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Structured biogenic habitats in estuarine and coastal landscapes (or seascapes) augment nekton species' production; yet, landscape setting may make restored habitats functionally redundant to co‐occurring habitats for some species. Few relationships between recruitment enhancement and continuous landscape metrics have been quantified, limiting our ability to incorporate functional redundancy into restoration practice. To address this gap, we quantified two landscape metrics, per cent structure of proximal habitat and near distance to co‐occurring structured habitats, for experimentally restored oyster reefs in an intertidal landscape in Middle Marsh, North Carolina, USA. We then examined relationships between each landscape metric and recruitment enhancement of juvenile pinfish (Lagodon rhomboides), a species that uses multiple biogenic habitats and has high site fidelity as juveniles. We estimated that reefs with <33% proximal structured habitat within 15 m and <59% within 50 m contributed to recruitment enhancement, as defined by greater juvenile pinfish abundances at reefs than controls and no overlap in 95% confidence intervals. Additionally, functional redundancy, assigned according to per cent structure of proximal habitat within 15 or 50 m of restored reefs, reduced estimates of nekton recruitment enhancement in this experimental landscape by 58.3% or 33.3%, respectively. Estimates of nekton production augmented by restoration may be inflated if they have not been adjusted to account for habitat redundancy. Synthesis and applications. Landscape metrics offer some predictive capacity to help restoration practitioners avoid habitat redundancy for recruitment enhancement and extend beyond considering individual habitats toward integrating landscape scale processes into predictions and restoration practice. We demonstrated a straightforward process for restoration practitioners to identify where habitats may be redundant and incorporate the landscape into restoration siting decisions: delineate co‐occurring structured habitat with publicly accessible orthoimagery and model juvenile nekton relationships with proximal percent structure and near distance to other structured habitats. [ABSTRACT FROM AUTHOR]

Autonomous Reef Monitoring Structures (ARMS) are used worldwide to assess cryptic diversity, especially on coral reefs. They were developed as standardised tools, yet conditions of deployment, such as immersion duration and/or deployment and retrieval seasons, vary among studies. Here we studied temporal and seasonal variability in coral reef cryptic communities sampled with 15 ARMS on a single coral reef slope site at Reunion Island, Southwest Indian Ocean. Settlement patterns and temporal succession of Eukaryote communities were investigated across three immersion times (6 months, 1 year, 2 years), two immersion seasons (hot vs. cool) and three fractions (500–2000 μm, 106–500 μm, sessile) using two genetic markers (18S, COI). Both markers detected different taxa with different resolutions, but broadly similar patterns of community composition and structure. While OTU diversity of communities did not change with immersion time and season, these parameters significantly affected community structure and composition. Our results showed a decrease of the similarity of ARMS communities with duration of immersion, and a strong temporal turnover of species with only a small proportion of the diversity persisting over time. The small proportion of OTUs assigned at phylum level highlights the uniqueness of the Mascarene cryptobiome. [ABSTRACT FROM AUTHOR]

Coral bleaching, a consequence of stressed symbiotic relationships between corals and algae, has escalated due to intensified heat stress events driven by climate change. Despite global efforts, current early warning systems lack local precision. Our study, spanning 2015–2017 in the Mesoamerican Reef, revealed prevalent intermediate bleaching, peaking in 2017. By scrutinizing 23 stress exposure and sensitivity metrics, we accurately predicted 75% of bleaching severity variation. Notably, distinct thermal patterns—particularly the climatological seasonal warming rate and various heat stress metrics—emerged as better predictors compared to conventional indices (such as Degree Heating Weeks). Surprisingly, deeper reefs with diverse coral communities showed heightened vulnerability. This study presents a framework for coral reef bleaching vulnerability assessment, leveraging accessible data (including historical and real-time sea surface temperature, habitat variables, and species composition). Its operational potential lies in seamless integration with existing monitoring systems, offering crucial insights for conservation and management. A study on the Mesoamerican Reef shows that the climatological rate of seasonal warming and heat stress metrics more accurately predict coral bleaching severity than conventional indices, enhancing regional early warning systems for better conservation strategies. [ABSTRACT FROM AUTHOR]

Ocean ecosystems have been subjected to anthropogenic influences for centuries, but the scale of past ecosystem changes is often unknown. For centuries, the European flat oyster (Ostrea edulis), an ecosystem engineer providing biogenic reef habitats, was a culturally and economically significant source of food and trade. These reef habitats are now functionally extinct, and almost no memory of where or at what scales this ecosystem once existed, or its past form, remains. The described datasets present qualitative and quantitative extracts from written records published between 1524 and 2022. These show: (1) locations of past flat oyster fisheries and/or oyster reef habitat described across its biogeographical range, with associated levels of confidence; (2) reported extent of past oyster reef habitats, and; (3) species associated with these habitats. These datasets will be of use to inform accelerating flat oyster restoration activities, to establish reference models for anchoring adaptive management of restoration action, and in contributing to global efforts to recover records on the hidden history of anthropogenic-driven ocean ecosystem degradation. [ABSTRACT FROM AUTHOR]

Multibeam echosounders provide ideal data for the semi-automated seabed feature extraction and accurate morphometric measurements. In this study, bathymetric and raw backscatter data were initially used to manually delimit the reef morphologies found in an insular semi-enclosed gulf in the northern Aegean Sea (Gera Gulf, Lesvos Island, Greece). The complexity of this environment makes it an ideal area to "crash test" (test to the limit) and compare the results of the delineation methods. A large number of (more than 7000) small but prominent reefs were detected, which made manual mapping extremely time-consuming. Three semi-automated tools were also employed to map the reefs: the Benthic Terrain Modeler (BTM), Confined Morphologies Mapping (CoMMa), and eCognition Multiresolution Segmentation. BTM did not function properly with irregular reef footprints, but by modifying both the bathymetry and slope, the outcome was improved, producing accurate results that appeared to exceed the accuracy of manual mapping. CoMMa, a new GIS morphometric toolbox, was a "one-stop shop" that, besides generating satisfactory reef delineation results (i.e., detecting the same total reef area as the manual method), was also used to extract the morphometric characteristics of the polygons resulting from all the methods. Lastly, the Multiresolution Segmentation also gave satisfactory results with the highest precision. To compare the final maps with the distribution of the reefs, mapcurves were created to estimate the goodness-of-fit (GOF) with the Precision, Recall, and F1 Scores producing values higher than 0.78, suggesting a good detection accuracy for the semi-automated methods. The analysis reveals that the semi-automated methods provided more efficient results in comparison with the time-consuming manual mapping. Overall, for this case study, the modification of the bathymetry and slope enabled the results' accuracy to be further enhanced. This study asserts that the use of semi-automated mapping is an effective method for delineating the geomorphometry of intricate relief and serves as a powerful tool for habitat mapping and decision-making. [ABSTRACT FROM AUTHOR]

The development of trait‐based approaches has accelerated our understanding of how communities assemble, respond to environmental change and may best be managed in the Anthropocene. Understanding the magnitude and pattern of interspecific variability forms a critical underpinning of trait‐based approaches while exploring intraspecific variability can identify the potential of species to adapt to changing environmental drivers. Our work is motivated by the critical need for a novel conceptual framework for understanding the functional ecology of macroalgae, as the current paradigm is still mired in functional group models developed in the 1980s.Our objective was to quantify interspecific and intraspecific functional trait variability in three common and morphologically diverse species of tropical marine macroalgae by exploring traits relating to the ecological functions of resource acquisition, resistance to herbivory, and resistance to physical disturbance and the trade‐offs between them.We quantified intraspecific and interspecific variability of 11 functional traits for three common and morphologically diverse species of tropical macroalgae from five fringing reefs of Mo'orea, French Polynesia that were likely to capture a wide range of environmental variability. Differences in traits among species and sites were determined with PERMANOVA, visualised with non‐metric multidimensional scaling, and trade‐offs between pairs of traits explored with correlation. Finally, spatial patterns among select traits across all species were quantified.Species clustered together in distinctly different trait spaces driven by trade‐offs among suites of functional traits. Two of three species had considerable intraspecific variability, though this variability occurred at different scales, while one clustered tightly. Exploration of individual traits across species and sites revealed trade‐offs between two strategies for resource acquisition, growing tall and strong versus investing in large surface area.Synthesis. We captured novel patterns of interspecific and intraspecific variability for tropical marine macroalgae. We found fundamental differences in traits between species that may represent ecological strategies while considerable intraspecific variability demonstrates a wide range in abilities to respond to environmental drivers. Overall, our work provides novel insights into intra and interspecific trait variation that form an essential underpinning for using a trait‐based framework in a taxon that is increasingly dominant on tropical reefs. [ABSTRACT FROM AUTHOR]

The die‐off of the long‐spined sea urchin Diadema antillarum in the 1980s highlighted its crucial role as a primary grazer in tropical western Atlantic coral reefs. However, natural recovery has been slow, exacerbated by a new die‐off in 2022. Interest in actively restoring D. antillarum populations has grown with the emergence of culture and rearing techniques. Restocking reefs with laboratory‐reared urchins shows potential for enhancing coral reef resilience by reducing algal cover and promoting coral settlement, but success rates vary. Predation and migration contribute to low retention rates, with distinguishing between them is challenging. In this study near Saba, Caribbean Netherlands, we released 200 laboratory‐reared D. antillarum on a reef and monitored for D. antillarum retention and potential D. antillarum predator presence and interaction for 35 days. Only 40% of the urchins were still present on the reef after day one. The Spanish hogfish Bodianus rufus was identified as the primary daytime predator, responsible for nine direct predation events. No nighttime predation was observed, but interaction with a batwing coral crab Carpilius corallinus was noted. These insights can help optimize future restocking attempts and emphasize the importance of assessing predator presence beforehand. Reefs with high abundances of predators such as Spanish hogfish should be avoided for D antillarum restocking. In addition, before being released, lab‐reared animals should be given time to acclimate to conditions in the wild by being placed in protected in situ cages. Here, they could also grow to larger sizes that are less vulnerable to predation. [ABSTRACT FROM AUTHOR]

Coral reefs face threats from climate change and local pressures that lead to reductions in their physical structure, impacting biodiversity by limiting habitat availability. Despite many efforts to actively restore damaged reefs, few projects provide thorough evaluations of their success. This study measured the success of the "Reef Star" method at the Mars Coral Reef Restoration Project in Indonesia in reestablishing the physical structure of reef habitats that were destroyed by blast fishing. We used photogrammetry surveys to measure the physical habitat structure of 17 large sites (1000 m2 each), calculating three complementary measures of small‐ and large‐scale habitat complexity across degraded, restored, and naturally healthy coral reefs. We demonstrate that the restoration efforts have successfully restored small‐scale habitat complexity, as described by surface complexity metrics (3.22 ± 0.27 on restored reefs; 2.85 ± 0.26 on healthy reefs) and fractal dimension (2.27 ± 0.02 on restored reefs; 2.24 ± 0.02 on healthy reefs). This demonstrates the capacity for restored reefs to recover important ecosystem functions that are lost in degradation. However, while restoration has delivered some increases in large‐scale habitat complexity compared to degraded reefs, restored reefs still exhibit lower values of maximum vertical relief than healthy reefs, due to a lack of large physical structures. This lack of available large‐scale habitat might impact fish populations, meaning that restored reefs with limited large‐scale complexity may only support a restricted range of ecosystem functions. Effective reef restoration strategies must use a mixture of different methods that target the recovery of structural complexity at multiple scales. [ABSTRACT FROM AUTHOR]

Stony coral tissue loss disease (SCTLD) has swept through Florida reefs and caused mass mortality of numerous coral species. In the wake of these losses, efforts are underway to propagate coral species impacted by SCTLD and promote population recovery. However, numerous knowledge gaps must be addressed to effectively grow, outplant, and restore populations of the slower growing, massive species that were lost. Here, we used sexual recruits of Diploria labyrinthiformis spawned in captivity to understand how conditioning, coral size, and nutritional status at outplanting affect coral survivorship, growth, and susceptibility to predation. We found that ex situ conditioning with supplemental feeding increased coral growth rates, resulting in larger sized corals at the time of outplanting. In turn, these corals had higher growth rates in the field and a lower probability of being removed by predators than outplants that were conditioned in in situ nurseries. Additionally, we found that coral size was an important predictor of survivorship, suggesting that hastening the speed at which young corals grow and outplanting larger juveniles can improve restoration outcomes. Taken together, our results suggest that providing supplemental food to corals at ex situ facilities confers benefits that could help restore populations of massive coral species impacted by SCTLD. [ABSTRACT FROM AUTHOR]

Implementation of coral restoration practices within reef management strategies is accelerating globally to support reef resilience and recovery. However, full costs underpinning restoration project feasibility have historically been underreported yet are critical to informing restoration cost-benefit decision-making. Such knowledge is especially lacking for Australia's Great Barrier Reef (GBR), where a coral restoration program led by reef tourism operators, Coral Nurture Program (CNP), was initiated in 2018 (northern GBR) and continues to scale. Here we describe the early outcomes and costs of implementing similar tourism-led asexual coral propagation and outplanting practices in a new region, the Whitsundays (central GBR) through the CNP. Specifically, we detail the local operational and environmental context of CNP Whitsundays, describe the costs of implementation and continuation of restoration activities, as well as evaluate survivorship of coral outplants across three restoration sites for nine months after project establishment (August 2022 to June 2023). Baseline benthic surveys revealed relatively low hard coral cover at restoration sites (ranging from 3.22-8.67%), which significantly differed in benthic composition from coral collection sites (ranging 16.67-38.06%), supporting strong motivation by tourism operators to undertake restoration activities. Mean coral survivorship of coral outplants in fate-tracked plots differed between the three restoration sites after 267 days (ranging 23.33-47.58%), with declines largely driven by coral detachment. Early-stage cost-effectiveness (costs relative to outplant survival) associated with implementation of restoration activity varied widely from US$33.04-178.55 per surviving coral (n = 4,425 outplants) depending on whether 'in-kind' costs, restoration activity (outplanting only vs. total costs encompassing planning through to monitoring), site-based survivorship, or a combination of these factors, were considered. As coral reef restoration projects continue to be established globally, our results highlight the need for ongoing, long-term monitoring that can inform adaptive practice, and fully transparent costreporting to understand and improve feasibility for any given project. We further highlight the inherent context-dependency of restoration costs, and the importance of considering local social-environmental contexts and their associated cost-benefits in economic rationale for reef restoration projects. [ABSTRACT FROM AUTHOR]

A critical component of ecosystem restoration projects involves using genetic data to select source material that will enhance success under current and future climates. However, the complexity and expense of applying genetic data is a barrier to its use outside of specialised scientific contexts. To help overcome this barrier, we developed Reef Adapt (www.reefadapt.org), an innovative, globally applicable and expandable web platform that incorporates genetic, biophysical and environmental prediction data into marine restoration and assisted gene flow planning. The Reef Adapt tool provides maps that identify areas with populations suited to user-specified restoration/recipient sites under current and future climate scenarios. We demonstrate its versatility and practicality with four case studies of ecologically and evolutionarily diverse taxa: the habitat-forming corals Pocillopora damicornis and Acropora kenti, and macroalgae Phyllospora comosa and Ecklonia radiata. Reef Adapt is a management-ready tool to aid restoration and conservation efforts amidst ongoing habitat degradation and climate change. Aiming to accelerate research in the field of marine restoration, 'Reef Adapt' integrates genetic, environmental, and biophysical data to predict populations suited to 'local' and 'future' climates for marine restoration [ABSTRACT FROM AUTHOR]

The composition of coral-reef sediments is highly variable across space and time, and differences in the life histories of the dominant calcifying organisms on reefs contribute to the heterogeneity of reef sediments. Previous studies have suggested that variations in coral-reef bioerosion can influence spatial and temporal variations of sedimentary assemblages: elevated erosion rates of dead coral skeletons can trigger a pulse of coral-derived sediments and cause a shift in the dominance of sedimentary grains from coralline algae, such as Halimeda, to coral. We assessed the variability of the sedimentary composition and bioerosion rates of reefs at different spatial scales to determine the association between these two variables. We surveyed the benthic assemblages on reefs exhibiting different ecological states and collected samples of the associated sediments. We calculated the carbonate budget for each site and compared their variability at different hierarchical levels to the variability of their respective sedimentary assemblages. At the scale of sites (1–10 km), Halimeda cover was a significant predictor of the relative abundance of Halimeda grains. Both the relative abundance of coral grains and reef bioerosion rates varied significantly at the scale of locality (tens to hundreds of km), with high abundances of coral grains in the sediments coinciding with high rates of bioerosion. The main drivers of bioerosion at our localities were parrotfish assemblages dominated by large size classes of excavating species such as Sparisoma viride. Reef sediments may reflect the gross degree of bioerosion pressure that reefs experience, and historical changes in bioerosion rates could potentially be assessed by examining the sediments across temporal scales. [ABSTRACT FROM AUTHOR]

Promoting resilience is highly relevant to preserving biodiversity and ecosystem functioning. For coral reefs, parrotfish protection emerged as a mainstream action for reversing the degradation experienced by these systems. The rationale is that restoring their populations will increase grazing activity and reinforce control of fast‐growing macroalgae, facilitating coral cover recovery. A lack of a link between parrotfish trends and macroalgae and coral cover trends at a large scale has, however, often been the case. Suggesting more complex underlying dynamics that should be reexamined. In this review, we discuss how lumping parrotfish species as if they were functionally redundant may obscure trends. And how a lack of appreciation of other functions around the parrotfish paradigm, specifically bioerosion, may have unforeseen and potentially adverse effects on degraded reefs. We show that bioerosion responded more directly and quickly to spatial and temporal changes in parrotfish assemblages than macroalgae consumption, arguably due to the varying vulnerability among Caribbean parrotfishes to fisheries and habitat loss. For highly degraded reefs, positive changes in parrotfish populations could hence compromise the remaining coral skeleton structures and the reef framework, further accentuating reef degradation, where increases in macroalgae consumption could not necessarily compensate for higher rates of bioerosion. [ABSTRACT FROM AUTHOR]

Oyster reef living shorelines are popular solutions to mitigate coastal hazards while providing ecosystem services, and their hydrodynamic characteristics deserve further examination. This paper reports an experimental and numerical study of the hydrodynamic behavior of a bagged oyster shell (BOS) reef under regular waves. The dependence of the pore pressure within the reef and the hydrodynamic coefficients on the reef height, length, porosity, and wave parameters are investigated. The results show that the normalized maximum pore pressure p s _ m ∗ decreases from the seaside of the BOS reef to its leeside and decreases with increasing dimensionless reef length. With increasing wave steepness, p s _ m ∗ fluctuates with an overall increasing trend. With increasing BOS reef porosity, p s _ m ∗ decreases at seaside locations and increases at leeside locations; simultaneously, the wave reflection coefficient Kr and the wave dissipation coefficient Kd decrease, and the wave transmission coefficient Kt increases. With increasing wave steepness for a given wave period, Kr and Kt tend to increase, but Kd exhibits the opposite trend. As the dimensionless reef height and length increase, Kt decreases and Kd increases. Multivariate nonlinear regression and genetic programming-based symbolic regression methods are individually used to derive two formulas for predicting the wave transmission coefficient, with the formula from the latter method being found to give a higher prediction accuracy. [ABSTRACT FROM AUTHOR]

Tropical reef ecosystems are strongly influenced by the composition of coral species, but the factors influencing coral diversity and distributions are not fully understood. Here we demonstrate that large variations in the relative abundance of three major coral species across adjacent Caribbean reef sites are strongly related to their different low O2 tolerances. In laboratory experiments designed to mimic reef conditions, the cumulative effect of repeated nightly low O2 drove coral bleaching and mortality, with limited modulation by temperature. After four nights of repeated low O2, species responses also varied widely, from > 50% bleaching in Acropora cervicornis to no discernable sensitivity of Porites furcata. A simple metric of hypoxic pressure that combines these experimentally derived species sensitivities with high‐resolution field data accurately predicts the observed relative abundance of species across three reefs. Only the well‐oxygenated reef supported the framework‐building hypoxia‐sensitive Acropora cervicornis, while the hypoxia‐tolerant weedy species Porites furcata was dominant on the most frequently O2‐deplete reef. Physiological exclusion of acroporids from these O2‐deplete reefs underscores the need for hypoxia management to reduce extirpation risk. [ABSTRACT FROM AUTHOR]

The 3D wave flume experiments and OpenFOAM numerical simulation study of a monopile mounted on reef flat impacted by solitary wave were presented in this paper. The reef model has a 1:4 slope and the monopile with a diameter of 0.15 m is mounted on the reef flat. In the experiments, the incident solitary wave height is determined to be 30% of the water depth. The surface elevation along the fringing reef, velocity at a particular place and the wave impact load on the monopile are recorded. The RANS numerical simulation is carried out by using the realizable k-e turbulence model, and it was verified with physical experimental data. Based on the experimental data and RANS simulation results, the hydrodynamic characteristics of solitary wave propagation on the reef flat and the solitary wave impacts on the monopile mounted on reef flat are studied, and the influence of the solitary wave impact on the monopile under various slopes and incident wave heights is discussed. The research results have certain engineering guidance significance for the site selection and protection of pile foundations. [ABSTRACT FROM AUTHOR]

Hard substrate communities can impact coral reef growth by adding or removing calcium carbonate when they act as encrusters or bioeroders, respectively. Although such sclerobiont communities are known across the Phanerozoic, the Triassic saw a substantial increase in reef macrobioerosion. This study provides the first quantitative assessment of sclerobionts in a Late Triassic (Norian) reef coral community (from the Nayband Formation in central Iran) and establishes some post-Paleozoic trends in reef bioerosion. Sclerobionts were common on the dominant coral Pamiroseris rectilamellosa and covered between 0 and 26.4% of total coral surface area among the 145 colonies investigated. Encrustation was significantly more prevalent (1.78% of total area) than bioerosion (0.36% of total area). The underside of corals was 3.5 times more affected by sclerobionts than the upper surfaces. This suggests that the sclerobionts preferentially colonized dead parts of the corals. The main encrusting taxa were polychaete worms (76.2%), followed by bivalves (11.9%). The main bioeroders were Polychaeta (51.4%), Porifera (22.2%), and Bivalvia (20.7%). The lack of a correlation between encrustation and bioerosion intensity suggests that the number of sclerobionts is not simply a function of exposure time before final burial. Our review of the published literature suggests a declining trend in the relative importance of bivalves, polychaetes and cirripeds in reefs, whereas sponges increased in importance from the Triassic until today. [ABSTRACT FROM AUTHOR]

The article presents a comparative analysis of the Paleozoic and Cenozoic reef formation, mainly in terms of the position of reefs in the basins of continental and oceanic blocks. It is shown that the main formation of reefs took place in the Cenozoic directly in the oceans, including boundaries between oceans and continents, and, to an extremely limited scales, in the basins of the continental segment. In the Paleozoic, reefs were formed not only in oceans, but also in spacious basins of continental block. This is one of the manifestations of the general evolution of carbonate accumulation, when the Paleozoic carbonate sediments were formed in such shallow-water bodies that covered very significant surfaces of continents. [ABSTRACT FROM AUTHOR]

Low-lying, tropical, coral-reef-lined coastlines are becoming increasingly vulnerable to wave-driven flooding due to population growth, coral reef degradation, and sea-level rise. Early-warning systems (EWSs) are needed to enable coastal authorities to issue timely alerts and coordinate preparedness and evacuation measures for their coastal communities. At longer timescales, risk management and adaptation planning require robust assessments of future flooding hazard considering uncertainties. However, due to diversity in reef morphologies and complex reef hydrodynamics compared to sandy shorelines, there have been no robust analytical solutions for wave runup to allow for the development of large-scale coastal wave-driven flooding EWSs and risk assessment frameworks for reef-lined coasts. To address the need for fast, robust predictions of runup that account for the natural variability in coral reef morphologies, we constructed the BEWARE-2 (Broad-range Estimator of Wave Attack in Reef Environments) meta-process modeling system. We developed this meta-process model using a training dataset of hydrodynamics and wave runup computed by the XBeach Non-Hydrostatic process-based hydrodynamic model for 440 combinations of water level, wave height, and wave period with 195 representative reef profiles that encompass the natural diversity in real-world fringing coral reef systems. Through this innovation, BEWARE-2 can be applied in a larger range of coastal settings than meta-models that rely on a parametric description of the coral reef geometry. In the validation stage, the BEWARE-2 modeling system produced runup results that had a relative root mean square error of 13 % and relative bias of 5 % relative to runup simulated by XBeach Non-Hydrostatic for a large range of oceanographic forcing conditions and for diverse reef morphologies (root mean square error and bias 0.63 and 0.26 m, respectively, relative to mean simulated wave runup of 4.85 m). Incorporating parametric modifications in the modeling system to account for variations in reef roughness and beach slope allows for systematic errors (relative bias) in BEWARE-2 predictions to be reduced by a factor of 1.5–6.5 for relatively coarse or smooth reefs and mild or steep beach slopes. This prediction provided by the BEWARE-2 modeling system is faster by 4–5 orders of magnitude than the full, process-based hydrodynamic model and could therefore be integrated into large-scale EWSs for tropical, reef-lined coasts and used for large-scale flood risk assessments. [ABSTRACT FROM AUTHOR]

In the face of rising global temperatures, coral reefs experience coral mass bleaching and mortality. Subtropical and mesophotic environments may represent refugia for reef corals under climate change, where they can survive and eventually recolonize degraded areas. Using a comprehensive database of fossil reefs, we empirically assess the efficacy of subtropical, deeper, and turbid mesophotic environments to restore coral reefs after past global warming events. We focus on tropical coral reefs over the last 275 million years and four rapid climate warming events, which coincided with global reef crises in the geological record. In the aftermath of such hyperthermal events, we observed an increase in the proportions of reefs occurring in deeper (blue) mesophotic environments. Additionally, we found a trend of reef distributions and coral shifting towards higher latitudes. The number of coral occurrences in turbid (brown mesophotic) environments also increased after hyperthermal events. Our results suggest that subtropical, blue, and brown mesophotic environments may have served as immediate refugia for shallow-water coral species escaping warming seawater. While the patterns of reef range shifts and the establishment of blue and brown mesophotic refugia following ancient hyperthermal events provide some hope for coral reefs under current climate change, re-establishement of background reef conditions took most times millions of years. Ante el incremento de temperatura global, los arrecifes coralinos están experimentando eventos masivos de blanqueamiento y mortalidad. Los ambientes subtropicales y mesofóticos pueden representar refugios para los corales arrecifales, en los cuales pueden escapar de los efectos del cambio climático, sobrevivir y desde allí recolonizar áreas previamente degradadas. Mediante el uso de una exhaustiva base de datos en arrecifes coralinos, en este estudio se evaluó empíricamente la eficacia de los ambientes subtropicales y mesofóticos, tanto de aguas turbias someras (marrones) como de aguas claras profundas (azules), en la recuperación de arrecifes coralinos después de eventos hipertermales en el pasado. Nuestro enfoque estuvo en los arrecifes coralinos tropicales durante los últimos 275 millones de años y cuatro eventos de calentamiento climático rápido, los cuales coinciden con crisis globales en la ocurrencia de arrecifes en el registro fósil. Como consecuencia de dichos eventos hipertermales, observamos un aumento del número de arrecifes en ambientes mesofóticos de aguas profundas (azules). Además, encontramos una tendencia en la distribución de arrecifes y corales que se desplazan hacia latitudes más altas. También se observó un aumento en el número de corales que estuvieron presentes en ambientes de aguas turbias (marrones) después de dichos eventos hipertermales. Nuestros resultados sugieren que, en el pasado, los ambientes subtropicales, mesofóticos azules y mesofóticos marrones pudieron haber servido como refugios inmediatos para las especies de coral de aguas someras, en los cuales encuentran condiciones atenuantes ante el calentamiento oceánico. Si bien los patrones de desplazamiento de los arrecifes en el rango latitudinal y el establecimiento de refugios mesofóticos de aguas marrones y azules posteriores a eventos hipertermales brindan una luz de esperanza para el futuro de los arrecifes coralinos de cara al cambio climático actual, nuestros resultados evidencian que el restablecimiento de los arrecifes puede tomar millones de años. [ABSTRACT FROM AUTHOR]

Rubble is ubiquitous on coral reefs and can aggregate into fields, forming a significant component of the reef substrate. Rubble fields often remain unconsolidated, with the component rubble pieces subject to movement that is dependent on hydrodynamic forcing, rubble size, shape, and other factors. Settlement of corals to rubble fields has long been assumed, but the dynamic movement of rubble pieces has been presumed to deter settlement and is thought to contribute to high post-settlement mortality. Rubble often forms on coral reefs following severe disturbances, and is predicted to increase under climate change, with the potential to impact settlement and recruitment-dependent recovery processes. Through a series of laboratory and field experiments, we demonstrate that corals from broadcast spawning species on the Great Barrier Reef will settle on unstable substrates, even those in constant motion. We also observed more coral spat on settlement tiles suspended in the water column than those fixed to the reef using a common approach to censusing settlement. Sampling of natural rubble on the reef 50 days after a mass-spawning event confirmed the presence of similar numbers of coral settlers on rubble and on tiles fixed to the reef. These results suggest that rubble fields are places of significant settlement for broadcast spawning corals. Suspended tiles were also surprisingly effective in collecting coral settlers, demonstrating that a change in sampling protocol can produce significant variation in settlement data and strengthening the argument for standardisation of settlement-monitoring protocols, particularly at a time of growing need for reliable metrics. These results also suggest that movement of rubble is not precluding settlement outright, but rather post-settlement processes (i.e. competition, predation, shading or burial by shifting rubble) are limiting recruitment to rubble patches. Consequently, rubble stabilisation may increase the survival of spat that have settled in these environments. [ABSTRACT FROM AUTHOR]

Densities of juvenile corals (≤ 50 mm diameter) are expected to vary between geographically isolated and more spatially proximate reefs, and may constrain local recovery potential. This study compared juvenile coral densities and their relationships with local abundance of adult congenerics at geographically isolated reefs within Australia's Coral Sea Marine Park (CSMP) versus highly connected reefs within the Great Barrier Reef Marine Park (GBRMP). Three latitudinal regions and two habitats (reef crest and slope) were examined within both marine parks to test for spatial variation. Densities of juvenile corals in the CSMP (13.99 ± 0.72 juveniles 10 m−2) were significantly lower compared to those in the GBRMP (23.72 ± 1.86 juveniles 10 m−2). Specifically, there were significantly less Acropora and Pocillopora juveniles on the reef crest in the central CSMP compared to the GBRMP. Relationships between juvenile abundance and percent coral cover were greatest for Acropora and Pocillopora in the GBRMP. This may be due to the low range of coral cover estimates recorded in the CSMP, especially for Acropora (0–15%). Low juvenile coral abundance, and in particular, the lack of fast-growing juvenile corals (e.g., Acropora) in the Central CSMP, in combination with low cover of broodstock (particularly Acropora) on CSMP reefs, poses a significant constraint on post-disturbance recovery capacity, possibly attributable to isolation and limited connectivity among reefs in this region. [ABSTRACT FROM AUTHOR]

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In February 2010, the cargo vessel M/V Vogetrader ran aground on a forereef in Oahu, Hawaii. Baseline surveys documented considerable damage to coral communities. Several restoration actions were implemented in 2013, including active restoration (rubble removal, coral outplanting) and passive restoration (natural recovery), with the goal of returning corals to their pre-disturbance state. In 2022, repeated surveys were conducted across three injury zones that varied in the severity of impact and the restoration actions employed to provide a rare assessment of restoration outcomes a decade post-grounding. We found coral recovery to be contingent on the severity of impact and the quality of the impacted habitat, not the amount of active restoration. Despite rubble removal efforts, present-day rubble cover was significantly higher at the impact sites compared to the reference sites and appeared to constrain recovery in the injury zone where grounding impacts destabilized the reef framework. Outplant efforts did not increase coral density or mean size relative to natural recovery sites, though this may be the result of an ineffective outplant design rather than failed outplanting as a whole. The sites closest to returning to a pre-disturbance state were the passive restoration sites. This, however, likely reflects the low severity of grounding impacts and the marginal (e.g., small and sparse) population of corals at these sites. These findings suggest that the extent of active restoration actions should be carefully and intentionally scaled to the severity and spatial extent of impact (with greater impacted areas receiving greater amounts of restoration), and that with sufficient time, marginal reef habitats with a low impact severity can likely recover from passive restoration alone. [ABSTRACT FROM AUTHOR]

This article, titled "Natural Recovery of a Coral Population After a Severe Typhoon in Taiwan," explores the recovery of a coral population (genus Pocillopora) following a typhoon in Taiwan. The study utilized long-term monitoring and found that there was a high initial recruitment of Pocillopora individuals, leading to the establishment of a juvenile population that rapidly developed into mature adults within six years. However, despite the emergence of a Pocillopora-dominated state on the reef, the population growth rate declined. The study emphasizes the importance of long-term data in understanding coral demographics. [Extracted from the article]

The sea urchin Diadema africanum is a macro-herbivore found in the rocky reef systems of the West African region and Macaronesian archipelagos. Over several decades, high densities of this species have generated marine barrens in certain areas at the Canary Islands. In contrast, more recently, during the last few years, the species has suffered mass mortality events that continue to the present day. In this study, we used 9,109 Single Nucleotide Polymorphisms (SNPs) and a fragment of a mitochondrial gene to evaluate the species' population structure, effects of mass mortalities on its diversity, and potential local adaptation across the Canary Islands and Cabo Verde. Our research provides compelling evidence of low genomic diversity and homogeneity across the studied area for neutral markers, along with recent demographic fluctuations. The high connectivity among distant areas likely allows a rapid recovering of the populations from local mortality events. Interestingly, we also observed genomic sub-structure from 405 SNPs identified as candidate loci under selection for seawater temperature. The lack of divergence among distant sites and the low diversity found can be attributed to the species' divergence from a small ancestral genomic pool, followed by a contemporary demographic expansion, and ongoinggene flow. [ABSTRACT FROM AUTHOR]

Cryptofauna are an overlooked faunal group due to their hidden nature and the use of conventional survey methods, despite playing a significant role in the ecosystem complex as keystone taxa. In this study, a structural framework, viz. cryptofauna monitoring structure (CMS) was developed to assess cryptofauna living in the lagoon reef environment and their preference to various substrates. The efficiency of CMS modules was tested by deploying them in coral lagoons in Agatti and Kavaratti of the Lakshadweep Archipelago, India. A total of 24 CMS units, sets of four, were deployed in these islands at live coral, dead coral and sandy habitat sites. Retrieval of CMS units revealed a total of 424 individuals of motile and sessile organisms representing 12 different taxonomic groups collected. Among the habitats, the sandy area had a high taxa number while the dead coral area had a high taxa abundance. Polychaetes and gastropods were the dominant faunal groups regardless of habitat and island. The present study suggests that CMS can be an efficient tool to assess cryptofauna diversity, which could make monitoring cryptobionts more affordable and environment-friendly. In addition, this study lays the foundation for research into cryptic reef benthos in India. [ABSTRACT FROM AUTHOR]

ABSTRACT Coastal algal reef ecosystems, which are formed by the skeletal carbonate of crustose coralline algae (CCA), provide vital habitats for a diverse range of marine organisms and serve as valuable archives of long‐term environmental data. Despite the importance of these reef ecosystems, there is currently a lack of available information regarding the accretion rates of CCA in subtropical intertidal zones in the Taoyuan algal reef. We measured the vertical accretion and horizontal growth of CCA cultured in two aquaculture tanks over a 9‐month period. The vertical accretion and horizontal growth rate of CCA was approximately 0.29–0.43 and 5.5 μm·day−1 (the extrapolated annual value is equivalent to 0.11–0.16 and 2.0 mm·year−1, respectively). Newly colonized CCA had faster horizontal growth of approximately 110 μm·day−1 (equivalent to 40.2 mm·year−1). These results highlight the slow and gradual process of algal reef ecosystem formation in the subtropical intertidal zones. The CCA had a faster lateral growth rate as seen in the newly settled CCA. These findings contribute to our understanding of the overall growth dynamics of CCA. [ABSTRACT FROM AUTHOR]

Coral reef ecosystems are highly threatened and can be extremely sensitive to the effects of climate change. Multiple shark species rely on coral reefs as important habitat and, as such, play a number of significant ecological roles in these ecosystems. How environmental stress impacts routine, site-attached reef shark behavior, remains relatively unexplored. Here, we combine 8 years of acoustic tracking data (2013-2020) from grey reef sharks resident to the remote coral reefs of the Chagos Archipelago in the Central Indian Ocean, with a satellite-based index of coral reef environmental stress exposure. We show that on average across the region, increased stress on the reefs significantly reduces grey reef shark residency, promoting more diffuse space use and increasing time away from shallow forereefs. Importantly, this impact has a lagged effect for up to 16 months. This may have important physiological and conservation consequences for reef sharks, as well as broader implications for reef ecosystem functioning. As climate change is predicted to increase environmental stress on coral reef ecosystems, understanding how site-attached predators respond to stress will be crucial for forecasting the functional significance of altering predator behavior and the potential impacts on conservation for both reef sharks and coral reefs themselves. Environmental stress on coral reefs is increasing. Authors show a stress-related reduction in residency of grey reef sharks on the remote reefs of the Chagos Archipelago, promoting more diffuse space use and increased time away from the shallow forereefs. [ABSTRACT FROM AUTHOR]

Adaptation of reef-building corals to global warming depends upon standing heritable variation in tolerance traits upon which selection can act. Yet limited knowledge exists on heat-tolerance variation among conspecific individuals separated by metres to hundreds of kilometres. Here, we performed standardized acute heat-stress assays to quantify the thermal tolerance traits of 709 colonies of Acropora spathulata from 13 reefs spanning 1060 km (9.5° latitude) of the Great Barrier Reef. Thermal thresholds for photochemical efficiency and chlorophyll retention varied considerably among individual colonies both among reefs (approximately 6°C) and within reefs (approximately 3°C). Although tolerance rankings of colonies varied between traits, the most heat-tolerant corals (i.e. top 25% of each trait) were found at virtually all reefs, indicating widespread phenotypic variation. Reef-scale environmental predictors explained 12–62% of trait variation. Corals exposed to high thermal averages and recent thermal stress exhibited the greatest photochemical performance, probably reflecting local adaptation and stress pre-acclimatization, and the lowest chlorophyll retention suggesting stress pre-sensitization. Importantly, heat tolerance relative to local summer temperatures was the greatest on higher latitude reefs suggestive of higher adaptive potential. These results can be used to identify naturally tolerant coral populations and individuals for conservation and restoration applications. [ABSTRACT FROM AUTHOR]

Cameron Penney's MArch thesis project, Toronto's Terrestrial Reef: Biorock's Infrastructural Biogeochemical Futures, is an intensive material exploration of biorock—a carbon-sequestering, limestone-like, concrete alternative—to create a synthetic geo/ecological scaffold in urban Toronto. This essay focuses on a single project figure: a series of photographs of biorock models grown in a self-constructed wet lab and analyzed in a chemistry dry lab. Drawing from model histories in architecture and science, the essay suggests that as physical models increasingly detach from their conventional disciplinary roles, their capacity to make worlds—in this case a biogeochemical world of synthetic geological accretions—radically expands. [ABSTRACT FROM AUTHOR]

One of the most significant features of the Northwest Atlantic, the Gulf Stream influences high magnitude environmental fluctuations in deep habitats across the South Atlantic Bight. Amid this variability, the Blake Plateau harbors extensive reefs formed by cold‐water corals that were previously assumed to rely on narrow ranges of temperature, currents, and particulate supply. A benthic lander collected near‐bed conditions at the Richardson Reef Complex, a cold‐water reef dominated by the scleractinian Desmophyllum pertusum at 830 m within the path of the Gulf Stream. Specific behavior of the Gulf Stream resulted in recurring environmental patterns at depth. During offshore meanders, deep stream components intruded onto the reef and caused rapid (3.74°C per hour) temperature increases up to 10.8°C (> 5°C above the site mean) and increased chlorophyll. Within 2 d of peak temperatures, intrusions were replaced by strong, turbid upwelling currents that rapidly cooled the site to temperature minima (4.13°C). While considerable environmental variability from the Gulf Stream may otherwise implicate a thermally stressful setting for corals, high‐temperature events were likely mitigated by their short duration (< 37.4 h) and physical coupling with enhanced organic material. This hypothesis was supported by high‐density clustering of D. pertusum occurrences within 50 km around the Gulf Stream's position along the South Atlantic Bight. This suggests that cold‐water corals experiencing environmental variability can be sustained by relationships between food supply, temperature, and currents that vary in strength along stochastic time scales, shedding further light on the niche of cold‐water corals. [ABSTRACT FROM AUTHOR]

Endolithic sponges are key players in carbonate cycling on coral reef systems. While their bioerosion of reef framework is relatively well studied, their role in biogenic sediment generation is poorly understood. In this study, the sedimentary attributes and production rates of eight Caribbean endolithic sponge species were characterized. The findings revealed notable species‐specific variations in sediment production rates (range: 1.0–6.3 kg CaCO3 m−2 yr−1), alongside consistency in sediment characteristics (modal sizes ranging from 39 to 48 μm). The species‐specific rates were used to explore reef‐scale variations in sponge‐derived sediment generation across 50 reef sites in the Mexican Caribbean. Significant between‐site variability was observed, with estimated annual sediment production ranging from < 0.01 to 0.84 kg m−2 of reef. Production was primarily driven by sponge abundance, with discernible spatial variations in the contributions of different species, which could be related to variability in local environmental conditions. The rapidity at which these sediment producers can utilize dead coral substrates, coupled with their positive response to the changing marine environment, highlights the growing importance of these sponges in modern degraded Caribbean reef systems. [ABSTRACT FROM AUTHOR]

Ecosystem engineers are organisms that modify their physical habitats in a way that alters resource availability and the structure of the communities they live in. The evolution of ecosystem engineers over the course of Earth history has thus been suggested to have been a driver of macroevolutionary and macroecological changes that are observed in the fossil record. However, the rise to dominance of ecosystem engineers has not been thoroughly reconstructed. Here, we investigate the history of bioturbation and reef‐building (two of the most important marine ecosystem engineering behaviours today) over the Phanerozoic. Using fossil occurrences from the Paleobiology Database, we reconstruct how common communities influenced by ecosystem engineers were in the oceans, how dominant ecosystem engineers were within their own communities, and the taxonomic and ecological composition of bioturbators and reef‐builders. We find that bioturbation has become an increasingly common ecosystem engineering behaviour over the Phanerozoic, while reef‐building ecosystem engineers have not become more dominant since their Devonian apex. We also identify unique bioturbation and reef‐building regimes that are characterized by different ecosystem engineering taxonomic groups, ecological modes, and dominance, suggesting that the nature of ecosystem engineering has at times rapidly shifted over the course of the Phanerozoic. These reconstructions will serve as important data for understanding how ecosystem engineers have driven changes in biodiversity and ecosystem structure over the course of Earth history. [ABSTRACT FROM AUTHOR]

Xeniidae is a soft coral family that has contributed to the diversity of tropical coral reef communities, including those found in Southeast Asia. From 50 soft coral samples of the family Xeniidae collected from coastal fringing reefs along the coast of central Vietnam, five species have been recorded belonging to two genera, Xenia (two species) and Heteroxenia (three species). Of five species, two were recorded for the first time in Vietnam are Xenia novaebritaniae Ashworth, 1900 and Heteroxenia elisabethae Kölliker, 1874. An identification key was provided based on colony forms and morphological characters of sclerites for five xeniid corals in Vietnam. [ABSTRACT FROM AUTHOR]

This essay weaves an 'upena of critical discourse to contribute to a Kanaka Maoli abolitionist theory and praxis. Following the lead of Kumu Haunani-Kay Trask, I explore the intersection of the Black Radical Tradition and Critical Hawaiian Studies at the nexus of carcerality and multiple forms of Native and Black Dispossessions. Specifically, this essay builds upon Tiffany Lethabo King's The Black Shoals and George Terry Kanalu Young's Rethinking the Native Hawaiian Past to imagine and create freedom places beyond incommensurability. With a study of Pu'uhonua (places of refuge) I investigate the pilina (intimacies) between Indigenous resurgence and Black struggles for liberation and abolition. I argue that the comprehensive abolition of carceral systems and the ongoing resurgence of Pu'uhonua are cooperative projects that can be imagined and built upon the shoal and the Papa (reef/foundation) to create new futures for Black and Indigenous comrades in pursuit of collective liberation. [ABSTRACT FROM AUTHOR]

Simple Summary: Between 2012 and 2023, using non-invasive photo-identification techniques, 23 specimens of grey reef sharks were identified in the Mozambique Channel off Nosy Be, in an area called "Mokarran". Some specimens have been re-sighted in this area for up to 1982 days. A probable aggregation and nursery area for this species may have been identified off the coast of Madagascar and, if confirmed, it will be necessary to provide for its protection. Following preliminary underwater observations of about 1000 h carried out monthly between 2012 and 2023 (except the years 2021 and 2022), 23 specimens of grey reef sharks were spotted and photo-identified off the coast of Nosy Be in Madagascar, on an emerging reef called "Mokarran" at a depth between 15 and 30 m. Over 10 years of observations, eight specimens were re-sighted, identified with a non-invasive photo-identification technique of part of the first dorsal and the caudal fin, and one specimen was re-identified after 1982 days from the first sighting, i.e., after more than 5 years. In addition, six specimens of probably pregnant females were also identified in the same area. The population was entirely made up of females. The aggregation area could represent a new nursery site which, if confirmed after further investigations, will require greater protection. [ABSTRACT FROM AUTHOR]

Liquid CO2 phase transition fracturing involves a physical expansion process using CO2 as the medium,characterized by its excellent safety, controllability, and applicability. Currently, there are few case studies on the application ofthis technology in subaqueous reef cleaning, and there is a lack of instructive operational schemes. Based on the example of thewharf project in Yangkeng operation area of Yanping New City Port, Nanping Port, Fujian, the calculation method of CO2 phasetransition fracturing single -hole energy and the preliminary value of TNT equivalent required for a cubic reef fracturing areproposed, and the calculation method of main technical parameters of this technology in subaqueous reef clearing constructionis described [ABSTRACT FROM AUTHOR]

Mass culturing coral larvae collected from spawn slicks during spawning events and rearing them directly on reefs is an important method for coral reef restoration as it utilizes high genetic diversity and is readily upscaled. Understanding optimal initial stocking densities in mass cultures is, therefore, central to optimizing larval production efficiency. Yet, no studies have focused on optimizing initial stocking densities while coral embryos are still floating, despite the influence of density‐dependent effects during larval culturing. This study aimed to (1) explore initial stocking densities based on slick coverage and (2) determine the effects of initial densities on embryo development to coral settlement and early post‐settlement survival. Wild coral spawn slicks were collected at Lizard Island and reared at different combinations of slick coverage and density based on tank volume. Immediate density‐dependent effects were observed in treatments with 45% slick coverage, which had lower abundances of embryos 12 hours post‐spawning. The 12‐hour embryo densities ranged from 1.7 to 10.7 mL−1 and continued to display a negative relationship between density and survival of developing larvae. Overall, a density of approximately 5.1 embryos mL‐1 was the optimal stocking density for larval survival to competency (16.5%). The proportion of settlement and early post‐settlement survival was negatively correlated with higher initial densities, while a positive relationship was observed between the abundance of competent larvae and those settled, including initial settlers and 2‐month‐old recruits. These results highlight the importance of both larval quality and supply, and opportunities for site and system‐specific optimization of larval production in future work. [ABSTRACT FROM AUTHOR]

Determining the efficacy of restoration practices is critical for enhancing and rebuilding degraded ecosystems. A fundamental question in marine restoration design is whether to employ active (e.g. using living plants or oysters that form the biogenic habitat) or passive (e.g. restoring the hydrology and sediment materials at the site) restoration strategies. Furthermore, the identity of sources used in restoring biogenic habitats could influence the effectiveness of restoration efforts. We present results from two independent experimental restoration efforts designed to explore the efficacy of these different approaches for the recovery of Crassostrea virginica (eastern oyster) reef habitat. Conducted from 2015–2020 in Rhode Island, USA, the restoration experiments compared 1) passive (unseeded shell) vs. active (seeded spat on shell) restoration methods in Ninigret Pond, and 2) restored reefs seeded with hatchery sourced vs. wild oyster lineages in Quonochontaug Pond. In Quonochontaug Pond, the hatchery-sourced line exhibited greater mortality than the wild lines. Restored reefs in both projects remained viable all four years post-restoration; however, low recruitment continues to limit the long-term sustainability of restored reefs in these Rhode Island systems. Natural mortality varied spatially within each coastal pond, ranging from 33–81% per year. Across both experiments, oyster mortality increased with rising temperature, salinity, and disease prevalence. Our results suggest that utilizing active restoration with spat spawned from multiple sources, including wild populations, may improve the success of oyster restoration. Future habitat restoration efforts should consider the environmental variability associated with restoration sites and the source of restoration species during project planning. [ABSTRACT FROM AUTHOR]

Food webs in ecotones linking adjacent ecosystems may depend on cross-ecosystem subsidies. In surf zones of temperate sandy beaches, higher-level consumers often rely on intertidal prey that utilize allochthonous primary production. We evaluated the importance of phytoplankton and kelp-based prey, as well as physical characteristics of beaches, to diet of a surf zone fish, barred surfperch (Amphistichus argenteus), through stomach content and stable isotope analyses. Our results suggested that barred surfperch rely on prey from both phytoplankton and kelp-based subsidies, but their relative contribution to diet varied widely across beaches. Sand crabs (Emerita analoga), which depend on phytoplankton, were abundant at every beach, but their contribution to diet in stomach contents varied from 2 to 87% among sites. At the majority of beaches, δ13C values of fish muscle tissue, which reflects diet integrated over time, were within 0.5 ‰ of sand crab values, suggesting a reliance on phytoplankton-based prey. However, kelp-dependent prey associated either with beach wrack or subtidal reefs was also present in surfperch stomachs from all beaches (up to 41–72%). The notable enrichment in 13C of juvenile surfperch at two beaches and adults at one beach relative to sand crabs suggested a longer-term contribution of kelp-based prey to fish diet. The detection of kelp-based prey in surfperch diets also indicates the potential for reciprocal subsidies in these ecotones. Our results suggest trophic connectivity between surf zones and kelp forests and sandy beaches is spatially variable and that opportunistic higher-level consumers can shift their diet in response to the availability of phytoplankton and kelp-based food resources. [ABSTRACT FROM AUTHOR]

The Paleo-Mesoproterozoic North Singhbhum Mobile Belt (NSMB) is a fold-thrust belt typically found in a collisional setting and is well known for hosting gold mineralisation. A study carried out in the northern part of NSMB depicts varieties of acid volcanic rocks along with mica schist, ferruginous cherty quartzite, black shale, and sheared granite, which are all ubiquitously traversed by quartz veins/reefs. In the study area, gold mineralisation is mostly restricted to brecciated quartz reef occurring ENE–WSW along S1 foliation, which also depicts syn to late kinematic brittle–ductile shearing. The petrographic studies of mineralised cherty variant of quartzite in quartz reef depict the presence of two generations of the quartz vein. The older one is smoky/bluish, altered, recrystallised and consists of disseminated and stringers of pyrite, chalcopyrite, etc., whereas the younger veins are milky white and lack mineralisation. The presence of pyrite–pyrrhotite and chalcopyrite–pyrrhotite associations and conversion of pyrite to pyrrhotite along fracture depicts prograde metamorphism. Trace elemental mineral chemistry depicts significant Au enrichment in pyrite. A positive correlation between Co and Ni concentrations in pyrite indicates hydrothermal origin. Au–As ratio explains the enrichment of gold in pyrite, where gold occurs as a solid solution in pyrite, which is generally referred to as invisible gold. The presence of gold grains/nuggets at the microscopic level and in pan concentrate as well as considerable analytical value in bulk rock coupled with occurrence in sulphide structure, points towards the bimodal nature of gold mineralisation. Mode of occurrence, nature of mineralisation, and surficial, structural and mineralogical characteristics suggest gold mineralisation of the study area is of orogenic type. [ABSTRACT FROM AUTHOR]

This article discusses the resurgence of the invasive polychaete species Ficopomatus enigmaticus in the Caspian Sea. The Caspian Sea has been affected by natural and human activities, resulting in the introduction of non-native species. F. enigmaticus, which was introduced from the Black Sea and the Sea of Azov in the mid-20th century, is one of eight polychaete species found in the Caspian Sea. The presence of F. enigmaticus has ecological and economic impacts, as it can alter habitats and food webs. The study reports the first resurgence of F. enigmaticus in the southern coasts of the Caspian Sea, specifically in the Anzali Port and Caspian Port areas. The research collected samples from various stations to study the dynamics of the Caspian Sea ecosystem. The study found that F. enigmaticus established aggregations in the marina of Caspian Port, but not in Anzali port. Over time, the density of F. enigmaticus increased in the marina, covering the canal walls. The document also mentions the impact of F. enigmaticus on the local ecology, including its contribution to water purification and potential safety hazards for recreational users. The changing Caspian environment, such as declining sea levels, may create opportunities for new invasions of alien species like F. enigmaticus. [Extracted from the article]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Shifts from saltmarsh to mangroves are well-documented at mangrove poleward boundaries. A regime shift from intertidal oyster (Crassostrea virginica) reefs to mangrove islands has recently been documented in transitional phases in Florida, USA. To understand the local drivers of an oyster/mangrove regime shift and potential tipping points leading to a permanent mangrove state, we tracked all mangrove propagules (n = 1681) across 15 intertidal oyster reefs with or without adult mangroves for 15 months in Mosquito Lagoon, FL. While no propagule bottleneck was observed, few (3.2%) mangrove propagules/seedlings survived on reefs with no prior encroachment, compared to 11.3% and 16.1% on reefs with established older (pre-1943) or newer (1943 to present) adult mangrove stands, respectively. In total, 90.6% of the arriving propagules were from the red mangrove Rhizophora mangle; 13.2% of these were alive at the end of this study. Survival was <1% for black (Avicenna germinans) and 0% for white (Laguncularia racemosa) mangroves. Factors that promoted red mangrove success included close proximity (≤0.3 m) to adult mangroves, especially black mangroves; partial, upright burial of propagules in sediment; and arrival on reefs after annual high-water season. Additionally, once reefs had 50% mangrove cover, the density of red mangrove seedlings increased from 0.04 to 0.46 individuals m−2. Although climate change has alleviated the impact of extreme freezes on mangroves, local factors determine whether the regime shift will be complete and permanent; positive feedback loops associated with established mangroves suggest mangrove recruitment on intertidal oyster reefs will continue to increase. [ABSTRACT FROM AUTHOR]

Consumers can play critical roles in ecosystem resilience by modifying community resistance and recovery rates. In coral reefs, grazers can increase reef resilience by controlling algae and maintaining open space for coral recruitment, but can also erode the reef framework critical for coral recovery. Here we examine the context‐dependent effects of herbivores on reef persistence in Caribbean Panamá. Using a series of lab and field experiments, we found that the erosional effects of the herbivorous reef urchin (Echinometra viridis) were 2 orders of magnitude greater on dead corals than live corals, and surveys across multiple similarly overfished reefs revealed a positive relationship between urchin densities and percent cover of bare dead coral with urchin densities exceeding 150 m−2 in some reefs. However, we observed that a mat‐forming zoanthid (Zoanthus pulchellus), found exclusively on dead corals, had an inverse spatial relationship with urchins. Through a series of field experiments, we found that zoanthid overgrowth repelled urchins, increased dead coral persistence, and decreased erosion of dead corals making up the reef framework by more than 50% over a 22‐month period. Our findings reveal that zoanthids can provide associational refuge to dead corals by enhancing their persistence under high urchin grazing pressure. We suggest that secondary space‐holders, such as zoanthids, may play increasingly important functional roles in degraded reef systems by shielding coral skeletons from external bioeroders. Moreover, the Stress Gradient Hypothesis, which predicts that the importance of positive interactions such as associational refuges increases with consumer pressure, extends to dead foundation species such as coral skeletons crucial for ecosystem recovery. [ABSTRACT FROM AUTHOR]

Although position within the estuarine landscape is known to influence structural characteristics and ecological functioning of many habitats, the influence of position on subtidal oyster reef characteristics and functioning is relatively understudied. This study assessed habitat provision by oysters and benthic macrofauna on subtidal bar and patch oyster reefs within the northwestern Gulf of Mexico estuary. Bar reefs had greater and more variable oyster density, biomass, and volume, as well as dead shell material, compared to patch reefs. Benthic macrofaunal community composition differed between reef types, with bar reefs hosting 11× and 30× higher biomass of Porcellanidae and Ampithoidae crustaceans, and patch reefs supporting 34× and 47× higher biomass of Eunicidae annelids and Leptocheliidae crustaceans. The environmental variables most highly correlated with macrofaunal communities on both bar and patch reefs were sediment chlorophyll-a, volume of dead oyster shells, and depth. Despite differences in structural characteristics and position within the estuarine landscape, subtidal oyster reefs are often managed as a single habitat type. Our findings emphasize the importance of considering location in oyster reef conservation and restoration efforts to better predict and optimize faunal provision outcomes. [ABSTRACT FROM AUTHOR]

Two Egyptian funerary boat models found during the 1903 excavations of Beni Hasan and the 1910-11 excavations at Meir provide significant insights for the study of ancient sailmaking. These models are unique in that – unlike most Egyptian funerary models – they feature highly detailed sails, complete with seaming, tabling, boltropes, and a possible sail reduction system. This analysis, undertaken as part of the Historic Sail Research Project, employing both visual examination and experimental reconstruction, concludes that these sails likely represent an authentic sailmaking method from Egypt's Middle Kingdom, while also moving the known emergence of sail reduction systems back several centuries. [ABSTRACT FROM AUTHOR]

The timing of larval production and release of organisms is important in understanding their presence and prevalence in the environment. On the subtropical coral reefs around Okinawa Island, Japan, the reproductive timing of many soft coral species is still largely unknown. In this study, we report the first documentation of in situ external brooding and planulae release of a stoloniferan octocoral observed on the coral reefs of Okinawa Island. We observe external brooding of embryos and developing larvae on the colony surface and the subsequent planulation of some azooxanthellate larvae of Clavularia cf. inflata from two coral reef sites in the northwestern region of Okinawa Island. These observations indicate that this species reproduces concurrently with other zooxanthellate coral reef anthozoans in the summer season. [ABSTRACT FROM AUTHOR]