micro-environment for multi-species coral colonies both in the Indo-Pacific and Atlantic regions. An assessment of such interactions between Indo-Pacific GBS Xestospongia testudinaria and stony corals performed for two groups of small Vietnamese islands in the Gulf of Thailand revealed at least 12 species of scleractinians associated with GBS. An average of 21.7% of all observed GBSs were found to interact with stony corals. The phenomenon of positive GBS–coral interactions without any restrictions on coral development can be regarded as a form of ecological facultative commensalism and warrants further investigation. Full article

Oyster reefs are receiving increasing attention due to severe survival challenges and their significant ecological service functions. Despite increased restorations worldwide, both natural and restored reefs have often not been monitored to an extent. Reef-building oyster populations are the foundation for the development of oyster reefs. In order to provide basic data for further protection and potential restoration of the oyster reef in the muddy tidal flats of Magu Island, in the middle of Dingzi Bay, the population structure and genetic diversity of the reef-building oysters were assessed through field investigation and molecular experiments. Results showed that the area of the oyster reef was 20,689 square meters and the oysters were Magallana gigas. The distribution of oyster patches revealed a reef building-up stage. The mean densities of the oysters were 3260.80 ind·m⁻² and 3097.60 ind·m⁻² in spring and autumn, respectively, and the biomasses were 25,209.38 g·m⁻² and 30,137.44 g·m⁻². The frequent distribution of shell height indicated two primary sizes divided by ages. Population genetic analyses based on partial mitochondrial cox1, cox3, and nad2 showed low nucleotide diversity and moderate haplotype diversity, proposing the population growth stage. Both the results of the population structure and genetic diversity suggested a developing status of the oyster reef on Magu Island. Full article

This article addresses the multifaceted challenges inherent in the development of the novel REEFS (Renewable Electric Energy From Sea) wave energy converter (WEC). Building on the submerged pressure differential principle, it frames similar WECs before focusing on REEFS that combines renewable energy generation with coastal protection, functioning as an artificial reef. The review follows chronological criteria, encompassing experimental proof-of-concept, small-scale laboratory modeling, simplified and advanced computational fluid dynamics (CFD) simulations, and the design of a forthcoming real-sea model deployment. Key milestones include the validation of a passive variable porosity system, demonstration of wave-to-wire energy conversion, and quantification of wave attenuation for coastal defense. Additionally, the study introduces a second patent-protected REEFS configuration, isolating internal components from seawater via an elastic enveloping membrane. Challenges related to scaling, numerical modeling, and funding are thoroughly examined. The results highlight the importance of the proof-of-concept as the keystone of the development process, underscore the relevance of mixed laboratory-computational approaches and emphasize the need for a balanced equilibrium between intellectual property safeguard and scientific publishing. The REEFS development trajectory offers interesting insights for researchers and developers navigating the complex innovation seas of emerging wave energy technologies. Full article

Weather routing is a critical guarantee for the safe and economical navigation of ships. Existing methods for weather routing still face challenges in selecting the appropriate planning granularity. A granularity that is overly coarse may result in routes passing through coastal and island-rich waters, such as coastal zones and reefs, thus compromising navigational safety. Conversely, a granularity that is excessively fine leads to an exponential increase in computational complexity, rendering the problem intractable. To address this issue, this paper proposes an efficient method for weather routing in coastal and island-rich waters, guided by ship trajectory big data: First, an adaptive quadtree is used to partition the navigable space into an adaptive grid, based on which a route network is constructed using ship trajectory big data. Next, a ship motion model is introduced to build both static and dynamic marine environmental fields, which are used to dynamically update the time weights of the route network. Finally, using the updated route network as a guide, the method aims to minimize voyage time and employs an improved time-varying A* algorithm for weather routing. Experimental results show that the proposed method effectively adapts to coastal and island-rich waters, outperforming the baseline SIMROUTE in safety, optimization, and efficiency. Unlike SIMROUTE, which crosses restricted areas, it avoids such risks entirely. It achieves average reductions of 6.8% in route length and 4.3% in navigation time and is 5.8 times faster than SIMROUTE for fine-grained planning. This balances voyage time, safety, and efficiency, offering a practical weather routing solution. Full article

As a representative high-performance construction material, ultra-high performance concrete (UHPC) is typically prepared using quartz sand and steel fibers. To alleviate the shortage of building materials in island and reef regions, this study employs coral sand for UHPC preparation and investigates the effects of different fibers on its mechanical properties. This study demonstrates that this approach mitigates brittle failure patterns and enhances the durability of structures. To investigate the enhancement effects of PE and steel fibers on the mechanical properties of coral sand ultra-high performance concrete (CSUHPC), 12 mix designs were formulated, including a plain (no fiber) reference group and PE fiber-reinforced, steel fiber-reinforced, and hybrid fiber combinations. Compressive tests, tensile tests, and three-point bending tests on pre-notched beams were conducted. Key parameters such as 28-day compressive strength, tensile strength, and flexural strength and toughness were measured. A multi-criteria evaluation framework was established to comprehensively assess the integrated performance of each group. The experimental results demonstrated that fiber incorporation significantly enhanced the compressive strength and fracture properties of CSUHPC compared to the plain reference group. Steel fiber-only reinforcement exhibited the most pronounced improvement in compressive strength and fracture properties, while hybrid fiber combinations provided superior tensile performance. Through the established multi-criteria evaluation framework, the optimal comprehensive performance was achieved with a 3% steel fiber dosage, achieving improvements of 0.93 times in compressive strength, 2.80 times in tensile strength, 1.84 times in flexural strength, 192.08 times in fracture energy, and 1.84 times in fracture toughness relative to the control group. Full article

The literature on resilience-building in the Great Barrier Reef (GBR) is predominated by institutional voices. Although community involvement is appreciated in this scholarship, the perspectives are mainly those of scientists and researchers. Community input is used mainly to inform and strengthen academic findings, and there are few articles in the voices and words of GBR community members. Our opinion piece, with its majority co-authorship by the Stakeholder Advisory Group of Australia’s Reef Restoration and Adaptation Program (RRAP), addresses this literary gap. The piece draws upon the barriers to involvement in adaptation delivery as experienced by these GBR locals who have diverse backgrounds related to reef adaptation, including aquaculture, tourism, robotics, natural resource management, civil society, policy and Traditional Owner-led environmental stewardship. Currently, the social capital of communities is underutilised in GBR intervention delivery. However, with the urgency for action in the Reef, we call on governments and researchers to leverage the expertise, labour and infrastructure of local communities to strengthen institutional deployment capacities and thereby accelerate the scale and impact of adaptation efforts. We identify the key elements of inclusive deployment as shared leadership, flexible and inclusive funding, and innovative strategies to address permitting and regulatory barriers to community-led interventions deployment. Full article

Shallow warm-water coral reefs are among the most biodiverse and valuable ecosystems on Earth, supporting a quarter of all marine life and delivering critical ecosystem services such as coastal protection, food security, and economic benefits through tourism and fisheries. However, these ecosystems are under escalating threat from anthropogenic climate change, with tropical cyclones representing their most significant high-energy storm disturbances. Approximately 70% of the world’s coral reefs lie within the tropical cyclone belt, where the frequency, intensity, and rainfall associated with tropical cyclones are changing due to global warming. Coral reefs already compromised by climate-induced stressors—such as marine heatwaves, ocean acidification, and sea-level rise—are increasingly vulnerable to the compounding impacts of more intense and slower-moving cyclones. Projected changes in cyclone behaviour, including regional variations in storm intensity and rainfall, may further undermine coral reef resilience, pushing many reef systems toward irreversible degradation. Future impacts will be regionally variable but increasingly severe without immediate climate mitigation. Building reef resilience will require a combination of rapid global carbon emission reductions and ambitious adaptation strategies, including enhanced reef management and restoration and conservation efforts. The long-term survival of coral reefs now hinges on coordinated global action and support for reef-dependent communities. Full article

Coral reefs are increasingly threatened by global climate change, and mass bleaching and mortality events caused by elevated seawater temperature have led to coral loss worldwide. Hainan Island hosts extensive coral reef ecosystems in China, yet seasonal variation in Symbiodiniaceae communities within this region remains insufficiently understood. We aimed to investigate the temperature-driven adaptability regulation of the symbiotic Symbiodiniaceae community in reef-building corals, focusing on the environmental adaptive changes in its community structure in coral reefs between cold (23.6–24.6 °C) and warm (28.2–30.6 °C) months. Symbiodiniaceae shuffling and rare genotype turnover were discovered in adaptability variations in the symbiotic Symbiodiniaceae community between two months. Symbiodiniaceae genetic diversity increased during warm months, primarily due to temporal turnover of rare genotypes within the Cladocopium and Durusdinium genera. Coral Favites, Galaxea, and Porites exhibited the shuffling of Symbiodiniaceae between tolerant Durusdinium and sensitive Cladocopium. Symbiodiniaceae interactions in G. fascicularis and P. lutea exhibited the highest levels of stability with the increase in temperature, whereas the interactions in A. digitifera and P. damicornis showed the lowest levels of stability. Rare genotypes functioned as central hubs and important roles within Symbiodiniaceae communities, exhibiting minimal responsiveness to temperature fluctuations while maintaining community structural stability. The temperature-driven adaptability regulation of symbiotic Symbiodiniaceae could be achieved by Symbiodiniaceae shuffling and rare genotype turnover. The process might be aggravated by concurrent adverse factors, including elevated salinity, pollution, and anthropogenic disturbance. These findings provide insights into how the Symbiodiniaceae community influences the adaptation and resilience of coral hosts to temperature fluctuations in coral reefs. Furthermore, they may contribute to assessing the reef-building coral’s capacity to withstand environmental stressors associated with global climate change. Full article

The hydrocoral Millepora complanata (fire coral) plays a critical role in reef structure and relies on a symbiotic relationship with Symbiodiniaceae algae. Environmental stressors derived from climate change, such as UV radiation and elevated temperatures, disrupt this symbiosis, leading to bleaching and threatening reef survival. To gain insight into the thermal stress response of this reef-building hydrocoral, this study investigates the proteomic response of M. complanata to bleaching during the 2015–2016 El Niño event. Fragments from non-bleached and bleached colonies of the hydrocoral M. complanata were collected from a coral reef in the Mexican Caribbean, and proteomic extracts were analyzed using nano-liquid chromatography–tandem mass spectrometry (nano-LC-MS/MS). Uni- and multivariate analyses were applied to identify significant differences in protein abundance. A total of 52 proteins showed differential abundance, including 24 that showed increased expression and 28 whose expression decreased in bleached fragments. Differentially abundant proteins were associated with amino acid biosynthesis, carbohydrate metabolism, cytoskeleton organization, DNA repair, extracellular matrix composition, redox homeostasis, and protein modification. These molecular alterations reflect critical physiological adaptations that may influence stress sensitivity or tolerance in hydrocorals. The findings indicate that heat stress induces molecular responses involving protein refolding, enhanced vesicular transport, cytoskeletal reorganization, and modulation of redox activity. This contributes to a deeper understanding of the molecular mechanisms underlying bleaching in reef-building hydrozoans and broadens current knowledge beyond the more extensively studied anthozoan corals. Full article

During rapid-onset environmental catastrophes, scientists may not always have sufficient time to conduct proper environmental surveys in all representative areas. Although coral bleaching events can be predicted to a certain extent in some areas by tracking sea surface temperatures (SSTs), current models from NOAA’s Coral Reef Watch tend to underestimate severity of bleaching in the Indian Ocean, as was evident in March 2024 when corals began bleaching after only experiencing 1–2 degree-heating weeks. To characterize the impacts of this event, I conducted citizen science-style surveys at 22 sites along a 600-km stretch of the Kenyan coastline. Thereafter, I trained an artificial intelligence (AI) to extract coral abundance and bleaching data from 2300 coral reef images spanning 11–12 hectares of reef area to estimate both coral cover and bleaching prevalence. The AI’s accuracy was >80%, though it was prone to false-positive bleaching classifications. Bleaching severity varied significantly across sites, as well as over time, as seawater continued to warm over the duration of the study period; on average, over 75% of all reef-building scleractinians had bleached. Across the 22 sites, the mean healthy coral cover was only 7–8%, vs. >30% at sites in the same areas in the late 1990s. Whether these corals can recover, and then withstand such heatwaves in the future, will be known all too soon. Full article

Deliberative approaches to governance systems analysis and improvement are rare. Australia’s Great Barrier Reef (GBR) provides the context to describe an innovative approach that combines reflexive and interactive engagement processes to (a) develop and design a framework to assess the GBR’s complex governance system health; and (b) undertake a benchmark assessment of governance system health. We drew upon appreciative inquiry and used multiple lines of evidence, including an extensive literature review, governance system mapping, focus group discussions and personal interviews. Together, these approaches allowed us to effectively engage key actors in value judgements about twenty key characteristic attributes of the governance system. These attributes were organised into four clusters which enabled us to broadly describe and benchmark the system. These included the following: (i) system coherence; (ii) connectivity and capacity; (iii) knowledge application; (iv) operational aspects of governance. This process facilitated deliberative discussion and consensus-building around attribute health and priorities for transformative action. This was achieved through the inclusion of diverse perspectives from across the governance system, analysis of rich datasets, and the provision of guidance from the project’s Steering Committee and Technical Working Group. Our inclusive, collaborative and deliberative approach, its analytical depth, and the framework’s repeatability enable continuous monitoring and adaptive improvement of the GBR governance system and can be readily applied to complex governance systems elsewhere. Full article