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Panja AK, Jaiswal S, Haldar S. Time series (2003-15) analysis of selected physicochemical parameters in Indian Ocean: Cumulative impacts prediction on coral bleaching using machine learning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 933:173002. [PMID: 38710398 DOI: 10.1016/j.scitotenv.2024.173002] [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: 12/29/2023] [Revised: 04/23/2024] [Accepted: 05/03/2024] [Indexed: 05/08/2024]
Abstract
Coral bleaching is an important ecological threat worldwide, as the coral ecosystem supports a rich marine biodiversity to survive. Sea surface temperature was considered a major culprit; however, later it was observed that other water parameters like pH, tCO2, fCO2, salinity, dissolved oxygen, etc. also play a significant role in bleaching. In the present study, all these parameters of the Indian Ocean area for 15 years (2003-2017) were collected and analysed using machine learning language. The main aim is to see the cumulative impacts of various ocean parameters on coral bleaching. Introducing machine learning in environmental impact assessment studies is a new approach, and the prediction of coral bleaching using simulation of physico-chemical parameters interactions shows 94.4 % accuracy for the prediction of the future bleaching event. This study can be probably the first step in the application of the machine learning language for the prediction of coral bleaching in the field of marine science.
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Affiliation(s)
- Atanu Kumar Panja
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar 364 002, Gujarat, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sweta Jaiswal
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar 364 002, Gujarat, India
| | - Soumya Haldar
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar 364 002, Gujarat, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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2
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Hackerott S, Virdis F, Flood PJ, Souto DG, Paez W, Eirin-Lopez JM. Relationships between phenotypic plasticity and epigenetic variation in two Caribbean Acropora corals. Mol Ecol 2023; 32:4814-4828. [PMID: 37454286 DOI: 10.1111/mec.17072] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/29/2023] [Accepted: 07/03/2023] [Indexed: 07/18/2023]
Abstract
The plastic ability for a range of phenotypes to be exhibited by the same genotype allows organisms to respond to environmental variation and may modulate fitness in novel environments. Differing capacities for phenotypic plasticity within a population, apparent as genotype by environment interactions (GxE), can therefore have both ecological and evolutionary implications. Epigenetic gene regulation alters gene function in response to environmental cues without changes to the underlying genetic sequence and likely mediates phenotypic variation. DNA methylation is currently the most well described epigenetic mechanism and is related to transcriptional homeostasis in invertebrates. However, evidence quantitatively linking variation in DNA methylation with that of phenotype is lacking in some taxa, including reef-building corals. In this study, spatial and seasonal environmental variation in Bonaire, Caribbean Netherlands was utilized to assess relationships between physiology and DNA methylation profiles within genetic clones across different genotypes of Acropora cervicornis and A. palmata corals. The physiology of both species was highly influenced by environmental variation compared to the effect of genotype. GxE effects on phenotype were only apparent in A. cervicornis. DNA methylation in both species differed between genotypes and seasons and epigenetic variation was significantly related to coral physiological metrics. Furthermore, plastic shifts in physiology across seasons were significantly positively correlated with shifts in DNA methylation profiles in both species. These results highlight the dynamic influence of environmental conditions and genetic constraints on the physiology of two important Caribbean coral species. Additionally, this study provides quantitative support for the role of epigenetic DNA methylation in mediating phenotypic plasticity in invertebrates.
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Affiliation(s)
- Serena Hackerott
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
- Florida International University, Miami, Florida, USA
| | - Francesca Virdis
- Reef Renewal Foundation Bonaire, Kralendijk, Caribbean Netherlands
| | - Peter J Flood
- Florida International University, Miami, Florida, USA
| | - Daniel Garcia Souto
- Genomes and Disease, Centre for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
- Department of Zoology, Genetics and Physical Anthropology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Wendy Paez
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
- Florida International University, Miami, Florida, USA
| | - Jose M Eirin-Lopez
- Environmental Epigenetics Laboratory, Institute of Environment, Florida International University, Miami, Florida, USA
- Florida International University, Miami, Florida, USA
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3
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Schoepf V, Baumann JH, Barshis DJ, Browne NK, Camp EF, Comeau S, Cornwall CE, Guzmán HM, Riegl B, Rodolfo-Metalpa R, Sommer B. Corals at the edge of environmental limits: A new conceptual framework to re-define marginal and extreme coral communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 884:163688. [PMID: 37105476 DOI: 10.1016/j.scitotenv.2023.163688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/14/2023] [Accepted: 04/19/2023] [Indexed: 05/07/2023]
Abstract
The worldwide decline of coral reefs has renewed interest in coral communities at the edge of environmental limits because they have the potential to serve as resilience hotspots and climate change refugia, and can provide insights into how coral reefs might function in future ocean conditions. These coral communities are often referred to as marginal or extreme but few definitions exist and usage of these terms has therefore been inconsistent. This creates significant challenges for categorising these often poorly studied communities and synthesising data across locations. Furthermore, this impedes our understanding of how coral communities can persist at the edge of their environmental limits and the lessons they provide for future coral reef survival. Here, we propose that marginal and extreme coral communities are related but distinct and provide a novel conceptual framework to redefine them. Specifically, we define coral reef extremeness solely based on environmental conditions (i.e., large deviations from optimal conditions in terms of mean and/or variance) and marginality solely based on ecological criteria (i.e., altered community composition and/or ecosystem functioning). This joint but independent assessment of environmental and ecological criteria is critical to avoid common pitfalls where coral communities existing outside the presumed optimal conditions for coral reef development are automatically considered inferior to coral reefs in more traditional settings. We further evaluate the differential potential of marginal and extreme coral communities to serve as natural laboratories, resilience hotspots and climate change refugia, and discuss strategies for their conservation and management as well as priorities for future research. Our new classification framework provides an important tool to improve our understanding of how corals can persist at the edge of their environmental limits and how we can leverage this knowledge to optimise strategies for coral reef conservation, restoration and management in a rapidly changing ocean.
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Affiliation(s)
- Verena Schoepf
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands; UWA Oceans Institute, University of Western Australia, Perth, Western Australia, Australia.
| | - Justin H Baumann
- Department of Biology, Mount Holyoke College, South Hadley, MA, USA
| | - Daniel J Barshis
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - Nicola K Browne
- School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia
| | - Emma F Camp
- Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Steeve Comeau
- Sorbonne Université, CNRS-INSU, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-mer, France
| | - Christopher E Cornwall
- School of Biological Sciences and Coastal People: Southern Skies, Victoria University of Wellington, Wellington, New Zealand
| | - Héctor M Guzmán
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - Bernhard Riegl
- Department of Marine and Environmental Sciences, Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, FL, USA
| | - Riccardo Rodolfo-Metalpa
- ENTROPIE, IRD, Université de la Réunion, CNRS, IFREMER, Université de Nouvelle-Calédonie, Nouméa, New Caledonia; Labex ICONA, International CO(2) Natural Analogues Network, Japan
| | - Brigitte Sommer
- School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
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Enochs IC, Studivan MS, Kolodziej G, Foord C, Basden I, Boyd A, Formel N, Kirkland A, Rubin E, Jankulak M, Smith I, Kelble CR, Manzello DP. Coral persistence despite marginal conditions in the Port of Miami. Sci Rep 2023; 13:6759. [PMID: 37185619 PMCID: PMC10130011 DOI: 10.1038/s41598-023-33467-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 04/13/2023] [Indexed: 05/17/2023] Open
Abstract
Coral cover has declined worldwide due to anthropogenic stressors that manifest on both global and local scales. Coral communities that exist in extreme conditions can provide information on how these stressors influence ecosystem structure, with implications for their persistence under future conditions. The Port of Miami is located within an urbanized environment, with active coastal development, as well as commercial shipping and recreational boating activity. Monitoring of sites throughout the Port since 2018 has revealed periodic extremes in temperature, seawater pH, and salinity, far in excess of what have been measured in most coral reef environments. Despite conditions that would kill many reef species, we have documented diverse coral communities growing on artificial substrates at these sites-reflecting remarkable tolerance to environmental stressors. Furthermore, many of the more prevalent species within these communities are now conspicuously absent or in low abundance on nearby reefs, owing to their susceptibility and exposure to stony coral tissue loss disease. Natural reef frameworks, however, are largely absent at the urban sites and while diverse fish communities are documented, it is unlikely that these communities provide the same goods and services as natural reef habitats. Regardless, the existence of these communities indicates unlikely persistence and highlights the potential for coexistence of threatened species in anthropogenic environments, provided that suitable stewardship strategies are in place.
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Affiliation(s)
- Ian C Enochs
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, U.S. National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA.
| | - Michael S Studivan
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, U.S. National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, 33149, USA
| | - Graham Kolodziej
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, U.S. National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, 33149, USA
| | | | - Isabelle Basden
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, U.S. National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, 33149, USA
| | - Albert Boyd
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, U.S. National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, 33149, USA
| | - Nathan Formel
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Amanda Kirkland
- Biological Sciences Department, University of New Orleans, New Orleans, LA, 70148, USA
| | - Ewelina Rubin
- Soil and Water Sciences Department, Genetics Institute, University of Florida, Gainesville, FL, 32611, USA
| | - Mike Jankulak
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, U.S. National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, 33149, USA
| | - Ian Smith
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, U.S. National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, 33149, USA
| | - Christopher R Kelble
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, U.S. National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA
| | - Derek P Manzello
- Satellite Oceanography and Climatology Division, Center for Satellite Applications and Research, U.S. National Oceanic and Atmospheric Administration, College Park, MD, USA
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5
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Pei Y, Chen S, Zhang Y, Olga V, Li Y, Diao X, Zhou H. Coral and it's symbionts responses to the typical global marine pollutant BaP by 4D-Proteomics approach. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 307:119440. [PMID: 35623566 DOI: 10.1016/j.envpol.2022.119440] [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: 01/07/2022] [Revised: 04/13/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
The symbiosis of corals, zooxanthellae, and microbes is the foundation of the coral reef ecosystem. In addition to global warming, marine pollutants are another important factor causing the breakdown of coral symbiosis. Benzo(a)pyrene (BaP) is a globally widespread marine environmental pollutant that poses a severe threat to marine ecosystems. However, responses of coral symbionts to global marine pollutant stress remain unclear. In this study, we selected Acropora formosa as the target coral to explore its response to 50 μg L-1 BaP stress using diaPASEF proteomics and 16s rRNA microbiome analysis. The results showed that: 1) the coral symbionts were sensitive to BaP stress; 2) the photosynthetic system of zooxanthellae was crucial for the balance of symbiotic relationships; 3) the destruction of the photosynthetic system induced a zooxanthellae hypoxic stress response; 4) corals adapted to BaP stress by promoting non-essential protein degradation and changing energy metabolism strategies; 5) symbiotic bacteria showed strong adaptability to BaP. This study not only fills the gap in understanding the response mechanism of coral symbionts under BaP stress, but also provides fundamental data for coral reef protection strategies.
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Affiliation(s)
- Yuebin Pei
- State Key Laboratory of South China Sea Marine Resource Utilisation, Hainan University, Haikou, 570228, China; School of Life Sciences, Hainan University, Haikou, 570228, China; One Health Institute, Hainan University, Haikou, Hainan, 570228, China
| | - Shuai Chen
- State Key Laboratory of South China Sea Marine Resource Utilisation, Hainan University, Haikou, 570228, China; School of Life Sciences, Hainan University, Haikou, 570228, China; One Health Institute, Hainan University, Haikou, Hainan, 570228, China
| | - Yuting Zhang
- State Key Laboratory of South China Sea Marine Resource Utilisation, Hainan University, Haikou, 570228, China; School of Life Sciences, Hainan University, Haikou, 570228, China; One Health Institute, Hainan University, Haikou, Hainan, 570228, China
| | - Volovych Olga
- State Key Laboratory of South China Sea Marine Resource Utilisation, Hainan University, Haikou, 570228, China; School of Life Sciences, Hainan University, Haikou, 570228, China
| | - Yuanchao Li
- Hainan Academy of Ocean and Fisheries Sciences, Haikou, 571126, China
| | - Xiaoping Diao
- State Key Laboratory of South China Sea Marine Resource Utilisation, Hainan University, Haikou, 570228, China
| | - Hailong Zhou
- State Key Laboratory of South China Sea Marine Resource Utilisation, Hainan University, Haikou, 570228, China; School of Life Sciences, Hainan University, Haikou, 570228, China; One Health Institute, Hainan University, Haikou, Hainan, 570228, China.
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6
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Chen M, Chia HK, Martin P, Lee JN, Bettens RPA, Tanzil JTI. A half-century record of coral skeletal P/Ca reveals late 20th century nutrient pollution in Port Dickson, Malaysia. MARINE POLLUTION BULLETIN 2022; 181:113875. [PMID: 35777326 DOI: 10.1016/j.marpolbul.2022.113875] [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: 09/10/2021] [Revised: 05/23/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Anthropogenic nutrient pollution has been identified as one of the key stressors of coastal ecosystems. However, the paucity of long-term nutrient records limits our understanding of both the extent of nutrient pollution as well as of the ecological impacts. Here, using coral skeletal phosphorus (P/Ca), we reconstructed a half-a-century record of seawater phosphate at Port Dickson, Malaysia. The P/Ca in the coral revealed an up to 8-fold increase in coral P/Ca from the late 1970s to 2000s, likely linked to increases in fertilizer use (R2 = 0.47) and variabilities in rainfall (R2 = 0.17). The rise in coral P/Ca in coincided with a contemporaneous 18 % decrease in coral skeletal density, suggesting phosphate enrichment may impact the growth and structural integrity of reef-building corals. Given the importance of both agriculture and heavy reliance on coral reefs by populations in Southeast Asia, our study highlights continue the need to develop environmental management upstream of coastal zones.
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Affiliation(s)
- Mengli Chen
- Tropical Marine Science Institute, National University of Singapore, Singapore.
| | - Hao Kai Chia
- Department of Chemistry, National University of Singapore, Singapore
| | - Patrick Martin
- Asian School of the Environment, Nanyang Technological University, Singapore.
| | - Jen Nie Lee
- Faculty of Science and Marine Environment, University of Malaysia Terengganu, Kuala Nerus, Malaysia; Marine Ecosystem Research Centre, Faculty of Science & Technology, Universiti Kebangssan Malaysia, Bangi, Malaysia
| | - Ryan P A Bettens
- Department of Chemistry, National University of Singapore, Singapore
| | - Jani T I Tanzil
- Tropical Marine Science Institute, National University of Singapore, Singapore
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7
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Chen M, Carrasco G, Park E, Morgan K, Tay SHX, Tanzil J, Ooi SK, Zhou K, Boyle EA. Monsoonal variations of lead (Pb) in coastal waters around Singapore. MARINE POLLUTION BULLETIN 2022; 179:113654. [PMID: 35460947 DOI: 10.1016/j.marpolbul.2022.113654] [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: 01/26/2022] [Revised: 04/03/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
Anthropogenic lead (Pb) has been the overwhelming Pb source to the global ocean, primarily contributed from Pb gasoline and industrial emissions. However, since Pb gasoline has been phased out globally, questions about whether there was a decrease in seawater Pb concentration, or if there are other sources taking over remains unclear in Southeast Asia. Here, combining Pb concentrations in seawater from Singapore Strait in 2010-2017; trap sediment in 2018-2019; and the previously published coral reconstruction covering 1975-2010; we found that the seawater Pb concentration in Singapore Strait over past decades followed the regional gasoline emissions, and no additional major source had contributed the Pb in the seawater since ~2010. The present-day Pb in Singapore Straits' water mainly follows the monsoonal current reversals, with variable degrees of scavenging that peak in inter-monsoon season. Minor Pb sources still contribute to some local-scale variabilities, despite a decadal-scale decreasing trend of Pb in seawater.
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Affiliation(s)
- Mengli Chen
- Tropical Marine Science Institute, National University of Singapore, Singapore; Center of Environmental Sensing and Modelling, Singapore-MIT Alliance on Research and Technology, Singapore.
| | - Gonzalo Carrasco
- Tropical Marine Science Institute, National University of Singapore, Singapore; Center of Environmental Sensing and Modelling, Singapore-MIT Alliance on Research and Technology, Singapore; Earth Observatory of Singapore, Nanyang Technological University, Singapore
| | - Edward Park
- Earth Observatory of Singapore, Nanyang Technological University, Singapore; National Institute of Education, Nanyang Technological University, Singapore; Asian School of the Environment, Nanyang Technological University, Singapore
| | - Kyle Morgan
- Earth Observatory of Singapore, Nanyang Technological University, Singapore; Asian School of the Environment, Nanyang Technological University, Singapore
| | - Serene Hui Xin Tay
- Tropical Marine Science Institute, National University of Singapore, Singapore
| | - Jani Tanzil
- Tropical Marine Science Institute, National University of Singapore, Singapore
| | - Seng Keat Ooi
- Tropical Marine Science Institute, National University of Singapore, Singapore; Department of Civil and Environmental Engineering, National University of Singapore, Singapore
| | - Kuanbo Zhou
- Center of Environmental Sensing and Modelling, Singapore-MIT Alliance on Research and Technology, Singapore; College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Edward A Boyle
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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Buckingham MC, D’Angelo C, Chalk TB, Foster GL, Johnson KG, Connelly Z, Olla C, Saeed M, Wiedenmann J. Impact of nitrogen (N) and phosphorus (P) enrichment and skewed N:P stoichiometry on the skeletal formation and microstructure of symbiotic reef corals. CORAL REEFS (ONLINE) 2022; 41:1147-1159. [PMID: 37334145 PMCID: PMC10276130 DOI: 10.1007/s00338-022-02223-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 01/15/2022] [Indexed: 06/20/2023]
Abstract
Reported divergent responses of coral growth and skeletal microstructure to the nutrient environment complicate knowledge-based management of water quality in coral reefs. By re-evaluating published results considering the taxonomy of the studied corals and the N:P stoichiometry of their nutrient environment, we could resolve some of the major apparent contradictions. Our analysis suggests that Acroporids behave differently to several other common genera and show distinct responses to specific nutrient treatments. We hypothesised that both the concentrations of dissolved inorganic N and P in the water and their stoichiometry shape skeletal growth and microstructure. We tested this hypothesis by exposing Acropora polystoma fragments to four nutrient treatments for > 10 weeks: high nitrate/high phosphate (HNHP), high nitrate/low phosphate (HNLP), low nitrate/high phosphate (LNHP) and low nitrate/low phosphate (LNLP). HNHP corals retained high zooxanthellae densities and their linear extension and calcification rates were up to ten times higher than in the other treatments. HNLP and LNLP corals bleached through loss of symbionts. The photochemical efficiency (Fv/Fm) of residual symbionts in HNLP corals was significantly reduced, indicating P-starvation. Micro-computed tomography (µCT) of the skeletal microstructure revealed that reduced linear extension in nutrient limited or nutrient starved conditions (HNLP, LNHP, LNLP) was associated with significant thickening of skeletal elements and reduced porosity. These changes can be explained by the strongly reduced linear extension rate in combination with a smaller reduction in the calcification rate. Studies using increased skeletal density as a proxy for past thermal bleaching events should consider that such an increase in density may also be associated with temperature-independent response to the nutrient environment. Furthermore, the taxonomy of corals and seawater N:P stoichiometry should be considered when analysing and managing the impacts of nutrient pollution. Supplementary Information The online version contains supplementary material available at 10.1007/s00338-022-02223-0.
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Affiliation(s)
- M. C. Buckingham
- School of Ocean and Earth Science (SOES), University of Southampton, Southampton, UK
| | - C. D’Angelo
- School of Ocean and Earth Science (SOES), University of Southampton, Southampton, UK
| | - T. B. Chalk
- School of Ocean and Earth Science (SOES), University of Southampton, Southampton, UK
| | - G. L. Foster
- School of Ocean and Earth Science (SOES), University of Southampton, Southampton, UK
| | | | - Z. Connelly
- School of Ocean and Earth Science (SOES), University of Southampton, Southampton, UK
| | - C. Olla
- School of Ocean and Earth Science (SOES), University of Southampton, Southampton, UK
| | - M. Saeed
- School of Ocean and Earth Science (SOES), University of Southampton, Southampton, UK
| | - J. Wiedenmann
- School of Ocean and Earth Science (SOES), University of Southampton, Southampton, UK
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9
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Tyohemba RL, Humphries MS, Schleyer MH, Porter SN. Accumulation of commonly used agricultural herbicides in coral reef organisms from iSimangaliso Wetland Park, South Africa. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 294:118665. [PMID: 34902525 DOI: 10.1016/j.envpol.2021.118665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/24/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Coral reefs are amongst the most biodiverse ecosystems on earth, but are significantly impacted by agricultural runoff. Despite herbicides being commonly detected in coastal waters, the possibility of herbicide accumulation in coral reef species has largely been overlooked. We investigate the accumulation of several herbicides in five species of coral reef invertebrates collected from ten sites along the Maputaland coast, South Africa. Multiple herbicide residues were detected in 95% of the samples, with total average concentrations across sites ranging between 25.2 ng g-1 to 51.3 ng g-1 dw. Acetochlor, alachlor and hexazinone were the predominant herbicides detected at all sites, with atrazine and simazine detected less frequently. Significant interactive effects were detected between sites nested in reef complex crossed with species, based on multiple and total herbicide concentrations. In general, multivariate herbicide concentrations varied significantly between species within and across most sites. Contrastingly, the concentrations of the different herbicides and that of total herbicide did not differ between conspecifics at most sites nested in their respective reef complexes. On average, highest total herbicide concentrations were measured in soft coral (Sarcophyton glaucum; 90.4 ± 60 ng g-1 and Sinularia gravis; 42.7 ± 25 ng g-1) and sponge (Theonela swinhoei; 39.0 ± 40 ng g-1) species, while significantly lower concentrations were detected in hard corals (Echinopora hirsutissima; 10.5 ± 5.9 ng g-1 and Acropora austera; 5.20 ± 4.5 ng g-1) at most sites. Agricultural runoff entering the ocean via the uMfolozi-St Lucia Estuary and Maputo Bay are likely sources of herbicide contamination to coral reefs in the region. There is an urgent need to assess the long-term effects of herbicide exposure on coral reef communities.
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Affiliation(s)
- Raymond L Tyohemba
- School of Chemistry, University of the Witwatersrand, Johannesburg, Private Bag 3, Wits, 2050, South Africa
| | - Marc S Humphries
- School of Chemistry, University of the Witwatersrand, Johannesburg, Private Bag 3, Wits, 2050, South Africa
| | - Michael H Schleyer
- Oceanographic Research Institute, PO Box 10712, Marine Parade, Durban, 4056, South Africa
| | - Sean N Porter
- Oceanographic Research Institute, PO Box 10712, Marine Parade, Durban, 4056, South Africa.
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10
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Goh TZY, Bauman AG, Januchowski-Hartley FA, Morgan KM, Seah JCL, Todd PA. Growth and carbonate production of crustose coralline algae on a degraded turbid reef system. MARINE POLLUTION BULLETIN 2021; 173:113135. [PMID: 34801889 DOI: 10.1016/j.marpolbul.2021.113135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
Crustose coralline algae (CCA) and other encrusting calcifiers drive carbonate production on coral reefs. However, little is known about the rates of growth and calcification of these organisms within degraded turbid reef systems. Here we deployed settlement cards (N = 764) across seven reefs in Singapore for two years to examine spatio-temporal variation in encrusting community composition and CCA carbonate production. Our results showed that CCA was the dominant encrusting taxa (63.7% ± 18.3SD) across reefs. CCA carbonate production rates (0.009-0.052 g cm-2 yr-1) were less than half of those reported for most Indo-Pacific reefs, but similar to other turbid reef systems. Highest CCA carbonate production rates were observed furthest from Singapore's main shipping port, due to a relative increase in CCA cover on the offshore reefs. Our results suggest that proximity to areas of high industrialisation and ship traffic may reduce the cover of encrusting calcifying organisms and CCA production rates which may have negative, long-term implications for the stabilisation of nearshore reefs in urbanised settings.
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Affiliation(s)
- Tiffany Z Y Goh
- Department of Biological Sciences, National University of Singapore, 117543, Singapore.
| | - Andrew G Bauman
- Department of Biological Sciences, National University of Singapore, 117543, Singapore
| | | | - Kyle M Morgan
- Asian School of the Environment, Nanyang Technological University, Singapore 637459, Singapore
| | - Jovena C L Seah
- Department of Biological Sciences, National University of Singapore, 117543, Singapore
| | - Peter A Todd
- Department of Biological Sciences, National University of Singapore, 117543, Singapore
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11
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Fong J, Todd PA. Spatio-temporal dynamics of coral-macroalgal interactions and their impacts on coral growth on urbanised reefs. MARINE POLLUTION BULLETIN 2021; 172:112849. [PMID: 34425366 DOI: 10.1016/j.marpolbul.2021.112849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 08/07/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Interactions between corals and macroalgae are important in influencing benthic community structures on coral reefs and have become increasingly common occurrences. However, little is known about their temporal variation as most studies have only documented them from single surveys. To investigate the dynamics of coral-macroalgal interactions, we surveyed three urbanised reefs in Singapore bi-monthly for three years. We found that the frequency of coral-macroalgal interactions varied greatly across sites and seasons. The extent of coral-macroalgal contact was positively correlated with macroalgal abundance, but the correlation differed significantly among macroalgal genera. The growth rates of Goniopora, Montipora and Pavona corals, but not Platygra, were also negatively correlated with the extent of macroalgal interactions. Overall, our results highlight that coral-macroalgal interactions are spatially and temporally dynamic, with varying effects among coral species. It is critical to consider seasonal fluctuations of macroalgae if the overall long-term impacts of macroalgae are to be understood.
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Affiliation(s)
- Jenny Fong
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore.
| | - Peter A Todd
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore
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12
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Turak E, DeVantier L, Szava-Kovats R, Brodie J. Impacts of coastal land use change in the wet tropics on nearshore coral reefs: Case studies from Papua New Guinea. MARINE POLLUTION BULLETIN 2021; 168:112445. [PMID: 33991988 DOI: 10.1016/j.marpolbul.2021.112445] [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: 01/21/2021] [Revised: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
Logging and plantation agriculture are vital to economies and livelihoods in tropical nations, including Papua New Guinea. To meet global demand, hundreds of thousands of ha of diverse natural habitat have been logged, cleared and replaced with monoculture crops. Resulting hydrological changes have increased sediment, nutrient and pesticide runoff, impacting down-stream habitats. Here, case studies from Kimbe Bay (New Britain) and Mullins Harbour (Milne Bay), examine effects on nearshore coral reefs. In both places, logging and oil palm development had destabilized soils and removed or degraded riparian vegetation. Downstream, nearshore reefs had high silt levels, which, coincident with minor coral bleaching and predation by crown-of-thorns starfish, were correlated with high levels of coral mortality and low coral species richness. Sediment and related impacts can be reduced by effective catchment management, such as avoiding steep slopes, expanding stream and coastal buffer zones, minimizing fertilizer and pesticide use, monitoring and reactive management.
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Affiliation(s)
- Emre Turak
- Coral Reef Research, PO Box 129, Millaa Millaa, QLD, Australia.
| | | | | | - Jon Brodie
- Formerly ARC Centre of Excellence for Coral Reef Studies, College of Science and Engineering, James Cook University, Townsville, QLD, Australia
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13
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Abstract
Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.
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14
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Pang HE, Poquita-Du RC, Jain SS, Huang D, Todd PA. Among-genotype responses of the coral Pocillopora acuta to emersion: implications for the ecological engineering of artificial coastal defences. MARINE ENVIRONMENTAL RESEARCH 2021; 168:105312. [PMID: 33848694 DOI: 10.1016/j.marenvres.2021.105312] [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: 10/12/2020] [Revised: 03/11/2021] [Accepted: 03/18/2021] [Indexed: 06/12/2023]
Abstract
Stony corals are promising transplant candidates for the ecological engineering of artificial coastal defences such as seawalls as they attract and host numerous other organisms. However, seawalls are exposed to a wide range of environmental stressors associated with periods of emersion during low tide such as desiccation and changes in salinity, temperature, and solar irradiance. All of these variables have known deleterious effects on coral physiology, growth, and fitness. In this study, we performed parallel experiments (in situ and ex situ) to examine among-genotype responses of Pocillopora acuta to emersion by quantifying growth, photophysiological metrics (Fv/Fm, non-photochemical quenching [NPQ], endosymbiont density, and chlorophyll [chl] a concentration) and survival, following different emersion periods. Results showed that coral fragments emersed for longer durations (>2 h) exhibited reduced growth and survival. Endosymbiont density and NPQ, but not Fv/Fm and chl a concentration, varied significantly among genotypes across different durations of emersion. Overall, the ability of P. acuta to tolerate emersion for up to 2 h suggests its potential to serve as a 'starter species' for transplantation efforts on seawalls. Further, careful characterisation and selection of genotypes with a high capacity to withstand emersion can help maximise the efficacy of ecological engineering using coral transplants.
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Affiliation(s)
- Hui En Pang
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, 117558, Singapore
| | - Rosa Celia Poquita-Du
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, 117558, Singapore.
| | - Sudhanshi Sanjeev Jain
- Reef Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, 117558, Singapore
| | - Danwei Huang
- Reef Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, 117558, Singapore
| | - Peter A Todd
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, 117558, Singapore.
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15
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Prasetia R, Lim ZW, Teo A, Shlesinger T, Loya Y, Todd PA. Population dynamics and growth rates of free-living mushroom corals (Scleractinia: Fungiidae) in the sediment-stressed reefs of Singapore. ADVANCES IN MARINE BIOLOGY 2020; 87:115-140. [PMID: 33293008 DOI: 10.1016/bs.amb.2020.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The reefs of Singapore provide an excellent opportunity to study the population dynamics and growth rates of free-living mushroom corals (Fungiidae) under sediment-stressed conditions. Transect surveys at four study sites revealed a total of 11 free-living mushroom coral species-the same 11 species as those found by local studies since the 1980s. The abundance of the four most common species ranged from 1.0 to 68.3 Ind. per 100m2, while their population size-structure showed a common pattern of a higher proportion of small-sized corals than large-sized ones (i.e. positively skewed size-structure), although very few individuals of the smallest-size classes were recorded for any of the four species. A more positively skewed size-structure for each of the four most common species was observed at the reef slope (5-6m depth) than at the reef crest (2-3m depth), possibly due to a slower growth rate caused by light reduction with depth. All the mushroom corals studied exhibited a decline in growth rate with increasing size and weight, indicating determinate growth. Growth rate of each of the four most common species was similar among the study sites, despite variation in environmental conditions. Our results demonstrate species richness stability over the past three decades, suggesting that these free-living mushroom coral assemblages comprise species that are well-adapted to the chronic high sedimentation characteristic of Singapore's reefs. However, if the paucity of individuals of the smallest-size classes reflects poor recruitment and/or early mortality, there may be some cause for concern. Our robust baseline data can contribute to a long-term monitoring strategy for determination of changes in mushroom coral population dynamics.
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Affiliation(s)
- Rian Prasetia
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
| | - Zi Wei Lim
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Aaron Teo
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Tom Shlesinger
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, United States
| | - Yossi Loya
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Peter A Todd
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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16
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Heery EC, Oh RKE, Taira D, Ng D, Chim CK, Hartanto RS, Hsiung AR, Chai TMF, Loke LHL, Yeo HHJ, Todd PA. Human-engineered hydrodynamic regimes as a driver of cryptic microinvertebrate assemblages on urban artificial shorelines. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 725:138348. [PMID: 32302835 DOI: 10.1016/j.scitotenv.2020.138348] [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: 10/01/2019] [Revised: 02/02/2020] [Accepted: 03/29/2020] [Indexed: 06/11/2023]
Abstract
Urban shorelines undergo substantial hydrodynamic changes as a result of coastal engineering and shoreline armouring that can alter sedimentation, turbidity, and other factors. These changes often coincide with major shifts in the composition and distribution of marine biota, however, rarely are hydrodynamic-mediated factors confirmed experimentally as the mechanism underpinning these shifts. This study first characterized hydrodynamic-related distribution patterns among epilithic and epiphytic microinvertebrates on urban seawalls in Singapore. We found reduced microinvertebrate abundances and distinct microinvertebrate community structure within benthic turf algae in areas where coastal defences had reduced wave energy and increased sediment deposition, among other hydrodynamic-related abiotic changes. Low-exposure areas also had reduced densities of macroinvertebrate grazers and less dense turf algae (lower mass per cm2) than adjacent high-exposure areas. Using harpacticoid copepods as a model taxon, we performed a reciprocal transplant experiment to discern between the effects of exposure-related conditions and grazing. Results from the experiment indicate that conditions associated with restricted wave energy from shoreline engineering limit harpacticoid population densities, as transplantation to low-exposure areas led to rapid reductions in abundance. At the same time, we found no effect from grazer exclusion cages, suggesting harpacticoids are minimally impacted by exposure-related gradients in gastropod macrograzer densities over short time scales. Given the key role of intertidal microinvertebrates, particularly harpacticoids, in nearshore food webs, we postulate that human-engineered hydrodynamic regimes are an important factor shaping marine ecosystem functioning in urban areas.
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Affiliation(s)
- Eliza C Heery
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore.
| | - Rachel K E Oh
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore
| | - Daisuke Taira
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore
| | - Dillen Ng
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore
| | - C K Chim
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore; Keppel-NUS Corporate Laboratory, Faculty of Engineering, National University of Singapore, Block E1A, #03-03, 1 Engineering Drive 2, Singapore 117576, Singapore; St. John's Island National Marine Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore 119227, Singapore
| | - Rania S Hartanto
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore
| | - Amanda R Hsiung
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore
| | - Tiffany M F Chai
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore; School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom
| | - Lynette H L Loke
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore
| | - Hannah H J Yeo
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore
| | - Peter A Todd
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Block S3, Singapore 117558, Singapore
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17
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Ng CSL, Huang D, Toh KB, Sam SQ, Kikuzawa YP, Toh TC, Taira D, Chan YKS, Hung LZT, Sim WT, Rashid AR, Afiq-Rosli L, Ng NK, Chou LM. Responses of urban reef corals during the 2016 mass bleaching event. MARINE POLLUTION BULLETIN 2020; 154:111111. [PMID: 32319927 DOI: 10.1016/j.marpolbul.2020.111111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/25/2020] [Accepted: 03/25/2020] [Indexed: 05/28/2023]
Abstract
Predicting the bleaching responses of corals is crucial in light of frequent heat stress events to manage further losses of biodiversity and ecosystem functioning, especially for reefs impacted by urbanisation. We examined if the coral cover and community at various Singapore sites changed during the 2016 global coral bleaching event. Bleaching prevalence varied widely among sites in June 2016, and was best explained by site and coral species. While some sites were minimally impacted, others registered significant decreases in coral cover and community changes persisting till March 2017, when normal colouration was mostly regained by corals. Bleaching susceptibility was associated with larger corallites in hermaphrodites and smaller corallites in gonochores (probably due to the cost of maintaining dual sexual functions in hermaphrodites), and with increasing proximity between polyps (likely because thermal damage would be less contained among polyps with greater physiological integration). However, bleaching resilience-the capacity to regain baseline pigmentation-was poorly explained by the traits studied. Our findings suggest that the interplay between local conditions and species composition strongly affects bleaching outcomes on urbanised reefs, and underscore the utility of coral traits for predicting bleaching responses to help in formulating appropriate management strategies.
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Affiliation(s)
- Chin Soon Lionel Ng
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558; Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore.
| | - Danwei Huang
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558; Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore
| | - Kok Ben Toh
- Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore; School of Natural Resources and Environment, University of Florida, 103 Black Hall, Gainsville, FL 32611, United States of America
| | - Shu Qin Sam
- Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore
| | - Yuichi Preslie Kikuzawa
- Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore
| | - Tai Chong Toh
- Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore; College of Alice and Peter Tan, National University of Singapore, 8 College Avenue East, 138615, Singapore
| | - Daisuke Taira
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558; Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore
| | - Yong Kit Samuel Chan
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558
| | - Ling Zi Tracy Hung
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558
| | - Wan Ting Sim
- Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore
| | - Ahmad Rafiuddin Rashid
- Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore
| | - Lutfi Afiq-Rosli
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558; Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore
| | - Ngan Kee Ng
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558
| | - Loke Ming Chou
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558; Tropical Marine Science Institute, National University of Singapore, 14 Kent Ridge Road, 119223, Singapore
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18
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Gillmore ML, Gissi F, Golding LA, Stauber JL, Reichelt-Brushett AJ, Severati A, Humphrey CA, Jolley DF. Effects of dissolved nickel and nickel-contaminated suspended sediment on the scleractinian coral, Acropora muricata. MARINE POLLUTION BULLETIN 2020; 152:110886. [PMID: 32479277 DOI: 10.1016/j.marpolbul.2020.110886] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 12/27/2019] [Accepted: 01/06/2020] [Indexed: 06/11/2023]
Abstract
Intensification of lateritic nickel mining in Southeast Asia and Melanesia potentially threatens coastal ecosystems from increased exposure to nickel and suspended sediment. This study investigated the response of Acropora muricata when exposed to either dissolved nickel, clean suspended sediment or nickel-contaminated suspended sediment for 7 days, followed by a 7-d recovery period. Significant bleaching and accumulation of nickel in coral tissue was observed only after exposure to high dissolved nickel concentrations and nickel-spiked suspended sediment. No effect on A. muricata was observed from exposure to a particulate-bound nickel concentration of 60 mg/kg acid-extractable nickel at a suspended sediment concentration of 30 mg/L TSS. This study demonstrates that bioavailability of nickel associated with suspended sediment exposure plays a key role in influencing nickel toxicity to corals. These findings assist in assessments of risk posed by increasing nickel mining activities on tropical marine ecosystems.
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Affiliation(s)
- Megan L Gillmore
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia; CSIRO Land and Water, Lucas Heights, NSW 2234, Australia.
| | - Francesca Gissi
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia; CSIRO Oceans and Atmosphere, Lucas Heights, NSW 2234, Australia
| | - Lisa A Golding
- CSIRO Land and Water, Lucas Heights, NSW 2234, Australia
| | | | - Amanda J Reichelt-Brushett
- Marine Ecology Research Centre, School of Environment Science and Engineering, Southern Cross University, Lismore, NSW 2480, Australia
| | - Andrea Severati
- National Sea Simulator, Australian Institute of Marine Science, Townsville, QLD 4810, Australia
| | - Craig A Humphrey
- National Sea Simulator, Australian Institute of Marine Science, Townsville, QLD 4810, Australia
| | - Dianne F Jolley
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
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19
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Monteil Y, Teo A, Fong J, Bauman AG, Todd PA. Effects of macroalgae on coral fecundity in a degraded coral reef system. MARINE POLLUTION BULLETIN 2020; 151:110890. [PMID: 32056657 DOI: 10.1016/j.marpolbul.2020.110890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/17/2019] [Accepted: 01/06/2020] [Indexed: 06/10/2023]
Abstract
Global declines in live coral cover and the proliferation of macroalgae on coral reefs is leading to increased coral-macroalgal interactions that impact reef recovery. However, the effects of macroalgae on coral sexual reproduction-a fundamental life-history process for maintaining population abundances-have rarely been quantified. Here, we examined the direct effects of macroalgae contact on the fecundity (eggs mesentery-1) of two coral species, Echinopora lamellosa and Merulina ampliata, across three degraded reefs in Singapore. Increasing macroalgae contact from 5% to 25% significantly reduced fecundity in colonies of both species by 67-82%, and also reduced M. ampliata egg sizes by 11.4%. These results suggest the diversion of energy from reproduction towards other processes such as repair and defence, and also reveal potential differential energy allocation strategies among coral taxa. While corals on Singapore's impacted reefs continue to produce eggs, increasing macroalgae that suppresses coral fecundity may constrain future reef recovery.
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Affiliation(s)
- Yann Monteil
- Université de La Rochelle, Pôle Sciences, Laboratoire de Biologie et d'Environnement Marins, FRE2727, Avenue Michel Crépeau, 17042 La Rochelle, Cedex, France
| | - Aaron Teo
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 117543, Singapore
| | - Jenny Fong
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 117543, Singapore
| | - Andrew G Bauman
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 117543, Singapore.
| | - Peter A Todd
- Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore, 117543, Singapore
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20
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Dumalagan EE, Cabaitan PC, Bridge TCL, Go KT, Quimpo TJR, Olavides RDD, Munar JC, Villanoy CL, Siringan FP. Spatial variability in benthic assemblage composition in shallow and upper mesophotic coral ecosystems in the Philippines. MARINE ENVIRONMENTAL RESEARCH 2019; 150:104772. [PMID: 31442824 DOI: 10.1016/j.marenvres.2019.104772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/12/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
Mesophotic coral ecosystems (MCEs) have received increasing attention in recent years in recognition of their unique biodiversity and also their potential importance as refuges from disturbance events. However, knowledge of the composition of MCEs and how they vary in space is lacking in many regions, particularly the Coral Triangle biodiversity hotspot. Here, we compared the benthic components and coral genera composition between shallow-water reefs (SWRs, 8-13 m depth) and upper MCEs (30-40 m) in four locations in the Philippines that are exposed to differing environmental conditions. Coral cover, abundance, and generic diversity were lower in MCEs than SWRs at three of the four locations. Benthic composition and coral generic composition also varied significantly among locations for both shallow and deep sites. Differences in benthic composition among sites was due primarily to variation in hard corals, macroalgae, sand and silt, while variation in coral assemblage was due to differences in abundance of encrusting Porites, branching Acropora, branching Seriatopora. Our results showed that the composition of MCE communities varied significantly from adjacent shallow reefs, but also among MCEs in differing geographic locations. Furthermore, our results suggest disturbances affecting shallow-water reefs, particularly sedimentation, also negatively impact MCEs, and that depth therefore provides no potential refuge from these disturbances. We recommend that conservation of MCEs consider spatial variability in community composition among sites, and urge further research to better understand the spatial variation in the composition of MCE communities in the Philippines.
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Affiliation(s)
- Edwin E Dumalagan
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines
| | - Patrick C Cabaitan
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines.
| | - Tom C L Bridge
- Biodiversity and Geosciences Program, Museum of Tropical Queensland, Queensland Museum Network, 70-102 Flinders St, Townsville, QLD, 4810, Australia; Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, 101 Angus Smith Drive, Townsville, QLD, 4811, Australia
| | - Kevin Thomas Go
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines
| | - Timothy Joseph R Quimpo
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines
| | - Ronald Dionnie D Olavides
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines
| | - Jeffrey C Munar
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines
| | - Cesar L Villanoy
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines
| | - Fernando P Siringan
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines
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21
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Browne N, Braoun C, McIlwain J, Nagarajan R, Zinke J. Borneo coral reefs subject to high sediment loads show evidence of resilience to various environmental stressors. PeerJ 2019; 7:e7382. [PMID: 31428541 PMCID: PMC6698134 DOI: 10.7717/peerj.7382] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 06/29/2019] [Indexed: 11/20/2022] Open
Abstract
For reefs in South East Asia the synergistic effects of rapid land development, insufficient environmental policies and a lack of enforcement has led to poor water quality and compromised coral health from increased sediment and pollution. Those inshore turbid coral reefs, subject to significant sediment inputs, may also inherit some resilience to the effects of thermal stress and coral bleaching. We studied the inshore turbid reefs near Miri, in northwest Borneo through a comprehensive assessment of coral cover and health in addition to quantifying sediment-related parameters. Although Miri’s Reefs had comparatively low coral species diversity, dominated by massive and encrusting forms of Diploastrea, Porites, Montipora, Favites, Dipsastrea and Pachyseris, they were characterized by a healthy cover ranging from 22 to 39%. We found a strong inshore to offshore gradient in hard coral cover, diversity and community composition as a direct result of spatial differences in sediment at distances <10 km. As well as distance to shore, we included other environmental variables like reef depth and sediment trap accumulation and particle size that explained 62.5% of variation in benthic composition among sites. Miri’s reefs showed little evidence of coral disease and relatively low prevalence of compromised health signs including bleaching (6.7%), bioerosion (6.6%), pigmentation response (2.2%), scars (1.1%) and excessive mucus production (0.5%). Tagged colonies of Diploastrea and Pachyseris suffering partial bleaching in 2016 had fully (90–100%) recovered the following year. There were, however, seasonal differences in bioerosion rates, which increased five-fold after the 2017 wet season. Differences in measures of coral physiology, like that of symbiont density and chlorophyll a for Montipora, Pachyseris and Acropora, were not detected among sites. We conclude that Miri’s reefs may be in a temporally stable state given minimal recently dead coral and a limited decline in coral cover over the last two decades. This study provides further evidence that turbid coral reefs exposed to seasonally elevated sediment loads can exhibit relatively high coral cover and be resilient to disease and elevated sea surface temperatures.
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Affiliation(s)
- Nicola Browne
- Molecular and Life Sciences, Curtin University, Perth, WA, Australia.,Curtin Malaysia Research Institute, Curtin University, Miri, Sarawak, Malaysia
| | - Christina Braoun
- Department of Biology, Chemistry and Pharmacy, Freie Universität, Berlin, Germany
| | - Jennifer McIlwain
- Molecular and Life Sciences, Curtin University, Perth, WA, Australia.,Curtin Malaysia Research Institute, Curtin University, Miri, Sarawak, Malaysia
| | - Ramasamy Nagarajan
- Department of Applied Geology, Curtin University, Miri, Sarawak, Malaysia
| | - Jens Zinke
- Molecular and Life Sciences, Curtin University, Perth, WA, Australia.,Curtin Malaysia Research Institute, Curtin University, Miri, Sarawak, Malaysia.,Department of Biology, Chemistry and Pharmacy, Freie Universität, Berlin, Germany.,School of Geography, Geology and Environment, Centre for Palaeobiology, University of Leicester, Leicester, UK.,Australian Institute of Marine Science, Townsville, WA, Australia
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22
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Todd PA, Heery EC, Loke LHL, Thurstan RH, Kotze DJ, Swan C. Towards an urban marine ecology: characterizing the drivers, patterns and processes of marine ecosystems in coastal cities. OIKOS 2019. [DOI: 10.1111/oik.05946] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Peter A. Todd
- Experimental Marine Ecology Laboratory, Dept of Biological Sciences, National Univ. of Singapore 16 Science Drive 4 Singapore 117558
| | - Eliza C. Heery
- Experimental Marine Ecology Laboratory, Dept of Biological Sciences, National Univ. of Singapore 16 Science Drive 4 Singapore 117558
| | - Lynette H. L. Loke
- Experimental Marine Ecology Laboratory, Dept of Biological Sciences, National Univ. of Singapore 16 Science Drive 4 Singapore 117558
| | - Ruth H. Thurstan
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, Univ. of Exeter Penryn UK
| | - D. Johan Kotze
- Faculty of Biological and Environmental Sciences, Ecosystems and Environment Research Programme, Univ. of Helsinki Lahti Finland
| | - Christopher Swan
- Dept of Geography & Environmental Systems, Univ. of Maryland Baltimore County Baltimore MD USA
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23
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Strahl J, Rocker MM, Fabricius KE. Contrasting responses of the coral Acropora tenuis to moderate and strong light limitation in coastal waters. MARINE ENVIRONMENTAL RESEARCH 2019; 147:80-89. [PMID: 31010596 DOI: 10.1016/j.marenvres.2019.04.003] [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: 01/25/2019] [Revised: 04/02/2019] [Accepted: 04/03/2019] [Indexed: 06/09/2023]
Abstract
Coastal water quality and light attenuation can detrimentally affect coral health. This study investigated the effects of light limitation and reduced water quality on the physiological performance of the coral Acropora tenuis. Branches of individual colonies were collected in 2 m water depth at six inshore reefs at increasing distances from major river sources in the Great Barrier Reef, along a strong water quality gradient in the Burdekin and a weak gradient in the Whitsunday region. Rates of net photosynthesis, dark respiration, and light and dark calcification were determined at daily light integrals (DLI) of moderate (13.86-16.38 mol photons m-2 d-1), low (7.92-9.36 mol photons m-2 d-1) and no light (0 mol photons m-2 d-1), in both the dry season (October 2013, June 2014) and the wet season (February 2014). Along the strong but not the weak water quality gradient, rates of net photosynthesis, dark respiration and light calcification increased towards the river mouth both in the dry and the wet seasons. Additionally, a ∼50% light reduction (from moderate to low light), as often found in shallow turbid waters in the Burdekin region, reduced rates of net photosynthesis and light calcification by up to 70% and 50%. The data show the acclimation potential in A. tenuis to river derived nutrients and sediments at moderate DLI (i.e., in very shallow water). However, prolonged and frequent periods of low DLI (i.e., in deeper water, especially after high river sediment discharges) will affect the corals' energy balance, and may represent a major factor limiting the depth distribution of these corals in turbid coastal reefs.
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Affiliation(s)
- Julia Strahl
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg, Ammerländer Heerstraße 231, 23129, Oldenburg, Germany; Institute of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Carl von Ossietzky Str. 9-11, 26111, Oldenburg, Germany.
| | - Melissa M Rocker
- Australian Institute of Marine Science, PMB #3, Townsville MC, QLD, 4810, Australia
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24
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Chow GSE, Chan YKS, Jain SS, Huang D. Light limitation selects for depth generalists in urbanised reef coral communities. MARINE ENVIRONMENTAL RESEARCH 2019; 147:101-112. [PMID: 31029435 DOI: 10.1016/j.marenvres.2019.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 04/18/2019] [Accepted: 04/18/2019] [Indexed: 06/09/2023]
Abstract
Depth range is an important species trait for coral reef organisms, yet it remains to be quantified and analysed adequately among tropical coral species. Filling this knowledge gap is crucial as the depth limits of corals are related to important environmental factors such as light and temperature. Furthermore, the health and survivorship of corals may be threatened due to warming-induced sea-level rise, particularly for colonies living at the deeper limits of species depth ranges. Here we collected benthic and environmental data along the reef profile to characterise the depth ranges of coral species, and analysed species diversity and community structure in relation to possible depth-related biophysical parameters on the sediment-stressed reefs of Singapore. The results reveal clear environmental covariations with depth, expectedly with light availability showing the most marked decline as depth increases. Live coral cover, species richness and diversity are associated positively and significantly with light, which also structures coral communities along the reef profile more strongly than temperature or sediment levels. Relatedly, we detect species-specific depth distributions with two main strategies observed among coral species: shallow specialists and depth generalists. We suggest that corals in Singapore are unlikely to be impacted by light limitation specifically as sea level rises due to the wider depth range of the deeper species. Our data will inform conservation efforts especially in the selection of sites and depths for coral transplantation.
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Affiliation(s)
- Gwendolyn S E Chow
- Department of Biological Sciences, National University of Singapore, 117558, Singapore
| | - Y K Samuel Chan
- Department of Biological Sciences, National University of Singapore, 117558, Singapore
| | | | - Danwei Huang
- Department of Biological Sciences, National University of Singapore, 117558, Singapore; Tropical Marine Science Institute, National University of Singapore, 119227, Singapore.
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25
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Low JKY, Fong J, Todd PA, Chou LM, Bauman AG. Seasonal variation of Sargassum ilicifolium (Phaeophyceae) growth on equatorial coral reefs. JOURNAL OF PHYCOLOGY 2019; 55:289-296. [PMID: 30506680 DOI: 10.1111/jpy.12818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
Temporal and spatial variations in Sargassum ilicifolium thallus density and length were investigated on equatorial coral reefs in Singapore from November 2011 to October 2012. Thalli density varied little throughout the year, however, we found strong seasonal patterns in thallus length and identified temperature as the significant driver. Sargassum ilicifolium reached maximum length in December (110.39 ± 2.37 cm) during periods of cooler water temperatures, and minimum length in May (9.88 ± 0.48 cm) during periods of warmer water temperatures. Significant spatial variation was also observed for both thallus density and length of S. ilicifolium among reefs. Within reefs, densities of S. ilicifolium were higher on reef flats (20.40 ± 0.40 individuals · 0.25 m-2 ) compared to upper reef slopes (5.66 ± 0.23 individuals · 0.25 m-2 ). Our findings highlight that marked seasonality in the growth of canopy-forming macroalgae can occur within equatorial reef systems where temperature ranges are restricted (<3°C).
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Affiliation(s)
| | - Jenny Fong
- Experimental Marine Ecology Laboratory, National University of Singapore, Singapore, 117558
| | - Peter A Todd
- Experimental Marine Ecology Laboratory, National University of Singapore, Singapore, 117558
| | - Loke Ming Chou
- Tropical Marine Science Institute, National University of Singapore, Singapore, 119227
| | - Andrew G Bauman
- Experimental Marine Ecology Laboratory, National University of Singapore, Singapore, 117558
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26
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Marques JA, Costa PG, Marangoni LFB, Pereira CM, Abrantes DP, Calderon EN, Castro CB, Bianchini A. Environmental health in southwestern Atlantic coral reefs: Geochemical, water quality and ecological indicators. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 651:261-270. [PMID: 30236843 DOI: 10.1016/j.scitotenv.2018.09.154] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/19/2018] [Accepted: 09/12/2018] [Indexed: 06/08/2023]
Abstract
Climate change, pollution and increased runoff are some of the main drivers of coral reefs degradation worldwide. However, the occurrence of runoff and marine pollution, as well as its ecological effects in South Atlantic coral reefs are still poorly understood. The aim of the present work is to characterize the terrigenous influence and contamination impact on the environmental health of five reefs located along a gradient of distance from a river source, using geochemical, water quality, and ecological indicators. Stable isotopes and sterols were used as geochemical indicators of sewage and terrigenous organic matter. Dissolved metal concentrations (Cu, Zn, Cd, and Pb) were used as indicators of water quality. Population density, bleaching and chlorophyll α content of the symbiont-bearing foraminifer Amphistegina gibbosa, were used as indicators of ecological effects. Sampling was performed four times during the year to assess temporal variability. Sediment and water quality indicators showed that reefs close to the river discharge experience nutrient enrichment and sewage contamination, and metals concentrations above international environmental quality guidelines. Higher levels of contamination were strongly related to the higher frequency of bleaching and lower density in A. gibbosa populations. The integrated evaluation of stable isotopes, sterols and metals provided a consistent diagnostic about sewage influence on the studied reefs. Additionally, the observed bioindicator responses evidenced relevant ecological effects. The water quality, geochemical and ecological indicators employed in the present study were effective as biomonitoring tools to be applied in reefs worldwide.
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Affiliation(s)
- Joseane A Marques
- Programa de Pós-Graduação em Oceanografia Biológica, Universidade Federal do Rio Grande (IO/FURG), Av. Itália, km 8, Rio Grande, RS 96203900, Brazil; Instituto Coral Vivo, Rua dos Coqueiros, 87, Santa Cruz Cabralia, BA 45807000, Brazil.
| | - Patricia G Costa
- Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (ICB/FURG), Av Itália, km 8, Rio Grande, RS 96203900, Brazil
| | - Laura F B Marangoni
- Programa de Pós-Graduação em Oceanografia Biológica, Universidade Federal do Rio Grande (IO/FURG), Av. Itália, km 8, Rio Grande, RS 96203900, Brazil; Instituto Coral Vivo, Rua dos Coqueiros, 87, Santa Cruz Cabralia, BA 45807000, Brazil
| | - Cristiano M Pereira
- Instituto Coral Vivo, Rua dos Coqueiros, 87, Santa Cruz Cabralia, BA 45807000, Brazil; Programa de Pós-Graduação em Zoologia, Universidade Federal do Rio de Janeiro (MNRJ/UFRJ), Quinta da Boa Vista, Rio de Janeiro, RJ 20940040, Brazil
| | - Douglas P Abrantes
- Programa de Pós-Graduação em Zoologia, Universidade Federal do Rio de Janeiro (MNRJ/UFRJ), Quinta da Boa Vista, Rio de Janeiro, RJ 20940040, Brazil
| | - Emiliano N Calderon
- Instituto Coral Vivo, Rua dos Coqueiros, 87, Santa Cruz Cabralia, BA 45807000, Brazil; Programa de Pós-Graduação em Ciências Ambientais e Conservação, Universidade Federal do Rio de Janeiro (NUPEM/UFRJ), Av São José do Barreto, s/n, Macaé, RJ 27971550, Brazil
| | - Clovis B Castro
- Instituto Coral Vivo, Rua dos Coqueiros, 87, Santa Cruz Cabralia, BA 45807000, Brazil; Museu Nacional, Universidade Federal do Rio de Janeiro (MNRJ/UFRJ), Quinta da Boa Vista, Rio de Janeiro, RJ 20940-040, Brazil
| | - Adalto Bianchini
- Instituto Coral Vivo, Rua dos Coqueiros, 87, Santa Cruz Cabralia, BA 45807000, Brazil; Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (ICB/FURG), Av Itália, km 8, Rio Grande, RS 96203900, Brazil
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27
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Bioaccumulation of trace metals in octocorals depends on age and tissue compartmentalization. PLoS One 2018; 13:e0196222. [PMID: 29684058 PMCID: PMC5912762 DOI: 10.1371/journal.pone.0196222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/09/2018] [Indexed: 11/26/2022] Open
Abstract
Trace metal dynamics have not been studied with respect to growth increments in octocorals. It is particularly unknown whether ontogenetic compartmentalization of trace metal accumulation is species-specific. We studied here for the first time the intracolonial distribution and concentrations of 18 trace metals in the octocorals Subergorgia suberosa, Echinogorgia complexa and E. reticulata that were retrieved from the northern coast of Taiwan. Levels of trace metals were considerably elevated in corals collected at these particular coral habitats as a result of diverse anthropogenic inputs. There was a significant difference in the concentration of metals among octocorals except for Sn. Both species of Echinogorgia contained significantly higher concentrations of Cu, Zn and Al than Subergorgia suberosa. We used for the first time exponential growth curves that describe an age-specific relationship of octocoral trace metal concentrations of Cu, Zn, Cd, Cr and Pb where the distance from the grip point was reflecting younger age as linear regressions. The larger colony (C7) had a lower accumulation rate constant than the smaller one (C6) for Cu, Zn, Cd, Cr and Pb, while other trace metals showed an opposite trend. The Cu concentration declined exponentially from the grip point, whereas the concentrations of Zn, Cd, Cr and Pb increased exponentially. In S. suberosa and E. reticulata, Zn occurred primarily in coenosarc tissues and Zn concentrations increased with distance from the grip point in both skeletal and coenosarc tissues. Metals which appeared at high concentrations (e.g. Ca, Zn and Fe) generally tended to accumulate in the outer coenosarc tissues, while metals with low concentrations (e.g. V) tended to accumulate in the soft tissues of the inner skeleton.
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28
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Humanes A, Fink A, Willis BL, Fabricius KE, de Beer D, Negri AP. Effects of suspended sediments and nutrient enrichment on juvenile corals. MARINE POLLUTION BULLETIN 2017; 125:166-175. [PMID: 28818603 DOI: 10.1016/j.marpolbul.2017.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 07/03/2017] [Accepted: 08/01/2017] [Indexed: 06/07/2023]
Abstract
Three to six-month-old juveniles of Acropora tenuis, A. millepora and Pocillopora acuta were experimentally co-exposed to nutrient enrichment and suspended sediments (without light attenuation or sediment deposition) for 40days. Suspended sediments reduced survivorship of A. millepora strongly, proportional to the sediment concentration, but not in A. tenuis or P. acuta juveniles. However, juvenile growth of the latter two species was reduced to less than half or to zero, respectively. Additionally, suspended sediments increased effective quantum yields of symbionts associated with A. millepora and A. tenuis, but not those associated with P. acuta. Nutrient enrichment did not significantly affect juvenile survivorship, growth or photophysiology for any of the three species, either as a sole stressor or in combination with suspended sediments. Our results indicate that exposure to suspended sediments can be energetically costly for juveniles of some coral species, implying detrimental longer-term but species-specific repercussions for populations and coral cover.
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Affiliation(s)
- Adriana Humanes
- ARC Centre of Excellence for Coral Reef Studies, College of Science and Engineering, James Cook University, 4811 Townsville, Queensland, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University, Australian Institute of Marine Science, Townsville, Queensland 4811, Australia; Australian Institute of Marine Science, 4810 Townsville, Queensland, Australia.
| | - Artur Fink
- Max-Planck Institute for Marine Microbiology, Bremen, Germany
| | - Bette L Willis
- ARC Centre of Excellence for Coral Reef Studies, College of Science and Engineering, James Cook University, 4811 Townsville, Queensland, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University, Australian Institute of Marine Science, Townsville, Queensland 4811, Australia
| | - Katharina E Fabricius
- AIMS@JCU, Division of Research & Innovation, James Cook University, Australian Institute of Marine Science, Townsville, Queensland 4811, Australia; Australian Institute of Marine Science, 4810 Townsville, Queensland, Australia
| | - Dirk de Beer
- Max-Planck Institute for Marine Microbiology, Bremen, Germany
| | - Andrew P Negri
- AIMS@JCU, Division of Research & Innovation, James Cook University, Australian Institute of Marine Science, Townsville, Queensland 4811, Australia; Australian Institute of Marine Science, 4810 Townsville, Queensland, Australia
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29
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Allen AS, Seymour AC, Rittschof D. Chemoreception drives plastic consumption in a hard coral. MARINE POLLUTION BULLETIN 2017; 124:198-205. [PMID: 28743368 DOI: 10.1016/j.marpolbul.2017.07.030] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/12/2017] [Accepted: 07/13/2017] [Indexed: 06/07/2023]
Abstract
The drivers behind microplastic (up to 5mm in diameter) consumption by animals are uncertain and impacts on foundational species are poorly understood. We investigated consumption of weathered, unfouled, biofouled, pre-production and microbe-free National Institute of Standards plastic by a scleractinian coral that relies on chemosensory cues for feeding. Experiment one found that corals ingested many plastic types while mostly ignoring organic-free sand, suggesting that plastic contains phagostimulents. Experiment two found that corals ingested more plastic that wasn't covered in a microbial biofilm than plastics that were biofilmed. Additionally, corals retained ~8% of ingested plastic for 24h or more and retained particles appeared stuck in corals, with consequences for energetics, pollutant toxicity and trophic transfer. The potential for chemoreception to drive plastic consumption in marine taxa has implications for conservation.
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Affiliation(s)
- Austin S Allen
- Duke University, 135 Duke Marine Lab Road, Beaufort, NC 28516, USA.
| | | | - Daniel Rittschof
- Duke University, 135 Duke Marine Lab Road, Beaufort, NC 28516, USA
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30
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Modelling for management: Coral photo-physiology and growth potential under varying turbidity regimes. Ecol Modell 2017. [DOI: 10.1016/j.ecolmodel.2017.08.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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31
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Bauman AG, Hoey AS, Dunshea G, Feary DA, Low J, Todd PA. Macroalgal browsing on a heavily degraded, urbanized equatorial reef system. Sci Rep 2017; 7:8352. [PMID: 28827630 PMCID: PMC5567118 DOI: 10.1038/s41598-017-08873-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/19/2017] [Indexed: 11/09/2022] Open
Abstract
The removal of macroalgal biomass is critical to the health of coral reef ecosystems. Previous studies on relatively intact reefs with diverse and abundant fish communities have quantified rapid removal of macroalgae by herbivorous fishes, yet how these findings relate to degraded reef systems where fish diversity and abundance are markedly lower and algal biomass substantially higher, is unclear. We surveyed roving herbivorous fish communities and quantified their capacity to remove the dominant macroalga Sargassum ilicifolium on seven reefs in Singapore; a heavily degraded urbanized reef system. The diversity and abundance of herbivorous fishes was extremely low, with eight species and a mean abundance ~1.1 individuals 60 m-2 recorded across reefs. Consumption of S. ilicifolium varied with distance from Singapore's main port with consumption being 3- to 17-fold higher on reefs furthest from the port (Pulau Satumu: 4.18 g h-1; Kusu Island: 2.38 g h-1) than reefs closer to the port (0.35-0.78 g h-1). Video observations revealed a single species, Siganus virgatus, was almost solely responsible for removing S. ilicifolium biomass, accounting for 83% of the mass-standardized bites. Despite low herbivore diversity and intense urbanization, macroalgal removal by fishes on some Singaporean reefs was directly comparable to rates reported for other inshore Indo-Pacific reefs.
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Affiliation(s)
- Andrew G Bauman
- Experimental Marine and Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore.
| | - Andrew S Hoey
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia
| | - Glenn Dunshea
- Ecological Marine Services, 2/3 Thomsen St, Millbank, QLD 4670, Australia.,Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350, Copenhagen, Denmark
| | - David A Feary
- Fish Ecology Research Group, School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Jeffrey Low
- National Biodiversity Centre, National Parks Board, 1 Cluny Road, Singapore, 259569, Singapore
| | - Peter A Todd
- Experimental Marine and Ecology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
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32
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Rocker MM, Francis DS, Fabricius KE, Willis BL, Bay LK. Variation in the health and biochemical condition of the coral Acropora tenuis along two water quality gradients on the Great Barrier Reef, Australia. MARINE POLLUTION BULLETIN 2017; 119:106-119. [PMID: 28460877 DOI: 10.1016/j.marpolbul.2017.03.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 03/19/2017] [Accepted: 03/31/2017] [Indexed: 06/07/2023]
Abstract
This study explores how plasticity in biochemical attributes, used as indicators of health and condition, enables the coral Acropora tenuis to respond to differing water quality regimes in inshore regions of the Great Barrier Reef. Health attributes were monitored along a strong and weak water quality gradient, each with three reefs at increasing distances from a major river source. Attributes differed significantly only along the strong gradient; corals grew fastest, had the least dense skeletons, highest symbiont densities and highest lipid concentrations closest to the river mouth, where water quality was poorest. High nutrient and particulate loads were only detrimental to skeletal density, which decreased as linear extension increased, highlighting a trade-off. Our study underscores the importance of assessing multiple health attributes in coral reef monitoring. For example, autotrophic indices are poor indicators of coral health and condition, but improve when combined with attributes like lipid content and biomass.
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Affiliation(s)
- Melissa M Rocker
- Australian Institute of Marine Science, PMB #3, Townsville MC, QLD 4810, Australia; AIMS@JCU, Australian Institute of Marine Science, James Cook University, Townsville, QLD 4811, Australia; College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia; Deakin University, Geelong, School of Life and Environmental Sciences, Waurn Ponds Campus, Pigdons Rd, Waurn Ponds, VIC 3216, Australia.
| | - David S Francis
- Deakin University, Geelong, School of Life and Environmental Sciences, Warrnambool Campus, Princes Hwy, Sherwood Park, PO Box 423, Warrnambool, VIC 3280, Australia
| | | | - Bette L Willis
- College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Line K Bay
- Australian Institute of Marine Science, PMB #3, Townsville MC, QLD 4810, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
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33
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27 years of benthic and coral community dynamics on turbid, highly urbanised reefs off Singapore. Sci Rep 2016; 6:36260. [PMID: 27824083 PMCID: PMC5099948 DOI: 10.1038/srep36260] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 10/12/2016] [Indexed: 11/09/2022] Open
Abstract
Coral cover on reefs is declining globally due to coastal development, overfishing and climate change. Reefs isolated from direct human influence can recover from natural acute disturbances, but little is known about long term recovery of reefs experiencing chronic human disturbances. Here we investigate responses to acute bleaching disturbances on turbid reefs off Singapore, at two depths over a period of 27 years. Coral cover declined and there were marked changes in coral and benthic community structure during the first decade of monitoring at both depths. At shallower reef crest sites (3–4 m), benthic community structure recovered towards pre-disturbance states within a decade. In contrast, there was a net decline in coral cover and continuing shifts in community structure at deeper reef slope sites (6–7 m). There was no evidence of phase shifts to macroalgal dominance but coral habitats at deeper sites were replaced by unstable substrata such as fine sediments and rubble. The persistence of coral dominance at chronically disturbed shallow sites is likely due to an abundance of coral taxa which are tolerant to environmental stress. In addition, high turbidity may interact antagonistically with other disturbances to reduce the impact of thermal stress and limit macroalgal growth rates.
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34
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Differential Response of Coral Assemblages to Thermal Stress Underscores the Complexity in Predicting Bleaching Susceptibility. PLoS One 2016; 11:e0159755. [PMID: 27438593 PMCID: PMC4954682 DOI: 10.1371/journal.pone.0159755] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/06/2016] [Indexed: 11/19/2022] Open
Abstract
Coral bleaching events have been predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes is dependent on many factors and an understanding of these underlying drivers is crucial for conservation management. In 2013, a mild bleaching episode ensued in response to elevated sea temperature on the sediment-burdened reefs in Singapore. Surveys of seven sites highlighted variable bleaching susceptibility among coral genera-Pachyseris and Podabacia were the most impacted (31% of colonies of both genera bleached). The most susceptible genera such as Acropora and Pocillopora, which were expected to bleach, did not. Susceptibility varied between less than 6% and more than 11% of the corals bleached, at four and three sites respectively. Analysis of four of the most bleached genera revealed that a statistical model that included a combination of the factors (genus, colony size and site) provided a better explanation of the observed bleaching patterns than any single factor alone. This underscored the complexity in predicting the coral susceptibility to future thermal stress events and the importance of monitoring coral bleaching episodes to facilitate more effective management of coral reefs under climate change.
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