Reef Formation Research Articles

Palaeozoic and Cenozoic reef formation. An attempt in comparative analysis

An article contains a comparative analysis of the Palaeozoic and Cenozoic reef formation, mainly in terms of the position of reefs in the basins of continental and oceanic blocks. It is shown that in the Cenozoic the main formation of reefs took place directly in the oceans, including at the boundaries between oceans and continents, and, to an extremely limited extent, in the basins of the continental segment. In the Palaeozoic, along with oceanic reef formation, there was intensive development in extensive basins of the continental block. This is one of the manifestations of the general evolution of carbonate accumulation, when the Palaeozoic carbonate sediments were formed in similar shallow water bodies that covered very significant surfaces of the continents.

Comparative analysis of codon usage patterns in 16 chloroplast genomes of suborder Halimedineae.

The Halimedineae are marine green macroalgae that play crucial roles as primary producers in various habitats, including coral reefs, rocky shores, embayments, lagoons, and seagrass beds. Several tropical species have calcified thalli, which contribute significantly to the formation of coral reefs. In this study, we investigated the codon usage patterns and the main factors influencing codon usage bias in 16 chloroplast genomes of the suborder Halimedineae. Nucleotide composition analysis revealed that the codons of these species were enriched in A/U bases and preferred to end in A/U bases, and the distribution of GC content followed a trend of GC1 > GC2 > GC3. 30 optimal codons encoding 17 amino acids were identified, and most of the optimal codons and all of the over-expressed codons preferentially ended with A/U. The neutrality plot, effective number of codons (ENc) plot, and parity rule 2 (PR2) plot analysis indicated that natural selection played a major role in shaping codon usage bias of the most Halimedineae species. The genetic relationships based on their RSCU values and chloroplast protein-coding genes showed the closely related species have similar codon usage patterns. This study describes, for the first time, the codon usage patterns and characterization of Halimedineae chloroplast genomes, and provides new insights into the evolution of this suborder.

Paleozoic and Cenozoic Reef Formation. An Attempt at Comparative Analysis

Paleozoic and Cenozoic Reef Formation. An Attempt at Comparative Analysis

Biological control of ultra-skeleton mineralization in coral

Abstract Understanding the mineralization of coral is significant for the formation of coral reefs and paleoclimatic reconstructions. However, the fundamental mechanisms involved in biomineralization are poorly understood. A combination of Raman spectral and cross-polarized reflected light microscopy imaging was used to examine the three-dimensional spatial distribution of the skeletal ultrastructures and their associated mineral, organic, and water chemistry in coral, which enable insight into the spatial growth features of the ultrastructures and possible formation processes. A possible mechanism is proposed that controls the formation of skeletal ultrastructures, which likely involves compartmentalized calcifying cells and their related cellular activities. This could clarify the association between coral skeletal mineralization and biology, and it may be beneficial to better protection and application of coral reefs.

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.

Classification, density, and spatial distribution of polychaete reefs in the Coorong, South Australia

The cosmopolitan species Ficopomatus enigmaticus is one of the most prominent providers of polychaete reefs in shallow and brackish waters. The effects of polychaete reefs on the environment can be positive or negative subject to their structural complexity and vary with local environmental conditions and over time. The Coorong is a large temperate estuarine and lagoonal system with extensive polychaete reefs built by F. enigmaticus. The aims of this study were to (1) classify polychaete reefs based on size and morphology, (2) quantify reef density, (3) assess their spatial distribution and (4) assess the correlation between reefs (e.g., density, size) with the environmental gradient. Structural morphologies of F. enigmaticus were classified as either halo, circular, irregular, platform or fringing reef types. The largest densities of polychaete reefs were recorded in the vicinity of the mouth of the estuary with 224 reefs per ha compared to the lagoon (62 reefs per ha). The most common reef morphology was circular and largest sizes in the lagoon were positively correlated with salinity, chlorophyll a, TRIX (trophic index) and bicarbonate. The largest reef diameter recorded was 11.3 m, exceeding previously known F. enigmaticus circular reef formations globally. The growth of large circular reefs may have benefitted from low flows and eutrophic conditions in the Coorong during the last two decades. This study serves as an important baseline for future assessments of reef change in a Ramsar listed wetland. Furthermore, this study highlights reef characteristics of F. enigmaticus across an environmental gradient, which can be informative for the management of flow and eutrophication in estuaries and coastal lagoons.

Coral Communities Distribution in the Context of Site’s Reef Formation Type in Wakatobi National Park, Indonesia

Coral Communities Distribution in the Context of Site’s Reef Formation Type in Wakatobi National Park, Indonesia

Innovative Agrowaste Banana Peel Extract-Based Magnetic Iron Oxide Nanoparticles for Eco-Friendly Oxidative Shield and Freshness Fortification

This study presents the synthesis of agro-waste banana peel extract-based magnetic iron oxide nanoparticles (BPEx-MIONPs), emphasizing antioxidant capacity and food preservation. Using iron (III) chloride hexahydrate (FeCl3 · 6 H2O) as a precursor and a reducing agent from agro-waste peel extract, a precisely controlled process yielded BPEx-MIONPs. Characterization involved X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). XRD revealed tetragonal Fe2O3, cubic magnetite structure, and monoclinic FexOy-NPs with an average size of 14.8 nm. TEM and SEM revealed diverse morphologies. TEM displayed both spherical and elongated nanoparticles, with some appearing as thin fibrils. In contrast, SEM images depicted an array primarily consisting of spherical nanoparticles, resembling coral reef formations. FTIR confirmed Fe–O bonds (1000 –400 cm-1). The antioxidant assessment showed robust DPPH free radical scavenging; BPEx achieved 100% inhibition at 18 min, and BPEx-MIONPs had an IC50 of ~ 136 µg/mL. BPEx-MIONPs, stabilized with banana-based bioplastic, effectively preserved grapes, reducing weight loss to 6.2% on day 3, compared to the control (19.0%). This pioneering study combines banana peel antioxidants with magnetic iron oxide nanoparticles, providing sustainable solutions for food preservation and nano-packaging. Ongoing research aims to refine conditions and explore broader applications of BPEx-MIONPs.Graphical

Defining the role of Sabellaria alveolata reefs as nursery areas for juvenile fish: first evidence from drone-based imagery and underwater visual census data

The biogenic reefs built by the honeycomb worm Sabellaria alveolata constitute priority habitats along Atlanto-Mediterranean coastal areas. Despite their wide extent and important ecological role, the nursery value of S. alveolata reefs remains unclear, and more information is needed to define how such structured habitats affect juvenile fish assemblages. In this study, habitat use by juveniles of 7 fish species was investigated by underwater visual census (UVC) at 3 study sites representing a gradient of complexity of Sabellaria reef habitats, spanning from a large and uniform reef to patchy and isolated small reef formations. Sabellaria reef metrics derived by drone-based cartography and GIS analysis were used to quantitatively monitor the seasonal structural changes occurring due to the natural dynamics of the reefs. We also tested the potential effect of Sabellaria habitats on the growth and relative condition factor (Kn) of white seabream Diplodus sargus juveniles. Five of the 7 surveyed species, especially sparid fishes, showed a clear preferential association with Sabellaria formations. Generalized additive modelling revealed a significant effect of the compactness ratio on estimated fish densities at high and low index values. The juvenile fish sampled on Sabellaria reefs exhibited higher values of Kn than those sampled on rocky habitats, supporting the hypothesis that structural complexity positively affected their condition. We provide evidence on habitat use by juveniles, suggesting that the presence of the Sabellaria reef may act as a nursery and affect local fish density in Mediterranean coastal waters.

Osinskaya subformation of the Usolsky formation of the Lower Cambrian of the central and southern parts of the Nepa-Botuoba anteclise: structure, formation conditions and biostratigraphical characteristics

Relevance. Geological prospecting carried out recently throughout the Lena-Tunguska oil-and-gas province makes studies of carbonates of the Osinskaya subformation particularly relevant, as they make it possible to establish the patterns of hydrocarbon trap formation. Aim. To present the results of the lithological and facial, biostratigraphic and petrophysical studies of the Osinskaya subformation in the southern and central part of the Nepa-Botuoba anteclise. Objects. Carbonate rocks of the middle Osinskaya subformation of the Usolskiy Formation of the Lower Cambrian Tommotian Stage, studied from well cores. Methods. GIS complex, detailed lithological and sedimentological description of the core, sequential stratigraphic analysis, petrographic analysis of 300 samples and examination of paleontological remains taken from the core; analysis. Results. Based on these studies, three sedimentation zones were identified, traced, and described for the first time: deep-water, marginal, and shallow-water. The deep-water zone is characterized by uncompensated sedimentation, the presence of single reefs, and confinement to depressions and troughs. It was flanked by an edge zone of carbonate platform associated with elevated thicknesses of the subformation and distribution of reefs over the area. It was followed by a shallow-water zone, represented by medium and reduced thicknesses of the Osinskaya subformation, its sediments are composed of carbonate grained and clayey rocks with small single reefs. The localized marginal zone of the extended carbonate platform agrees with the previously identified Chambinsko-Altybsko-Mirninskaya and Verkhnetokhomsko-Katsko-Pilyudinskaya zones of distribution of reef-like organogenic structures. On the basis of the studied wells, the structure of three formations according to the lithologic-facial profile was described. The paper introduces the authors’ variant of conducting the boundaries of the members. It was revealed that in the deep-water zone the prospects of searching for reservoir rocks are associated with single carbonate structures, in the marginal zone with area bioherms, and in the shallow-water zone with detrital deposits and shallow bioherms. The paleontological finds are shown to be confined to the selected sedimentation zones and beds. It was determined that algae diagnosed in the boudstones (autochthonous) were involved in the formation of the second and third strata, the edge zone of the carbonate platform. Archaeocyaths were diagnosed in detrital carbonate rocks of the second pack (allochthonous) in well no. 7 and autochthonous in boudstones of well no. 2X. Cribriciates were diagnosed in the boudstones of the third member (autochthonous). Archaeocyaths, cribriciates, namacalatusses, and calcareous algae studied from the cores of wells West Yaractinian no. 45, 361, Bolshetyrskaya no. 7, 3X, 2X, 4X, 5X, 6X were major edificators of Early Cambrian organogenic structures (biostromes, bioherms, bioherms massifs, reef formations).

A memetic dynamic coral reef optimisation algorithm for simultaneous training, design, and optimisation of artificial neural networks

Artificial Neural Networks (ANNs) have been used in a multitude of real-world applications given their predictive capabilities, and algorithms based on gradient descent, such as Backpropagation (BP) and variants, are usually considered for their optimisation. However, these algorithms have been shown to get stuck at local optima, and they require a cautious design of the architecture of the model. This paper proposes a novel memetic training method for simultaneously learning the ANNs structure and weights based on the Coral Reef Optimisation algorithms (CROs), a global-search metaheuristic based on corals’ biology and coral reef formation. Three versions based on the original CRO combined with a Local Search procedure are developed: (1) the basic one, called Memetic CRO; (2) a statistically guided version called Memetic SCRO (M-SCRO) that adjusts the algorithm parameters based on the population fitness; (3) and, finally, an improved Dynamic Statistically-driven version called Memetic Dynamic SCRO (M-DSCRO). M-DSCRO is designed with the idea of improving the M-SCRO version in the evolutionary process, evaluating whether the fitness distribution of the population of ANNs is normal to automatically decide the statistic to be used for assigning the algorithm parameters. Furthermore, all algorithms are adapted to the design of ANNs by means of the most suitable operators. The performance of the different algorithms is evaluated with 40 classification datasets, showing that the proposed M-DSCRO algorithm outperforms the other two versions on most of the datasets. In the final analysis, M-DSCRO is compared against four state-of-the-art methods, demonstrating its superior efficacy in terms of overall accuracy and minority class performance.

The Lanseria palaeosol: Implications for palaeoweathering and terrestrial life at ∼2.6 Ga on the Kaapvaal Craton

Archaean palaeosols are a rare record of surface processes on the early Earth. We report on the discovery of a palaeoweathering profile developed at the contact between Mesoarchaean basement and the Neoarchaean to Palaeoproterozoic Transvaal Supergroup along the northern margin of the Johannesburg Dome, Kaapvaal Craton. Granodiorite ∼3.1 Ga old was subjected to weathering just prior to the deposition of the ∼2.6 Ga Black Reef Formation. The ∼25 m-thick profile is dominated by a palaeosaprolite and organic matter-rich palaeosol remnant at the top that experienced erosion upon marine transgression on the Kaapvaal Craton. The Al concentration of the profile, sericite content and chemical index of alteration (CIA) values progressively increase from the parent granodiorite towards the nonconformity as Fe, Mg, Na and Ca concentrations decrease. The decrease of Co and Zn together with Fe and the retention of U, V and Cr collectively suggest a reducing and acidic environment at the time of weathering. Carbonaceous matter with negative δ13C isotopic values (−27 to −23 ‰V-PDB) in the palaeosol is compatible with the former presence of photoautotrophic microbes. Copper depletion and mobility of P may indicate the presence of organic acids that enhanced chemical weathering of the bedrock. The palaeoweathering profile was subjected to diagenetic-hydrothermal K-metasomatism, regional metamorphism and deformation, which collectively transformed the regolith into a quartz-sericite schist, as it presently occurs. Despite these modifications, the original record of palaeoweathering and microbial colonisation is well preserved. Colonisation of a large swath of the Kaapvaal Craton by terrestrial soil-dwelling microbiota at 2.60 Ga is recorded in abundant soil-derived carbonaceous matter in transgressive marine conglomerates that erosively overlie the palaeosol.

Paleozoic reef formation in the Pechora syneclise and the Caspian basin – a comparative analysis

In the two marginal depressions of the East European Platform, the Pechora syneclise and the Caspian depression, reef formations are widely represented, but the stratigraphic intervals of their development are far from equal. In the Pechora syneclise, reef formation began in the second half of the Llandoverian, reached its maximum in the Frasnian and was replaced by the development of reef hills in the Famennian. The structures are represented both as asymmetric reefs framing the shallow zones at their boundary with relatively deep paleobasins and in the form of single structures within the latter. The reefs of the next global maximums, the Late Visean-Serpukhovian and Lower Permian, are developed only marginally at the boundary with the Ural paleoocean and its relic, the Pre-Urals foreland basin. In the Caspian basin, reefs of all three global maxima of development are present, and there are both asymmetric reef systems framing the shelf edges and symmetric intra-basin isolated structures. Such difference is due to the different paleogeomorphological type of the basins. The Caspian basin was sharply differentiated in depth throughout the Middle and Late Paleozoic, which led to the formation of reefs rising above the bottom of these basins. In the Pechora syneclise, depth differentiation of the basins occurred only in the late Devonian. Generally weakly dissected shallow seas of the Visiean-Serpukhovian and early Permian did not provide conditions for the formation of powerful reefs protruding above the seafloor. The latter were formed only on the edge of the Ural paleoocean, and in the Permian ‒ on the edge of the Pre-Ural foreland basin.

Paleozoic Reef Formation in the Pechora Syneclise and the Caspian Basin: A Comparative Analysis

Paleozoic Reef Formation in the Pechora Syneclise and the Caspian Basin: A Comparative Analysis

The Middle-Upper Eocene in the Northern Plateau of the Bahariya Depression, Western Desert (Egypt) and correlation with other Tethyan sectors

This study describes the paleoenvironmental evolution of the Middle-Upper Eocene succession exposed along the northern plateau of the Bahariya Depression (Western Desert, Egypt). Based on detailed field observations and facies analysis, twenty-one facies were recognized and grouped into five facies associations: tidal flat to restricted marine (FA1), lagoonal (FA2), ramp crest (FA3), middle ramp (FA4), and siliciclastic-dominated foreshore–shoreface (FA5). These facies associations were developed in a gently dipping mixed siliciclastic-carbonate ramp which was connected with siliciclastic coastal-shelf depositional system. The biogenic assemblages described in the Middle-Upper Eocene deposits show a mixing of photozoan and heterozoan associations, indicating euphotic to mesophotic inner to mid-ramp settings under mesotrophic-oligotrophic conditions. The succession shows a transition from photozoan to heterozoan carbonates and a shift towards inner ramp settings. The formation and the evolution of the northern Bahariya platform reflect the complex interplay of synsedimentary tilting due to post-Middle Eocene inversion phase, high-frequency sea-level changes, transition from warm to humid climate and paleoecological parameters. The sedimentation pattern including distinct lateral changes in facies and thicknesses are largely controlled by tectonics. Long-term sea level changes were responsible for the unconformities associated with major regressions. The Middle-Upper Eocene strata display a characteristic up-section increase in clastic input from the hinterlands through tectonic uplift and/or a change to a cooling climate. The shift to a colder climate, which was a result of a global temperature decrease, led to the maximum northward retreat of the Neo-Tethys Ocean. During the Eocene epoch, carbonates dominated by Larger Benthic Foraminifera (LBF) were prevalent along the entire Tethyan margins. This was linked to a decline in coral reef formations. Comparisons with other southern and western-central Tethyan sectors showed that small coral reef build-ups in widely scattered localities could exist in broad LBF-rich ramps. Consequently, zooxanthellate corals were only able to flourish locally in marginal environments under specific ecological conditions.

Using Museum collections to assess the impact of industrialization on mussel (Mytilus edulis) calcification.

Mytilus edulis is a commercially and ecologically important species found along the east coast of the United States. Ecologically, M. edulis improves water quality through filtration feeding and provides habitat formation and coastal protection through reef formation. Like many marine calcifiers, ocean warming, and acidification are a growing threat to these organisms-impacting their morphology and function. Museum collections are useful in assessing long-term environmental impacts on organisms in a natural multi-stressor environment, where acclimation and adaptation can be considered. Using the American Museum of Natural History collections ranging from the early 1900s until now, we show that shell porosity changes through time. Shells collected today are significantly more porous than shells collected in the 1960s and, at some sites, than shells collected from the early 1900s. The disparity between porosity changes matches well with the warming that occurred over the last 130 years in the north Atlantic suggesting that warming is causing porosity changes. However, more work is required to discern local environmental impacts and to fully identify porosity drivers. Since, porosity is known to affect structural integrity, porosity increasing through time could have negative consequences for mussel reef structural integrity and hence habitat formation and storm defenses.

Strontium Isotopic, Ostracod fauna, and Paleoenvironmental Features of the Late Miocene Sequence in Mut/Dağpazarı Region (Southern Turkey)

The primary focus of this study was the Dağpazarı village in the Mut region of Mersin, southern Turkey. In this research area, two stratigraphic sections were meticulously measured. The study conducted a comprehensive examination of the Middle-Late Miocene period in the Dağpazarı, Ballı, and Mut Formations by analyzing the ostracod fauna and utilizing strontium isotope chemostratigraphic dating. This research determined that the upper levels of the Mut/Köselerli formations, specifically from the Burdigalian to Serravallian, signify the commencement of the Miocene succession in the study area.The Dağpazarı Formation, characterized by abundant silty-clay, Ostrea fossils, and lignite layers, is deposited unconformably just above these levels.This formation contains the following ostracod taxa; Bairdia subdeltoidea, C. glypta, Cytheridea acuminata acuminata, Acanthocythereis hystrix, Krithe monosteracensis, Neomonoceratina mouliana, Hemicyprideis sp., Cistacythereis caelatura, Cyherella terguemi, T. prava, K. langhiana, A. ulicznyi, Pokornyella deformis minor, Loxoconcha alata, Tenedocythere salebrosa. Furthermore, the planktonic foraminifera species are; O. universa, Globigerinoides trilobus, Glb. ruber, Orbulina bilobata, Glb. sacculifer, O. suturalis, and the formation includes abundant bryozoa, echinoid spines, gastropods such as Terebralia at distinct levels, and fish otolith. The formation, dating from the late Serravallian to the early Tortonian, exhibits the shallow reef characteristics that continued to develop in the late Miocene.The formation consists of dark green, bulbous weathered claystone, Bairdia subdeltoidea and Ostrea which are reduced in size at the levels that pass into hard clayey sandstone, abundant benthic foraminifera with abundant echinoid spines. The formation consists of benthic foraminifera, hard clayey sandstone, and weathered dark green claystone, which contains numerous echinoid spines.Ostrea and Bairdia subdeltoidea are also present. The upper section of the analyzed succession concludes with silty, compact, clayey limestone layers and light-colored limestone bands. The Tırtar Ballı Formation, which conformably overlays the Dağpazarı Formation, signifies the culmination of a relatively recent reef formation during the Tortonian period.Ostracod species such as Aurila pigadiana, Thalmannia hodgii, Buntonia sublatissima dertonensis, Bairdia subdeltoidea, Aurila sp. Bassiouni have been defined. The limestones also contain abundant benthic foraminifera and echinoid spines. The 87Sr/86Sr ratio analyzed from the carbonate sample obtained from the Dağpazarı formation is 0.708920. Based on these isotope data, the age of the Dağpazarı formation was calculated to be 8.7 million years (Ma).

Microbial Reefs Predominated by Leiolites in the Zhanxia Formation of Cambrian from Qinhuangdao City,Hebei Province

Stromatolites, thrombolites, leiolites and dendrites are juxtaposed and classified as typical microbial carbonates, with leiolite characterized by cryptocrystalline lithology, undeveloped agglomerate structure, lacking obvious macroscopic structure and clot. Since its designation in 1995, leiolites have been rarely observed and recognized in strata and modern analogies are scarce, whoch makes the report of a leiolite example extremely important. In order to research the characteristics of leiolites in Cambrian of North China Platform, combine the methods of field sampling observation and observation of indoor microscopic characteristics under the microscope and selected microbial reefs predominated by leiolites with thickness of tens of meters develop intensively at the top of the Forced Regression system domain of the Cambrian Zhangxia Formation in Qinhuangdao, Hebei Province was selected, which constitutes a three-order sequence as research object. Leiolite consists of dense mud crystals and a small amount of microlithophores, and the Filamental Girvanella similar to the modern Plectonema is visible in the dense mud crystals that make up leiolites, while Epiphyton and Hedstroemia can be seen locally in the bushy mud crystals. It is indicated that microbial reefs predominated by leiolites are influenced by complex organic mineralization processes or by early cyanobacteria-dominated lithification occurring within microbial membranes or microbial mats. Therefore, in understanding the formation of ancient microbial reefs, the microbial reef predominated by leiolites at the Cambrian Zhangxia Formation in Qinhuangdao, formed by the calcification of microbial mats, are an important window.

Tectonically assisted emplacement of oceanic intraplate volcanoes: The Bathymetrists Seamounts, central Atlantic

The origin of broad intraplate volcanic provinces has been related to deep mantle plumes or shallow lithospheric processes, e.g., underlying large fault systems. One example of an understudied intraplate volcanic province is the Bathymetrists Seamounts (BSM) in the central-eastern Atlantic, an area with dense and extended fracture zones, but the BSM has been associated with a mantle plume origin. Extensive bathymetric mapping and seafloor sampling show that most BSM-seamounts resemble flat-topped guyots capped by carbonate platforms. Vesicular, volcanoclastic samples imply that their tops formed near sea level, followed by reef formation during cessation of volcanism and crustal subsidence. Erosion determines the seamount irregularity proportional to their sizes. Strong ellipticity of some seamounts is related to multiple vents that erupted along fractures. The orientation of the volcanoes, carbonate platforms, and morphological lineaments of the BSM show particular trends that reveal information on their origin and formation mechanisms. Geomorphological analyses indicate a structural control on volcano emplacement related to underlying lithospheric faults resembling a Riedel shear pattern. The stress field corresponding to their orientations is related to a NE-SW tensional setting, fitting to the prevalent tectonic setting ~56–38 Ma years ago that coincides with the BSM formation and an increase in spreading rates. A change in movement of the African plate during this time, together with the reactivation of fracture zones of the strongly sheared equatorial Atlantic, created pathways in the lithosphere and possibly enhanced magmatism. The seamounts do not show distinct differences in erosion state, morphology, carbonate platform depth, or Mn-crust thickness, in contrast to what would be expected for an age progression within the seamount chain. Our observations, therefore, do not support a plume mantle source. While the magmatic source remains undefined, we show that tectonic pathways determined the shape of the seamounts and enabled the broad emplacement of the Bathymetrists seamount chain.

BIOMIMICRY OF NATURAL REEF HYDRODYNAMICS IN AN ARTIFICIAL SPUR AND GROOVE REEF FORMATION

An artificial spur-and-groove (SAG) reef formation designed to perform as a submerged breakwater was studied. Not only do natural SAG reefs effectively attenuate waves, but they also create important circulation within the system that encourages the success of corals and the overall ecosystem. Modular components were developed and imported into the CFD software FLOW-3D® HYDRO to test the wave-structure interaction while adjusting the geometry of the structure, wave conditions, and depth due to tidal changes in environmental conditions similar to Moloka’i, Hawaii. Results showed highest wave height reduction with larger wave heights as well as lower submergence during low tide conditions.