Reef Features Research Articles

Editorial preface to special issue: Paleoecology and evolution of Paleozoic corals and reef ecosystems

The Paleozoic Era was an interval of profound changes in metazoan reef ecosystems, which became magnificent in scale and diversity, owing to the evolution of various skeletal reef builders especially corals and sponges. This special issue comprises 16 papers that improve our understanding on the complex evolution and paleoecology of corals and metazoan reef ecosystems, and their response to environmental changes through the Cambrian to Permian. The case studies present detailed evidence that helps to reconstruct the complicated interactions among reef organisms, the succession of metazoan reefs, and their relations to paleoenvironments. Some key findings address (i) Cambrian reefs and microbe–metazoan reef transition to the Ordovician, (ii) reef component and paleoecological features of Siluro-Devonian coral-stromatoporoid reefs, and (iii) growth characteristics, paleogeography, and reef formation of Late Paleozoic corals and sponges. As such, this special issue will stimulate further work on reef studies and be of interest to a broad community of paleoecologists, to scholars in various fields of the geosciences as well as to reef biologists.

Multi-Scale Coral Reef and Seascape Habitat Variables Combine to Influence Reef Fish Assemblages

While benthic characteristics of coral reef habitats are a major driver of the structure of coral reef fish assemblages, non-reef habitats adjacent to coral reefs (e.g., mangroves, seagrass beds, and macroalgal beds) can affect reef fish assemblages. Here, we investigate how reef fish assemblages respond to local-scale benthic habitats within a coral reef and larger-scale adjacent seascape features (habitats within 500 m of coral reefs) on Siquijor Island in the Philippines. We examined an abundance of species for the entire reef fish assemblage and within the assemblages of parrotfishes (subfamily Scarinae) and wrasses (family Labridae). Five distinct habitat types were identified in a cluster analysis, which incorporated benthic characteristics within coral reefs and habitats adjacent to coral reefs. We found that the diversity and structure of coral reef fish assemblages were affected by benthic characteristics within coral reefs and also by benthic habitat types adjacent to coral reefs. Individual species responses and juveniles of certain species demonstrated uniquely high abundances in habitat clusters characterized by the non-reef habitats surrounding coral reefs. Considering coral reef habitats and adjacent non-reef habitats as a holistic, interconnected seascape will provide better estimations of the drivers of the structures of coral reef fish assemblages.

Microorganisms and dissolved metabolites distinguish Florida's Coral Reef habitats.

As coral reef ecosystems experience unprecedented change, effective monitoring of reef features supports management, conservation, and intervention efforts. Omic techniques show promise in quantifying key components of reef ecosystems including dissolved metabolites and microorganisms that may serve as invisible sensors for reef ecosystem dynamics. Dissolved metabolites are released by reef organisms and transferred among microorganisms, acting as chemical currencies and contributing to nutrient cycling and signaling on reefs. Here, we applied four omic techniques (taxonomic microbiome via amplicon sequencing, functional microbiome via shotgun metagenomics, targeted metabolomics, and untargeted metabolomics) to waters overlying Florida's Coral Reef, as well as microbiome profiling on individual coral colonies from these reefs to understand how microbes and dissolved metabolites reflect biogeographical, benthic, and nutrient properties of this 500-km barrier reef. We show that the microbial and metabolite omic approaches each differentiated reef habitats based on geographic zone. Further, seawater microbiome profiling and targeted metabolomics were significantly related to more reef habitat characteristics, such as amount of hard and soft coral, compared to metagenomic sequencing and untargeted metabolomics. Across five coral species, microbiomes were also significantly related to reef zone, followed by species and disease status, suggesting that the geographic water circulation patterns in Florida also impact the microbiomes of reef builders. A combination of differential abundance and indicator species analyses revealed metabolite and microbial signatures of specific reef zones, which demonstrates the utility of these techniques to provide new insights into reef microbial and metabolite features that reflect broader ecosystem processes.

Integrating assemblage structure and habitat mapping data into the design of a multispecies reef fish survey

AbstractObjectiveSince 2010, three spatially disjunct reef fish video surveys have provided fishery‐independent data critical to the assessment and management of reef fishes in the Gulf of Mexico. Although analytical approaches have recently been developed to integrate data from these surveys into a single measure of relative abundance and size composition, a more parsimonious approach would be to integrate survey efforts under a single Gulf‐wide survey design. Accordingly, we conducted a retrospective analysis of historical video‐ and habitat‐mapping data to develop a novel stratified random sampling design for conducting surveys of natural and artificial reef habitats.MethodsWe conducted a series of classification and regression tree analyses to delineate both spatial and habitat strata, and conducted simulations to assess the performance of an optimized survey design.ResultSpatially, classification and regression tree results identified three depth strata (10–25 m, >25–50 m, >50–180 m) and three regional strata (north‐central Gulf, Big Bend, southwest Florida) in the eastern Gulf. For both natural and artificial reefs, habitat strata were delineated based on a combination of relative relief (low, medium, high) and size of the individual reef feature, although reef scale differed markedly between natural (<100 m2, 100–1000 m2, >1000 m2) and artificial habitats (<25 m2, 25–100 m2, >100 m2). To optimize effort among sampling strata, effort was allocated proportionally based on a combination of habitat availability and managed‐species richness for each stratum. Simulation results indicated that relative median biases were <10% and relative median absolute deviations <30% on estimates of abundance for most species examined on natural reefs under the optimal design, except Greater Amberjack Seriola dumerili. These measures of bias and imprecision were similar or higher for most species simulated using simple random and stratified random survey designs. Estimated relative median bias and relative median absolute deviations were notably higher for artificial reef surveys.ConclusionBased on these results, survey efforts were integrated as the Gulf Fishery Independent Survey of Habitat and Ecosystem Resources (G‐FISHER) in 2020.

Relating fish populations to coral colony size and complexity

A goal of coral reef management is to provide habitat and nursery areas for fish populations. This requires simple and reliable methods for characterizing biological and physical reef features that contribute to fish habitat. Most attempts to establish this relationship have been performed on small-scale, site-specific study areas where variability in fish populations and reef structure is limited and results may be insufficiently robust for extrapolation beyond those sites. Most studies also include geological structures, like ridges and rock formations that provide fish habitat but are not amenable to management action. A focus on the role of Scleractinia (stony corals) may better inform decisions aimed at improving fish habitat. Stony corals provide the structural foundation of coral reefs and are the target of numerous management actions. Data from three broad-area, multi-station reef surveys of fish and stony coral colonies were examined to identify correlations between fish population measures (density, taxa richness and biomass) and both biological (taxa richness and live surface area) and physical (number, size and structural complexity) attributes of scleractinian coral populations. Strongest correlations were found with physical coral features, particularly coral colony height. Characterizing this relationship will improve fishery management tools and support status and trend assessment of the worldwide decline in the physical stature of reefs.

Alexander Dalrymple, the Utility of Coral Reefs, and Charles Darwin's Structure and Distribution of Coral Reefs.

This paper aims to establish the connection between the theoretical and practical aims of the Office of the Hydrographer of the British Admiralty and Charles Darwin's (1809-1882) work on coral reefsfrom 1835 to 1842.I also emphasize the consistent zoological as well as geological reasoning contained in these texts. The Office's influences have been previously overlooked, despite the Admiralty's interest in using coral reefs as natural instruments. I elaborate on this by introducing the work of Alexander Dalrymple (1737-1808), the first hydrographer of the Admiralty and a figure who has flown under the radar of the history of coral reef theories. I show that Dalrymple introduced a unified account of coral reefs in which multiple features of the coral reefs, such as their shape, slope of the sides, ridges, channels, and elevation relative to the water, were all explained by the action of the winds and waves-and proposed that one could use these features to predict seafaring conditions around the islands. Then, I show that Darwin's "Coral Islands" (1835) and his Coral Reefs monograph (1842) spoke to these hydrographical issues and did so, at times, by way of zoological reasoning. It was, for instance, the coral behavior and the related notion of a zoological or botanical station that ultimately proved the biggest blow to the Admiralty's aim to use the coral reefs as instruments because it eroded many uniform predictions regarding the past or future of a coral reef. Connecting these themes leads us to a surprising conclusion: that Darwin's theory of coral reefs, long a model instance of Darwin making uniform predictable inferences, was, in actuality, also his first formal encounter with something at times the entire opposite.

Cambrian Series 2 (Stage 4) calcimicrobial reefs in Shandong Province, North China: Calcimicrobial diversity and contribution to reef construction

Calcimicrobes together with archaeocyaths became significant in reef construction during the early Cambrian; however, purely calcimicrobial reefs have not been as well documented as archaeocyath-bearing reefs. Here we describe the age-specific features of calcimicrobial reefs of the Zhushadong Formation (Cambrian Series 2, Stage 4) at the Sunmayu and Jinhe sections in Shandong Province, North China. The calcimicrobial reefs of the Sunmayu section are constructed mainly by Epiphyton, Kordephyton, and tubiform microbes. The reefs are in some cases dominated by Amgaina, passing from a framework of Kordephyton, Epiphyton, and tubiform microbes to dendritic growth of Epiphyton, and finally to aggregations of Amgaina. Calcimicrobial reefs in the Jinhe section are likewise constructed mainly by Epiphyton, Kordephyton, and tubiform microbes, but with subordinate Tarthinia and Bija. Epiphyton and Kordephyton as well as Amgaina were thus the main framework builders in the Zhushadong calcimicrobial reefs. Tubiform microbes contributed as encrusters, enhancing the framework rigidity, whereas Tarthinia and Bija played subordinate roles as encrusters and consolidators. Interreef deposits of the Sunmayu reefs are of peloidal or ooidal grainstone; these reefs are inferred to have formed in a high-energy shoal setting. In contrast, interreef deposits of the Jinhe reefs are of peloidal and intraclastic wackestone or grainstone with bioclasts such as trilobites and hyoliths. Tubular cavities, possibly representing burrows, are common in the spaces among frameworks. These calcimicrobial reefs are interpreted to have formed in a subtidal setting, where the water energy was lower than that in the Sunmayu section. In North China, reefs of Cambrian Epoch 2 are limited, as development of the carbonate platform began only toward the end of that epoch. The reefs of the Zhushadong Formation are therefore among the earliest on the North China Platform. The calcimicrobial reefs contain various kinds of calcimicrobes, and the calcimicrobial assemblages are similar to or more diverse than those of coeval archaeocyath-bearing reefs during this period of archaeocyath decline. Calcimicrobes thus flourished at that time and contributed greatly to the construction of reefs. These purely calcimicrobial reefs provide further information on the spatial and temporal changes in calcimicrobial diversity and reef construction during the period before and after the extinction of archaeocyaths.

Identifying Hydraulic Characteristics Related to Fishery Activities Using Numerical Analysis and an Automatic Identification System of a Fishing Vessel

Many countries worldwide promote artificial reef projects to increase and preserve fishery resources; however, how artificial reefs form fisheries is unclear. Nevertheless, specific hydraulic features of artificial reefs may attract fish. We selected an underwater reef as a research site to clarify this hypothesis. In this study, environmental conditions around the underwater reef were modeled and quantitatively assessed using numerical analysis. We identified two hydraulic features related to fish attraction: the wake region and the local upwelling region. Their spatial distributions were superimposed on the path of a fishing vessel that was monitored using an automatic identification system (AIS). We showed that various hydraulic characteristics (such as wake region, local upwelling region, and flow velocity) identified in the path of the fishing vessel can be quantitatively evaluated. Increasing amounts of information from the AIS can be used to identify the hydraulic features that attract the most fish and therefore improve the productivities of artificial reefs.

Patch reefs as sources of long and continuous skeletal records of horizontal reef expansion in Dongsha Atoll, South China Sea

Atolls are annular midocean reefs with various topographical features. The reef rim of an atoll encloses a central lagoon and lagoonal patch reefs therein. Two hypotheses explaining the origins of patch reefs in atoll lagoons have been developed: the karst hypothesis and the growth hypothesis, which emphasize the role of uneven erosion and uneven timing of reef accretion (especially horizontal expansion), respectively, in the formation and growth of patch reefs. In this study, we investigated trends in the locations, depths, ages, sizes, and other features of flat-top and pinnacle-top reefs in the Dongsha Atoll in the South China Sea by analyzing bathymetric LiDAR images and performing U-Th dating on samples we collected from various reefs in the atoll. Three of our main findings were consistent with the growth hypothesis: (1) the differences in ages of the centers of different flat-top patch reefs reflected the different times at which each patch reef reached the surface and started to expand horizontally; (2) the top surfaces of individual flat-top patch reefs had old centers and young peripheries, reflecting horizontal growth; and (3) all the pinnacle-top reefs we examined had more live corals on their tips than on the surrounding bases. We observed no positive correlation between the ages of the centers and the diameters of flat-top patch reefs; that is, larger reefs did not necessarily have older centers, indicating that various complex factors affect the expansion and age patterns of patch reefs. Overall, the findings of this study provide support for the growth hypothesis and for the use of flat-top patch reefs as sources of easily accessible long-term coral skeletal records. They may therefore serve as a reference for future studies on asymmetric reef expansion and other relevant topics.

Assessment of the Sabellaria alveolata reefs’ structural features along the Southern coast of Sicily (Strait of Sicily, Mediterranean Sea)

The honeycomb worm Sabellaria alveolata is a gregarious tube-dwelling polychaete that builds remarkable biogenic reefs in marine coastal waters. Sabellaria alveolata reefs are considered valuable marine habitats requiring protection measures for their conservation, as they play a key role in the functioning of coastal ecosystems. Sabellarid reefs are extensively developed along the Atlantic coasts of Europe and reported for the Mediterranean Sea and the Italian coasts, where large reefs have been recorded in several localities. Fragmentary information is available on their health status, Sabellaria reefs thus being listed as “Data Deficient” in the Red List of Marine Habitats. To fill this knowledge gap, this study focused on the analysis of the structure of three reefs found along the southern coast of Sicily. In particular, we aimed to assess their phases with respect to the natural cycle that characterizes the sabellarid reefs. Reef features were analyzed both on the macroscale, based on the bioconstruction size (diameter and thickness) and degree of fragmentation, and on the microscale, based on the measurement of worm density, opercular length and sand porch presence. This study reveals relevant differences among reefs of the studied locations. These differences we attributeto the temporal shift linked to the natural reef phases, albeit further analyses are needed to understand the possible effect of natural and anthropogenic sources of variation on the Southern Sicilian reefs. In conclusion, Sabellaria reefs are a unique and persistent habitat along the Sicilian coast requiring proper management and conservation measures.

Variation of mean flow and turbulence characteristics within canopies of restored intertidal oyster reefs as a function of restoration age

The ecological benefits of healthy oyster populations have led to mounting interest in restoration of degraded reef habitats and design of nature-based reef features. However, hydrodynamic studies of restored oyster reef remain sparse, and little is known about changes in mean flow and turbulence as a function of time since restoration. In this study, we investigate hydrodynamic differences between restored (restoration age: <1 y, 2 y, 4 y), degraded, and intact intertidal oyster reefs in a shallow, microtidal estuary. Field experiments conducted at each reef were designed to characterize variability in flow and turbulence associated with differences in reef morphology and restoration age, addressing research questions of whether and when hydrodynamic function is reestablished following restoration. Minor differences in normalized turbulence parameters within the canopies of restored and reference reefs (2 cm above bottom) were associated with variable channel-to-reef velocity attenuation, which was linked to heterogeneity in oyster canopy structure as characterized by high-resolution laser scans. Within-canopy turbulence characteristics and normalized Reynolds stresses were significantly elevated on restored and reference reefs compared to the degraded reef, emphasizing the role of reef restoration in changing near-bed hydrodynamics. Above-canopy (9 cmab) turbulence was hydrodynamically similar across live reference and restored reefs of all restoration ages, with estimated roughness heights that scaled with the canopy height. Comparisons between intact and restored reefs indicate that properly restored reefs can reach hydrodynamic similarity with historically intact reefs within 1 year of restoration, a conclusion that supports the use of reef restoration as a tool to reestablish hydrodynamic functions on degraded reefs.

Biogeography of reef water microbes from within-reef to global scales

Seawater microorganisms play an important role in coral reef ecosystem functioning and can be influenced by biological, chemical, and physical features of reefs. As coral reefs continue to respond to environmental changes, the reef seawater microbiome has been proposed as a conservation tool for monitoring perturbations. However, the spatial variability of reef seawater microbial communities is not well studied, limiting our ability to make generalizable inferences across reefs. In order to better understand how microorganisms are distributed at multiple spatial scales, we examined seawater microbial communities in Florida Reef Tract and US Virgin Islands reef systems using a nested sampling design. On 3 reefs per reef system, we sampled seawater at regular spatial intervals close to the benthos. We assessed the microbial community composition of these waters using ribosomal RNA gene amplicon sequencing. Our analysis revealed that reef water microbial communities varied as a function of reef system and individual reefs, but communities did not differ within reefs and were not significantly influenced by benthic composition. For the reef system and inter-reef differences, abundant microbial taxa were found to be potentially useful indicators of environmental difference due to their high prevalence and variance. We further examined reef water microbial biogeography on a global scale using a secondary analysis of 5 studies, which revealed that microbial communities were more distinct with increasing geographic distance. These results suggest that biogeography is a distinguishing feature for reef water microbiomes, and that development of monitoring criteria may necessitate regionally specific sampling and analyses.

A novel feature descriptor based coral image classification using extreme learning machine with ameliorated chimp optimization algorithm

Coral reefs are one of the most biodiverse and productive ecosystems on earth, which acts as a habitat and provides food to a wide range of organisms. The coral reefs protect the coasts from storms, waves, and erosion. Unfortunately, this ecosystem is under threat by various natural and manmade factors, including pollution, ocean acidification, sedimentation, and climate change. The marine ecosystems need to be monitored regularly in order to minimize the aforementioned threats. Hence, an automated classification system is necessary for the classification of coral images. In this paper, a novel method called “Systematic Local Directional Encoded Derivative Binary Pattern” (SLDEDBP) is proposed to extract the coral reef feature values. In this descriptor, the feature values are derived using two phases: Local Directional Derivative Binary Pattern (LDDBP) and Systematic Local Discriminate Binary pattern (SLDBP). In the LDDBP phase, the eight directional kirsch mask is employed in each 3 × 3 neighbourhood window to extract the directional edge response of an image. Then, in the SLDBP phase, the local neighbourhood pixel values are divided into four non-overlapping groups of Z, M, TZ (Tilted Z), and TM (Tilted M) to extract unique features values by considering the centre pixel value in a 3 × 3 neighbourhood window. Finally, the derived feature values of LDDBP and SLDBP are concatenated to procedure final discriminate feature values. The extracted feature values of coral images are applied to a hybridized method called Ameliorated Chimp Optimization Algorithm with Extreme Learning Machine Classifier (AChOA-ELM) to optimize the relative weight of the input and biases of neural networks. This avoids overfitting and makes the model more generalized and robust. The proposed AChOA-ELM method performance is evaluated using different databases of coral and standard images. The reliability of the proposed model has been evaluated utilizing the model performance metrics, accuracy (ACC), true positive rate (TPR), true negative rate (TNR), false-positive rate (FPR), precision (PRC), positive predictive value (PPV), and F1 score. The findings reveal that the proposed hybrid AChOA-ELM achieves greater classification accuracy with a faster coverage rate than other existing methods. In the presence of the image data augmentation technique, the EILAT2 dataset achieves the highest classification accuracy of 99%, whereas MLC dataset achieves the lowest classification accuracy of 94.86%.

SCUBA tourism and coral reefs: a social-ecological network analysis of governance challenges in Indonesia

ABSTRACT In this article, we conduct a social-ecological network analysis of SCUBA tourism human–environmental interactions in the Gili MATra Marine Park in Indonesia. Network methodologies are being increasingly applied, but this study represents – to our knowledge – a first example focusing on the governance of the SCUBA tourism sector. We developed a novel mixed methodology for data collection, data integration and data analyses specific to SCUBA tourism to understand human–nature interactions. This includes interviews with business operators, the use of secondary data on reef compositions and health, and a randomized survey sample of SCUBA tourist perceptions. Our findings indicate a densely interconnected network of social cooperation driven by older and larger businesses with historical leadership roles. High intensity and partially selective patterns of reef use exist, explained by numerous factors including tourist preferences for reef features, site names and business location. However, the analysis of ecological connectivity indicates high dive site similarity, suggesting that alternative sites exist for reducing crowds and increasing safety while still meeting tourist preferences. We discuss methodological innovations and linking results to context with qualitative data. We also propose social-ecological hypotheses (motifs) linked to system outcomes for future SCUBA tourism research.

Wave Energy Dissipation in a Shallow Coral Reef Lagoon Using Marine X‐Band Radar Data

AbstractA novel approach for estimating wave energy dissipation on a coral reef barrier is studied using X‐Band radar technology. The prominent features of coral reefs, including the delineation of reef morphological structure, wave energy dissipation and wave transformation processes are obtained in a reef lagoon in San Andres Island, Colombia. Results show that reef attenuates incident waves by approximately 75% due to both frictional processes and wave breaking, with an equivalent bottom roughness of 0.20 m and a wave friction factor of 0.18. These parameters are comparable with estimates reported in other shallow coral reef lagoons as well as at seagrass meadows obtained using in‐situ measurements. Also, the mean height of the reef elements Hbed and its standard deviation σb are also estimated in the entire radar coverage area. Hbed and σb (0.5 and 7.66 cm respectively) are in the same order of magnitude of measured data reported by previous studies and in good agreement with the geometric parameters proposed by in‐canopy flow models for branched species, such as Stylophora and Pocillopora, which are also common in the coral carpets of San Andres Island. This work proposes a completely novel use for X‐Band radars by describing prominent features in barrier‐reef systems including the delineation of the reef structure and wave energy dissipation.

Benefits beyond 'features': Cooperative monitoring highlights MPA value for enhanced seabed integrity

The global marine environment has seen recent rapid growth in Marine Protected Areas (MPAs). In UK (English) waters, MPAs incorporate Special Protection Areas (SPAs), Special Areas of Conservation (SACs) and Marine Conservation Zones (MCZs), each with specific conservation objectives. In accordance with legislation, the UK has adopted a feature-based approach to MPA designation and monitoring, whereby protection of listed species and habitats are prioritised. The Eddystone Reef (part of the Start Point to Plymouth Sound and Eddystone SAC, South West UK) is designated solely for its reef features. The reef is at high risk from fisheries, particularly bottom-towed fishing gear. On 1st of January 2014 bottom-towed fisheries were prohibited within designated areas of the reef. In this study, images from drop-down camera surveys were analysed to quantitatively assess patterns in diversity and abundance of benthic fauna on reef and mixed substratum habitats that are closed, and remain open, to bottom-towed fisheries. Coarse sediments in areas closed to bottom-towed gear supported a greater abundance of sessile, upright, slow growing species (e.g. pink sea fans, ross coral, branching sponges) than were present in areas still actively towed over. Coarse sediments open to bottom-towed gear had greater abundances of motile, scavenging or opportunistic species. This study highlights the potential for positive conservation benefits beyond the traditional feature-based approach to MPA designation and monitoring. Further conservation gains could be made by reducing fragmentation of protected habitats and by increasing area coverage of statutory controls on bottom-towed fishing in already designated MPAs.

Coral reef pore recognition and feature extraction based on borehole image

The coral reef pores are the main reservoir space of oil and gas resources. Through determining the structural form and distribution characteristics of pores, it can be helpful for scientific and reasonable stratigraphic division and reservoir evaluation, and provide basic data for the efficient development of using coral reefs as oil and gas reservoir sites. The core difficulty of interpretation and evaluation of coral reef pore structure and distribution characteristics is the pore recognition and feature extraction. In view of problems of low accuracy and efficiency in the recognition and feature extraction of coral reef pore at present, this paper proposes a method of coral reef pore recognition and feature extraction based on borehole image data. First of all, based on the borehole image and combined with the pore characteristics in borehole image, this paper proposes the coral reef pore recognition method. By using the feature of color gradient difference between the pore and the non pore in the borehole image, it realizes the segmentation of coral reef pore with low noise and weak interference. On the basis of obvious coral reef pores, the contour tracking method and image filling system of coral reef pore are established. Then, on the basis of traditional eight connected region marking algorithm, a pore region feature extraction method is proposed. The equivalent relationship between the temporary mark and the final mark is established, and an evaluation criterion that can comprehensively reflect the pore region feature parameters in the borehole image is formed. Finally, a systematic analysis and a comparison of results are carried out based on the actual coral reef borehole images. The results are consistent with the real values, which verifies the correctness of method.

Reading Reef in the Anthropocene

Set between Sri Lankan independence and the outbreak of civil war, Romesh Gunesekera’s Reef features a marine biologist named Salgado who predicts the decay of the island’s coral exoskeleton, a fragile barrier against inundation by the sea. Critics overwhelmingly view the eroding reef as a symbolic harbinger of the violence that eventually engulfed Sri Lanka. But this essay takes the novel’s motif of dying coral and rising seas more literally, reading Reef as an incipient work of postcolonial Anthropocene fiction. A finalist for the 1994 Booker Prize, Reef preceded a wave of climate novels published by prominent authors after the turn of the millennium. More remarkable, it appeared five years before the first major report linking widespread coral damage to anthropogenic climate change. While Salgado’s research serves as a failed fictional antecedent to these findings, his servant Triton ultimately perceives that carbon emissions are destroying the reef. Indeed, what makes Gunesekera’s novel a postcolonial work of Anthropocene fiction is precisely Triton’s status as a servant. I argue that this status not only enables Triton to perceive the material and social conditions that cause climate change. It also shapes his interspecies perspective, allowing Triton to think and feel like a reef.

Quantifying Social-Ecological Scale Mismatches Suggests People Should Be Managed at Broader Scales Than Ecosystems

<h2>Summary</h2> The management of natural resources creates feedbacks between ecosystems and societies, both of which exist at characteristic scales. Theory predicts that sustainability is higher when governance and management scales align with scales of ecological heterogeneity. We analyzed the areas of institutions (10,030 permissions from 7,478 permits in the Great Barrier Reef Marine Park, 2007–2017) and compared these with the areas of reef features and non-reef marine bioregions. Permission extents were bimodal; 72% were fine scale (median 16.5 km²), and 28% were broad scale (median 99,193 km²). Biophysical data were unimodal and at significantly smaller scales than permissions. Different permission scales for different activities indicated adaptability within the permitting system. Our analysis demonstrates a new approach to quantifying scale mismatches. It suggests that discrete institutional scales exist but differ from ecological scales and that rules at broader scales than the managed resource may allow greater adaptation and responsiveness by human users than rules at the same scales.

Using remote sensing techniques to interpret geomorphological features along the east coast of the Red Sea, at Yanbu, Saudi Arabia

Yanbu is the second largest port and population settlement on the Saudi Arabian Red Sea coast. With the increasing development of its nearby coast, the geomorphological characteristics of the region must be studied in detail in order to inform future developments of the region. This study examines the region’s suitability for future development. A high-resolution map of the coastal area under study was drawn by analysing Shuttle Radar Topography Mission-Digital Elevation Model (SRTM-DEM) data and Advanced Spaceborne Thermal Emission and Reflection Radiometer-Digital Elevation Model (ASTER-DEM) data, using remote sensing images from Landsat satellites. Landsat ETM+ images taken in 2000 and 2015, alongside remote sensing analyses, field observations, and geological mapping, were used to describe the geomorphological and topographical characteristics of the Yanbu coast. Both principal component analysis (PCA) and false colour composite (FCC) were the most effective remote sensing techniques for mapping the geomorphological characteristics of the coastal plain. The true colour of the combination bands 3, 2, and 1 was the best at showing the areas and features of coral reefs. Thus, the main geomorphological units in the study area were identified, including wadi systems, dunes, alluvial fans and fan deltas, fluvial terraces, sabkhas, coral reefs, platform reefs, islands, sharms, and sea heads.