1
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Muruga P, Siqueira AC, Bellwood DR. Meta-analysis reveals weak associations between reef fishes and corals. Nat Ecol Evol 2024; 8:676-685. [PMID: 38374185 DOI: 10.1038/s41559-024-02334-7] [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: 08/07/2023] [Accepted: 01/18/2024] [Indexed: 02/21/2024]
Abstract
Habitat associations underpin species ecologies in high-diversity systems. Within tropical, shallow water coral reefs, the relationship between fishes and corals is arguably the most iconic and highly scrutinized. A strong relationship between fishes and reef-building hard corals is often assumed, a belief supported by studies that document the decline of reef fishes following coral loss. However, the extent of this relationship is often unclear, as evidenced by conflicting reports. Here we assess the strength of this ecological association by relying on literature that has surveyed both fishes and corals synchronously. We quantitatively synthesize 723 bivariate correlation coefficients (from 66 papers), published over 38 years, that relate fish metrics (abundance, biomass and species richness) with the percentage of hard coral cover. Remarkably, despite extensive variation, the pattern of association on a global scale reveals a predominantly positive, albeit weak (|r| < 0.4), correlation. Even for commonly hypothesized drivers of fish-coral associations, fish family and trophic group, associations were consistently weak. These findings question our assumptions regarding the strength and ubiquity of fish-coral associations, and caution against assuming a direct and omnipresent relationship between these two iconic animal groups.
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Affiliation(s)
- Pooventhran Muruga
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland, Australia.
| | - Alexandre C Siqueira
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
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2
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Engleman A, Cox K, Brooke S. Dead but not forgotten: complexity of Acropora palmata colonies increases with greater composition of dead coral. PeerJ 2023; 11:e16101. [PMID: 37842045 PMCID: PMC10576496 DOI: 10.7717/peerj.16101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 08/25/2023] [Indexed: 10/17/2023] Open
Abstract
Coral reefs are highly biodiverse ecosystems that have declined due to natural and anthropogenic stressors. Researchers often attribute reef ecological processes to corals' complex structure, but effective conservation requires disentangling the contributions of coral versus reef structures. Many studies assessing the relationships between reef structure and ecological dynamics commonly use live coral as a proxy for reef complexity, disregarding the contribution of dead coral skeletons to reef habitat provision or other biogeochemical reef dynamics. This study aimed to assess the contribution of dead coral to reef complexity by examining structural variations in live and dead Acropora palmata colonies. We used photogrammetry to reconstruct digital elevation models (DEMs) and orthomosaics of the benthic region immediately surrounding 10 A. palmata colonies. These reconstructions were used to quantify structural metrics, including surface rugosity, fractal dimension, slope, planform curvature, and profile curvature, as a function of benthic composition (i.e., live A. palmata, dead A. palmata, or non-A. palmata substrate). The results revealed that dead coral maintained more varied profile curvatures and higher fractal dimensions than live or non-coral substrate. Conversely, A. palmata colonies with a higher proportion of live coral displayed more uniform structure, with lower fractal dimensions and less variability in profile curvature measures. Other metrics showed no significant difference among substrate types. These findings provide novel insights into the structural differences between live and dead coral, and an alternative perspective on the mechanisms driving the observed structural complexity on reefs. Overall, our results highlight the overlooked potential contributions of dead coral to reef habitat provision, ecological processes, and other biogeochemical reef dynamics, and could have important implications for coral reef conservation.
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Affiliation(s)
- Abigail Engleman
- Department of Biological Science, Florida State University, Tallahassee, United States of America
- Coastal and Marine Laboratory, Florida State University, St. Teresa, FL, United States of America
- Marine Station, Smithsonian, Fort Pierce, FL, United States of America
| | - Kieran Cox
- Marine Station, Smithsonian, Fort Pierce, FL, United States of America
- Biology Department, University of Victoria, Victoria, British Columbia, Canada
- Hakai Institute, Calvert Island, British Columbia, Canada
| | - Sandra Brooke
- Coastal and Marine Laboratory, Florida State University, St. Teresa, FL, United States of America
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3
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Perry CT, Salter MA, Lange ID, Kochan DP, Harborne AR, Graham NAJ. Geo‐ecological functions provided by coral reef fishes vary among regions and impact reef carbonate cycling regimes. Ecosphere 2022. [DOI: 10.1002/ecs2.4288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Chris T. Perry
- Geography, Faculty of Environment, Science & Economy University of Exeter Exeter UK
| | - Michael A. Salter
- Geography, Faculty of Environment, Science & Economy University of Exeter Exeter UK
| | - Ines D. Lange
- Geography, Faculty of Environment, Science & Economy University of Exeter Exeter UK
| | - David P. Kochan
- Institute of Environment & Department of Biological Sciences Florida International University North Miami Florida USA
| | - Alastair R. Harborne
- Institute of Environment & Department of Biological Sciences Florida International University North Miami Florida USA
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4
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Collins WP, Bellwood DR, Morais RA. The role of nocturnal fishes on coral reefs: A quantitative functional evaluation. Ecol Evol 2022; 12:e9249. [PMID: 36052298 PMCID: PMC9412246 DOI: 10.1002/ece3.9249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/01/2022] [Accepted: 07/08/2022] [Indexed: 11/25/2022] Open
Abstract
The ecological functions of nocturnal coral reef fishes are poorly known. Yet, nocturnal resources for coral reef consumers are theoretically as abundant and productive, if not more so, than their diurnal counterparts. In this study, we quantify and contrast the energetic dynamics of nocturnal and diurnal fishes in a model coral reef ecosystem, evaluating whether they attain similar levels of biomass production. We integrated a detailed dataset of coral reef fish counts, comprising diurnal and nocturnal species, in sites sheltered and exposed to wave action. We combined somatic growth and mortality models to estimate rates of consumer biomass production, a key ecosystem function. We found that diurnal fish assemblages have a higher biomass than nocturnal fishes: 104% more in sheltered sites and 271% more in exposed sites. Differences in productivity were even more pronounced, with diurnal fishes contributing 163% more productivity in sheltered locations, and 558% more in exposed locations. Apogonidae dominated biomass production within the nocturnal fish assemblage, comprising 54% of total nocturnal fish productivity, which is proportionally more than any diurnal fish family. The substantially lower contributions of nocturnal fishes to biomass and biomass production likely indicate constraints on resource accessibility. Taxa that overcome these constraints may thrive, as evidenced by apogonids. This study highlights the importance of nocturnal fishes in underpinning the flow of energy and nutrients from nocturnal resources to reef communities; a process driven mainly by small, cryptic fishes.
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Affiliation(s)
- William P. Collins
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland Australia
| | - David R. Bellwood
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland Australia
| | - Renato A. Morais
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland Australia
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5
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Tsai CH, Sweatman HPA, Thibaut LM, Connolly SR. Volatility in coral cover erodes niche structure, but not diversity, in reef fish assemblages. SCIENCE ADVANCES 2022; 8:eabm6858. [PMID: 35704577 PMCID: PMC9200288 DOI: 10.1126/sciadv.abm6858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 05/02/2022] [Indexed: 05/26/2023]
Abstract
The world's coral reefs are experiencing increasing volatility in coral cover, largely because of anthropogenic environmental change, highlighting the need to understand how such volatility will influence the structure and dynamics of reef assemblages. These changes may influence not only richness or evenness but also the temporal stability of species' relative abundances (temporal beta-diversity). Here, we analyzed reef fish assemblage time series from the Great Barrier Reef to show that, overall, 75% of the variance in abundance among species was attributable to persistent differences in species' long-term mean abundances. However, the relative importance of stochastic fluctuations in abundance was higher on reefs that experienced greater volatility in coral cover, whereas it did not vary with drivers of alpha-diversity. These findings imply that increased coral cover volatility decreases temporal stability in relative abundances of fishes, a transformation that is not detectable from static measures of biodiversity.
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Affiliation(s)
- Cheng-Han Tsai
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
- Australian Institute of Marine Science, Townsville MC, QLD 4810, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, Townsville, QLD 4811, Australia
| | | | - Loïc M. Thibaut
- School of Mathematics and Statistics, University of New South Wales, Sydney, NSW 2052, Australia
- Centre for Population Genomics, Garvan Institute of Medical Research and UNSW Sydney, Sydney, NSW, Australia
- Centre for Population Genomics, Murdoch Children’s Research Institute, Melbourne, VIC, Australia
| | - Sean R. Connolly
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, Townsville, QLD 4811, Australia
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
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6
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Tebbett SB, Morais J, Bellwood DR. Spatial patchiness in change, recruitment, and recovery on coral reefs at Lizard Island following consecutive bleaching events. MARINE ENVIRONMENTAL RESEARCH 2022; 173:105537. [PMID: 34837738 DOI: 10.1016/j.marenvres.2021.105537] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/16/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
The world's coral reef ecosystems are steadily being reconfigured by climate change. Lizard Island, on Australia's Great Barrier Reef, offers an opportunity to examine coral reef reassembly following disturbance, as this location has been impacted by consecutive tropical cyclones and consecutive coral bleaching events. Based on repeatedly monitoring the same 349 photoquadrats around Lizard Island over a 5-year period (2016-2021) we revealed that bleaching in 2016 drove a ∼50% reduction in hard coral cover, and a concomitant increase in algal turf cover. From 2018 to 2021, significant increases (>600%) in coral cover were detected on two semi-exposed reefs and were associated with substantial Acropora recruitment. By contrast, fourteen lagoonal and back reefs exhibited virtually no recovery nor Acropora recruitment. Given that the timeframe between disturbances is set to decrease, our results suggest that some recovery is possible immediately after severe cumulative disturbances, although this recovery may be highly spatially heterogenous.
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Affiliation(s)
- Sterling B Tebbett
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia.
| | - Juliano Morais
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia
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7
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Castejón‐Silvo I, Terrados J, Nguyen T, Jutfelt F, Infantes E. Increased energy expenditure is an indirect effect of habitat structural complexity loss. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Inés Castejón‐Silvo
- Mediterranean Institute for Advanced StudiesIMEDEA (CSIC‐UIB) Esporles Spain
| | - Jorge Terrados
- Mediterranean Institute for Advanced StudiesIMEDEA (CSIC‐UIB) Esporles Spain
| | - Thanh Nguyen
- Department of Marine Sciences Gothenburg University Kristineberg Sweden
| | - Fredrik Jutfelt
- Department of Biology Norwegian University of Science and Technology Trondheim Norway
| | - Eduardo Infantes
- Department of Marine Sciences Gothenburg University Kristineberg Sweden
- Norwegian Institute for Water Research Oslo Norway
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8
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Dangerous demographics in post-bleach corals reveal boom-bust versus protracted declines. Sci Rep 2021; 11:18787. [PMID: 34552159 PMCID: PMC8458526 DOI: 10.1038/s41598-021-98239-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/03/2021] [Indexed: 11/08/2022] Open
Abstract
Thermal-stress events have changed the structure, biodiversity, and functioning of coral reefs. But how these disturbances affect the dynamics of individual coral colonies remains unclear. By tracking the fate of 1069 individual Acropora and massive Porites coral colonies for up to 5 years, spanning three bleaching events, we reveal striking genus-level differences in their demographic response to bleaching (mortality, growth, and recruitment). Although Acropora colonies were locally extirpated, substantial local recruitment and fast growth revealed a marked capacity for apparent recovery. By contrast, almost all massive Porites colonies survived and the majority grew in area; yet no new colonies were detected over the 5 years. Our results highlight contrasting dynamics of boom-and-bust vs. protracted declines in two major coral groups. These dangerous demographics emphasise the need for caution when documenting the susceptibility and perceived resistance or recovery of corals to disturbances.
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9
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Froehlich CYM, Klanten
OS, Hing ML, Dowton M, Wong MYL. Uneven declines between corals and cryptobenthic fish symbionts from multiple disturbances. Sci Rep 2021; 11:16420. [PMID: 34385506 PMCID: PMC8361158 DOI: 10.1038/s41598-021-95778-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 07/09/2021] [Indexed: 02/07/2023] Open
Abstract
With the onset and increasing frequency of multiple disturbances, the recovery potential of critical ecosystem-building species and their mutual symbionts is threatened. Similar effects to both hosts and their symbionts following disturbances have been assumed. However, we report unequal declines between hosts and symbionts throughout multiple climate-driven disturbances in reef-building Acropora corals and cryptobenthic coral-dwelling Gobiodon gobies. Communities were surveyed before and after consecutive cyclones (2014, 2015) and heatwaves (2016, 2017). After cyclones, coral diameter and goby group size (i.e., the number of gobies within each coral) decreased similarly by 28-30%. After heatwave-induced bleaching, coral diameter decreased substantially (47%) and gobies mostly inhabited corals singly. Despite several coral species persisting after bleaching, all goby species declined, leaving 78% of corals uninhabited. These findings suggest that gobies, which are important mutual symbionts for corals, are unable to cope with consecutive disturbances. This disproportionate decline could lead to ecosystem-level disruptions through loss of key symbiont services to corals.
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Affiliation(s)
- Catheline Y. M. Froehlich
- grid.1007.60000 0004 0486 528XFaculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2500 Australia
| | - O. Selma Klanten
- grid.117476.20000 0004 1936 7611School of Life Sciences, University of Technology Sydney, Sydney, NSW 2007 Australia
| | - Martin L. Hing
- grid.1007.60000 0004 0486 528XFaculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2500 Australia
| | - Mark Dowton
- grid.1007.60000 0004 0486 528XFaculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2500 Australia
| | - Marian Y. L. Wong
- grid.1007.60000 0004 0486 528XFaculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2500 Australia
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10
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Brandl SJ, Johansen JL, Casey JM, Tornabene L, Morais RA, Burt JA. Extreme environmental conditions reduce coral reef fish biodiversity and productivity. Nat Commun 2020; 11:3832. [PMID: 32737315 PMCID: PMC7395083 DOI: 10.1038/s41467-020-17731-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/10/2020] [Indexed: 12/11/2022] Open
Abstract
Tropical ectotherms are hypothesized to be vulnerable to environmental changes, but cascading effects of organismal tolerances on the assembly and functioning of reef fish communities are largely unknown. Here, we examine differences in organismal traits, assemblage structure, and productivity of cryptobenthic reef fishes between the world’s hottest, most extreme coral reefs in the southern Arabian Gulf and the nearby, but more environmentally benign, Gulf of Oman. We show that assemblages in the Arabian Gulf are half as diverse and less than 25% as abundant as in the Gulf of Oman, despite comparable benthic composition and live coral cover. This pattern appears to be driven by energetic deficiencies caused by responses to environmental extremes and distinct prey resource availability rather than absolute thermal tolerances. As a consequence, production, transfer, and replenishment of biomass through cryptobenthic fish assemblages is greatly reduced on Earth’s hottest coral reefs. Extreme environmental conditions, as predicted for the end of the 21st century, could thus disrupt the community structure and productivity of a critical functional group, independent of live coral loss. Brandl, Johansen et al. compare organismal traits, community structure, and productivity dynamics of cryptobenthic reef fishes across two locations, the Arabian Gulf and the Gulf of Oman, the former of which harbors the world’s hottest coral reefs. They show that environmental extremes in the Arabian Gulf result in dramatically less diverse, abundant, and productive cryptobenthic fish assemblages, which could foreshadow the future of coral reef biodiversity and functioning.
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Affiliation(s)
- Simon J Brandl
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada. .,CESAB-FRB, 5 Rue de l'École de Médecine, 34000, Montpellier, France. .,PSL Université Paris: CNRS-EPHE-UPVD USR3278 CRIOBE, Université de Perpignan, Perpignan, France. .,Laboratoire d'Excellence "CORAIL,", Perpignan, France.
| | - Jacob L Johansen
- Hawai'i Institute of Marine Biology, University of Hawai'i at Manoa, Kane'ohe, HI, USA. .,Marine Biology Laboratory, Centre for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.
| | - Jordan M Casey
- PSL Université Paris: CNRS-EPHE-UPVD USR3278 CRIOBE, Université de Perpignan, Perpignan, France.,Laboratoire d'Excellence "CORAIL,", Perpignan, France
| | - Luke Tornabene
- School of Aquatic and Fishery Sciences and the Burke Museum of Natural History and Culture, University of Washington, Seattle, WA, USA
| | - Renato A Morais
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia.,College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - John A Burt
- Marine Biology Laboratory, Centre for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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