1
|
Hay Q, Pak E, Gardner L, Shaw A, Roger LM, Lewinski NA, Segal RA, Reynolds AM. A mathematical model for wound healing in the reef-building coral Pocillopora damicornis. J Theor Biol 2024; 593:111897. [PMID: 38971400 DOI: 10.1016/j.jtbi.2024.111897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 07/01/2024] [Accepted: 07/01/2024] [Indexed: 07/08/2024]
Abstract
Coral reefs, among the most diverse ecosystems on Earth, currently face major threats from pollution, unsustainable fishing practices , and perturbations in environmental parameters brought on by climate change. Corals also sustain regular wounding from other sea life and human activity. Recent reef restoration practices have even involved intentional wounding by systematically breaking coral fragments and relocating them to revitalize damaged reefs, a practice known as microfragmentation. Despite its importance, very little research has explored the inner mechanisms of wound healing in corals. Some reef-building corals have been observed to initiate an immunological response to wounding similar to that observed in mammalian species. Utilizing prior models of wound healing in mammalian species as the mathematical basis, we formulated a mechanistic model of wound healing, including observations of the immune response and tissue repair in scleractinian corals for the species Pocillopora damicornis. The model consists of four differential equations which track changes in remaining wound debris, number of cells involved in inflammation, number of cells involved in proliferation, and amount of wound closure through re-epithelialization. The model is fit to experimental wound size data from linear and circular shaped wounds on a live coral fragment. Mathematical methods, including numerical simulations and local sensitivity analysis, were used to analyze the resulting model. The parameter space was also explored to investigate drivers of other possible wound outcomes. This model serves as a first step in generating mathematical models for wound healing in corals that will not only aid in the understanding of wound healing as a whole, but also help optimize reef restoration practices and predict recovery behavior after major wounding events.
Collapse
Affiliation(s)
- Quintessa Hay
- Department of Mathematics & Applied Mathematics, Virginia Commonwealth University, Richmond, VA, USA
| | - Eunice Pak
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Luke Gardner
- Department of Mathematics & Applied Mathematics, Virginia Commonwealth University, Richmond, VA, USA
| | - Anna Shaw
- Department of Mathematics & Applied Mathematics, Virginia Commonwealth University, Richmond, VA, USA
| | - Liza M Roger
- Department of Chemical & Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ, USA; School of Ocean Futures, Arizona State University, Tempe, AZ, USA
| | - Nastassja A Lewinski
- Department of Chemical & Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Rebecca A Segal
- Department of Mathematics & Applied Mathematics, Virginia Commonwealth University, Richmond, VA, USA
| | - Angela M Reynolds
- Department of Mathematics & Applied Mathematics, Virginia Commonwealth University, Richmond, VA, USA.
| |
Collapse
|
2
|
Burgess SC, Turner AM, Johnston EC. Niche breadth and divergence in sympatric cryptic coral species ( Pocillopora spp.) across habitats within reefs and among algal symbionts. Evol Appl 2024; 17:e13762. [PMID: 39100752 PMCID: PMC11294925 DOI: 10.1111/eva.13762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/05/2024] [Accepted: 07/10/2024] [Indexed: 08/06/2024] Open
Abstract
While the presence of morphologically cryptic species is increasingly recognized, we still lack a useful understanding of what causes and maintains co-occurring cryptic species and its consequences for the ecology, evolution, and conservation of communities. We sampled 724 Pocillopora corals from five habitat zones (the fringing reef, back reef, and fore reef at 5, 10, and 20 m) at four sites around the island of Moorea, French Polynesia. Using validated genetic markers, we identified six sympatric species of Pocillopora, most of which cannot be reliably identified based on morphology: P. meandrina (42.9%), P. tuahiniensis (25.1%), P. verrucosa (12.2%), P. acuta (10.4%), P. grandis (7.73%), and P. cf. effusa (2.76%). For 423 colonies (58% of the genetically identified hosts), we also used psbA ncr or ITS2 markers to identify symbiont species (Symbiodiniaceae). The relative abundance of Pocillopora species differed across habitats within the reef. Sister taxa P. verrucosa and P. tuahiniensis had similar niche breadths and hosted the same specialist symbiont species (mostly Cladocopium pacificum) but the former was more common in the back reef and the latter more common deeper on the fore reef. In contrast, sister taxa P. meandrina and P. grandis had the highest niche breadths and overlaps and tended to host the same specialist symbiont species (mostly C. latusorum). Pocillopora acuta had the narrowest niche breadth and hosted the generalist, and more thermally tolerant, Durusdinium gynnii. Overall, there was a positive correlation between reef habitat niche breadth and symbiont niche breadth-Pocillopora species with a broader habitat niche also had a broader symbiont niche. Our results show how fine-scale variation within reefs plays an important role in the generation and coexistence of cryptic species. The results also have important implications for how niche differences affect community resilience, and for the success of coral restoration practices, in ways not previously appreciated.
Collapse
Affiliation(s)
- Scott C. Burgess
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
| | - Alyssa M. Turner
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
| | - Erika C. Johnston
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
- Present address:
Hawai‘i Institute of Marine BiologyKāne‘oheHawaiiUSA
| |
Collapse
|
3
|
Primov KD, Burdick DR, Lemer S, Forsman ZH, Combosch DJ. Genomic data reveals habitat partitioning in massive Porites on Guam, Micronesia. Sci Rep 2024; 14:17107. [PMID: 39048606 PMCID: PMC11269739 DOI: 10.1038/s41598-024-67992-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 07/18/2024] [Indexed: 07/27/2024] Open
Abstract
Corals in marginal reef habitats generally exhibit less bleaching and associated mortality compared to nearby corals in more pristine reef environments. It is unclear, however, if these differences are due to environmental differences, including turbidity, or genomic differences between the coral hosts in these different environments. One particularly interesting case is in the coral genus Porites, which contains numerous morphologically similar massive Porites species inhabiting a wide range of reef habitats, from turbid river deltas and stagnant back reefs to high-energy fore reefs. Here, we generate ddRAD data for 172 Porites corals from river delta and adjacent (<0.5 km) fore reef populations on Guam to assess the extent of genetic differentiation among massive Porites corals in these two contrasting environments and throughout the island. Phylogenetic and population genomic analyses consistently identify seven different clades of massive Porites, with the two largest clades predominantly inhabiting either river deltas or fore reefs, respectively. No population structure was detected in the two largest clades, and Cladocopium was the dominant symbiont genus in all clades and environments. The perceived bleaching resilience of corals in marginal reefs may therefore be attributed to interspecific differences between morphologically similar species, in addition to potentially mediating environmental differences. Marginal reef environments may therefore not provide a suitable refuge for many reef corals in a heating world, but instead host additional cryptic coral diversity.
Collapse
Affiliation(s)
- Karim D Primov
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA.
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA.
| | - David R Burdick
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
| | - Sarah Lemer
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
| | - Zac H Forsman
- King Abdullah University of Science and Technology, 23955, Thuwal, Saudi Arabia
| | - David J Combosch
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
| |
Collapse
|
4
|
van Woesik R, Kratochwill C. A global database on coral recovery following marine heatwaves. Sci Data 2024; 11:367. [PMID: 38605060 PMCID: PMC11009248 DOI: 10.1038/s41597-024-03221-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 04/03/2024] [Indexed: 04/13/2024] Open
Abstract
Coral reefs support the world's most diverse marine ecosystem and provide invaluable goods and services for millions of people worldwide. They are however experiencing frequent and intensive marine heatwaves that are causing coral bleaching and mortality. Coarse-grained climate models predict that few coral reefs will survive the 3 °C sea-surface temperature rise in the coming century. Yet, field studies show localized pockets of coral survival and recovery even under high-temperature conditions. Quantifying recovery from marine heatwaves is central to making accurate predictions of coral-reef trajectories into the near future. Here we introduce the world's most comprehensive database on coral recovery following marine heatwaves and other disturbances, called Heatwaves and Coral-Recovery Database (HeatCRD) encompassing 29,205 data records spanning 44 years from 12,266 sites, 83 countries, and 160 data sources. These data provide essential information to coral-reef scientists and managers to best guide coral-reef conservation efforts at both local and regional scales.
Collapse
Affiliation(s)
- Robert van Woesik
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, Florida, 32901, United States of America.
| | - Chelsey Kratochwill
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, Florida, 32901, United States of America
| |
Collapse
|
5
|
Walker AS, Kratochwill CA, van Woesik R. Past disturbances and local conditions influence the recovery rates of coral reefs. GLOBAL CHANGE BIOLOGY 2024; 30:e17112. [PMID: 38273580 DOI: 10.1111/gcb.17112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 01/27/2024]
Abstract
Corals are being increasingly subjected to marine heatwaves. Theory suggests that increasing the intensity of disturbances reduces recovery rates, which inspired us to examine the recovery rates of coral cover following marine heatwaves, cyclones, and other disturbances at 1921 study sites, in 58 countries and three oceans, from 1977 to 2020. In the Atlantic Ocean, coral cover has decreased fourfold since the 1970s, and recovery rates following disturbances have been relatively slow, except in the Antilles. By contrast, reefs in the Pacific and Indian Oceans have maintained coral cover and recovery rates over time. There were positive relationships between rates of coral recovery and prior cyclone and heatwave frequency, and negative relationships between rates of coral recovery and macroalgae cover and distance to shore. A recent increase in the variance in recovery rates in some ecoregions of the Pacific and Indian Oceans suggests that some reefs in those ecoregions may be approaching a phase shift. While marine heatwaves are increasing in intensity and frequency, our results suggest that regional and local conditions influence coral recovery rates, and therefore, effective local management efforts can help reefs recover from disturbances.
Collapse
Affiliation(s)
- Andrew S Walker
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, Florida, USA
| | - Chelsey A Kratochwill
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, Florida, USA
| | - Robert van Woesik
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, Florida, USA
| |
Collapse
|
6
|
Lucas CC, Lima IC, Garcia TM, Tavares TCL, Carneiro PBM, Teixeira CEP, Bejarano S, Rossi S, Soares MO. Turbidity buffers coral bleaching under extreme wind and rainfall conditions. MARINE ENVIRONMENTAL RESEARCH 2023; 192:106215. [PMID: 37890231 DOI: 10.1016/j.marenvres.2023.106215] [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: 11/07/2022] [Revised: 09/23/2023] [Accepted: 09/29/2023] [Indexed: 10/29/2023]
Abstract
Coral reefs in turbid waters have been hypothesized to be a refuge from climate change. These naturally occurring communities were brought into the spotlight because some of their species exhibited record levels of resistance to marine heatwaves (MHWs) by disturbance-tolerant corals. However, long-term monitoring data on the drivers of coral bleaching in these extreme reef habitats are scarce. Here, we describe the population structure and bleaching rates of a widespread and resilient coral (Siderastrea stellata). We examine the links between environmental factors, namely, rainfall, wind speed, turbidity, solar irradiance, sea surface temperature, MHWs, and coral bleaching status under the worst recorded drought cycle in the Tropical South Atlantic (2013-2015). We examined 2880 colonies, most of which (∼93%) fit in the size group of 2-10 cm, with a small number (∼1%) of larger and older colonies (>20 cm). The results indicated the absence of MHWs and normal sea surface temperature variations (between 26.6 °C and 29.3 °C), however, we detected an extreme rainfall deficit (30-40% less annual volume precipitation). In general, a high proportion (44-84%) of bleached colonies was found throughout the months when turbidity decreased. Siderastrea is the only reef-building coral that comprises this seascape with encrusting and low-relief colonies. During drought periods, cloudiness is reduced, turbidity and wind speed are reduced, and solar irradiance increase, driving coral bleaching in turbid reefs. However, episodic rainfall and higher wind speeds increase turbidity and decrease coral bleaching. Our hypothesis is that turbidity decreases during drought periods which increases bleaching risk to corals even without thermal stress. Our results suggest that turbidity may have related to wind and rainfall to provoke the coral bleaching phenomenon.
Collapse
Affiliation(s)
- Caroline Costa Lucas
- Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil.
| | - Italo Cesar Lima
- Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil
| | - Tatiane Martins Garcia
- Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil
| | | | | | | | - Sonia Bejarano
- Reef Systems Group, Leibniz Centre for Tropical Marine Research (ZMT), Fahrenheitstraße 6, 28359 Bremen, Germany
| | - Sergio Rossi
- Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil; Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona (UAB), Cerdanyolla del Vallés, Barcelona, Spain; Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (DISTEBA), Università del Salento, Lecce, Italy
| | - Marcelo O Soares
- Institute of Marine Sciences (LABOMAR), Federal University of Ceará (UFC), Fortaleza, Brazil; Reef Systems Group, Leibniz Centre for Tropical Marine Research (ZMT), Fahrenheitstraße 6, 28359 Bremen, Germany
| |
Collapse
|
7
|
McQuagge A, Pahl KB, Wong S, Melman T, Linn L, Lowry S, Hoadley KD. Cellular traits regulate fluorescence-based light-response phenotypes of coral photosymbionts living in-hospite. Front Physiol 2023; 14:1244060. [PMID: 37885802 PMCID: PMC10598705 DOI: 10.3389/fphys.2023.1244060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/21/2023] [Indexed: 10/28/2023] Open
Abstract
Diversity across algal family Symbiodiniaceae contributes to the environmental resilience of certain coral species. Chlorophyll-a fluorescence measurements are frequently used to determine symbiont health and resilience, but more work is needed to refine these tools and establish how they relate to underlying cellular traits. We examined trait diversity in symbionts from the generas Cladocopium and Durusdinium, collected from 12 aquacultured coral species. Photophysiological metrics (ΦPSII, σPSII, ρ, τ1, τ2, antenna bed quenching, non-photochemical quenching, and qP) were assessed using a prototype multi-spectral fluorometer over a variable light protocol which yielded a total of 1,360 individual metrics. Photophysiological metrics were then used to establish four unique light-response phenotypic variants. Corals harboring C15 were predominantly found within a single light-response phenotype which clustered separately from all other coral fragments. The majority of Durusdinium dominated colonies also formed a separate light-response phenotype which it shared with a few C1 dominated corals. C15 and D1 symbionts appear to differ in which mechanisms they use to dissipate excess light energy. Spectrally dependent variability is also observed across light-response phenotypes that may relate to differences in photopigment utilization. Symbiont cell biochemical and structural traits (atomic C:N:P, cell size, chlorophyll-a, neutral lipid content) was also assessed within each sample and differ across light-response phenotypes, linking photophysiological metrics with underlying primary cellular traits. Strong correlations between first- and second-order traits, such as Quantum Yield and cellular N:P content, or light dissipation pathways (qP and NPQ) and C:P underline differences across symbiont types and may also provide a means for using fluorescence-based metrics as biomarkers for certain primary-cellular traits.
Collapse
Affiliation(s)
- Audrey McQuagge
- Department of Biology, University of Alabama, Tuscaloosa, AL, United States
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| | - K. Blue Pahl
- Department of Biology, University of Alabama, Tuscaloosa, AL, United States
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| | - Sophie Wong
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
- Department of Environmental Science, University of Virginia, Charlottesville, VA, United States
| | - Todd Melman
- Reef Systems Coral Farm, New Albany, OH, United States
| | - Laura Linn
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| | - Sean Lowry
- Department of Biology, University of Alabama, Tuscaloosa, AL, United States
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| | - Kenneth D. Hoadley
- Department of Biology, University of Alabama, Tuscaloosa, AL, United States
- Dauphin Island Sea Lab, Dauphin Island, AL, United States
| |
Collapse
|
8
|
Zuo X, Qin B, Teng J, Duan X, Yu K, Su F. Optimized spatial and temporal pattern for coral bleaching heat stress alerts for China's coral reefs. MARINE ENVIRONMENTAL RESEARCH 2023; 191:106152. [PMID: 37604086 DOI: 10.1016/j.marenvres.2023.106152] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/10/2023] [Accepted: 08/16/2023] [Indexed: 08/23/2023]
Abstract
Most studies on coral bleaching alerts use common Degree Heating Week (DHW) thresholds; however, these may underestimate historical patterns of heat stress for coral reef ecosystems. Taking an optimized DHW threshold for coral bleaching alerts for Coral Reef Watch (CRW) and Coral Reef Temperature Anomaly Database (CoRTAD) products, we analyzed the precise spatial and temporal pattern of heat stress on China's coral reefs from 2010 to 2021 in the South China Sea (SCS) and the Beibu Gulf (BG). We compared acute heat stress using common and optimized thresholds. Results indicated that the ocean warming rate in 2010-2021 was approximately 0.43 ± 0.22 °C/10a, showing a significant increase in the northern SCS and the BG. More severe bleaching events were predicted by the optimized thresholds and the high-frequency areas were mainly in the northern SCS. The number and intensity of years with severe heat stress anomalies was in the order 2020 > 2014 > 2010 > 2015. Heat stress duration was the longest in the Xisha Islands among offshore archipelagos, and longest in 2020-2021 in Weizhou Island in BG in the relative high-latitude inshore reefs. These abnormal events were mainly caused by El Niño, but La Niña was also involved in 2020.
Collapse
Affiliation(s)
- Xiuling Zuo
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Binni Qin
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Juncan Teng
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Xiaopeng Duan
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Kefu Yu
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University, Nanning, 530004, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519080, China.
| | - Fenzhen Su
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
9
|
Keighan R, van Woesik R, Yalon A, Nam J, Houk P. Moderate chlorophyll-a environments reduce coral bleaching during thermal stress in Yap, Micronesia. Sci Rep 2023; 13:9338. [PMID: 37291208 PMCID: PMC10250426 DOI: 10.1038/s41598-023-36355-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 06/01/2023] [Indexed: 06/10/2023] Open
Abstract
Thermal-stress events on coral reefs lead to coral bleaching, mortality, and changes in species composition. The coral reefs of Yap, in the Federated States of Micronesia, however, remained largely unaffected by major thermal-stress events until 2020, when temperatures were elevated for three months. Twenty-nine study sites were examined around Yap to determine geographical and taxonomic patterns of coral abundance, bleaching susceptibility, and environmental predictors of bleaching susceptibility. Island-wide, 21% (± 14%) of the coral cover was bleached in 2020. Although inner reefs had a greater proportion of thermally-tolerant Porites corals, the prevalence of bleaching was consistently lower on inner reefs (10%) than on outer reefs (31%) for all coral taxa. Corals on both inner and outer reefs along the southwestern coast exhibited the lowest prevalence of coral bleaching and had consistently elevated chlorophyll-a concentrations. More broadly, we revealed a negative relationship between bleaching prevalence and (moderate) chlorophyll-a concentrations that may have facilitated resistance to thermal stress by reducing irradiance and providing a heterotrophic energy source to benefit some corals exposed to autotrophic stress. Southwestern reefs also supported a high but declining fish biomass, making these bleaching-resistant and productive reefs a potential climate-change refuge and a prime target for conservation.
Collapse
Affiliation(s)
- Rachael Keighan
- University of Guam Marine Laboratory, UoG Station, Mangilao, GU, 96923, USA
| | - Robert van Woesik
- Institute for Global Ecology, Florida Institute of Technology, 150 West University Blvd, Melbourne, Fl, 32901, USA
| | - Anthony Yalon
- Yap State Division of Marine Resources, Colonia, Yap, FM 96943, Federated States of Micronesia
| | - Joe Nam
- Yap Community Action Program, Colonia, Yap, FM 96943, Federated States of Micronesia
| | - Peter Houk
- University of Guam Marine Laboratory, UoG Station, Mangilao, GU, 96923, USA.
| |
Collapse
|
10
|
Zhao Y, Chen M, Chung TH, Chan LL, Qiu JW. The 2022 summer marine heatwaves and coral bleaching in China's Greater Bay Area. MARINE ENVIRONMENTAL RESEARCH 2023:106044. [PMID: 37321888 DOI: 10.1016/j.marenvres.2023.106044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/24/2023] [Accepted: 06/02/2023] [Indexed: 06/17/2023]
Abstract
From July to August 2022, scleractinian coral communities in China's Greater Bay Area (GBA) in the northern South China Sea (nSCS) experienced an unprecedented bleaching event, despite the fact that coral communities in this area are often considered coral thermal refugia due to their high latitude distribution. Field surveys of six sites covering three main coral distribution areas of the GBA revealed that coral bleaching occurred at all sites. Bleaching was more severe in shallow water (1-3 m) than in deep water (4-6 m), as indicated by both percent bleached cover (51.80 ± 10.04% vs. 7.09 ± 7.37%) and bleached colonies (45.86 ± 11.22% vs. 6.58 ± 6.53%). Coral genera Acropora, Favites, Montipora, Platygyra, Pocillopora, and Porites showed high susceptibility to bleaching, and Acropora and Pocillopora suffered high post-bleaching mortality. In the three areas surveyed, analysis of oceanographic data detected marine heatwaves (MHWs) during the summer, with mean intensities between 1.62 and 1.97 °C and durations between 5 and 22 days. These MHWs were primarily driven by increased shortwave radiation due to strong western Pacific Subtropical High (WPSH), combined with reduced mixing between the surface and deep upwelling waters due to reduced wind speed. Comparing with histological oceanographic data showed that the 2022 MHWs were unprecedented, and there was a significant increase in the frequency, intensity, and total days of MHWs during 1982-2022. Furthermore, the heterogeneous distribution of summer MHW characteristics indicates that the coastal upwelling may modulate the spatial distribution of summer MHWs in nSCS through its cooling effect. Overall, our study indicates that MHWs may have affected the structure of the subtropical coral communities in the nSCS, and impaired their potential as thermal refugia.
Collapse
Affiliation(s)
- Yu Zhao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, PR China
| | - Mingru Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, PR China; Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration (USER), Xiamen University, Xiamen, 361102, PR China.
| | - Tzu Hao Chung
- State Key Laboratory of Marine Pollution and Department of Biomedical Sciences, City University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Leo Lai Chan
- State Key Laboratory of Marine Pollution and Department of Biomedical Sciences, City University of Hong Kong, Hong Kong Special Administrative Region, China; Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, 518057, PR China
| | - Jian-Wen Qiu
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, PR China; Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.
| |
Collapse
|
11
|
Wang L, Xu J, Liu H, Wang S, Ou W, Zhang M, Wei F, Luo S, Chen B, Zhang S, Yu K. Ultrasensitive and on-site eDNA detection for the monitoring of crown-of-thorns starfish densities at the pre-outbreak stage using an electrochemical biosensor. Biosens Bioelectron 2023; 230:115265. [PMID: 36996547 DOI: 10.1016/j.bios.2023.115265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/02/2023] [Accepted: 03/24/2023] [Indexed: 03/29/2023]
Abstract
The coral reef crisis has significantly intensified over the last decades, mainly due to severe outbreaks of crown-of-thorns starfish (COTS). Current ecological monitoring has failed to detect COTS densities at the pre-outbreak stage, thus preventing early intervention. In this work, we developed an effective electrochemical biosensor modified by a MoO2/C nanomaterial, as well as a specific DNA probe that could detect trace COTS environmental DNA (eDNA) at a lower detection limit (LOD = 0.147 ng/μL) with excellent specificity. The reliability and accuracy of the biosensor were validated against the standard methods by an ultramicro spectrophotometer and droplet digital PCR (p > 0.05). The biosensor was then utilized for the on-site analysis of seawater samples from SYM-LD and SY sites in the South China Sea. For the SYM-LD site suffering an outbreak, the COTS eDNA concentrations were 0.33 ng/μL (1 m, depth) and 0.26 ng/μL (10 m, depth), respectively. According to the ecological survey, the COTS density was 500 ind/hm2 at the SYM-LD site, verifying the accuracy of our measurements. At the SY site, COTS eDNA was also detected at 0.19 ng/μL, but COTS was not found by the traditional survey. Hence, larvae were possibly present in this region. Therefore, this electrochemical biosensor could be used to monitor COTS populations at the pre-outbreak stages, and potentially serve as a revolutionary early warning method. We will continue to improve this method for picomolar or even femtomolar detection of COTS eDNA.
Collapse
Affiliation(s)
- Liwei Wang
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China; School of Resources, Environment and Materials, Guangxi, Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials, Nanning, 530003, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519080, China
| | - Jiarong Xu
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China; School of Resources, Environment and Materials, Guangxi, Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials, Nanning, 530003, China
| | - Hongjie Liu
- School of Resources, Environment and Materials, Guangxi, Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials, Nanning, 530003, China; School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China; College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Shaopeng Wang
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China
| | - Wenchao Ou
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China
| | - Man Zhang
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China
| | - Fen Wei
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China
| | - Songlin Luo
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China
| | - Biao Chen
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China
| | - Shaolong Zhang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Kefu Yu
- School of Marine Sciences, Coral Reef Research Center of China, Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519080, China.
| |
Collapse
|
12
|
Shlesinger T, van Woesik R. Oceanic differences in coral-bleaching responses to marine heatwaves. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 871:162113. [PMID: 36773903 DOI: 10.1016/j.scitotenv.2023.162113] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 02/02/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
Anomalously high ocean temperatures have increased in frequency, intensity, and duration over the last several decades because of greenhouse gas emissions that cause global warming and marine heatwaves. Reef-building corals are sensitive to such temperature anomalies that commonly lead to coral bleaching, mortality, and changes in community structure. Yet, despite these overarching effects, there are geographical differences in thermal regimes, evolutionary histories, and past disturbances that may lead to different bleaching responses of corals within and among oceans. Here we examined the overall bleaching responses of corals in the Atlantic, Indian, and Pacific Oceans, using both a spatially explicit Bayesian mixed-effects model and a deep-learning neural-network model. We used a 40-year global dataset encompassing 23,288 coral-reef surveys at 11,058 sites in 88 countries, from 1980 to 2020. Focusing on ocean-wide differences we assessed the relationships between the percentage of bleached corals and different temperature-related metrics alongside a suite of environmental variables. We found that while high sea-surface temperatures were consistently, and strongly, related to coral bleaching within all oceans, there were clear geographical differences in the relationships between coral bleaching and most environmental variables. For instance, there was an increase in coral bleaching with depth in the Atlantic Ocean whereas the opposite was observed in the Indian Ocean, and no clear trend could be seen in the Pacific Ocean. The standard deviation of thermal-stress anomalies was negatively related to coral bleaching in the Atlantic and Pacific Oceans, but not in the Indian Ocean. Globally, coral bleaching has progressively occurred at higher temperatures over the last four decades within the Atlantic, Indian, and Pacific Oceans, although, again, there were differences among the three oceans. Together, such patterns highlight that historical circumstances and geographical differences in oceanographic conditions play a central role in contemporary coral-bleaching responses.
Collapse
Affiliation(s)
- Tom Shlesinger
- Institute for Global Ecology, Florida Institute of Technology, Melbourne 32901, FL, USA
| | - Robert van Woesik
- Institute for Global Ecology, Florida Institute of Technology, Melbourne 32901, FL, USA.
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Qin B, Yu K, Zuo X. Study of the bleaching alert capability of the CRW and CoRTAD coral bleaching heat stress products in China's coral reefs. MARINE ENVIRONMENTAL RESEARCH 2023; 186:105939. [PMID: 36924536 DOI: 10.1016/j.marenvres.2023.105939] [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: 12/18/2022] [Revised: 02/20/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Coral bleaching heat stress products provide real-time and rapid coral bleaching alerts for coral reefs globally. However, geographical variations in the alert accuracy of multi-source coral bleaching heat stress products exist. Taking the coral reefs in the South China Sea (SCS) as the study area, we evaluated and improved the coral bleaching alert capabilities of two coral bleaching heat stress products: Coral Reef Watch (CRW) and Coral Reef Temperature Anomaly Database (CoRTAD). Using in situ coral bleaching survey data and evaluation indicators, the optimized thresholds of degree heating weeks (DHWs) for coral bleaching alerts were determined. The results in the SCS indicated that, first, CRW was better than CoRTAD for coral bleaching event alerts. However, both products underestimated coral bleaching events using the common DHW thresholds of 4°C-weeks and 8°C-weeks. Second, the DHW optimized threshold for CRW was 3.32°C-weeks for coral bleaching event alerts and 4.52°C-weeks for severe coral bleaching event alerts. For CoRTAD products, the DHW optimized threshold was 2.36°C-weeks for coral bleaching event alerts and 4.14°C-weeks for severe coral bleaching event alerts. This study proposed a method to evaluate and optimize the alert capability of multi-source coral bleaching heat stress products, which can provide more accurate basic data for coral reef ecosystem health assessment and contribute to global coral reef ecosystem protection and restoration.
Collapse
Affiliation(s)
- Binni Qin
- School of Marine Sciences, Guangxi University, Nanning, 530004, China; Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China
| | - Kefu Yu
- School of Marine Sciences, Guangxi University, Nanning, 530004, China; Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519080, China
| | - Xiuling Zuo
- School of Marine Sciences, Guangxi University, Nanning, 530004, China; Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, 530004, China.
| |
Collapse
|
15
|
Virgen-Urcelay A, Donner SD. Increase in the extent of mass coral bleaching over the past half-century, based on an updated global database. PLoS One 2023; 18:e0281719. [PMID: 36780497 PMCID: PMC9925063 DOI: 10.1371/journal.pone.0281719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 01/31/2023] [Indexed: 02/15/2023] Open
Abstract
The recurrence of mass coral bleaching and associated coral mortality in the past few decades have raised questions about the future of coral reef ecosystems. Although coral bleaching is well studied, our understanding of the spatial extent of bleaching events continues to be limited by geographical biases in data collection. To address this gap, we updated a previous observational database and spatially modelled the probability of past bleaching occurrence. First, an existing raw observational database was updated to cover the 1963-2017 period using searches of the academic and grey literature and outreach to coral reef monitoring organizations. Then, in order to provide spatially-explicit global coverage, we employed indicator kriging to spatially model the probability of bleaching occurrence each year from 1985 through 2017 at 0.05° x 0.05° lat-long resolution. The updated raw database has 37,774 observations, including 22,650 positive bleaching reports, three times that in the previous version. The spatial interpolation suggests that 71% of the world's coral reefs likely (>66% probability) experienced bleaching at least once during the 1985 and 2017 period. The mean probability of bleaching across all reefs globally was 29-45% in the most severe bleaching years of 1998, 2005, 2010 and 2016. Modelled bleaching probabilities were positively related with annual maximum Degree Heating Weeks (DHW), a measure of thermal stress, across all years (p<0.001), and in each global bleaching event (p<0.01). In addition, the annual maximum DHW of reef cells that very likely (>90% probability) experienced bleaching increased over time at three times the rate of all reef cells, suggesting a possible increase in reef thermal tolerance. The raw and spatially interpolated databases can be used by other researchers to enhance real-time predictions, calibrate models for future projections, and assess the change in coral reef response to thermal stress over time.
Collapse
Affiliation(s)
- Alejandra Virgen-Urcelay
- Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia, Canada
| | - Simon D. Donner
- Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Geography, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
| |
Collapse
|
16
|
Rodriguez-Ruano V, Toth LT, Enochs IC, Randall CJ, Aronson RB. Upwelling, climate change, and the shifting geography of coral reef development. Sci Rep 2023; 13:1770. [PMID: 36750639 PMCID: PMC9905564 DOI: 10.1038/s41598-023-28489-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 01/19/2023] [Indexed: 02/09/2023] Open
Abstract
The eastern tropical Pacific is oceanographically unfavorable for coral-reef development. Nevertheless, reefs have persisted there for the last 7000 years. Rates of vertical accretion during the Holocene have been similar in the strong-upwelling Gulf of Panamá (GoP) and the adjacent, weak-upwelling Gulf of Chiriquí (GoC); however, seasonal upwelling in the GoP exacerbated a climate-driven hiatus in reef development in the late Holocene. The situation is now reversed and seasonal upwelling in the GoP currently buffers thermal stress, creating a refuge for coral growth. We developed carbonate budget models to project the capacity of reefs in both gulfs to keep up with future sea-level rise. On average, the GoP had significantly higher net carbonate production rates than the GoC. With an estimated contemporary reef-accretion potential (RAP) of 5.5 mm year-1, reefs in the GoP are projected to be able to keep up with sea-level rise if CO2 emissions are reduced, but not under current emissions trajectories. With an estimated RAP of just 0.3 mm year-1, reefs in the GoC are likely already unable to keep up with contemporary sea-level rise in Panamá (1.4 mm year-1). Whereas the GoP has the potential to support functional reefs in the near-term, our study indicates that their long-term persistence will depend on reduction of greenhouse gases.
Collapse
Affiliation(s)
- Victor Rodriguez-Ruano
- Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL, 32901, USA.
| | - Lauren T Toth
- U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, 600 4th St. South, St. Petersburg, FL, 33701, USA
| | - Ian C Enochs
- 3NOAA, Atlantic Oceanographic and Meteorological Laboratory, Ocean Chemistry and Ecosystem Division, 4301 Rickenbacker Cswy., Miami, FL, 33149, USA
| | - Carly J Randall
- Australian Institute of Marine Science, PMB No. 3, Townsville, QLD, 4810, Australia
| | - Richard B Aronson
- Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL, 32901, USA
| |
Collapse
|
17
|
Page CA, Giuliano C, Bay LK, Randall CJ. High survival following bleaching underscores the resilience of a frequently disturbed region of the Great Barrier Reef. Ecosphere 2023. [DOI: 10.1002/ecs2.4280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Affiliation(s)
- Cathie A. Page
- Australian Institute of Marine Science Townsville Queensland Australia
| | | | - Line K. Bay
- Australian Institute of Marine Science Townsville Queensland Australia
| | - Carly J. Randall
- Australian Institute of Marine Science Townsville Queensland Australia
| |
Collapse
|
18
|
Elma E, Gullström M, Yahya SAS, Jouffray JB, East HK, Nyström M. Post-bleaching alterations in coral reef communities. MARINE POLLUTION BULLETIN 2023; 186:114479. [PMID: 36549237 DOI: 10.1016/j.marpolbul.2022.114479] [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: 05/22/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
We explored the extent of post-bleaching impacts, caused by the 2014-2016 El Niño Southern Oscillation (ENSO) event, on benthic community structure (BCS) and herbivores (fish and sea urchins) on seven fringing reefs, with differing protection levels, in Zanzibar, Tanzania. Results showed post-bleaching alterations in BCS, with up to 68 % coral mortality and up to 48 % increase in turf algae cover in all reef sites. Herbivorous fish biomass increased after bleaching and was correlated with turf algae increase in some reefs, while the opposite was found for sea urchin densities, with significant declines and complete absence. The severity of the impact varied across individual reefs, with larger impact on the protected reefs, compared to the unprotected reefs. Our study provides a highly relevant reference point to guide future research and contributes to our understanding of post-bleaching impacts, trends, and evaluation of coral reef health and resilience in the region.
Collapse
Affiliation(s)
- Eylem Elma
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK; Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden.
| | - Martin Gullström
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Huddinge, Sweden
| | - Saleh A S Yahya
- Institute of Marine Sciences, University of Dar es Salaam, Zanzibar, Tanzania
| | | | - Holly K East
- Department of Geography and Environmental Sciences, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, UK
| | - Magnus Nyström
- Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden
| |
Collapse
|
19
|
Spady BL, Skirving WJ, Liu G, De La Cour JL, McDonald CJ, Manzello DP. Unprecedented early-summer heat stress and forecast of coral bleaching on the Great Barrier Reef, 2021-2022. F1000Res 2022; 11:127. [PMID: 36415207 PMCID: PMC9652503 DOI: 10.12688/f1000research.108724.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/15/2022] [Indexed: 12/02/2022] Open
Abstract
The Great Barrier Reef (GBR) is predicted to undergo its sixth mass coral bleaching event during the Southern Hemisphere summer of 2021-2022. Coral bleaching-level heat stress over the GBR is forecast to start earlier than any previous year in the satellite record (1985-present). The National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch (CRW) near real-time satellite-based heat stress products were used to investigate early-summer sea surface temperature (SST) and heat stress conditions on the GBR during late 2021. As of 14 December 2021, values of instantaneous heat stress (Coral Bleaching HotSpots) and accumulated heat stress over a 12-week running window (Degree Heating Weeks) on the GBR were unprecedented in the satellite record. Further, 89% of GBR satellite reef pixels for this date in 2021 had a positive seven-day SST trend of greater than 0.2 degrees Celsius/week. Background temperatures (the minimum temperature over the previous 29 days) were alarmingly high, with 87% of GBR reef pixels on 14 December 2021 being greater than the maximum SST over that same 29-day period for any year from 1985-2020. The GBR is starting the 2021-2022 summer season with more accumulated heat than ever before, which could have disastrous consequences for the health, recovery, and future of this critical reef system.
Collapse
Affiliation(s)
- Blake L. Spady
- Center for Satellite Applications and Research, Satellite Oceanography and Climate Division, U.S. National Oceanic and Atmospheric Administration, College Park, Maryland, 20740, USA,ReefSense Pty, Ltd., P.O. Box 343, Aitkenvale, Queensland, 4814, Australia,
| | - William J. Skirving
- Center for Satellite Applications and Research, Satellite Oceanography and Climate Division, U.S. National Oceanic and Atmospheric Administration, College Park, Maryland, 20740, USA,ReefSense Pty, Ltd., P.O. Box 343, Aitkenvale, Queensland, 4814, Australia
| | - Gang Liu
- Center for Satellite Applications and Research, Satellite Oceanography and Climate Division, U.S. National Oceanic and Atmospheric Administration, College Park, Maryland, 20740, USA,Earth System Science Interdisciplinary Center, Cooperative Institute for Satellite Earth System Studies, University of Maryland, College Park, Maryland, 20740, USA
| | - Jacqueline L. De La Cour
- Center for Satellite Applications and Research, Satellite Oceanography and Climate Division, U.S. National Oceanic and Atmospheric Administration, College Park, Maryland, 20740, USA,Earth System Science Interdisciplinary Center, Cooperative Institute for Satellite Earth System Studies, University of Maryland, College Park, Maryland, 20740, USA
| | - Cathy J. McDonald
- ReefSense Pty, Ltd., P.O. Box 343, Aitkenvale, Queensland, 4814, Australia
| | - Derek P. Manzello
- Center for Satellite Applications and Research, Satellite Oceanography and Climate Division, U.S. National Oceanic and Atmospheric Administration, College Park, Maryland, 20740, USA
| |
Collapse
|
20
|
Toth LT, Courtney TA, Colella MA, Kupfner Johnson SA, Ruzicka RR. The past, present, and future of coral reef growth in the Florida Keys. GLOBAL CHANGE BIOLOGY 2022; 28:5294-5309. [PMID: 35789026 PMCID: PMC9542952 DOI: 10.1111/gcb.16295] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/22/2022] [Accepted: 05/26/2022] [Indexed: 05/06/2023]
Abstract
Coral-reef degradation is driving global-scale reductions in reef-building capacity and the ecological, geological, and socioeconomic functions it supports. The persistence of those essential functions will depend on whether coral-reef management is able to rebalance the competing processes of reef accretion and erosion. Here, we reconstructed census-based carbonate budgets of 46 reefs throughout the Florida Keys from 1996 to 2019. We evaluated the environmental and ecological drivers of changing budget states and compared historical trends in reef-accretion potential to millennial-scale baselines of accretion from reef cores and future projections with coral restoration. We found that historically, most reefs had positive carbonate budgets, and many had reef-accretion potential comparable to the ~3 mm year-1 average accretion rate during the peak of regional reef building ~7000 years ago; however, declines in reef-building Acropora palmata and Orbicella spp. corals following a series of thermal stress events and coral disease outbreaks resulted in a shift from positive to negative budgets for most reefs in the region. By 2019, only ~15% of reefs had positive net carbonate production. Most of those reefs were in inshore, Lower Keys patch-reef habitats with low water clarity, supporting the hypothesis that environments with naturally low irradiance may provide a refugia from thermal stress. We caution that our estimated carbonate budgets are likely overly optimistic; comparison of reef-accretion potential to measured accretion from reef cores suggests that, by not accounting for the role of nonbiological physical and chemical erosion, census-based carbonate budgets may underestimate total erosion by ~1 mm year-1 (-1.15 kg CaCO3 m-2 year-1 ). Although the present state of Florida's reefs is dire, we demonstrate that the restoration of reef-building corals has the potential to help mitigate declines in reef accretion in some locations, which could allow some key ecosystem functions to be maintained until the threat of global climate change is addressed.
Collapse
Affiliation(s)
- Lauren T. Toth
- U.S. Geological SurveySt. Petersburg Coastal and Marine Science CenterSt. PetersburgFloridaUSA
| | - Travis A. Courtney
- Scripps Institution of OceanographyUniversity of California San DiegoLa JollaCaliforniaUSA
- Department of Marine SciencesUniversity of Puerto Rico MayagüezMayagüezPuerto Rico
| | - Michael A. Colella
- Fish & Wildlife Research Institute, Florida Fish & Wildlife Conservation CommissionSt. PetersburgFloridaUSA
| | | | - Robert R. Ruzicka
- Fish & Wildlife Research Institute, Florida Fish & Wildlife Conservation CommissionSt. PetersburgFloridaUSA
| |
Collapse
|
21
|
Mao Q, Gu S, Li H, Lash GG, Zhang T, Xie X, Guo Z. Rare earth element geochemistry of Middle Devonian reefal limestones of the Dianqiangui Basin, South China: implications for nutrient sources and expansion of the reef ecosystem. PeerJ 2022; 10:e13663. [PMID: 35898942 PMCID: PMC9310798 DOI: 10.7717/peerj.13663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 06/10/2022] [Indexed: 01/17/2023] Open
Abstract
The Givetian Age witnessed the greatest expansion of stromatoporoid-coral reefs from low to higher latitudes of the Phanerozoic. Multi-proxy seawater surface temperature reconstruction suggests the establishment of a super-greenhouse climate as a major reason for reef expansion, yet many questions remain. This article presents the results of a rare earth element and yttrium (herein referred to as REY, derived from REE + Y) geochemical study as well as mineralogy and oxygen isotope values of two well-documented Middle Givetian reefal carbonate sections (Jiwozhai and Buzhai) of the Jiwozhai Formation of South China. The nearshore Jiwozhai patch reef succession displays greater biodiversity and more abundant coral than the marginal platform Upper Buzhai reef. Reefal and micritic carbonates of the Jiwozhai section are characterized by shale-like post-Archean Australian Shale (PAAS)-normalized REY patterns, by very weak negative Ce anomaly values (Ce/Ce* 0.80-0.96; average = 0.89), slightly elevated Y/Ho values (28.9-39.1; average = 34.1), and near-unity values of (Pr/Yb)N (average = 0.87), (Pr/Tb)N (average = 0.80), and (Tb/Yb)N (average = 1.09). Moreover, REY patterns of deposits of the Jiwozhai section differ markedly from those of modern seawater. The described geochemical aspects of the Jiwozhai section and the positive correlation of REY and Th contents displayed by the section point to a terrestrial siliciclastic contribution contemporaneous with reef-building. In contrast, REY patterns of the Upper Buzhai reef section samples are similar to those of modern seawater characterized by light rare earth element (LREE) depletion (average (Pr/Yb)N = 0.76), negative Ce anomalies (average Ce/Ce* = 0.88), and average super-chondritic Y/Ho ratios (average = 45.4)). Slightly positive Eu anomalies (Eu/Eu* = 0.93-1.94; average = 1.36) of the Upper Buzhai reef section samples are attributed to the negligible effect of hydrothermal fluids. Middle REE (MREE) enrichment (average (Tb/Yb)N = 1.48) of Buzhai section carbonate samples and positive correlation of REY and Th suggest a riverine input. Combined with siliciclastic mineralogy, oxygen isotope values, and reef-building biota morphology of the studied two sections, we suggest that terrestrial nutrients delivered by rivers far outweighed upwelling as a source of nutrients supplied to the Givetian reef ecosystem of South China. Coral and stromatoporoid in tropic oceans thrived in turbid water containing abundant terrestrial sediment and the nutrient-laden water helped expand reef-builder habitats during the Givetian time.
Collapse
Affiliation(s)
- Qi Mao
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, Guizhou, China
| | - Shangyi Gu
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, Guizhou, China,Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, Guizhou University, Guiyang, Guizhou, China
| | - Huan Li
- Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, School of Geosciences and Info-Physics, Central South University, Changsha, Hunan, China
| | - Gary G. Lash
- Department of Geosciences, State University of New York College at Fredonia, Fredonia, NY, United States of America
| | - Tianyi Zhang
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, Guizhou, China
| | - Xiaofeng Xie
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, Guizhou, China
| | - Zidong Guo
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, Guizhou, China
| |
Collapse
|
22
|
Herbert-Read JE, Thornton A, Amon DJ, Birchenough SNR, Côté IM, Dias MP, Godley BJ, Keith SA, McKinley E, Peck LS, Calado R, Defeo O, Degraer S, Johnston EL, Kaartokallio H, Macreadie PI, Metaxas A, Muthumbi AWN, Obura DO, Paterson DM, Piola AR, Richardson AJ, Schloss IR, Snelgrove PVR, Stewart BD, Thompson PM, Watson GJ, Worthington TA, Yasuhara M, Sutherland WJ. A global horizon scan of issues impacting marine and coastal biodiversity conservation. Nat Ecol Evol 2022; 6:1262-1270. [PMID: 35798839 DOI: 10.1038/s41559-022-01812-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 05/24/2022] [Indexed: 11/09/2022]
Abstract
The biodiversity of marine and coastal habitats is experiencing unprecedented change. While there are well-known drivers of these changes, such as overexploitation, climate change and pollution, there are also relatively unknown emerging issues that are poorly understood or recognized that have potentially positive or negative impacts on marine and coastal ecosystems. In this inaugural Marine and Coastal Horizon Scan, we brought together 30 scientists, policymakers and practitioners with transdisciplinary expertise in marine and coastal systems to identify new issues that are likely to have a significant impact on the functioning and conservation of marine and coastal biodiversity over the next 5-10 years. Based on a modified Delphi voting process, the final 15 issues presented were distilled from a list of 75 submitted by participants at the start of the process. These issues are grouped into three categories: ecosystem impacts, for example the impact of wildfires and the effect of poleward migration on equatorial biodiversity; resource exploitation, including an increase in the trade of fish swim bladders and increased exploitation of marine collagens; and new technologies, such as soft robotics and new biodegradable products. Our early identification of these issues and their potential impacts on marine and coastal biodiversity will support scientists, conservationists, resource managers and policymakers to address the challenges facing marine ecosystems.
Collapse
Affiliation(s)
| | - Ann Thornton
- Conservation Science Group, Department of Zoology, Cambridge University, Cambridge, UK.
| | - Diva J Amon
- SpeSeas, D'Abadie, Trinidad and Tobago.,Marine Science Institute, University of California, Santa Barbara, CA, USA
| | | | - Isabelle M Côté
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Maria P Dias
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Department of Animal Biology, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal.,BirdLife International, The David Attenborough Building, Cambridge, UK
| | - Brendan J Godley
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | - Sally A Keith
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Emma McKinley
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| | - Lloyd S Peck
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Ricardo Calado
- ECOMARE, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Santiago University Campus, Aveiro, Portugal
| | - Omar Defeo
- Laboratory of Marine Sciences (UNDECIMAR), Faculty of Sciences, University of the Republic, Montevideo, Uruguay
| | - Steven Degraer
- Royal Belgian Institute of Natural Sciences, Operational Directorate Natural Environment, Marine Ecology and Management, Brussels, Belgium
| | - Emma L Johnston
- School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | | | - Peter I Macreadie
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood Campus, Burwood, Victoria, Australia
| | - Anna Metaxas
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - David O Obura
- Coastal Oceans Research and Development in the Indian Ocean, Mombasa, Kenya.,School of Biological Sciences, University of Queensland, St Lucia, Brisbane, Queensland, Australia
| | - David M Paterson
- Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews, UK
| | - Alberto R Piola
- Servício de Hidrografía Naval, Buenos Aires, Argentina.,Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos, CONICET/CNRS, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Anthony J Richardson
- School of Mathematics and Physics, The University of Queensland, St Lucia, Brisbane, Queensland, Australia.,Commonwealth Scientific and Industrial Research Organisation (CSIRO) Oceans and Atmosphere, Queensland Biosciences Precinct, St Lucia, Brisbane, Queensland, Australia
| | - Irene R Schloss
- Instituto Antártico Argentino, Buenos Aires, Argentina.,Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina.,Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur, Ushuaia, Argentina
| | - Paul V R Snelgrove
- Department of Ocean Sciences and Biology Department, Memorial University, St John's, Newfoundland and Labrador, Canada
| | - Bryce D Stewart
- Department of Environment and Geography, University of York, York, UK
| | - Paul M Thompson
- Lighthouse Field Station, School of Biological Sciences, University of Aberdeen, Cromarty, UK
| | - Gordon J Watson
- Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth, UK
| | - Thomas A Worthington
- Conservation Science Group, Department of Zoology, Cambridge University, Cambridge, UK
| | - Moriaki Yasuhara
- School of Biological Sciences, Area of Ecology and Biodiversity, Swire Institute of Marine Science, Institute for Climate and Carbon Neutrality, Musketeers Foundation Institute of Data Science, and State Key Laboratory of Marine Pollution, The University of Hong Kong, Kadoorie Biological Sciences Building, Hong Kong, China
| | - William J Sutherland
- Conservation Science Group, Department of Zoology, Cambridge University, Cambridge, UK.,Biosecurity Research Initiative at St Catharine's (BioRISC), St Catharine's College, University of Cambridge, Cambridge, UK
| |
Collapse
|
23
|
Mo S, Chen T, Chen Z, Zhang W, Li S. Marine heatwaves impair the thermal refugia potential of marginal reefs in the northern South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 825:154100. [PMID: 35218829 DOI: 10.1016/j.scitotenv.2022.154100] [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: 10/09/2021] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 06/14/2023]
Abstract
Frequent marine heatwaves (MHWs), concurrent with climate warming, threaten global low-latitude, pristine coral reefs, leading to growing interest in identifying marginal coral reefs (relatively high-latitude and/or turbid reef environments) that can serve as thermal refugia from mass coral bleaching. However, the thermal refugia potential of marginal reefs remains controversial. We evaluated the thermal refugia potential of inshore reefs in the northern South China Sea (nSCS), a globally typical marginal reef system, by characterizing the long-term trend of MHW intensity and frequency and assessing thermal stress during a mass bleaching event in summer 2020. An unprecedented peak intensity of around 20 °C-weeks of cumulative heat stress, associated with a prolonged anomalous western Pacific subtropical high (WPSH) and weakened monsoon activity, induced record-breaking bleaching. The geographical variability of bleaching was strongly related to the extent of heat exposure and satellite-derived temperature anomalies. Under ongoing global warming, the frequency and intensity of MHWs over nSCS coral habitats show a markedly increasing trend, especially during the last decade. Intense MHWs and coral bleaching have already occurred throughout all El Niño-Southern Oscillation (ENSO) phases (e.g., 2010, 2015, and 2020). Climate change has pushed marginal coral reefs to or beyond the limits of their resilience, and frequent MHW events have amplified the increasing risk of thermal stress. There are no long-term thermal refugia for marginal reefs in the nSCS.
Collapse
Affiliation(s)
- Shaohua Mo
- Beihai Marine Environmental Monitoring Center Station, State Oceanic Administration, Beihai 536000, China
| | - Tianran Chen
- Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
| | - Zesheng Chen
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Wenjing Zhang
- South China Sea Information Center, State Oceanic Administration, Guangzhou 510310, China
| | - Shu Li
- Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| |
Collapse
|
24
|
Asner GP, Vaughn NR, Martin RE, Foo SA, Heckler J, Neilson BJ, Gove JM. Mapped coral mortality and refugia in an archipelago-scale marine heat wave. Proc Natl Acad Sci U S A 2022; 119:e2123331119. [PMID: 35500122 PMCID: PMC9171643 DOI: 10.1073/pnas.2123331119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/11/2022] [Indexed: 12/20/2022] Open
Abstract
Corals are a major habitat-building life-form on tropical reefs that support a quarter of all species in the ocean and provide ecosystem services to millions of people. Marine heat waves continue to threaten and shape reef ecosystems by killing individual coral colonies and reducing their diversity. However, marine heat waves are spatially and temporally heterogeneous, and so too are the environmental and biological factors mediating coral resilience during and following thermal events. This combination results in highly variable outcomes at both the coral bleaching and mortality stages of every event. This, in turn, impedes the assessment of changing reef-scale patterns of thermal tolerance or places of resistance known as reef refugia. We developed a large-scale, high-resolution coral mortality monitoring capability based on airborne imaging spectroscopy and applied it to a major marine heat wave in the Hawaiian Islands. While water depth and thermal stress strongly mediated coral mortality, relative coral loss was also inversely correlated with preheat-wave coral cover, suggesting the existence of coral refugia. Subsequent mapping analyses indicated that potential reef refugia underwent up to 40% lower coral mortality compared with neighboring reefs, despite similar thermal stress. A combination of human and environmental factors, particularly coastal development and sedimentation levels, differentiated resilient reefs from other more vulnerable reefs. Our findings highlight the role that coral mortality mapping, rather than bleaching monitoring, can play for targeted conservation that protects more surviving corals in our changing climate.
Collapse
Affiliation(s)
- Gregory P. Asner
- Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI 96720
| | - Nicholas R. Vaughn
- Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI 96720
| | - Roberta E. Martin
- Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI 96720
| | - Shawna A. Foo
- Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI 96720
| | - Joseph Heckler
- Center for Global Discovery and Conservation Science, Arizona State University, Hilo, HI 96720
| | - Brian J. Neilson
- Department of Land and Natural Resources, Division of Aquatic Resources, Honolulu, HI 96813
| | - Jamison M. Gove
- Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, Honolulu, HI 96818
| |
Collapse
|
25
|
Johnson JV, Dick JTA, Pincheira-Donoso D. Marine protected areas do not buffer corals from bleaching under global warming. BMC Ecol Evol 2022; 22:58. [PMID: 35508975 PMCID: PMC9066861 DOI: 10.1186/s12862-022-02011-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/18/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The rising temperature of the oceans has been identified as the primary driver of mass coral reef declines via coral bleaching (expulsion of photosynthetic endosymbionts). Marine protected areas (MPAs) have been implemented throughout the oceans with the aim of mitigating the impact of local stressors, enhancing fish biomass, and sustaining biodiversity overall. In coral reef regions specifically, protection from local stressors and the enhanced ecosystem function contributed by MPAs are expected to increase coral resistance to global-scale stressors such as marine heatwaves. However, MPAs still suffer from limitations in design, or fail to be adequately enforced, potentially reducing their intended efficacy. Here, we address the hypothesis that the local-scale benefits resulting from MPAs moderate coral bleaching under global warming related stress. RESULTS Bayesian analyses reveal that bleaching is expected to occur in both larger and older MPAs when corals are under thermal stress from marine heatwaves (quantified as Degree Heating Weeks, DHW), but this is partially moderated in comparison to the effects of DHW alone. Further analyses failed to identify differences in bleaching prevalence in MPAs relative to non-MPAs for coral reefs experiencing different levels of thermal stress. Finally, no difference in temperatures where bleaching occurs between MPA and non-MPA sites was found. CONCLUSIONS Our findings suggest that bleaching is likely to occur under global warming regardless of protected status. Thus, while protected areas have key roles for maintaining ecosystem function and local livelihoods, combatting the source of global warming remains the best way to prevent the decline of coral reefs via coral bleaching.
Collapse
Affiliation(s)
- Jack V Johnson
- Macrobiodiversity Lab, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK
| | - Jaimie T A Dick
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK
| | - Daniel Pincheira-Donoso
- Macrobiodiversity Lab, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK.
| |
Collapse
|
26
|
Luo Y, Huang L, Lei X, Yu X, Liu C, Jiang L, Sun Y, Cheng M, Gan J, Zhang Y, Zhou G, Liu S, Lian J, Huang H. Light availability regulated by particulate organic matter affects coral assemblages on a turbid fringing reef. MARINE ENVIRONMENTAL RESEARCH 2022; 177:105613. [PMID: 35429821 DOI: 10.1016/j.marenvres.2022.105613] [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: 09/16/2021] [Revised: 12/08/2021] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Recently, increasing evidence suggests that reef-building corals exposed to elevated suspended solids (SS) are largely structured by changes in underwater light availability (ULA). However, there are few direct and quantitative observations in situ support for this hypothesis; in particular, the contribution of SS to the diffuse attenuation coefficient of the photosynthetically active radiation (Kd-PAR) variations is not yet fully understood. Here, we investigated the variations in ULA, the structure of coral assemblages, and the concentration and composition of SS on the Luhuitou fringing reef, Sanya, China. Light attenuation was rapid (Kd-PAR: 0.60 ± 0.39 m-1) resulting in a shallow euphotic depth (Zeu-PAR) (<11 m). Benthic PAR showed significant positive correlations with branching and corymbose corals (e.g. Acropora spp.), while massive and encrusting species (e.g. Porites spp.) dominated the coral communities and showed no significant correlations with PAR. These results indicate that the depth range available for coral growth is shallow and the tolerance to low-light stress differs among coral species. Notably, Kd-PAR showed no significant correlations with the grain size fractions of SS, whereas significant positive correlations were found with its organic fraction content, demonstrating that the light attenuation of SS is mainly regulated by particulate organic matter (POM). Intriguingly, our isotopic evidence revealed that POM concentration contributed the most to changes in Kd-PAR, with its source being slightly less important. Combined, our results highlight ULA regulated by POM is an important factor in contributing to changes in coral assemblages on inshore turbid reefs, and reducing the input of terrestrial materials, especially POM, is an effective measure to alleviate the low-light stress on sensitive coral species.
Collapse
Affiliation(s)
- Yong Luo
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lintao Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xinming Lei
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Xiaolei Yu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chengyue Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Lei Jiang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Youfang Sun
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Meng Cheng
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianfeng Gan
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuyang Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Guowei Zhou
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Sheng Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Jiansheng Lian
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Southern Marine Science and Engineering Guangdong Laboratory Guangzhou, Guangzhou, 511458, China
| | - Hui Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China; Sanya National Marine Ecosystem Research Station, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
27
|
Herrán N, Narayan GR, Doo SS, Klicpera A, Freiwald A, Westphal H. High-resolution imaging sheds new light on a multi-tier symbiotic partnership between a "walking" solitary coral, a sipunculan, and a bivalve from East Africa. Ecol Evol 2022; 12:e8633. [PMID: 35342582 PMCID: PMC8928893 DOI: 10.1002/ece3.8633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/19/2022] [Accepted: 01/25/2022] [Indexed: 01/19/2023] Open
Abstract
Marine symbioses are integral to the persistence of ecosystem functioning in coral reefs. Solitary corals of the species Heteropsammia cochlea and Heterocyathus aequicostatus have been observed to live in symbiosis with the sipunculan worm Aspidosiphon muelleri muelleri, which inhabits a cavity within the coral, in Zanzibar (Tanzania). The symbiosis of these photosymbiotic corals enables the coral holobiont to move, in fine to coarse unconsolidated substrata, a process termed as "walking." This allows the coral to escape sediment cover in turbid conditions which is crucial for these light-dependent species. An additional commensalistic symbiosis of this coral-worm holobiont is found between the Aspidosiphon worm and the cryptoendolithic bivalve Jousseaumiella sp., which resides within the cavity of the coral skeleton. To understand the morphological alterations caused by these symbioses, interspecific relationships, with respect to the carbonate structures between these three organisms, are documented using high-resolution imaging techniques (scanning electron microscopy and µCT scanning). Documenting multi-layered symbioses can shed light on how morphological plasticity interacts with environmental conditions to contribute to species persistence.
Collapse
Affiliation(s)
- Natalia Herrán
- Leibniz Centre for Tropical Marine Ecology (ZMT)BremenGermany
- Department of Geosciences (FB5)University of BremenBremenGermany
- Leibniz Institute for Baltic Sea Research WarnemündeWarnemündeGermany
| | - Gita R. Narayan
- Leibniz Centre for Tropical Marine Ecology (ZMT)BremenGermany
| | - Steve S. Doo
- Leibniz Centre for Tropical Marine Ecology (ZMT)BremenGermany
- King Abdullah University of Science and Technology (KAUST)ThuwalSaudi Arabia
| | - André Klicpera
- Leibniz Centre for Tropical Marine Ecology (ZMT)BremenGermany
- Microtrac Retsch GmbHBitterfeldGermany
| | - André Freiwald
- Department of Geosciences (FB5)University of BremenBremenGermany
- Senckenberg am Meer (SaM)WilhelmshavenGermany
| | - Hildegard Westphal
- Leibniz Centre for Tropical Marine Ecology (ZMT)BremenGermany
- Department of Geosciences (FB5)University of BremenBremenGermany
- King Abdullah University of Science and Technology (KAUST)ThuwalSaudi Arabia
| |
Collapse
|
28
|
Dong S, Lei Y, Bi H, Xu K, Li T, Jian Z. Biological Response of Planktic Foraminifera to Decline in Seawater pH. BIOLOGY 2022; 11:biology11010098. [PMID: 35053097 PMCID: PMC8773009 DOI: 10.3390/biology11010098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/30/2021] [Accepted: 01/05/2022] [Indexed: 11/16/2022]
Abstract
Understanding the way in which a decline in ocean pH can affect calcareous organisms could enhance our ability to predict the impacts of the potential decline in seawater pH on marine ecosystems, and could help to reconstruct the paleoceanographic events over a geological time scale. Planktic foraminifera are among the most important biological proxies for these studies; however, the existing research on planktic foraminifera is almost exclusively based on their geochemical indices, without the inclusion of information on their biological development. Through a series of on-board experiments in the western tropical Pacific (134°33′54″ E, 12°32′47″ N), the present study showed that the symbiont-bearing calcifier Trilobatus sacculifer—a planktic foraminifer—responded rapidly to a decline in seawater pH, including losing symbionts, bleaching, etc. Several indices were established to quantify the relationships between these biological parameters and seawater pH, which could be used to reconstruct the paleoceanographic seawater pH. We further postulated that the loss of symbionts in planktic foraminifera acts as an adaptive response to the stress of low pH. Our results indicate that an ongoing decline in seawater pH may hinder the growth and calcification of planktic foraminifera by altering their biological processes. A reduction in carbonate deposition and predation could have profound effects on the carbon cycle and energy flow in the marine food web.
Collapse
Affiliation(s)
- Shuaishuai Dong
- Laboratory of Marine Organism Taxonomy and Phylogeny, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (S.D.); (K.X.)
| | - Yanli Lei
- Laboratory of Marine Organism Taxonomy and Phylogeny, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (S.D.); (K.X.)
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (Y.L.); (T.L.); (Z.J.)
| | - Hongsheng Bi
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomon, MD 20688, USA;
| | - Kuidong Xu
- Laboratory of Marine Organism Taxonomy and Phylogeny, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (S.D.); (K.X.)
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tiegang Li
- Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
- Correspondence: (Y.L.); (T.L.); (Z.J.)
| | - Zhimin Jian
- State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
- Correspondence: (Y.L.); (T.L.); (Z.J.)
| |
Collapse
|
29
|
Santodomingo N, Perry C, Waheed Z, Syed Hussein MAB, Rosedy A, Johnson KG. Marine litter pollution on coral reefs of Darvel Bay (East Sabah, Malaysia). MARINE POLLUTION BULLETIN 2021; 173:112998. [PMID: 34624630 DOI: 10.1016/j.marpolbul.2021.112998] [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: 05/02/2021] [Revised: 07/29/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Marine litter is recognized as an increasing component of marine ecosystem pollution. In this baseline study, we document the magnitude, types, sources, and potential impacts of litter on six coral reefs in East Sabah. We applied a simplified classification of litter to extract abundance data from video transects. The average density was 10.7 items per 100 m2. Plastics represent 91% and the remaining 9% were metal, glass, and wood. Most (~70%) plastics are single-use items derived from dumping. Discarded fishing gear accounts for ~25%. Litter pollution increases closer to urban developments, with Sakar reef having higher densities (51 items per 100 m2), and higher Clean Coast Index (CCI = 10.2, dirty) and higher Plastic Abundance Index (PAI = 4.68) scores. This method could and should be readily integrated into ongoing monitoring programs to support assessments of the extent and magnitude of marine litter pollution on reefs worldwide.
Collapse
Affiliation(s)
- Nadiezhda Santodomingo
- Department of Earth Sciences, Natural History Museum, Cromwell Road, SW7 5BD London, United Kingdom.
| | - Chris Perry
- Geography, College of Life & Environmental Sciences, University of Exeter, Rennes Drive, EX4 4RJ Exeter, United Kingdom
| | - Zarinah Waheed
- Borneo Marine Research Institute, University Malaysia Sabah, Kota Kinabalu, Malaysia
| | | | - Allia Rosedy
- Borneo Marine Research Institute, University Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Kenneth G Johnson
- Department of Earth Sciences, Natural History Museum, Cromwell Road, SW7 5BD London, United Kingdom
| |
Collapse
|
30
|
Anthropogenic pressures and life history predict trajectories of seagrass meadow extent at a global scale. Proc Natl Acad Sci U S A 2021; 118:2110802118. [PMID: 34725160 PMCID: PMC8609331 DOI: 10.1073/pnas.2110802118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/17/2021] [Indexed: 12/14/2022] Open
Abstract
Seagrass meadows are threatened by multiple pressures, jeopardizing the many benefits they provide to humanity and biodiversity, including climate regulation and food provision through fisheries production. Conservation of seagrass requires identification of the main pressures contributing to loss and the regions most at risk of ongoing loss. Here, we model trajectories of seagrass change at the global scale and show they are related to multiple anthropogenic pressures but that trajectories vary widely with seagrass life-history strategies. Rapidly declining trajectories of seagrass meadow extent (>25% loss from 2000 to 2010) were most strongly associated with high pressures from destructive demersal fishing and poor water quality. Conversely, seagrass meadow extent was more likely to be increasing when these two pressures were low. Meadows dominated by seagrasses with persistent life-history strategies tended to have slowly changing or stable trajectories, while those with opportunistic species were more variable, with a higher probability of either rapidly declining or rapidly increasing. Global predictions of regions most at risk for decline show high-risk areas in Europe, North America, Japan, and southeast Asia, including places where comprehensive long-term monitoring data are lacking. Our results highlight where seagrass loss may be occurring unnoticed and where urgent conservation interventions are required to reverse loss and sustain their essential services.
Collapse
|
31
|
Bollati E, Rosenberg Y, Simon-Blecher N, Tamir R, Levy O, Huang D. Untangling the molecular basis of coral response to sedimentation. Mol Ecol 2021; 31:884-901. [PMID: 34738686 DOI: 10.1111/mec.16263] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 12/23/2022]
Abstract
Urbanized coral reefs are often chronically affected by sedimentation and reduced light levels, yet many species of corals appear to be able to thrive under these highly disturbed conditions. Recently, these marginal ecosystems have gained attention as potential climate change refugia due to the shading effect of suspended sediment, as well as potential reservoirs for stress-tolerant species. However, little research exists on the impact of sedimentation on coral physiology, particularly at the molecular level. Here, we investigated the transcriptomic response to sediment stress in corals of the family Merulinidae from a chronically turbid reef (one genet each of Goniastrea pectinata and Mycedium elephantotus from Singapore) and a clear-water reef (multiple genets of G. pectinata from the Gulf of Aqaba/Eilat). In two ex-situ experiments, we exposed corals to either natural sediment or artificial sediment enriched with organic matter and used whole-transcriptome sequencing (RNA sequencing) to quantify gene expression. Analysis revealed a shared basis for the coral transcriptomic response to sediment stress, which involves the expression of genes broadly related to energy metabolism and immune response. In particular, sediment exposure induced upregulation of anaerobic glycolysis and glyoxylate bypass enzymes, as well as genes involved in hydrogen sulphide metabolism and in pathogen pattern recognition. Our results point towards hypoxia as a probable driver of this transcriptomic response, providing a molecular basis to previous work that identified hypoxia as a primary cause of tissue necrosis in sediment-stressed corals. Potential metabolic and immunity trade-offs of corals living under chronic sedimentation should be considered in future studies on the ecology and conservation of turbid reefs.
Collapse
Affiliation(s)
- Elena Bollati
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Department of Biology, Marine Biology Section, University of Copenhagen, Helsingør, Denmark
| | - Yaeli Rosenberg
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Noa Simon-Blecher
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Raz Tamir
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
| | - Oren Levy
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
| | - Danwei Huang
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Tropical Marine Science Institute, National University of Singapore, Singapore, Singapore.,Centre for Nature-based Climate Solutions, National University of Singapore, Singapore, Singapore
| |
Collapse
|
32
|
Lesser MP. Eutrophication on Coral Reefs: What Is the Evidence for Phase Shifts, Nutrient Limitation and Coral Bleaching. Bioscience 2021. [DOI: 10.1093/biosci/biab101] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Coral reefs continue to experience extreme environmental pressure from climate change stressors, but many coral reefs are also exposed to eutrophication. It has been proposed that changes in the stoichiometry of ambient nutrients increase the mortality of corals, whereas eutrophication may facilitate phase shifts to macroalgae-dominated coral reefs when herbivory is low or absent. But are corals ever nutrient limited, and can eutrophication destabilize the coral symbiosis making it more sensitive to environmental stress because of climate change? The effects of eutrophication are confounded not just by the effects of climate change but by the presence of chemical pollutants in industrial, urban, and agricultural wastes. Because of these confounding effects, the increases in nutrients or changes in their stoichiometry in coastal environments, although they are important at the organismal and community level, cannot currently be disentangled from each other or from the more significant effects of climate change stressors on coral reefs.
Collapse
Affiliation(s)
- Michael P Lesser
- University of New Hampshire, Durham, New Hampshire, United States
| |
Collapse
|
33
|
Canto MM, Fabricius KE, Logan M, Lewis S, McKinna LIW, Robson BJ. A benthic light index of water quality in the Great Barrier Reef, Australia. MARINE POLLUTION BULLETIN 2021; 169:112539. [PMID: 34153875 DOI: 10.1016/j.marpolbul.2021.112539] [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: 11/22/2020] [Revised: 04/15/2021] [Accepted: 05/19/2021] [Indexed: 06/13/2023]
Abstract
Good water quality is essential to the health of marine ecosystems, yet current metrics used to track water quality in the Great Barrier Reef are not strongly tied to ecological outcomes. There is a need for a better water quality index (WQI). Benthic irradiance, the amount of light reaching the seafloor, is critical for coral and seagrass health and is strongly affected by water quality. It therefore represents a strong candidate for use as a water quality indicator. Here, we introduce a new index based on remote sensing benthic light (bPAR) from ocean color. Resulting bPAR index timeseries, based on the extent to which the observed bPAR fell short of the locally- and seasonally-specific optimum, showed strong spatial and temporal variability, which was consistent with the dynamics that govern changes in water clarity in the Great Barrier Reef. Our new index is ecologically relevant, responsive to changes in light availability and provides a robust metric that may complement current Great Barrier Reef water quality metrics.
Collapse
Affiliation(s)
- Marites M Canto
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; Australian Institute of Marine Science, PMB3, Townsville MC, QLD 4810, Australia; AIMS@JCU, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia.
| | - Katharina E Fabricius
- Australian Institute of Marine Science, PMB3, Townsville MC, QLD 4810, Australia; AIMS@JCU, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - Murray Logan
- Australian Institute of Marine Science, PMB3, Townsville MC, QLD 4810, Australia
| | - Stephen Lewis
- Centre for Tropical Water and Aquatic Ecosystem Research, Catchment to Reef Research Group, James Cook University, Townsville, QLD 4811, Australia
| | - Lachlan I W McKinna
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; Go2Q Pty Ltd, Sunshine Coast, QLD 4556, Australia
| | - Barbara J Robson
- Australian Institute of Marine Science, PMB3, Townsville MC, QLD 4810, Australia; AIMS@JCU, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| |
Collapse
|
34
|
Carlson RR, Evans LJ, Foo SA, Grady BW, Li J, Seeley M, Xu Y, Asner GP. Synergistic benefits of conserving land-sea ecosystems. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01684] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
|
35
|
Gonzalez-Espinosa PC, Donner SD. Cloudiness reduces the bleaching response of coral reefs exposed to heat stress. GLOBAL CHANGE BIOLOGY 2021; 27:3474-3486. [PMID: 33964101 DOI: 10.1111/gcb.15676] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/25/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
Climate change and warming ocean temperatures are a threat to coral reef ecosystems. Since the 1980s, there has been an increase in mass coral bleaching and associated coral mortality due to more frequent and severe thermal stress. Although most research has focused on the role of temperature, coral bleaching is a product of the interacting effects of temperature and other environmental variables such as solar radiation. High light exacerbates the effects of thermal stress on corals, whereas reductions in light can reduce sensitivity to thermal stress. Here, we use an updated global dataset of coral bleaching observations (n = 35,769) from 1985 to 2017 and satellite-derived datasets of SST and clouds to examine for the first time at a global scale the influence of cloudiness on the likelihood of bleaching from thermal stress. We find that among coral reefs exposed to severe bleaching-level heat stress (Degree Heating Weeks >8°Cˑweek), bleaching severity is inversely correlated with the interaction of heat stress and cloud fraction anomalies (p < 0.05), such that higher cloudiness implies reduced bleaching response. A Random Forest model analysis employing different set of environmental variables shows that a model employing Degree Heating Weeks and the 30-day cloud fraction anomaly most accurately predicts bleaching severity (Accuracy = 0.834; Cohen's Kappa = 0.769). Based on these results and global warm-season cloudiness patterns, we develop a 'cloudy refugia' index which identifies the central equatorial Pacific and French Polynesia as regions where cloudiness is most likely to protect corals from bleaching. Our findings suggest that incorporating cloudiness into prediction models can help delineate bleaching responses and identify reefs which may be more resilient to climate change.
Collapse
Affiliation(s)
- Pedro C Gonzalez-Espinosa
- Department of Geography, University of British Columbia, Vancouver, BC, Canada
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
| | - Simon D Donner
- Department of Geography, University of British Columbia, Vancouver, BC, Canada
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
36
|
The Effects of Temperature, Light, and Feeding on the Physiology of Pocillopora damicornis, Stylophora pistillata, and Turbinaria reniformis Corals. WATER 2021. [DOI: 10.3390/w13152048] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Evidence has shown that individually feeding or reduced light can mitigate the negative effects of elevated temperature on coral physiology. We aimed to evaluate if simultaneous low light and feeding would mitigate, minimize, or exacerbate negative effects of elevated temperature on coral physiology and carbon budgets. Pocillopora damicornis, Stylophora pistillata, and Turbinaria reniformis were grown for 28 days under a fully factorial experiment including two seawater temperatures (ambient temperature of 25 °C, elevated temperature of 30 °C), two light levels (high light of 300 μmol photons m−2 s−1, low light of 150 μmol photons m−2 s−1), and either fed (Artemia nauplii) or unfed. Coral physiology was significantly affected by temperature in all species, but the way in which low light and feeding altered their physiological responses was species-specific. All three species photo-acclimated to low light by increasing chlorophyll a. Pocillopora damicornis required feeding to meet metabolic demand irrespective of temperature but was unable to maintain calcification under low light when fed. In T. reniformis, low light mitigated the negative effect of elevated temperature on total lipids, while feeding mitigated the negative effects of elevated temperature on metabolic demand. In S. pistillata, low light compounded the negative effects of elevated temperature on metabolic demand, while feeding minimized this negative effect but was not sufficient to provide 100% metabolic demand. Overall, low light and feeding did not act synergistically, nor additively, to mitigate the negative effects of elevated temperature on P. damicornis, S. pistillata, or T. reniformis. However, feeding alone was critical to the maintenance of metabolic demand at elevated temperature, suggesting that sufficient supply of heterotrophic food sources is likely essential for corals during thermal stress (bleaching) events.
Collapse
|
37
|
Baird ME, Mongin M, Rizwi F, Bay LK, Cantin NE, Morris LA, Skerratt J. The effect of natural and anthropogenic nutrient and sediment loads on coral oxidative stress on runoff-exposed reefs. MARINE POLLUTION BULLETIN 2021; 168:112409. [PMID: 33957497 DOI: 10.1016/j.marpolbul.2021.112409] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 04/16/2021] [Accepted: 04/17/2021] [Indexed: 06/12/2023]
Abstract
Recently, corals on the Great Barrier (GBR) have suffered mass bleaching. The link between ocean warming and coral bleaching is understood to be due to temperature-dependence of complex physiological processes in the coral host and algal symbiont. Here we use a coupled catchment-hydrodynamic-biogeochemical model, with detailed zooxanthellae photophysiology including photoadaptation, photoacclimation and reactive oxygen build-up, to investigate whether natural and anthropogenic catchment loads impact on coral bleaching on the GBR. For the wet season of 2017, simulations show the cross-shelf water quality gradient, driven by both natural and anthropogenic loads, generated a contrasting zooxanthellae physiological state on inshore versus mid-shelf reefs. The relatively small catchment flows and loads delivered during 2017, however, generated small river plumes with limited impact on water quality. Simulations show the removal of the anthropogenic fraction of the catchment loads delivered in 2017 would have had a negligible impact on bleaching rates.
Collapse
Affiliation(s)
- Mark E Baird
- CSIRO Oceans and Atmosphere, Hobart 7001, Australia.
| | | | - Farhan Rizwi
- CSIRO Oceans and Atmosphere, Hobart 7001, Australia
| | - Line K Bay
- Australian Institute of Marine Science, Townsville 4810, Australia
| | - Neal E Cantin
- Australian Institute of Marine Science, Townsville 4810, Australia
| | - Luke A Morris
- Australian Institute of Marine Science, Townsville 4810, Australia; AIMS@JCU, Australian Institute of Marine Science, College of Science and Engineering, Townsville 4811, Australia; College of Science and Engineering, James Cook University, Townsville 4811, Australia
| | | |
Collapse
|
38
|
Ranjbar Jafarabadi A, Dashtbozorg M, Raudonytė-Svirbutavičienė E, Riyahi Bakhtiari A. A potential threat to the coral reef environments: Polybrominated diphenyl ethers and phthalate esters in the corals and their ambient environment (Persian Gulf, Iran). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 775:145822. [PMID: 33631596 DOI: 10.1016/j.scitotenv.2021.145822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/08/2021] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
Pollution of the surrounding habitat poses one of the biggest threats to the coral health and even survival. This study focuses on the occurrence, distribution, bioaccumulation and bioconcentration of polybrominated diphenyl ethers (PBDEs) and phthalate esters (PAEs) in corals, their zooxanthellae and mucus, as well as in their ambient environment in Larak coral reef (Persian Gulf) for the first time. The highest concentrations of the pollutants were recorded in mucus, followed by zooxanthellae, tissue and skeleton. Soft corals with higher lipid content contained more PBDEs and PAEs. Pollutants were both efficiently bioconcentrated from water and bioaccumulated from the ambient sediment, albeit bioconcentration played the most prominent role. Elevated PBDEs and especially PAEs concentrations were detected in the skeletons of the bleached corals if compared to the skeleton samples of the non-bleached individuals.
Collapse
Affiliation(s)
- Ali Ranjbar Jafarabadi
- Department of Environmental Sciences, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran.
| | - Mehdi Dashtbozorg
- Department of Environmental Science, Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | | | - Alireza Riyahi Bakhtiari
- Department of Environmental Sciences, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran.
| |
Collapse
|
39
|
Toth LT, Precht WF, Modys AB, Stathakopoulos A, Robbart ML, Hudson JH, Oleinik AE, Riegl BM, Shinn EA, Aronson RB. Climate and the latitudinal limits of subtropical reef development. Sci Rep 2021; 11:13044. [PMID: 34158523 PMCID: PMC8219804 DOI: 10.1038/s41598-021-87883-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/06/2021] [Indexed: 11/09/2022] Open
Abstract
Climate plays a central role in coral-reef development, especially in marginal environments. The high-latitude reefs of southeast Florida are currently non-accreting, relict systems with low coral cover. This region also did not support the extensive Late Pleistocene reef development observed in many other locations around the world; however, there is evidence of significant reef building in southeast Florida during the Holocene. Using 146 radiometric ages from reefs extending ~ 120 km along Florida's southeast coast, we test the hypothesis that the latitudinal extent of Holocene reef development in this region was modulated by climatic variability. We demonstrate that although sea-level changes impacted rates of reef accretion and allowed reefs to backstep inshore as new habitats were flooded, sea level was not the ultimate cause of reef demise. Instead, we conclude that climate was the primary driver of the expansion and contraction of Florida's reefs during the Holocene. Reefs grew to 26.7° N in southeast Florida during the relatively warm, stable climate at the beginning of the Holocene Thermal Maximum (HTM) ~ 10,000 years ago, but subsequent cooling and increased frequency of winter cold fronts were associated with the equatorward contraction of reef building. By ~ 7800 years ago, actively accreting reefs only extended to 26.1° N. Reefs further contracted to 25.8° N after 5800 years ago, and by 3000 years ago reef development had terminated throughout southern Florida (24.5-26.7° N). Modern warming is unlikely to simply reverse this trend, however, because the climate of the Anthropocene will be fundamentally different from the HTM. By increasing the frequency and intensity of both warm and cold extreme-weather events, contemporary climate change will instead amplify conditions inimical to reef development in marginal reef environments such as southern Florida, making them more likely to continue to deteriorate than to resume accretion in the future.
Collapse
Affiliation(s)
- Lauren T Toth
- U.S. Geological Survey St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL, USA.
| | - William F Precht
- Marine and Coastal Programs, Dial Cordy & Associates, Inc., Miami, FL, USA
| | - Alexander B Modys
- Department of Geosciences, Florida Atlantic University, Boca Raton, FL, USA
| | | | - Martha L Robbart
- Marine and Coastal Programs, Dial Cordy & Associates, Inc., Miami, FL, USA.,Independent Consultant, Glenmont, NY, USA
| | | | - Anton E Oleinik
- Department of Geosciences, Florida Atlantic University, Boca Raton, FL, USA
| | - Bernhard M Riegl
- Department of Marine and Environmental Sciences, Nova Southeastern University, Dania Beach, FL, USA
| | - Eugene A Shinn
- College of Marine Science, University of South Florida, St. Petersburg, FL, 33701, USA
| | - Richard B Aronson
- Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, Melbourne, FL, USA
| |
Collapse
|
40
|
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.
Collapse
|
41
|
Donovan MK, Burkepile DE, Kratochwill C, Shlesinger T, Sully S, Oliver TA, Hodgson G, Freiwald J, van Woesik R. Local conditions magnify coral loss after marine heatwaves. Science 2021; 372:977-980. [PMID: 34045353 DOI: 10.1126/science.abd9464] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 03/25/2021] [Indexed: 11/02/2022]
Abstract
Climate change threatens coral reefs by causing heat stress events that lead to widespread coral bleaching and mortality. Given the global nature of these mass coral mortality events, recent studies argue that mitigating climate change is the only path to conserve coral reefs. Using a global analysis of 223 sites, we show that local stressors act synergistically with climate change to kill corals. Local factors such as high abundance of macroalgae or urchins magnified coral loss in the year after bleaching. Notably, the combined effects of increasing heat stress and macroalgae intensified coral loss. Our results offer an optimistic premise that effective local management, alongside global efforts to mitigate climate change, can help coral reefs survive the Anthropocene.
Collapse
Affiliation(s)
- Mary K Donovan
- Center for Global Discovery and Conservation Science and School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, AZ 85281, USA.
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Deron E Burkepile
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Chelsey Kratochwill
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL 32901, USA
| | - Tom Shlesinger
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL 32901, USA
| | - Shannon Sully
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL 32901, USA
| | - Thomas A Oliver
- Ecosystem Sciences Division, Pacific Islands Fisheries Science Center, NOAA Fisheries, Honolulu, HI 96818, USA
| | | | - Jan Freiwald
- Reef Check Foundation, Marina del Rey, CA 90292, USA
- Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA
| | - Robert van Woesik
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL 32901, USA
| |
Collapse
|
42
|
Sweet M, Burian A, Bulling M. Corals as canaries in the coalmine: Towards the incorporation of marine ecosystems into the 'One Health' concept. J Invertebr Pathol 2021; 186:107538. [PMID: 33545133 DOI: 10.1016/j.jip.2021.107538] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/14/2021] [Accepted: 01/18/2021] [Indexed: 01/04/2023]
Abstract
'One World - One Health' is a developing concept which aims to explicitly incorporate linkages between the environment and human society into wildlife and human health care. Past work in the field has concentrated on aspects of disease, particularly emerging zoonoses, and focused on terrestrial systems. Here, we argue that marine environments are crucial components of the 'One World - One Health' framework, and that coral reefs are the epitome of its underlying philosophy. That is, they provide vast contributions to a wide range of ecosystem services with strong and direct links to human well-being. Further, the sensitivity of corals to climate change, and the current emergence of a wide range of diseases, make coral reefs ideal study systems to assess links, impacts, and feedback mechanisms that can affect human and ecosystem health. There are well established protocols for monitoring corals, as well as global networks of coral researchers, but there remain substantial challenges to understanding these complex systems, their health and links to provisioning of ecosystem services. We explore these challenges and conclude with a look at how developing technology offers potential ways of addressing them. We argue that a greater integration of coral reef research into the 'One World - One Health' framework will enrich our understanding of the many links within, and between, ecosystems and human society. This will ultimately support the development of measures for improving the health of both humans and the environment.
Collapse
Affiliation(s)
- Michael Sweet
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, UK.
| | - Alfred Burian
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, UK
| | - Mark Bulling
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, UK
| |
Collapse
|
43
|
Quimpo TJR, Requilme JNC, Gomez EJ, Sayco SLG, Tolentino MPS, Cabaitan PC. Low coral bleaching prevalence at the Bolinao-Anda Reef Complex, northwestern Philippines during the 2016 thermal stress event. MARINE POLLUTION BULLETIN 2020; 160:111567. [PMID: 32891963 DOI: 10.1016/j.marpolbul.2020.111567] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 08/03/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Here, we examined the coral bleaching responses during the 2016 thermal stress event and post-bleaching changes in coral communities in the heavily disturbed reefs of the Bolinao-Anda Reef Complex (BARC), northwestern Philippines. Less than 25% of colonies bleached, with 77% attributed to five genera (Dipsastrea, Porites, Fungia, Seriatopora, and Montipora). Coral bleaching prevalence was associated with site location, coral composition, and coral abundance, suggesting that small-scale variation (<20 km) in coral communities (taxa and density) influences spatial variation in coral bleaching prevalence. There was no noticeable change in coral composition and cover two years after the bleaching event as exposure to chronic disturbance likely selected for the dominance of stress tolerant coral taxa and communities. Results show that the 2016 thermal stress event caused coral bleaching but with low prevalence at the BARC, which suggests that disturbed reefs may provide spatial refuge to coral communities from thermal stress.
Collapse
Affiliation(s)
- Timothy Joseph R Quimpo
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines
| | - Jeremiah Noelle C Requilme
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines
| | - Elizabeth J Gomez
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines
| | - Sherry Lyn G Sayco
- The Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines
| | - Mark Paulo S Tolentino
- 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.
| |
Collapse
|
44
|
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.
Collapse
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
| |
Collapse
|
45
|
Morgan KM, Perry CT, Arthur R, Williams HTP, Smithers SG. Projections of coral cover and habitat change on turbid reefs under future sea-level rise. Proc Biol Sci 2020; 287:20200541. [PMID: 32546095 PMCID: PMC7329041 DOI: 10.1098/rspb.2020.0541] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Global sea-level rise (SLR) is projected to increase water depths above coral reefs. Although the impacts of climate disturbance events on coral cover and three-dimensional complexity are well documented, knowledge of how higher sea levels will influence future reef habitat extent and bioconstruction is limited. Here, we use 31 reef cores, coupled with detailed benthic ecological data, from turbid reefs on the central Great Barrier Reef, Australia, to model broad-scale changes in reef habitat following adjustments to reef geomorphology under different SLR scenarios. Model outputs show that modest increases in relative water depth above reefs (Representative Concentration Pathway (RCP) 4.5) over the next 100 years will increase the spatial extent of habitats with low coral cover and generic diversity. More severe SLR (RCP8.5) will completely submerge reef flats and move reef slope coral communities below the euphotic depth, despite the high vertical accretion rates that characterize these reefs. Our findings suggest adverse future trajectories associated with high emission climate scenarios which could threaten turbid reefs globally and their capacity to act as coral refugia from climate change.
Collapse
Affiliation(s)
- Kyle M Morgan
- Asian School of the Environment, Nanyang Technological University, Singapore, Singapore.,School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Chris T Perry
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Rudy Arthur
- Computer Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Hywel T P Williams
- Computer Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Scott G Smithers
- Land and Water Science, College of Science and Engineering, James Cook University, Townsville, Australia
| |
Collapse
|