Search

A coordinated multi-year ocean exploration campaign on the Blake Plateau offshore of the southeastern U.S. has mapped what appears to be the most expansive cold-water coral (CWC) mound province thus far discovered. Nearly continuous CWC mound features span an area up to 500 km long and 110 km wide, with a core area of high-density mounds up to 254 km long by 42 km wide. This study synthesized bathymetric data from 31 multibeam sonar mapping surveys and generated a standardized geomorphic classification of the region in order to delineate and quantify CWC mound habitats and compare mound morphologies among subregions of the coral province. Based on the multibeam bathymetry, a total of 83,908 individual peak features were delineated, providing the first estimate of the overall number of potential CWC mounds mapped in the region to date. Five geomorphic landform classes were mapped and quantified: peaks (411 km2), valleys (3598 km2), ridges (3642 km2), slopes (23,082 km2), and flats (102,848 km2). The complex geomorphology of eight subregions was described qualitatively with geomorphic “fingerprints” (spatial patterns) and quantitatively by measurements of mound density and vertical relief. This study demonstrated the value of applying an objective automated terrain segmentation and classification approach to geomorphic characterization of a highly complex CWC mound province. Manual delineation of these features in a consistent repeatable way with a comparable level of detail would not have been possible.

Coral–algal interactions are pivotal in reef ecosystems globally as they can scale up ecosystem levels and lead to dominance shifts. In this study, we conducted a systematic review of global coral–algal interactions, identifying the most studied locations, species, and types of interactions. We then assessed how these interactions may be impacted by consumers and climate change. Over the past 20 years (2001–2020), coral and algae interactions were mostly explored in the Pacific, and the Caribbean and US East Coast, where branching and massive corals were the focus, while other coral growth forms received less attention, and effects on algae were often overlooked. Adult corals were generally reported to be damaged when directly interacting with algae through physical abrasion or allelopathy. Conversely, algae interactions were found to have a positive impact on juvenile corals by facilitating larval recruitment and settlement. As expected, coral–algal interactions and the type of coral–algal relationships vary globally, most likely due to differences in abiotic conditions, community composition and the number of studies performed in a region. Despite the large emphasis on the role of consumers in controlling coral–algal interactions, few studies directly explored the effects of herbivory on coral–algal interactions. Given the growing evidence that ocean warming and acidification can reduce the competitive ability of corals, understanding the dynamic relationships between coral, algae, and consumers under future climate change conditions is crucial in predicting future coral recruitment potential and reef composition patterns. Here, we highlight the main findings from coral–algal interaction studies performed in the last 20 year and point to future directions, such as: 1) diversifying location, coral species, growth forms and life phases; 2) considering effects on both sides of interaction, not neglecting effects on algae; and 3) taking a closer look into the role of consumers and microbiomes. Advancing our understanding of coral–algal interactions, as well as how these interactions shift under changing conditions, is critical in predicting how coral reef ecosystems may operate in the future. [ABSTRACT FROM AUTHOR]

The effect of microbial binding for the stabilization of steep carbonate slopes is well documented in Cenozoic examples but its significance and relationship with abiotic marine cements in Paleozoic reef systems and steep slopes is not clearly established. Here, samples from a Late Silurian (Ludlovian) reef complex are evaluated by using an integrated approach that involves petrographic and isotope analyses, cathodoluminescence microscopy, and environmental scanning electron microscopy. This study reveals the in situ production of mineral fabrics of microbial origins, including micrite, peloidal micrite with dendritic fabrics, meniscus, and bridge-like cements. This study stresses the leading role of microbes in the early lithification stages that led to the stabilization of Silurian steep carbonate slopes. These findings are further supported by the occurrence of fossilized microbes and extracellular polymeric substance. The micritic cements are the first step in the diagenetic paragenesis followed by abiotic fibrous and equant calcite cements whose stable isotope values are in concert with estimated values of calcite precipitated in equilibrium with Silurian seawater. Results from this project provide insights into the relationship between microbial binding and early abiotic marine cements in ancient reef systems and, further, provide evidence for a consortia of microbes that existed 440 Ma ago. [ABSTRACT FROM AUTHOR]

Coral reefs globally are experiencing more frequent and severe warming events due to anthropogenic driven climate change. Subtropical reefs experience more seasonal variability than lower latitude reefs making them typically more resilient to climate change. With relatively stable coral cover in comparison to other global coral reefs, Flower Garden Banks National Marine Sanctuary (FGBNMS) in the Gulf of Mexico is a series of 17 reefs and banks located on the continental shelf‐edge containing a variety of shallow (0–30 m) and mesophotic (30–150 m) coral reef habitats. Here, we use satellite data products to associate open ocean Argo float profiles with eddy features over FGBNMS to study the shelf‐edge reef environment spanning nearly two decades (2003–2022). Satellite data show that FGBNMS is frequently influenced (∼15 days/month) by mesoscale eddies. The upper water column variability (0–25 m) is most influenced by the seasonal mixed layer despite eddy interaction. Subsurface seasonal ranges of temperature and salinity are enhanced or suppressed depending on the influence of eddies in relation to the mixed layer depth. Within the mesophotic zone (0–150 m), the largest range of thermal variability between anticyclonic and cyclonic eddies is between 50 and 150 m upwards of 5°C. However, these observed dynamics will likely change as a result of eddy variability associated with projected warming and Loop Current weakening, leading to increased thermal stress in the future. Plain Language Summary: Coral reefs globally are threatened by climate change, yet some reefs are less impacted than others, such as coral reef habitats in Flower Garden Banks National Marine Sanctuary (FGBNMS) located in the northwestern Gulf of Mexico. This study demonstrates an exposure to large temperature and salinity ranges across different depths throughout the year which may aid in the resiliency and longevity of this ecosystem. The Gulf of Mexico contains some of the most energetic eddies, or spinning currents, in the world. While these eddies originate in the open ocean, they are mobile features that move onto FGBNMS over the shelf‐edge ∼15 days/month, translating open ocean physical and biogeochemical signatures. Here we find that the eddies on FGBNMS show significant alterations to temperature and salinity conditions. Importantly, the physical oceanography driving the eddy field is expected to weaken under climate change, potentially threatening this unique shelf‐edge reef system, and subjecting the coral reef habitats to warmer ocean temperatures in the future. Key Points: Argo floats can be used to study open ocean eddies that translate physical and biogeochemical conditions over the continental shelf‐edgeEddies increase the range of thermal variability within Flower Garden Banks National Marine Sanctuary half of the days in each monthMixed layer depth changes seasonally and within eddies, influencing temperature and salinity ranges over the reef [ABSTRACT FROM AUTHOR]

Population estimates are required for effective conservation of many rare marine species, but can be difficult to obtain. The critically endangered red handfish (Thymichthys politus) is a coastal anglerfish known only from two fragmented populations in southeast Tasmania, Australia. It is at a high risk of extinction due to low numbers, loss of habitat, and the impacts of climate change. To aid conservation efforts, we provide the first empirical population size estimates of red handfish and investigate other important aspects of the species' life history, such as growth, habitat association, and movement. We surveyed both red handfish local populations via underwater visual census on scuba over 3 years and used photographic mark‐recapture techniques to estimate biological parameters. In 2020, the local adult population size was estimated to be 94 (95% confidence interval [CI] 40–231) adults at one site, and 7 (95% CI 5–10) at the other site, suggesting an estimated global population of 101 adults. Movement of individuals was extremely limited at 48.5 m (± 77.7 S.D.) per year. We also found evidence of declining fish density, a declining proportion of juveniles, and increasing average fish size during the study. These results provide a serious warning that red handfish are likely sliding toward extinction, and highlight the urgent need to expand efforts for ex situ captive breeding to bolster numbers in the wild and maintain captive insurance populations, and to protect vital habitat to safeguard the species' ongoing survival in the wild. [ABSTRACT FROM AUTHOR]

Tropical macroalgae serve importance ecological roles on coral reefs but can supplant corals in phase shifts as shown worldwide. Thus, it is important to understand their fundamental photophysiology and effects on calcification mechanisms. We examined organic δ13C, inorganic CaCO3 δ13C and δ18O, and organic %C, %N, C:N of abundant macroalgae on Little Cayman Island (LCI) reefs across a broad light gradient (5–2,000 μmol photons m−2 s−1). We hypothesized that LCI macroalgae utilize greater CO2 in low light environments as carbon concentration mechanisms (CCMs) to take up HCO3− have high energetic costs. We proposed that calcification mechanisms are also influenced by light and Ci-use strategies. LCI macroalgae had organic δ13C values (-12‰ to -25‰) indicative of CCMs and exhibited only a 1–3‰ δ13C depletion under irradiances < 5 μmol photons m−2 s−1. Light and phyla were significant in a mixed model explaining ~ 80% of variance in organic δ13C. Organic δ13C was a weak predictor and light insignificant in explaining inorganic δ13C values of thalli carbonates. Biogenic carbonate δ13C values were taxa-specific based on cluster analysis of δ13C:δd18O ratios, an indication of diverse calcification mechanisms. LCI macroalgal photosynthesis utilized CCMs across a broad range of irradiances, thus greater CO2 availability under ocean acidification is not likely to enhance community dominance of macroalgae of concern (e.g., Lobophora sp.) due to shifts in photophysiology. The mechanisms of Ci sequestration for photosynthesis appeared to be mostly uncoupled from calcification mechanisms that were diverse across phyla, likely due to distinct macroalgal forms, sites of calcification and carbonate structure. [ABSTRACT FROM AUTHOR]

Beach ridges originate from various depositional processes and occur in a variety of settings. This paper assesses their nature and distribution on the islands of the Greater Caribbean based on a literature review and the identification of sites using Google Earth© 7.3 imagery. The morphological and orientation parameters were measured for each site, and a measure of storm density was developed. These were statistically analysed to develop a classification of beach ridge types. The results show a diversity of beach ridge systems, in terms of setting, morphology, composition and preservation. The presence or absence of an adjacent coral reef is a major differentiating element at the regional level. A regional beach ridge plain classification is proposed, including two main classes, marine beach ridges and river-associated beach ridges, with further sub-divisions based on exposure to hurricanes or hurricanes plus swell waves. [ABSTRACT FROM AUTHOR]

The study area, which consists of carbonate, is located in the unstable Mesopotamian basin on the Arabian plate, which makes it a field with high heterogeneity. It has a discrepancy in its bubble point pressure, which raises concerns about the faults or reefs that caused it. The study's main objective is to determine how faults and reefs impact production performance and pressure behavior under a future development strategy. This goal will be achieved by completing the necessary seismic, static, and dynamic models. After re-evaluating the seismic survey data, the seismic analysis detected many irregular amplitudes of reflected events and abrupt discontinuities, indicating either a reef or a fault. The static model was built based on seismic possible results and to make them as inputs for building the reservoir model. Based on the history-matching results, faults were detected, while reefs were ruled out. The development plan was implemented for the next 20 years in four cases, and case four had the most favorable results among all the cases, with production plateauing at 140 MSTB/D and a cumulative volume equal to 1.09 MMMSTB. The reservoir pressure behavior shows a hierarchical drop in all cases, with some differences, including a sharp decline in the area of the proposed wells and the fault, which has become a compartment that prevents reservoir compensation from adjacent regions.

Objective Research on reefs is highly important for determining sedimentary environments and for oil and gas exploration, but relatively few studies have been conducted on Carboniferous reefs in the Southwest Tarim Basin. Methods Early Carboniferous reefs of the Heshirafu Formation in the Artashi section in the Southwest Tarim Basin formed in the Middle-Late Visean section of the Early Carboniferous. Reef-building organisms and accessory organisms were not quite diversified; the former mainly consisted of colonial corals of different kinds and solitary corals of a small number, and the latter were mostly echinoderms. Results Their growth was suspended due to less supply of terrigenous materials largely related to the frequent sea level changes in the Early Carboniferous in the piedmont structures of the Southwest Tarim Basin. These reefs are among the products of the recovery of metazoan skeleton reefs across the globe after the Late Devonian mass extinction; their occurrence was accompanied by mid- to late-stage Visean climate warming and global sea level rise. These reefs are common in the Early Carboniferous Visean reefs worldwide. In addition, according to the overall sedimentary facies of the Heshirafu Formation in the Artashi section and the adjacent Hantiereke Formation in the Kushanhe section, it is speculated that a transgression occurred from southwest to northeast in the Visean period of the Early Carboniferous in the Southwest Tarim Basin when the global sea level was rising and a passive continental margin was simultaneously forming and beginning to sink. As a result, a narrow platform margin facies belt gradually took shape in the piedmont structure of the Southwest Tarim Basin. This belt was conducive to the development of biological reefs. Then, when the Heshirafu Formation formed, a depositional system of "shore facies-lagoon facies-platform margin facies-slope facies-continental shelf facies" developed in a seaward direction. Conclusion The classification of sedimentary systems can provide a reference for Carboniferous sedimentary environments and oil and gas exploration in the Southwest Tarim Basin.

Abstract Background Supra aortic obstruction in children is uncommon and is seen in certain unique conditions. While intraluminal obstruction due to heavy calcification is seen in older populations, it is not described in pediatric populations. The coral reef aorta is a rare and distinct calcifying disease causing luminal obstruction of the suprarenal aorta in adults. The definition of this diagnosis relies entirely on the unique aspects and consistency of the lesions, which are rock-hard, irregular, gritty plaques with a white luminal surface resembling a coral reef. However, no such case has been described in children. Case presentation We present an adolescent boy who presented with a heavily calcified ascending aortic lesion associated with aortopathy and hypertension, 12 years after an aortic coarctation repair. The investigations included echocardiography, magnetic resonance and computer-tomographic imaging. A 3-D model was printed in order to visualize and plan surgical steps in advance for safe placement of clamps and defining the extent of resection. In addition, it provided an idea about tissue quality, thickness, spatial relationship, and orientation in relation to surrounding structures. Successful resection and replacement of the diseased segment of the aorta were achieved on cardiopulmonary bypass support. Post-operative recovery was uneventful, and at 6-month follow-up, the patient is doing well. In this report, various aspects of such lesions have been discussed, including clinical presentations, complications, planning and conduct of a safe cardiopulmonary bypass, and precautions during surgery for a successful outcome. Conclusion Complicated obstructive aortic lesions in children require careful assessment, appropriate advanced imaging, and the use of 3-D printing technology in order to plan and perform safe and effective surgical management. The etiology of severe calcified aorta in children may be related to metabolic factors, previous surgery, use of a homograft, or an inflammatory process. However, it has yet to be proven.

Abstract In the seascape, species migrate between ecosystems to complete their life cycles, and such ontogenetic migrations create functional connections between ecosystems. Nevertheless, the scarcity of information on patch distribution, species life history and ecology limits its application in Marine Protected Areas (MPA) management. We use a potential connectivity network approach to analyze how Haemulon flavolineatum might move through a complex and diverse seascape by simulating part of its life cycle migrations among three ecosystems (reef, mangrove, and seagrass) in the MPA of Bahía Portete-Kaurrele (BPK), Colombia. We used available ecosystem cover maps to conduct habitat fragmentation analyses and evaluate structural connectivity in BPK using eight indices that describe ecosystem patches and how they are related. With published information on the H. flavolineatum home range and its ontogenetic migration distances, we estimated the potential functional connectivity (CONNECT and migration distances) between ecosystems by building bipartite graphs. The benthic habitat configuration of the BPK could allow Haemulon flavolineatum to complete at least two stages of its life cycle (stage 5 mangroves to reefs being more likely than stage 4 seagrass to mangroves). Ontogenetic migrations is possible since, patches of different ecosystems were highly intermixed (76%) rather than grouped (58%); reefs showed higher values of structural indices (patch area, largest patch, shape complexity, functional links) than mangrove (shortest distance to the nearest neighbor) and seagrass (representativeness); and juveniles migrate from mangroves to reef patches along the bay, but they could be isolated by distance when moving from particular seagrass to mangrove patches. Our methodological approach, which integrates ecological information (evidence-based ranges of species migration distances between habitat patches) and the seascape (spatial configuration of habitat patches and fragmentation) is novel for a marine fish species with ontogenetic migration to search for the likelihood of completing its life cycle stages. We discuss the need for ecological information on French grunts and the need to validate future models and scenarios.

In the seascape, species migrate between ecosystems to complete their life cycles, and such ontogenetic migrations create functional connections between ecosystems. Nevertheless, the scarcity of information on patch distribution, species life history and ecology limits its application in Marine Protected Areas (MPA) management. We use a potential connectivity network approach to analyze how Haemulon flavolineatum might move through a complex and diverse seascape by simulating part of its life cycle migrations among three ecosystems (reef, mangrove, and seagrass) in the MPA of Bahía Portete-Kaurrele (BPK), Colombia. We used available ecosystem cover maps to conduct habitat fragmentation analyses and evaluate structural connectivity in BPK using eight indices that describe ecosystem patches and how they are related. With published information on the H. flavolineatum home range and its ontogenetic migration distances, we estimated the potential functional connectivity (CONNECT and migration distances) between ecosystems by building bipartite graphs. The benthic habitat configuration of the BPK could allow Haemulon flavolineatum to complete at least two stages of its life cycle (stage 5 mangroves to reefs being more likely than stage 4 seagrass to mangroves). Ontogenetic migrations is possible since, patches of different ecosystems were highly intermixed (76%) rather than grouped (58%); reefs showed higher values of structural indices (patch area, largest patch, shape complexity, functional links) than mangrove (shortest distance to the nearest neighbor) and seagrass (representativeness); and juveniles migrate from mangroves to reef patches along the bay, but they could be isolated by distance when moving from particular seagrass to mangrove patches. Our methodological approach, which integrates ecological information (evidence-based ranges of species migration distances between habitat patches) and the seascape (spatial configuration of habitat patches and fragmentation) is novel for a marine fish species with ontogenetic migration to search for the likelihood of completing its life cycle stages. We discuss the need for ecological information on French grunts and the need to validate future models and scenarios. [ABSTRACT FROM AUTHOR]

Background: Supra aortic obstruction in children is uncommon and is seen in certain unique conditions. While intraluminal obstruction due to heavy calcification is seen in older populations, it is not described in pediatric populations. The coral reef aorta is a rare and distinct calcifying disease causing luminal obstruction of the suprarenal aorta in adults. The definition of this diagnosis relies entirely on the unique aspects and consistency of the lesions, which are rock-hard, irregular, gritty plaques with a white luminal surface resembling a coral reef. However, no such case has been described in children. Case presentation: We present an adolescent boy who presented with a heavily calcified ascending aortic lesion associated with aortopathy and hypertension, 12 years after an aortic coarctation repair. The investigations included echocardiography, magnetic resonance and computer-tomographic imaging. A 3-D model was printed in order to visualize and plan surgical steps in advance for safe placement of clamps and defining the extent of resection. In addition, it provided an idea about tissue quality, thickness, spatial relationship, and orientation in relation to surrounding structures. Successful resection and replacement of the diseased segment of the aorta were achieved on cardiopulmonary bypass support. Post-operative recovery was uneventful, and at 6-month follow-up, the patient is doing well. In this report, various aspects of such lesions have been discussed, including clinical presentations, complications, planning and conduct of a safe cardiopulmonary bypass, and precautions during surgery for a successful outcome. Conclusion: Complicated obstructive aortic lesions in children require careful assessment, appropriate advanced imaging, and the use of 3-D printing technology in order to plan and perform safe and effective surgical management. The etiology of severe calcified aorta in children may be related to metabolic factors, previous surgery, use of a homograft, or an inflammatory process. However, it has yet to be proven. [ABSTRACT FROM AUTHOR]

Offshore reefs in the Laurentian Great Lakes provide critical spawning habitats for native lake trout. Though many historic spawning reefs have been documented, thorough evaluation of the habitat they contain is rare. After decades of stocking, natural recruitment of lake trout has increased dramatically in the Illinois waters of Lake Michigan since 2010, reinforcing the need for information about the viability and distribution of spawning habitats.Using side‐scan sonar and underwater video, this study sought to map bottom substrates at Lake Bluff Reef and Gumby's Reef, offshore of the northern Illinois coast of Lake Michigan, to describe and quantify the availability of substrates suitable for lake trout spawning. Substrates were manually delineated in ArcGIS using side‐scan sonar imagery mosaics. Underwater video was used to verify substrate classifications through direct observation.Suitable spawning substrate consisting of fractured bedrock debris and piled boulder/cobble was observed at both reefs. Underwater video revealed the presence of lake trout at both reefs in the weeks leading up to the spawning season. The largest congregation of fish was observed in the vicinity of the shallowest points, steep slopes, and the largest patches of spawning substrate.The distribution, amount, and condition of spawning substrate available at each reef was in line with others studied in the region and their likely importance for lake trout spawning was reinforced by observed aggregations of mature fish.This study has expanded the inventory of well‐documented offshore reefs in the Illinois waters of Lake Michigan, enhancing appreciation of what is coming to be understood as the Illinois Reef Complex. Knowledge of the distribution and status of habitats critical to the life history of native fishes in the Great Lakes are necessary for managers to properly assess, manage, and conserve lake trout and other fish populations. [ABSTRACT FROM AUTHOR]

Reef reservoirs are characterised by a complex structure of void space, which is a combination of intergranular porosity, fractures, and vuggy voids distributed chaotically in the carbonate body in different proportions. This causes great uncertainty in the distribution of porosity and permeability properties in the reservoir volume, making field development a complex and unpredictable process associated with many risks. High densities of carbonate secondary alterations can lead to the formation of zones with abnormally high porosity and permeability—high permeability streaks or super-reservoirs. Taking into account super-reservoirs in the bulk of the deposit is necessary in the dynamic modelling of complex-structure reservoirs because it affects the redistribution of filtration flows and is crucial for reservoir management. This paper proposes a method for identifying superreservoirs by identifying enormously high values of porosity and permeability from different-scale study results, followed by the combination and construction of probabilistic curves of superreservoirs. Based on the obtained curves, three probabilistic models of the existence of a superreservoir were identified: P10, P50, and P90, which were further distributed in the volume of the reservoir and on the basis of which new permeability arrays were calculated. Permeability arrays were simulated in a dynamic model of the Alpha field. The P50 probabilistic model showed the best history matching after one iteration. [ABSTRACT FROM AUTHOR]

Linear buildups formed in tropical carbonate environments are often interpreted as bioconstructed reefs. Nevertheless, coastal processes can also form extensive sedimentary ridges exhibiting buildup morphologies. This study investigates two Miocene ridges developed along the Australian North West Shelf using 3D seismic and well data. Ridge 1 is ca. 30 m thick and >60 km long, and it is made of foraminiferal pack‐grainstones. It protects a lagoon with pinnacle morphologies. Ridge 2 is ca. 150 m thick and >80 km long. It is composed of quartz sand forming lobes. Both ridges have a continuous curvilinear front and are in a mid‐shelf setting. They mimic the modern Australian coastline. It is then proposed that Ridge 1 is either: (1) a barrier reef developed on a drowned shoreline, or (2) stacked carbonate aeolianites and beachrocks acting as a barrier. Ridge 2 is interpreted as stacked deltaic sands. This study demonstrates that lithified and buried coastal features of carbonate and siliciclastic nature can form extensive ridges exhibiting buildup morphologies. It is proposed that ridges formed by stacked coastal features are overall continuous with a curvilinear front, while reefal ridges are more discontinuous and exhibit deeper and more stable passes. [ABSTRACT FROM AUTHOR]

The green turtle Chelonia mydas is a large marine turtle present in tropical and subtropical seas of the Atlantic, Pacific and Indian Oceans. It is categorized as Endangered on the IUCN Red List based on the trend of nesting populations at 32 sites, of which only three are in the Pacific Ocean. New Caledonia is a sui generis overseas territory of France in the south-west Pacific Ocean c. 1,210 km east of Australia. The presence of green turtles in New Caledonian waters is known, although the main nesting sites are far from the main island, on remote uninhabited islands. Since 1988 field missions to these remote reefs, namely d'Entrecasteaux, Bellona and Chesterfield, have collected data to quantify the nesting of green turtles in New Caledonia. For the first time we analyse the data collected during these missions. D'Entrecasteaux, Bellona and Chesterfield Reefs host a large nesting colony of green turtles, with the upper credible estimate of nesting activities reaching 150,000 nesting tracks in some years. These numbers exceed the estimated number of green turtle activities in the Pacific. The trend of the number of nesting activities is stable and has the same relationship with the Southern Oscillation Index as observed at Australian nesting sites. Our recommendations for the French authorities are to continue monitoring these populations, collect new demographic parameters and ensure the protection of these remote reefs, which should be considered a national treasure for New Caledonia.

A lithological-paleoecological description of the organogenic structure of Mountain Sestra is given. A macro- and microscopic study of the fauna composing the structure was carried out, its percentage content in limestones and the role of each group of organisms in the reef formation process were determined. Based on the data obtained, six genetic types of limestones were identified: biohermic, biomorphic, detrital, biohemogenic, clastic and granular. Studies of the taxonomic composition and the structure of communities allowed us to identify three distinct stages in the development of organogenic structure corresponding to facies: 1) banks, 2) biostromes and 3) bioherms. A detailed description of each stage of development is given. Based on the description, assumptions are made about the initial stage of reef formation. The findings of some species of sphinctozoa new to this locality are reported: Colospongia globosa Belyaeva, 1991; Amblysiphonella regularis Zhang, 1983 and Discosiphonella squamilis Belyaeva, 1991.

In this study, the bacterial microbiota associated with apparently healthy corals of Acropora palmata, Orbicella faveolata, and Porites porites and the surrounding seawater and sediment were evaluated via the MiSeq Illumina sequencing of the V4 region of 16S rRNA at three reef sites in the Mexican Caribbean. Bacterial assemblages associated with apparently healthy corals and sediments showed no significant differences between sites. The colonies of A. palmata showed a dominance of families Amoebophilaceae, Spirochaetaceae, Myxococcaceae, and Cyclobacteriaceae. Meanwhile, the colonies of O. faveolata and P. porites revealed a high prevalence of the Rhodobacteraceae and Kiloniellaceae families. The families Rhodobacteraceae, Cryomorphaceae, Cyanobiaceae, and Flavobacteriaceae were predominant in seawater samples, while Pirellulaceae, Nitrosococcaceae, and Woeseiaceae were predominant in sediments. Variations in A. palmata bacterial assemblages were correlated with salinity, sea surface temperature, and depth. These variables, along with nitrate, phosphate, and ammonium concentrations, were also correlated with changes in the bacterial composition of P. porites, seawater, and sediments. However, none of the environmental variables were related to the bacterial taxa of O. faveolata. Aerobic chemoheterotrophy and fermentation, followed by nitrate reduction and ureolysis, were the metabolic functions with the highest occurrence in the bacterial assemblages associated with all substrates. [ABSTRACT FROM AUTHOR]

The green turtle Chelonia mydas is a large marine turtle present in tropical and subtropical seas of the Atlantic, Pacific and Indian Oceans. It is categorized as Endangered on the IUCN Red List based on the trend of nesting populations at 32 sites, of which only three are in the Pacific Ocean. New Caledonia is a sui generis overseas territory of France in the south-west Pacific Ocean c. 1,210 km east of Australia. The presence of green turtles in New Caledonian waters is known, although the main nesting sites are far from the main island, on remote uninhabited islands. Since 1988 field missions to these remote reefs, namely d'Entrecasteaux, Bellona and Chesterfield, have collected data to quantify the nesting of green turtles in New Caledonia. For the first time we analyse the data collected during these missions. D'Entrecasteaux, Bellona and Chesterfield Reefs host a large nesting colony of green turtles, with the upper credible estimate of nesting activities reaching 150,000 nesting tracks in some years. These numbers exceed the estimated number of green turtle activities in the Pacific. The trend of the number of nesting activities is stable and has the same relationship with the Southern Oscillation Index as observed at Australian nesting sites. Our recommendations for the French authorities are to continue monitoring these populations, collect new demographic parameters and ensure the protection of these remote reefs, which should be considered a national treasure for New Caledonia. [ABSTRACT FROM AUTHOR]

Modern scleractinian corals can display high phenotypic plasticity, which reflects an interplay among various environmental controls, such as sediment input, water hydrodynamics or light intensity. In particular, the latter can strongly influence the morphology of coral species living across broad depth gradients. Light intensity was also a factor shaping the colonies of extinct Palaeozoic tabulate corals (Anthozoa: Tabulata). Based on gradual transitions in morphology observed in corals from the Middle Devonian (Givetian stage, ~ 385 Ma) mesophotic coral ecosystems (MCE) of the Aferdou el Mrakib reef (Anti-Atlas mountains, Morocco) and comparative material originating from different palaeobathymetric and biogeographical settings, we show that Devonian tabulate corals, such as Roseoporella and Alveolites, were characterised by high phenotypic plasticity and the ability to dramatically change their morphology depending on the inferred light conditions. Such a mechanism is similar to that observed in modern scleractinians, e.g. Porites sillimaniana. This recurring morphological theme suggests that Palaeozoic tabulate corals shared many functional characteristics of modern scleractinians. [ABSTRACT FROM AUTHOR]

Due to the increasing emissions of carbon dioxide into the atmosphere, the absorption of this gas by the ocean is carried out at great speed, causing an increase in the acidity of seawater. This process, known as ocean acidification, leads to a reduction in the ability of many calcifying organisms to form their calcium carbonate structures. The objective of this research was to determine the net rates of calcium carbonate accretion (g CaCO3 cm-2 yr-1) of early successional taxa, in the marine-coastal ecosystem complex of Ensenada Rancho Luna, Cienfuegos. To quantify the net calcium carbonate accretion rates, 12 sampling devices were built based on the Vargas-Ángel et al. in 2015, positioning six of them in each ecosystem studied (mangrove and reef). The mean values of net calcium carbonate accretion rates were 0.87 ± 0.19 g CaCO3 cm-2 yr-1 in the reef and 0.59 ± 0.05 g CaCO3 cm-2 yr-1 in the mangrove swamp. Seven taxa were identified, corresponding to four early successional functional groups, grass (turf), CaCO3/sediment, Calcium-free functional group, and crusted coralline algae. The latter were the main contributors of CaCO3, being found mainly in the reef. Magnesite was determined as the dominant crystalline form of CaCO3, and crusty coralline algae, the group with the greatest vulnerability to the effect of ocean acidification. [ABSTRACT FROM AUTHOR]

In coral communities, herbivorous fish play a major role in maintaining and controlling algae, which are the base of the food chain in coral reefs. Among the herbivorous fish of coral reefs, the family Acanthuridae is one of the most abundant. Effects of this family on coral reefs can vary depending on their densities, ecosystem stability, and their interactions; therefore, determining the status of their populations is a concern. In the archipelago of San Andrés, Providencia, and Santa Catalina (ASAP) there is a lack of information on the status of the abundances and densities of this group. Through visual censuses of species of the genus Acanthurus, the population states in the ASAP coral communities and the population differences between the evaluated sites (San Andrés, isla cayo Bolívar, isla cayo Serrana and Providencia) were estimated. Showing an abundance of 6075 individuals, in addition to a positive relationship of abundances in the islands of San Andrés and Providencia with respect to the Bolívar and Serrana keys. Regarding the habitat preference of juveniles, a specialization and habitat preference of A. coeruleus was found for reef zones, while A. tractus showed a preference for mangroves. [ABSTRACT FROM AUTHOR]

Against the background of the UN decade on ecosystem restoration and the new EU Biodiversity Strategy for 2030, and in the context of marine spatial planning and complex maritime user conflicts, reliable information on habitat suitability for large‐scale restoration is an important prerequisite for implementing conservation management and for supporting successful, sustainable, and ecologically efficient restoration measures.In this study, habitat suitability was assessed using multicriteria decision analysis (MCDA) for the restoration of the European oyster, Ostrea edulis, in marine protected areas (MPAs) of the German Bight in the North Sea: Borkum Reef Ground (Borkum Riffgrund, BRG) and Sylt Outer Reef – Eastern German Bight (Sylter Außenriff, SAR).Based on site selection criteria, exclusion and suitability factors for the MCDA were defined. Results were integrated with the available geodata to produce habitat suitability maps for oyster restoration in the area of interest.Suitable as well as unsuitable habitats have been successfully identified for both MPAs: several hundred square kilometres (≥97.2% of BRG) or several thousand square kilometres (≥74.5% of SAR) were classified as ecologically and logistically suitable for oyster restoration measures in the respective MPAs. As oyster restoration is significantly limited by human activities (e.g. bottom trawl fisheries), the management of fisheries is an important prerequisite for successful oyster restoration in both MPAs. Results show that designated fishery management measures will increase the possibilities for oyster restoration.In BRG, our results correspond to the known historical distribution. In SAR, our results significantly exceed the historically known distribution. The habitat suitability analysis will facilitate decision‐making regarding ocean use, and will reduce restoration costs through targeted management activities in areas of high suitability and expand species recovery by improving the survival of reintroduced individuals.The habitat suitability analysis procedure is easily adaptable for application to other areas, other species, or other habitat restoration projects, or to other conservation management settings. The software applied is open source and the suitability calculation is described in detail to inform wider applications. [ABSTRACT FROM AUTHOR]

Beach ridges originate from various depositional processes and occur in a variety of settings. This paper assesses their nature and distribution on the islands of the Greater Caribbean based on a literature review and the identification of sites using Google Earth© 7.3 imagery. The morphological and orientation parameters were measured for each site, and a measure of storm density was developed. These were statistically analysed to develop a classification of beach ridge types. The results show a diversity of beach ridge systems, in terms of setting, morphology, composition and preservation. The presence or absence of an adjacent coral reef is a major differentiating element at the regional level. A regional beach ridge plain classification is proposed, including two main classes, marine beach ridges and river-associated beach ridges, with further sub-divisions based on exposure to hurricanes or hurricanes plus swell waves.

Reef reservoirs are characterised by a complex structure of void space, which is a combination of intergranular porosity, fractures, and vuggy voids distributed chaotically in the carbonate body in different proportions. This causes great uncertainty in the distribution of porosity and permeability properties in the reservoir volume, making field development a complex and unpredictable process associated with many risks. High densities of carbonate secondary alterations can lead to the formation of zones with abnormally high porosity and permeability—high permeability streaks or super-reservoirs. Taking into account super-reservoirs in the bulk of the deposit is necessary in the dynamic modelling of complex-structure reservoirs because it affects the redistribution of filtration flows and is crucial for reservoir management. This paper proposes a method for identifying superreservoirs by identifying enormously high values of porosity and permeability from different-scale study results, followed by the combination and construction of probabilistic curves of superreservoirs. Based on the obtained curves, three probabilistic models of the existence of a superreservoir were identified: P10, P50, and P90, which were further distributed in the volume of the reservoir and on the basis of which new permeability arrays were calculated. Permeability arrays were simulated in a dynamic model of the Alpha field. The P50 probabilistic model showed the best history matching after one iteration.

Citizen science is growing in importance for ecosystem management and long‐term monitoring. A large marine citizen‐science project operated by the Reef Environmental Education Foundation (2021, Reef environmental education foundation volunteer fish survey project database, World Wide Web electronic publication) collected logarithmic categorical data for species abundance across a number of otherwise understudied reefs in The Bahamas and Turks and Caicos during 1994–2020. We used several statistical models to estimate the presence and abundance of trends from these data. Variously specified abundance and presence‐absence models were fit to simulated count data, simulated categorized count data, and real‐world categorical data for Queen Triggerfish (Balistes vetula). These models produced simple patterns of presence and abundance from simulated data with minimal bias that were reasonable predictions based on cross‐validation. Based on model‐based estimates of presence and abundance, the Queen Triggerfish population decreased significantly in The Bahamas and Turks and Caicos during 1994–2020. This simple method for imputing abundance from size‐category counts at the level of individual diver observations, rather than aggregated across multiple observations, allows for higher resolution modeling of predictors of presence and abundance, with implications for other understudied reef‐dwelling species. [ABSTRACT FROM AUTHOR]

Several brachiopod-rich mud mounds occur in the upper Visean (Brigantian) of the Derbyshire Carbonate Platform succession in UK. The re-evaluation of the lithofacies architecture of a Derbyshire mud mound complex, developed in an intraplatform middle-ramp environment, led to the recognition of three lithofacies associations: (a) a 10 m thick basal unit of automicrite boundstone with siliceous sponge spicules and brachiopod–bryozoan packstone to wackestone beds; (b) a 10 m thick, 250 m wide, lens-shaped, convex-up massive core of clotted peloidal micrite and fenestellid bryozoan boundstone with sponge spicules; (c) inclined brachiopod–bryozoan–crinoid packstone flank beds. In the mud mound complex core, most of the carbonate mud with clotted peloidal and structureless micrite fabric is the result of biologically induced and influenced in-situ precipitation processes (automicrite). Brachiopods are not, as previously thought, limited to storm-scoured “pockets” in the mud mound complex core but are abundant and diverse in all lithofacies and lived on the irregular mud mound complex surface concentrating in depressions sustained by automicrite boundstone and the growth of bryozoans and sponges. The upper Visean Derbyshire mud mounds are, thus, representatives of a newly defined fenestellid bryozoan–brachiopod–siliceous sponge mud mound category, occurring in various middle–upper Visean Western European sites, a sub-type of the fenestellid bryozoan–crinoid–brachiopod Type 3 buildups of Bridges et al. (1995). These mud mounds, and other types of brachiopod-rich buildups, developed in carbonate platform settings between fair-weather and storm wave base, in dysphotic environments with dispersed food resources during the Visean. Brachiopod mud mound colonisation was favoured by moderate water depth, availability of food resources, and diverse substrates. [ABSTRACT FROM AUTHOR]

Insufficient comprehension of the seismic impact of the reef terrain, geology, and material properties of the reefs in the South China Sea still presents considerable impediments in studying the seismic response of reef engineering sites and assessing their seismic safety. To surmount this challenge, a seismic response analysis model of the reef-seawater system is established. This model takes into account the fluid-solid interaction effect, the wave radiation effect of the infinite seawater layer and the semi-infinite seabed, as well as the seismic wave input process of the reef-seawater system. Through targeted parameter analyses, the impact of various factors, including the shear wave velocity, thickness, and slope of distinct reef layers, the width of the reef flat, and the dynamic coupling effect of seawater on the seismic response of reef sites, is thoroughly examined. It has been determined that the seismic response of the reef site is markedly amplified as the shear wave velocity decreases and the thickness of the uppermost reef layer increases. While the effects of the slope gradient of the topmost reef layer and the width of the reef flat on the seismic response of the reef site are chiefly observed in the edge area and the central area, respectively. The layer of seawater plays a crucial role in radiation damping, serving as a medium for the dissipation of seismic energy and thereby weakening the overall seismic response of the reef site. [ABSTRACT FROM AUTHOR]

Stromatoporoids are the major constructors of a Givetian (Middle Devonian) fossil reef in shallow marine facies, in the Jiwozhai Member of the Dushan Formation, at Dahekou, near Dushan, Guizhou Province, South China. Stromatoporoids, together with other reef building and dwelling components (rugose corals, tabulates, chaetetids and others), form a high diversity community, making the Jiwozhai reef a palaeobiodiversity hotspot. In this study 11 species belonging to nine genera and four orders are identified, including Gerronostromaria grossum (Clathrodictyida), Pseudotrupetostroma porosum, and Salairella buecheliensis (Stromatoporida), Clathrocoilona spissa, Stictostroma saginatum, and Synthetostroma actinostromoides (Stromatoporellida) and ?Habrostroma laminosum, Parallelopora sp., Stachyodes costulata, Stachyodes fasciculata and Stachyodes sp. (Syringostromatida). Among them, Clathrocoilona spissa and Gerronostromaria grossum are the most abundant stromatoporoid taxa. Stromatoporoid growth form, size, substrate and growth interruption are considered to be key autecological parameters to evaluate their growth behaviour and contribution in reef formation. Skeletons of laminar Clathrocoilona spissa are commonly smaller (up to 40 mm in basal dimension and less than 2 mm in thickness) than other stromatoporoid taxa and frequently encrusted on other organisms. In contrast, Gerronostromaria grossum dominates the assemblage, with its larger laminar growth form (up to 500 mm in basal dimension and 40 mm in thickness) expanding both on bioclastic and clay-rich micritic substrate and shows repeated growth interruptions, altogether evidence that this taxon was resilient to environmental pressure and may have pioneered the reef development. The variation of growth preference among stromatoporoid taxa therefore indicates a different growth strategy of each stromatoporoid in this reef environment.

Recurrent green tide has been widely studied due to its severe damage to coastal ecosystem. Jinmeng Bay, a popular resort in northeastern China, has suffered from green tide events since 2015, after the constructions of artificial islands and submerged reefs. To investigate the potential impacts of artificial islands and reefs on the water quality in Jinmeng Bay, a MIKE 21 numerical model was established by coupling a hydrodynamic model with a transport model of Chemical Oxygen Demand (COD) and nitrate ion (NO3−). The changes in the water quality in Jinmeng Bay by the initial, first-stage and current construction conditions of artificial islands and submerged reefs were simulated. The model results indicated that: (1) The artificial islands and reefs in Jinmeng Bay hinder the tidal currents and weaken the tidal actions. (2) The weakened tidal actions at the estuary lead to the accretion of COD and NO3−. The neap tides generate a littoral zone with the high concentration of COD and NO3−, and the spring tides maintain the zone at the estuary. (3) NO3− is more sensitive than COD to the variation of hydrodynamic conditions. The NO3− concentration in the north of Conch artificial island is altered significantly, where the construction of the artificial structures decrease the concentration by ~30%, while the demolition of the connection road increases the concentration beyond its initial values by 16~21%. (4) Under the current construction conditions, the rising concentrations of COD (up to 2%) and NO3− (up to 40%) increase the frequency and scale of green tides in Jinmeng Bay considerably. Therefore, continuous monitoring of water quality is required for this region. [ABSTRACT FROM AUTHOR]

The article considers the examples and possibilities of using the emerging natural situation in the construction of port facilities and its impact on reducing the cost of construction. [ABSTRACT FROM AUTHOR]

In November 2020, we observed several individuals and collected one juvenile of an unidentified anthiadine fish (Serranidae) between depths of 250 and 307 m near vertical walls of rocky reefs in the northern Red Sea. Further morphological and molecular analyses revealed that the collected specimen matches Sacura boulengeri, a species previously reported only from the Gulf of Oman to India. [ABSTRACT FROM AUTHOR]

The rapid origination and diversification of major animal body plans during the early Cambrian coincide with the rise of Earth's first animal‐built framework reefs. Given the importance of scleractinian coral reefs as ecological facilitators in modern oceans, we investigate the impact of archaeocyathan (Class Archaeocyatha) reefs as engineered ecosystems during the Cambrian radiation. In this study, we present the first high‐resolution, three‐dimensional (3D) reconstructions of branching archaeocyathide (Order Archaeocyathida) individuals from three localities on the Laurentian paleocontinent. Because branched forms in sponges and corals display phenotypic plasticity that preserve the characteristics of the surrounding growth environment, we compare morphological measurements from our fossil specimens to those of modern corals to infer the surface conditions of Earth's first reefs. These data demonstrate that archaeocyaths could withstand and influence the flow of water, accommodate photosymbionts, and build topographically complex and stable structures much like corals today. We also recognize a stepwise increase in the roughness of reef environments in the lower Cambrian, which would have laid a foundation for more abundant and diverse coevolving fauna. [ABSTRACT FROM AUTHOR]

Since their discovery in the region in 2009, invasive Indonesian- native lionfish have been taking over the Belize Barrier Reef. As a result, populations of local species have dwindled as they are either eaten or outcompeted by the invaders. This has led to devastating losses ecologically and economically; massive industries in the local nations, such as fisheries and tourism, have suffered greatly. Attempting to combat this, local organizations, from nonprofits to ecotourism companies, have been manually spear- hunting them on scuba dives to cull the population. One such company, Reef Conservation Institute (ReefCI), operating out of Tom Owens Caye outside of Placencia, Belize, has dissected their caught lionfish for the past three years and kept logs of results. With little to no studies reliably indexing the Belizean lionfish population, this data set provides a priceless opportunity to take a first look and probe further questions about this relatively unstudied population. This project accomplished this by computing various population statistics using these records, including the differences in sex ratio, presence of supraorbital tentacles, length, age, and more. The results and combinations of these factors provide new insight on current theories surrounding lionfish and their anatomy, but more importantly it opens new questions, the answers to which can shed light on new techniques to more efficiently cull the population for the future. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience 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.)

The present study describes the population dynamics and life history parameters of the enigmatic tanaid Chondrochelia dubia collected in Paiva Beach, tropical coast of Brazil. The region was impacted by a large, unexpected oil spill from August to October 2019. Samples were taken monthly between July 2019 and July 2020 in beds of the red seaweed Jania capillacea. The abundance of individuals was negatively correlated with monthly rainfall, with higher abundances in drier months. There was an unexpected significant drop in abundance in September, possibly caused by contact with the crude oil, but the population recovered fully within two months. The parameters of the von Bertallanfy growth equation, calculated for the first time for the species, were Linf=5.26 mm; k=3.36 year–1; t0=0.0. Compared with other studies, the specimens are very small (2.04 ± 0.95 mm in length), females reach sexual maturity very early (L50=2.3 mm), and natural mortality is high (Z=M=5.77 year–1), indicating an opportunistic life strategy. This study reinforces the bioindication potential of C. dubia and the use of bootstrapped length-based methods to estimate key population parameters in small marine invertebrates.

Copyright of Spanish Journal of Palaeontology is the property of Socieadad Espanola de Paleontologia 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.)

Coral reefs are declining worldwide primarily because of bleaching and subsequent mortality resulting from thermal stress. Currently, extensive efforts to engage in more holistic research and restoration endeavors have considerably expanded the techniques applied to examine coral samples. Despite such advances, coral bleaching and restoration studies are often conducted within a specific disciplinary focus, where specimens are collected, preserved, and archived in ways that are not always conducive to further downstream analyses by specialists in other disciplines. This approach may prevent the full utilization of unexpended specimens, leading to siloed research, duplicative efforts, unnecessary loss of additional corals to research endeavors, and overall increased costs. A recent US National Science Foundationsponsored workshop set out to consolidate our collective knowledge across the disciplines of Omics, Physiology, and Microscopy and Imaging regarding the methods used for coral sample collection, preservation, and archiving. Here, we highlight knowledge gaps and propose some simple steps for collecting, preserving, and archiving coral-bleaching specimens that can increase the impact of individual coral bleaching and restoration studies, as well as foster additional analyses and future discoveries through collaboration. Rapid freezing of samples in liquid nitrogen or placing at -80 °C to -20 °C is optimal for most Omics and Physiology studies with a few exceptions; however, freezing samples removes the potential for many Microscopy and Imaging-based analyses due to the alteration of tissue integrity during freezing. For Microscopy and Imaging, samples are best stored in aldehydes. The use of sterile gloves and receptacles during collection supports the downstream analysis of host-associated bacterial and viral communities which are particularly germane to disease and restoration efforts. Across all disciplines, the use of aseptic techniques during collection, preservation, and archiving maximizes the research potential of coral specimens and allows for the greatest number of possible downstream analyses. [ABSTRACT FROM AUTHOR]

Artificial islands and reefs have been used in the Laurentian Great Lakes for over 40 years as a means of improving aquatic habitat; but research on their efficacy has primarily focused on their ability to increase the abundance of specific sportfish, top predators, or other keystone species. To understand the importance of islands in structuring the whole fish community, we took a holistic approach and analysed the effect of islands, location, and the interaction effect between the two in structuring fish communities in Hamilton Harbour, Lake Ontario using a 30-year electrofishing dataset. The effect of islands varied by location within the harbour, with some species showing a preference for islands in some locations while avoiding them in others. Island communities also tended to have significantly different species compositions, with higher index of biotic integrity scores and species richness, greater numbers of pollution intolerant fishes, centrarchids, and fewer generalist species. However, these results paled in comparison to the level of inter-annual variation in the fish community of the harbour, which has changed markedly over the 30-year time span. Taken together, our results highlight that while island creation can influence the fish community, the type and magnitude of effect will vary based on their distance to other suitable habitats (i.e., location within the system) and the design of the island itself. Further, the noted inter-annual variability emphasizes the importance of considering long time scales (> 10–20 years) when exploring fish community responses to habitat creation. Collectively, these results will help the design of more effective management strategies for restoring fish communities. [ABSTRACT FROM AUTHOR]

The first records are presented of Pomacanthus maculosus (Forsskål, 1775) in the Tropical Eastern Pacific. The natural range of this fish species extends from the Persian Gulf to the coast of East Africa. Two adults were recorded at Los Arcos de Mismaloya, México, one in June 2018 and another in September 2020, 1 km from the site of the first observation. This species was probably introduced into this area as an aquarium release due to proximity of the two sites to highly dense human population centers.

ABSTRACT Taxonomic investigations of phytoplankton community structure are very important for understanding the dynamics of these organisms in places like reefs, which present broad hydro-biological variation. This study aimed to determine and investigate phytoplankton community composition and biomass in natural pools of Atol das Rocas (3°51’ S; 33°49’ W), and to evaluate the possible influences of abiotic variables throughout different seasons. The oceanographic parameters used to assess the phytoplankton community and its biomass were chlorophyll a, salinity, water temperature, dissolved oxygen and dissolved inorganic nutrient content, namely ammonia, nitrate, nitrite, phosphate and silica. A total of 109 species were identified, distributed among four groups: Ochrophyta (52.3 %), Dinophyta (37.6 %), Cyanobacteria (7.33 %) and Haptophyta (2.75 %). Although none of the hydrological parameters were found to be statistically determinant, phytoplankton composition in all the studied pools was primarily associated with nutrient salts and there was a qualitative and quantitative increase in phytoplankton in the rainy season. This increase was due to the positive relationship between phytoplankton composition and nutrient salts when associated with local hydrodynamics, which provides more favorable conditions for the enrichment of diversity with emphasis on species that compose the benthic microflora.

In this study, the bacterial microbiota associated with apparently healthy corals of Acropora palmata, Orbicella faveolata, and Porites porites and the surrounding seawater and sediment were evaluated via the MiSeq Illumina sequencing of the V4 region of 16S rRNA at three reef sites in the Mexican Caribbean. Bacterial assemblages associated with apparently healthy corals and sediments showed no significant differences between sites. The colonies of A. palmata showed a dominance of families Amoebophilaceae, Spirochaetaceae, Myxococcaceae, and Cyclobacteriaceae. Meanwhile, the colonies of O. faveolata and P. porites revealed a high prevalence of the Rhodobacteraceae and Kiloniellaceae families. The families Rhodobacteraceae, Cryomorphaceae, Cyanobiaceae, and Flavobacteriaceae were predominant in seawater samples, while Pirellulaceae, Nitrosococcaceae, and Woeseiaceae were predominant in sediments. Variations in A. palmata bacterial assemblages were correlated with salinity, sea surface temperature, and depth. These variables, along with nitrate, phosphate, and ammonium concentrations, were also correlated with changes in the bacterial composition of P. porites, seawater, and sediments. However, none of the environmental variables were related to the bacterial taxa of O. faveolata. Aerobic chemoheterotrophy and fermentation, followed by nitrate reduction and ureolysis, were the metabolic functions with the highest occurrence in the bacterial assemblages associated with all substrates.

Coral reefs are declining worldwide primarily because of bleaching and subsequent mortality resulting from thermal stress. Currently, extensive efforts to engage in more holistic research and restoration endeavors have considerably expanded the techniques applied to examine coral samples. Despite such advances, coral bleaching and restoration studies are often conducted within a specific disciplinary focus, where specimens are collected, preserved, and archived in ways that are not always conducive to further downstream analyses by specialists in other disciplines. This approach may prevent the full utilization of unexpended specimens, leading to siloed research, duplicative efforts, unnecessary loss of additional corals to research endeavors, and overall increased costs. A recent US National Science Foundation-sponsored workshop set out to consolidate our collective knowledge across the disciplines of Omics, Physiology, and Microscopy and Imaging regarding the methods used for coral sample collection, preservation, and archiving. Here, we highlight knowledge gaps and propose some simple steps for collecting, preserving, and archiving coral-bleaching specimens that can increase the impact of individual coral bleaching and restoration studies, as well as foster additional analyses and future discoveries through collaboration. Rapid freezing of samples in liquid nitrogen or placing at −80 °C to −20 °C is optimal for most Omics and Physiology studies with a few exceptions; however, freezing samples removes the potential for many Microscopy and Imaging-based analyses due to the alteration of tissue integrity during freezing. For Microscopy and Imaging, samples are best stored in aldehydes. The use of sterile gloves and receptacles during collection supports the downstream analysis of host-associated bacterial and viral communities which are particularly germane to disease and restoration efforts. Across all disciplines, the use of aseptic techniques during collection, preservation, and archiving maximizes the research potential of coral specimens and allows for the greatest number of possible downstream analyses.

Habitat complexity and connectivity can influence the number of species and their diversity across a landscape. For the surf zones of ocean-exposed beaches, globally one of the longest habitat interfaces, the assumed low structural complexity, and apparent homogeneity, of the sandy seafloor habitats predicts low taxonomic and functional diversity. Here, we assessed how the configuration of the seascape and the context of different beach structure functional diversity and functional niche space of fish assemblages in surf zones. We expected that beaches that were well connected with highly productive and complex estuarine and reef habitats would support a greater level of functional diversity, and a greater degree of functional complementarity within different niches. We sampled surf zones at twenty-five beaches along 50 km of coastline in southeast Queensland, Australia. We calculated functional diversity and functional niche space using variation in the functional traits of fish assemblages. We found that increased proximity with nearby subtidal rocky reefs was the key feature of the coastline shaping functional diversity and functional niche space in surf zone fishes. These effects resulted in increased functional complementarity within a number of fish functional group niches when rocky reefs were nearby. We provide empirical evidence that habitat proximity can structure functional diversity and complementarity in the surf zones of ocean beaches, a system traditionally viewed as having low habitat heterogeneity. Our results highlight the focus management must take in conserving these highly connected ecosystems to avoid negative functional consequences. [ABSTRACT FROM AUTHOR]

Predicted sea‐level rise (SLR) is anticipated to alter tidal dynamics in the future and this will in turn alter coastal ecosystems, flood risk, and geomorphology. Coral reefs are bathymetrically complex environments where tides play a crucial role in larval and nutrient dispersal. This complexity makes coral reef environments challenging to simulate numerically as a large area needs to be simulated but also with high resolution to capture the complexity. To investigate the influence of SLR on tidal dynamics in coral reef systems we use an unstructured mesh numerical model, with spatially varying resolution, of the Great Barrier Reef (GBR). The present‐day conditions and a total of three future SLR scenarios are considered based on the RCP scenarios. The results focus on the major tidal constituents and tidal range. The M2 constituent generally decreases across gauge locations as sea‐level rises but S2 generally increases. O1 and K1 display small variations or no change. The tidal range experiences ±10% variation depending on the gauge location, meaning it is spatially varying and alters SLR by up to 10%. Overall, SLR will influence tidal dynamics across the GBR altering coastal flooding risk with a spatially varying impact. Management schemes should consider tidal range changes in addition to increases in extreme weather conditions to provide adequate preservation of the coastline, coastal cities and infrastructure in the future. Moreover, changes in tidal patterns and dynamics may alter the distributions of reef spores and larvae and should be included in future plans of reef management. Plain Language Summary: Sea‐level rise (SLR) alters the ebb and flow of tidal currents, as well as altering the tidal range. As sea level is projected to rise in the future it is anticipated that coastal regions will experience a change in tidal patterns also. In turn this will affect coastal flood risk, ecosystems and geomorphology. Coral reefs are complex environments with rapidly changing bathymetry but tides can play a vital role in their functioning. To determine the influence of SLR on changing tidal features in such complex environments, we simulate tides on the Great Barrier Reef, the world's largest reef ecosystem. In order to determine the effects of SLR, spatially‐varying resolution, where model resolution varies across the simulation area, can be used to capture the bathymetric complexity whilst simulating a large enough region. We carry out simulations consisting of the present‐day and three SLR scenarios. Results show complex spatial changes in tidal dynamics with some areas displaying little change, but others displaying a decrease or increase in tidal range that is around 10% of the sea level rise. Coastal management plans should take into consideration both SLR and tidal range changes to protect coastal cities and infrastructure in the future. Key Points: Sea‐level rise alters the tidal dynamics in the Great Barrier ReefChanges in tidal dynamics is spatially complex, with changes in tidal range of up to 10% of the sea‐level riseThe two main tidal component amplitudes change in the opposite direction [ABSTRACT FROM AUTHOR]

Sessile organisms exploit a life-history strategy in which adults are immobile and their growth position is determined at settlement. The morphological strategy exploited by these organisms has strong selective value, because it can allow beneficial matching of morphology to environmental and biological conditions. In benthic marine environments, a 'sheet-tree' morphology is a classic mechanism exploited by select sessile organisms, and milleporine hydrocorals provide one of the best examples of this strategy. Using 30-year analysis of Millepora sp. on the reefs of St. John, US Virgin Islands, I tested for the benefits of a sheet-tree morphology in mediating the ecological success of an important functional group of benthic space holders. The abundance of Millepora sp. chaotically changed from 1992 to 2021 in concert with hurricanes, bleaching and macroalgal crowding. Millepora sp. responded to these disturbances by exploiting their morphological strategy to increase the use of trees when their sheets were compromised by bleaching and spatial competition with macroalgae, and the use of sheets when their trees were broken by storms. Together, these results reveal the selective value of a plastic sheet-tree morphology, which can be exploited by sessile organisms to respond to decadal-scale variation in environmental conditions. [ABSTRACT FROM AUTHOR]