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Rajamohanan Pillai Ranith, Nandini Menon N, Elavumkudi Paulose Nobi, Alexkirubakaran Augustin Raj, Sigamani Sivaraj. Assessment of coral reef connectivity in improved organic carbon storage of seagrass ecosystems in Palk Bay, India. MARINE POLLUTION BULLETIN 2024; 207:116908. [PMID: 39232413 DOI: 10.1016/j.marpolbul.2024.116908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2024] [Revised: 08/28/2024] [Accepted: 08/28/2024] [Indexed: 09/06/2024]
Abstract
The increase in climate-related extreme events and ecosystem degradation demands consistent and sustainable climate mitigation efforts. Seagrass playing a key role in nature-based carbon sequestration mitigation strategy. Here, we investigated the role of coral reef connectivity in blue carbon dynamics with seagrass meadows with coral reef connectivity (SC areas) and without coral reef connectivity (SG areas) in Palk Bay, India. The high sediment organic carbon was recorded in SC areas (90.26 ± 25.68 Mg org.C/ha) and lower in SG areas (66.96 ± 12.6 Mg org.C/ha). The maximum above-ground biomass (AGB) was recorded in Syringodium isoetifolium (35.43 ± 8.50) in SC areas and the minimum in Halophila ovalis (7.59 ± 0.90) in SG areas, with a similar trend observed in below-ground biomass (BGB). Our findings highlight the importance of coral reefs in enhancing the blue carbon potential of seagrass ecosystems and underscore the need for integrated conservation and restoration strategies for coral reefs and seagrasses.
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Affiliation(s)
| | - Nandini Menon N
- Nansen Environmental Research Centre (India), Madavana, Kochi, Kerala, India
| | | | | | - Sigamani Sivaraj
- Sathyabama Institute of Science and Technology, Chennai, Tamilnadu, India.
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Titelboim D, Rothwell NJ, Lord OT, Harniman RL, Melbourne LA, Schmidt DN. Unexpected increase in structural integrity caused by thermally induced dwarfism in large benthic foraminifera. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231280. [PMID: 38601028 PMCID: PMC11004679 DOI: 10.1098/rsos.231280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/02/2024] [Accepted: 02/21/2024] [Indexed: 04/12/2024]
Abstract
Climate change is predicted to negatively impact calcification and change the structural integrity of biogenic carbonates, influencing their protective function. We assess the impacts of warming on the morphology and crystallography of Amphistegina lobifera, an abundant benthic foraminifera species in shallow environments. Specimens from a thermally disturbed field area, mimicking future warming, are about 50% smaller compared with a control location. Differences in the position of the ν1 Raman mode of shells between the sites, which serves as a proxy for Mg content and calcification temperature, indicate that calcification is negatively impacted when temperatures are below the thermal range facilitating calcification. To test the impact of thermal stress on the Young's modulus of calcite which contributes to structural integrity, we quantify elasticity changes in large benthic foraminifera by applying atomic force microscopy to a different genus, Operculina ammonoides, cultured under optimal and high temperatures. Building on these observations of size and the sensitivity analysis for temperature-induced change in elasticity, we used finite element analysis to show that structural integrity is increased with reduced size and is largely insensitive to calcite elasticity. Our results indicate that warming-induced dwarfism creates shells that are more resistant to fracture because they are smaller.
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Affiliation(s)
- Danna Titelboim
- School of Earth Sciences, University of Bristol, Bristol, UK
| | | | - Oliver T. Lord
- School of Earth Sciences, University of Bristol, Bristol, UK
| | | | - Leanne A. Melbourne
- School of Earth Sciences, University of Bristol, Bristol, UK
- Earth and Planetary Sciences Department, American Museum of Natural History, New York, NY, USA
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Xie W, Li J, Shi J, Zhang X, Usmani AS, Chen G. Probabilistic real-time natural gas jet fire consequence modeling of offshore platforms by hybrid deep learning approach. MARINE POLLUTION BULLETIN 2023; 192:115098. [PMID: 37295257 DOI: 10.1016/j.marpolbul.2023.115098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 05/01/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023]
Abstract
Natural gas jet fire induced by igniting blowouts has the potential to cause critical structure damage and great casualties of offshore platforms. Real-time natural gas jet fire plume prediction is essential to support the emergency planning to mitigate subsequent damage consequence and ocean pollution. Deep learning based on a large amount of Computational fluid dynamics (CFD) simulations has recently been applied to real-time fire modeling. However, existing approaches based on point-estimation theory are 'over-confident' when prediction deficiency exists, which reduce robustness and accuracy for emergency planning support. This study proposes probabilistic deep learning approach for real-time natural gas jet fire consequence modeling by integrating variational Bayesian inference with deep learning. Numerical model of natural gas jet fire from offshore platform is built and the natural gas jet fire scenarios are simulated to construct the benchmark dataset. Sensitivity analysis of pre-defined parameters such as MC (Monte Carlo) sampling number m and dropout probability p is conducted to determine the trade-off between model's accuracy and efficiency. The results demonstrated our model exhibits competitive accuracy with R2 = 0.965 and real-time capacity with an inference time of 12 ms. In addition, the predicted spatial uncertainty corresponding to spatial jet fire flame plume provides more comprehensive and reliable support for the following mitigation decision-makings compared to the state-of-the-art point-estimation based deep learning model. This study provides a robust alternative for constructing a digital twin of fire and explosion associated emergency management on offshore platforms.
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Affiliation(s)
- Weikang Xie
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong; Centre for Offshore Engineering and Safety Technology, China University of Petroleum, Qingdao, China
| | - Junjie Li
- Centre for Offshore Engineering and Safety Technology, China University of Petroleum, Qingdao, China
| | - Jihao Shi
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong; Centre for Offshore Engineering and Safety Technology, China University of Petroleum, Qingdao, China.
| | - Xinqi Zhang
- Centre for Offshore Engineering and Safety Technology, China University of Petroleum, Qingdao, China
| | - Asif Sohail Usmani
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Guoming Chen
- Centre for Offshore Engineering and Safety Technology, China University of Petroleum, Qingdao, China
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Moynihan MA, Amini S, Oalmann J, Chua JQI, Tanzil JTI, Fan TY, Miserez A, Goodkin NF. Crystal orientation mapping and microindentation reveal anisotropy in Porites skeletons. Acta Biomater 2022; 151:446-456. [PMID: 35963519 DOI: 10.1016/j.actbio.2022.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 11/28/2022]
Abstract
Structures made by scleractinian corals support diverse ocean ecosystems. Despite the importance of coral skeletons and their predicted vulnerability to climate change, few studies have examined the mechanical and crystallographic properties of coral skeletons at the micro- and nano-scales. Here, we investigated the interplay of crystallographic and microarchitectural organization with mechanical anisotropy within Porites skeletons by measuring Young's modulus and hardness along surfaces transverse and longitudinal to the primary coral growth direction. We observed micro-scale anisotropy, where the transverse surface had greater Young's modulus and hardness by ∼ 6 GPa and 0.2 GPa, respectively. Electron backscatter diffraction (EBSD) revealed that this surface also had a higher percentage of crystals oriented with the a-axis between ± 30-60∘, relative to the longitudinal surface, and a broader grain size distribution. Within a region containing a sharp microscale gradient in Young's modulus, nanoscale indentation mapping, energy dispersive spectroscopy (EDS), EBSD, and Raman crystallography were performed. A correlative trend showed higher Young's modulus and hardness in regions with individual crystal bases (c-axis) facing upward, and in crystal fibers relative to centers of calcification. These relationships highlight the difference in mechanical properties between scales (i.e. crystals, crystal bundles, grains). Observations of crystal orientation and mechanical properties suggest that anisotropy is driven by microscale organization and crystal packing, rather than intrinsic crystal anisotropy. In comparison with previous observations of nanoscale isotropy in corals, our results illustrate the role of hierarchical architecture in coral skeletons and the influence of biotic and abiotic factors on mechanical properties at different scales. STATEMENT OF SIGNIFICANCE: Coral biomineralization and the ability of corals' skeletal structure to withstand biotic and abiotic forces underpins the success of reef ecosystems. At the microscale, we show increased skeletal stiffness and hardness perpendicular to the coral growth direction. By comparing nano- and micro-scale indentation results, we also reveal an effect of hierarchical architecture on the mechanical properties of coral skeletons and hypothesize that crystal packing and orientation result in microscale anisotropy. In contrast to previous findings, we demonstrate that mechanical and crystallographic properties of coral skeletons can vary between surface planes, within surface planes, and at different analytical scales. These results improve our understanding of biomineralization and the effects of scale and direction on how biomineral structures respond to environmental stimuli.
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Affiliation(s)
- Molly A Moynihan
- Earth Observatory of Singapore, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore; Asian School of the Environment, Nanyang Technological University, Singapore, Singapore; Marine Biological Laboratory, Woods Hole, MA, USA.
| | - Shahrouz Amini
- Center for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore, Singapore; Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Potsdam, Germany
| | - Jeffrey Oalmann
- Earth Observatory of Singapore, Nanyang Technological University, Singapore, Singapore
| | - J Q Isaiah Chua
- Center for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jani T I Tanzil
- Earth Observatory of Singapore, Nanyang Technological University, Singapore, Singapore; St. John's Island National Marine Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, 119227, Singapore
| | - T Y Fan
- National Museum of Marine Biology and Aquarium, Pingtung, Taiwan
| | - Ali Miserez
- Center for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Nathalie F Goodkin
- Earth Observatory of Singapore, Nanyang Technological University, Singapore, Singapore; American Museum of Natural History, New York, NY, USA
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Domenici P, Seebacher F. The impacts of climate change on the biomechanics of animals: Themed Issue Article: Biomechanics and Climate Change. CONSERVATION PHYSIOLOGY 2020; 8:coz102. [PMID: 31976075 PMCID: PMC6956782 DOI: 10.1093/conphys/coz102] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/24/2019] [Accepted: 11/03/2019] [Indexed: 05/09/2023]
Abstract
Anthropogenic climate change induces unprecedented variability in a broad range of environmental parameters. These changes will impact material properties and animal biomechanics, thereby affecting animal performance and persistence of populations. Climate change implies warming at the global level, and it may be accompanied by altered wind speeds, wave action, ocean circulation, acidification as well as increased frequency of hypoxic events. Together, these environmental drivers affect muscle function and neural control and thereby movement of animals such as bird migration and schooling behaviour of fish. Altered environmental conditions will also modify material properties of animals. For example, ocean acidification, particularly when coupled with increased temperatures, compromises calcified shells and skeletons of marine invertebrates and byssal threads of mussels. These biomechanical consequences can lead to population declines and disintegration of habitats. Integrating biomechanical research with ecology is instrumental in predicting the future responses of natural systems to climate change and the consequences for ecosystem services such as fisheries and ecotourism.
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Affiliation(s)
- Paolo Domenici
- IAS-CNR, Località Sa Mardini, Torregrande, Oristano, 09170 Italy
| | - Frank Seebacher
- School of Life and Environmental Sciences A08, University of Sydney, Sydney, NSW 2006, Australia
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Plasticity in Three-Dimensional Geometry of Branching Corals Along a Cross-Shelf Gradient. DIVERSITY 2019. [DOI: 10.3390/d11030044] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Scleractinian corals often exhibit high levels of morphological plasticity, which is potentially important in enabling individual species to occupy benthic spaces across a wide range of environmental gradients. This study tested for differences in the three-dimensional (3D) geometry of three branching corals, Acropora nasuta, Pocillopora spp. and Stylophora pistillata among inner-, mid- and outer-shelf reefs in the central Great Barrier Reef, Australia. Important attributes of coral morphology (e.g., surface area to volume ratio) were expected to vary linearly across the shelf in accordance with marked gradients in environmental conditions, but instead, we detected non-linear trends in the colony structure of A. nasuta and Pocillopora spp. The surface area to volume ratio of both A. nasuta and Pocillopora spp. was highest at mid-shelf locations, (reflecting higher colony complexity) and was significantly lower at both inner-shelf and outer-shelf reefs. The branching structure of these corals was also far more tightly packed at inner-shelf and outer-shelf reefs, compared to mid-shelf reefs. Apparent declines in complexity and inter-branch spacing at inner and outer-shelf reefs (compared to conspecifics from mid-shelf reefs) may reflect changes driven by gradients of sedimentation and hydrodynamics. The generality and explanations of observed patterns warrant further investigation, which is very feasible using the 3D-photogrammetry techniques used in this study.
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Disturbance in Mesophotic Coral Ecosystems and Linkages to Conservation and Management. CORAL REEFS OF THE WORLD 2019. [DOI: 10.1007/978-3-319-92735-0_47] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Valderrama Ballesteros L, Matthews JL, Hoeksema BW. Pollution and coral damage caused by derelict fishing gear on coral reefs around Koh Tao, Gulf of Thailand. MARINE POLLUTION BULLETIN 2018; 135:1107-1116. [PMID: 30301009 DOI: 10.1016/j.marpolbul.2018.08.033] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 08/15/2018] [Accepted: 08/17/2018] [Indexed: 05/12/2023]
Abstract
Most lost fishing gear is made of non-biodegradable plastics that may sink to the sea floor or drift around in currents. It may remain unnoticed until it shows up on coral reefs, beaches and in other coastal habitats. Stony corals have fragile skeletons and soft tissues that can easily become damaged when they get in contact with lost fishing gear. During a dive survey around Koh Tao, a small island in the Gulf of Thailand, the impact of lost fishing gear (nets, ropes, cages, lines) was studied on corals representing six different growth forms: branching, encrusting, foliaceous, free-living, laminar, and massive. Most gear (>95%) contained plastic. Besides absence of damage (ND), three categories of coral damage were assessed: fresh tissue loss (FTL), tissue loss with algal growth (TLAG), and fragmentation (FR). The position of the corals in relation to the fishing gear was recorded as either growing underneath (Un) or on top (On), whereas corals adjacent to the gear (Ad) were used as controls. Nets formed the dominant type of lost gear, followed by ropes, lines and cages, respectively. Branching corals were most commonly found in contact with the gear and also around it. Tubastraea micranthus was the most commonly encountered coral species, either Un, On, or Ad. Corals underneath gear showed most damage, which predominantly consisted of tissue loss. Fragmentation was less common than expected, which may be related to the low fragility of T. micranthus as dominant branching species. Even if nets serve as substrate for corals, it is recommended to remove them from reefs, where they form a major component of the plastic pollution and cause damage to corals and other reef organisms.
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Affiliation(s)
| | | | - Bert W Hoeksema
- Taxonomy and Systematics Group, Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA, Leiden, the Netherlands.; Institute of Biology Leiden, Leiden University, P.O. Box 9505, 2300 RA, Leiden, the Netherlands.
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SEAMANCORE: A spatially explicit simulation model for assisting the local MANagement of COral REefs. Ecol Modell 2018. [DOI: 10.1016/j.ecolmodel.2018.05.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Harris DL, Rovere A, Casella E, Power H, Canavesio R, Collin A, Pomeroy A, Webster JM, Parravicini V. Coral reef structural complexity provides important coastal protection from waves under rising sea levels. SCIENCE ADVANCES 2018; 4:eaao4350. [PMID: 29503866 PMCID: PMC5829992 DOI: 10.1126/sciadv.aao4350] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 01/24/2018] [Indexed: 05/06/2023]
Abstract
Coral reefs are diverse ecosystems that support millions of people worldwide by providing coastal protection from waves. Climate change and human impacts are leading to degraded coral reefs and to rising sea levels, posing concerns for the protection of tropical coastal regions in the near future. We use a wave dissipation model calibrated with empirical wave data to calculate the future increase of back-reef wave height. We show that, in the near future, the structural complexity of coral reefs is more important than sea-level rise in determining the coastal protection provided by coral reefs from average waves. We also show that a significant increase in average wave heights could occur at present sea level if there is sustained degradation of benthic structural complexity. Our results highlight that maintaining the structural complexity of coral reefs is key to ensure coastal protection on tropical coastlines in the future.
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Affiliation(s)
- Daniel L. Harris
- Center for Marine Environmental Sciences (MARUM), Bremen University, Bremen, Germany
- Leibniz Centre for Tropical Marine Research, Bremen, Germany
- The University of Queensland, School of Earth and Environmental Sciences, Brisbane, Queensland, Australia
- Corresponding author.
| | - Alessio Rovere
- Center for Marine Environmental Sciences (MARUM), Bremen University, Bremen, Germany
- Leibniz Centre for Tropical Marine Research, Bremen, Germany
- Lamont-Doherty Earth Observatory, Columbia University, New York, NY 10964, USA
| | - Elisa Casella
- Leibniz Centre for Tropical Marine Research, Bremen, Germany
| | - Hannah Power
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, Australia
| | - Remy Canavesio
- Centre de Recherches Insulaires et Observatoire de l’Environnement, USR 3278 CNRS–École Pratique des Hautes Études (EPHE)–Université de Perpignan Via Domitia, Laboratoire d’Excellence (LabEX) “CORAIL,” University of Perpignan, 66860 Perpignan, France
| | - Antoine Collin
- EPHE, PSL Research University, CNRS LETG 6554, Dinard 35800, France
- LabEX CORAIL, Perpignan, France
| | - Andrew Pomeroy
- ARC Centre of Excellence for Coral Reef Studies, The University of Western Australia, Perth, Western Australia, Australia
- UWA Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia
- Australian Institute of Marine Science, Perth, Western Australia 6009, Australia
| | - Jody M. Webster
- Geocoastal Research Group, School of Geosciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Valeriano Parravicini
- Centre de Recherches Insulaires et Observatoire de l’Environnement, USR 3278 CNRS–École Pratique des Hautes Études (EPHE)–Université de Perpignan Via Domitia, Laboratoire d’Excellence (LabEX) “CORAIL,” University of Perpignan, 66860 Perpignan, France
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Baldock TE, Golshani A, Atkinson A, Shimamoto T, Wu S, Callaghan DP, Mumby PJ. Impact of sea-level rise on cross-shore sediment transport on fetch-limited barrier reef island beaches under modal and cyclonic conditions. MARINE POLLUTION BULLETIN 2015; 97:188-198. [PMID: 26093817 DOI: 10.1016/j.marpolbul.2015.06.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 06/05/2015] [Accepted: 06/08/2015] [Indexed: 06/04/2023]
Abstract
A one-dimensional wave model is combined with an analytical sediment transport model to investigate the likely influence of sea-level rise on net cross-shore sediment transport on fetch-limited barrier reef and lagoon island beaches. The modelling considers if changes in the nearshore wave height and wave period in the lagoon induced by different water levels over the reef flat are likely to lead to net offshore or onshore movement of sediment. The results indicate that the effects of SLR on net sediment movement are highly variable and controlled by the bathymetry of the reef and lagoon. A significant range of reef-lagoon bathymetry, and notably shallow and narrow reefs, appears to lead hydrodynamic conditions and beaches that are likely to be stable or even accrete under SLR. Loss of reef structural complexity, particularly on the reef flat, increases the chance of sediment transport away from beaches and offshore.
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Affiliation(s)
- T E Baldock
- School of Civil Engineering, University of Queensland, St Lucia, Qld 4072, Australia.
| | - A Golshani
- School of Civil Engineering, University of Queensland, St Lucia, Qld 4072, Australia
| | - A Atkinson
- School of Civil Engineering, University of Queensland, St Lucia, Qld 4072, Australia
| | - T Shimamoto
- School of Civil Engineering, University of Queensland, St Lucia, Qld 4072, Australia
| | - S Wu
- School of Civil Engineering, University of Queensland, St Lucia, Qld 4072, Australia
| | - D P Callaghan
- School of Civil Engineering, University of Queensland, St Lucia, Qld 4072, Australia
| | - P J Mumby
- Marine Spatial Ecology Lab, School of Biological Sciences, Goddard Building, The University of Queensland, St Lucia, Qld 4072, Australia
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