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Riera E, Mauroy B, Francour P, Hubas C. Establishing complexity targets to enhance artificial reef designs. Sci Rep 2024; 14:22060. [PMID: 39333629 PMCID: PMC11436664 DOI: 10.1038/s41598-024-72227-z] [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: 11/27/2023] [Accepted: 09/04/2024] [Indexed: 09/29/2024] Open
Abstract
Artificial reefs (AR), which are integral tools for fish management, ecological reconciliation and restoration efforts, require non-polluting materials and intricate designs that mimic natural habitats. Despite their three-dimensional complexity, current designs nowadays rely on empirical methods that lack standardised pre-immersion assessment. To improve ecosystem integration, we propose to evaluate 3-dimensional Computer-aided Design (3D CAD) models using a method inspired by functional ecology principles. Based on existing metrics, we assess geometric (C-convexity, P-packing, D-fractal dimension) and informational complexity (R-specific richness, H- diversity, J-evenness). Applying these metrics to different reefs constructed for habitat protection, biomass production and bio-mimicry purposes, we identify potential complexity target points (CTPs). This method provides a framework for improving the effectiveness of artificial reef design by allowing for the adjustment of structural properties. These CTPs represent the first step in enhancing AR designs. We can refine them by evaluating complexity metrics derived from 3D reconstructions of natural habitats to advance bio-mimicry efforts. In situ, post-immersion studies can help make the CTPs more specific for certain species of interest by exploring complexity-diversity or complexity-species distribution relationships at the artificial reef scale.
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Affiliation(s)
- Elisabeth Riera
- Université Côte d'Azur, CNRS, ECOSEAS, Parc Valrose, 06108, Nice Cedex 02, France.
- Muséum National d'Histoire Naturelle, UMR 8067 BOREA, MNHN-SU-CNRS-UCN-UA-IRD, Station Marine de Concarneau, Concarneau, France.
| | - Benjamin Mauroy
- Université Côte d'Azur, CNRS, UMR 7351 LJAD, Parc Valrose, 06108, Nice Cedex 02, France
| | - Patrice Francour
- Université Côte d'Azur, CNRS, ECOSEAS, Parc Valrose, 06108, Nice Cedex 02, France
| | - Cédric Hubas
- Muséum National d'Histoire Naturelle, UMR 8067 BOREA, MNHN-SU-CNRS-UCN-UA-IRD, Station Marine de Concarneau, Concarneau, France
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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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Silveira CB, Luque A, Haas AF, Roach TNF, George EE, Knowles B, Little M, Sullivan CJ, Varona NS, Wegley Kelly L, Brainard R, Rohwer F, Bailey B. Viral predation pressure on coral reefs. BMC Biol 2023; 21:77. [PMID: 37038111 PMCID: PMC10088212 DOI: 10.1186/s12915-023-01571-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 03/17/2023] [Indexed: 04/12/2023] Open
Abstract
BACKGROUND Predation pressure and herbivory exert cascading effects on coral reef health and stability. However, the extent of these cascading effects can vary considerably across space and time. This variability is likely a result of the complex interactions between coral reefs' biotic and abiotic dimensions. A major biological component that has been poorly integrated into the reefs' trophic studies is the microbial community, despite its role in coral death and bleaching susceptibility. Viruses that infect bacteria can control microbial densities and may positively affect coral health by controlling microbialization. We hypothesize that viral predation of bacteria has analogous effects to the top-down pressure of macroorganisms on the trophic structure and reef health. RESULTS Here, we investigated the relationships between live coral cover and viruses, bacteria, benthic algae, fish biomass, and water chemistry in 110 reefs spanning inhabited and uninhabited islands and atolls across the Pacific Ocean. Statistical learning showed that the abundance of turf algae, viruses, and bacteria, in that order, were the variables best predicting the variance in coral cover. While fish biomass was not a strong predictor of coral cover, the relationship between fish and corals became apparent when analyzed in the context of viral predation: high coral cover (> 50%) occurred on reefs with a combination of high predator fish biomass (sum of sharks and piscivores > 200 g m-2) and high virus-to-bacteria ratios (> 10), an indicator of viral predation pressure. However, these relationships were non-linear, with reefs at the higher and lower ends of the coral cover continuum displaying a narrow combination of abiotic and biotic variables, while reefs at intermediate coral cover showed a wider range of parameter combinations. CONCLUSIONS The results presented here support the hypothesis that viral predation of bacteria is associated with high coral cover and, thus, coral health and stability. We propose that combined predation pressures from fishes and viruses control energy fluxes, inhibiting the detrimental accumulation of ecosystem energy in the microbial food web.
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Affiliation(s)
- Cynthia B Silveira
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA.
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, 33149, USA.
| | - Antoni Luque
- Viral Information Institute, San Diego State University, San Diego, CA, 92182, USA
- Computational Science Research Center, San Diego State University, San Diego, CA, 92182, USA
- Department of Mathematics and Statistics, San Diego State University, San Diego, CA, 92182, USA
| | - Andreas F Haas
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Ty N F Roach
- Viral Information Institute, San Diego State University, San Diego, CA, 92182, USA
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, 96744, USA
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA
| | - Emma E George
- Botany Department, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Ben Knowles
- Department of Ecology and Evolutionary Biology, UC Los Angeles, Los Angeles, CA, 90095, USA
| | - Mark Little
- Viral Information Institute, San Diego State University, San Diego, CA, 92182, USA
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA
| | | | - Natascha S Varona
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Linda Wegley Kelly
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, 92037, USA
| | - Russel Brainard
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
- Pacific Islands Fisheries Science Center, National Oceanic & Atmospheric Administration, Honolulu, HI, 96818, USA
| | - Forest Rohwer
- Viral Information Institute, San Diego State University, San Diego, CA, 92182, USA
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA
| | - Barbara Bailey
- Viral Information Institute, San Diego State University, San Diego, CA, 92182, USA.
- Department of Mathematics and Statistics, San Diego State University, San Diego, CA, 92182, USA.
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Millington RC, Rogers A, Cox P, Bozec Y, Mumby PJ. Combined direct and indirect impacts of warming on the productivity of coral reef fishes. Ecosphere 2022. [DOI: 10.1002/ecs2.4108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Rebecca C. Millington
- College of Engineering, Mathematics and Physical Science University of Exeter Exeter UK
- Marine Spatial Ecology Lab, School of Biological Sciences The University of Queensland Brisbane Queensland Australia
| | - Alice Rogers
- School of Biological Sciences Victoria University of Wellington Wellington New Zealand
| | - Peter Cox
- College of Engineering, Mathematics and Physical Science University of Exeter Exeter UK
| | - Yves‐Marie Bozec
- Marine Spatial Ecology Lab, School of Biological Sciences The University of Queensland Brisbane Queensland Australia
| | - Peter J. Mumby
- Marine Spatial Ecology Lab, School of Biological Sciences The University of Queensland Brisbane Queensland Australia
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5
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Bowden CL, Streit RP, Bellwood DR, Tebbett SB. A 3D perspective on sediment turnover and feeding selectivity in blennies. MARINE POLLUTION BULLETIN 2022; 180:113799. [PMID: 35665616 DOI: 10.1016/j.marpolbul.2022.113799] [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: 02/17/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Sediments in algal turfs can modify a wide variety of key ecological processes on coral reefs. While some larger reef fishes can remove these turf-bound sediments, the role of small, yet abundant, cryptobenthic fishes is currently unclear. To address this knowledge gap, we explored the extent to which the blenny, Ecsenius stictus, can shape sediment dynamics on coral reefs by quantifying their sediment ingestion and space use. Per unit body mass, E. stictus process sediments at comparable rates to key parrotfish and surgeonfish species. However, in absolute terms, E. stictus has a negligible influence on net sediment dynamics, despite their abundance. Behavioural observations and 3D photogrammetry reveal that E. stictus preferentially feed and rest on elevated surfaces; potentially because of low sediment loads on these surfaces. Overall, E. stictus may be responding to sediment loads rather than manipulating them; it is a passenger rather than a driver in reef processes.
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Affiliation(s)
- Casey L Bowden
- 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.
| | - Robert P Streit
- 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
| | - 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
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6
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Harborne AR, Kochan DP, Esch MM, Fidler RY, Mitchell MD, Butkowski DW, González-Rivero M. Drivers of fine-scale diurnal space use by a coral-reef mesopredatory fish. JOURNAL OF FISH BIOLOGY 2022; 100:1009-1024. [PMID: 35099815 DOI: 10.1111/jfb.15006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/27/2022] [Accepted: 01/29/2022] [Indexed: 06/14/2023]
Abstract
The habitat preferences of many reef fishes are well established, but the use of space within these habitats by non-site-attached species is poorly studied. The authors examined the space use of a functionally important mesopredator, graysby (Cephalopholis cruentata), on six patch reefs in the Florida Keys. A 1 m2 -scale grid was constructed on each reef and 16 individual C. cruentata were tracked diurnally in situ to identify space use. At the patch reef scale, larger C. cruentata were more active and had larger observed home ranges, although home ranges were also affected by fish density and the abundances of prey and predators. The total time in each 1 m2 grid cell was regressed against a range of fine-scale biotic variables, including multiple variables derived from structure-from-motion three-dimensional digital reconstructions of each reef. Nonetheless, time in grid cells (preferred microhabitats) was only significantly positively correlated with the height of carbonate structures, likely because the cavities they enclose are particularly suitable for predator avoidance, resting and ambushing prey. The ongoing flattening of reefs in the region caused by negative carbonate budgets is thus likely to have significant effects on the abundance and space use of C. cruentata. In addition to examining spatial patterns, we analysed C. cruentata waiting times in each grid cell before moving. These times were best approximated by a truncated power-law (heavy-tailed) distribution, indicating a "bursty" pattern of relatively long periods of inactivity interspersed with multiple periods of activity. Such a pattern has previously been identified in a range of temperate ambush predators, and the authors extend this move-wait behaviour, which may optimize foraging success, to a reef fish for the first time. Understanding how C. cruentata uses space and time is critical to fully identify their functional role and better predict the implications of fishing and loss of reef structure.
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Affiliation(s)
- Alastair R Harborne
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - David P Kochan
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - Melanie M Esch
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - Robert Y Fidler
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
| | - Matthew D Mitchell
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
- Marine Biology Lab, Division of Science, New York University, Abu Dhabi, UAE
| | - Drew W Butkowski
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
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7
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Urbina‐Barreto I, Elise S, Guilhaumon F, Bruggemann JH, Pinel R, Kulbicki M, Vigliola L, Mou‐Tham G, Mahamadaly V, Facon M, Bureau S, Peignon C, Dutrieux E, Garnier R, Penin L, Adjeroud M. Underwater photogrammetry reveals new links between coral reefscape traits and fishes that ensure key functions. Ecosphere 2022. [DOI: 10.1002/ecs2.3934] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Affiliation(s)
- Isabel Urbina‐Barreto
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie Saint‐Denis France
- Creocean OI Sainte Clotilde France
| | - Simon Elise
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie Saint‐Denis France
| | - François Guilhaumon
- MARBEC, IRD, CNRS, Université de Montpellier, Ifremer Montpellier France
- IRD Saint‐Denis France
| | - J. Henrich Bruggemann
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie Saint‐Denis France
- Laboratoire d'Excellence CORAIL Perpignan France
| | | | - Michel Kulbicki
- Laboratoire d'Excellence CORAIL Perpignan France
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie, Université de Perpignan Nouméa France
| | - Laurent Vigliola
- Laboratoire d'Excellence CORAIL Perpignan France
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie Nouméa New Caledonia
| | - Gerard Mou‐Tham
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie Nouméa New Caledonia
| | | | | | - Sophie Bureau
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie Saint‐Denis France
| | - Christophe Peignon
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie Nouméa New Caledonia
| | | | | | - Lucie Penin
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie Saint‐Denis France
- Laboratoire d'Excellence CORAIL Perpignan France
| | - Mehdi Adjeroud
- Laboratoire d'Excellence CORAIL Perpignan France
- UMR 9220 ENTROPIE, Université de la Réunion, CNRS, IRD, IFREMER, Université de la Nouvelle‐Calédonie, Université de Perpignan Nouméa France
- PSL Université Paris, USR 3278 CRIOBE—EPHE‐UPVD‐CNRS Perpignan France
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Hadj-Hammou J, McClanahan TR, Graham NAJ. Decadal shifts in traits of reef fish communities in marine reserves. Sci Rep 2021; 11:23470. [PMID: 34873242 PMCID: PMC8648868 DOI: 10.1038/s41598-021-03038-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/26/2021] [Indexed: 11/09/2022] Open
Abstract
Marine reserves are known to impact the biomass, biodiversity, and functions of coral reef fish communities, but the effect of protective management on fish traits is less explored. We used a time-series modelling approach to simultaneously evaluate the abundance, biomass, and traits of eight fish families over a chronosequence spanning 44 years of protection. We constructed a multivariate functional space based on six traits known to respond to management or disturbance and affect ecosystem processes: size, diet, position in the water column, gregariousness, reef association, and length at maturity. We show that biomass increased with a log-linear trend over the time-series, but abundance only increased after 20 years of closure, and with more variation among reserves. This difference is attributed to recovery rates being dependent on body sizes. Abundance-weighted traits and the associated multivariate space of the community change is driven by increased proportions over time of the trait categories: 7-15 cm body size; planktivorous; species low in the water column; medium-large schools; and species with high levels of reef association. These findings suggest that the trait compositions emerging after the cessation of fishing are novel and dynamic.
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Affiliation(s)
- Jeneen Hadj-Hammou
- Lancaster University Environment Centre, Lancaster University, Lancaster, UK.
| | - Tim R McClanahan
- Wildlife Conservation Society, Global Marine Programs, Bronx, NY, 10460, USA
| | - Nicholas A J Graham
- Lancaster University Environment Centre, Lancaster University, Lancaster, UK
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9
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Ferrari R, Lachs L, Pygas DR, Humanes A, Sommer B, Figueira WF, Edwards AJ, Bythell JC, Guest JR. Photogrammetry as a tool to improve ecosystem restoration. Trends Ecol Evol 2021; 36:1093-1101. [PMID: 34404550 DOI: 10.1016/j.tree.2021.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/08/2021] [Accepted: 07/08/2021] [Indexed: 10/20/2022]
Abstract
Ecosystem restoration has been practiced for over a century and is increasingly supported by the emergent applied science of restoration ecology. A prerequisite for successful ecosystem restoration is determining meaningful and measurable goals. This requires tools to monitor success in a standardized way. Photogrammetry uses images to reconstruct landscapes and organisms in three dimensions, enabling non-invasive measurement of key success indicators with unprecedented accuracy. We propose photogrammetry can improve restoration success by: (i) facilitating measurable goals; (ii) innovating and standardizing indicators of success; and (iii) standardizing monitoring. While the case we present is specific to coral reefs, photogrammetry has enormous potential to improve restoration practice in a wide range of ecosystems.
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Affiliation(s)
- Renata Ferrari
- Australian Institute of Marine Sciences, Townsville, QLD 4810, Australia.
| | - Liam Lachs
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Daniel R Pygas
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
| | - Adriana Humanes
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Brigitte Sommer
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia; School of Life Sciences, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Will F Figueira
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
| | - Alasdair J Edwards
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - John C Bythell
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - James R Guest
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
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10
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Coral Reef Mapping with Remote Sensing and Machine Learning: A Nurture and Nature Analysis in Marine Protected Areas. REMOTE SENSING 2021. [DOI: 10.3390/rs13152907] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mapping habitats is essential to assist strategic decisions regarding the use and protection of coral reefs. Coupled with machine learning (ML) algorithms, remote sensing has allowed detailed mapping of reefs at meaningful scales. Here we integrated WorldView-3 and Landsat-8 imagery and ML techniques to produce a map of suitable habitats for the occurrence of a model species, the hydrocoral Millepora alcicornis, in coral reefs located inside marine protected areas in Northeast Brazil. Conservation and management efforts in the region were also analyzed, integrating human use layers to the ecological seascape. Three ML techniques were applied: two to derive base layers, namely geographically weighted regressions for bathymetry and support vector machine classifier (SVM) for habitat mapping, and one to build the species distribution model (MaxEnt) for Millepora alcicornis, a conspicuous and important reef-building species in the area. Additionally, human use was mapped based on the presence of tourists and fishers. SVM yielded 15 benthic classes (e.g., seagrass, sand, coral), with an overall accuracy of 79%. Bathymetry and its derivative layers depicted the topographical complexity of the area. The Millepora alcicornis distribution model identified distance from the shore and depth as topographical factors limiting the settling and growth of coral colonies. The most important variables were ecological, showing the importance of maintaining high biodiversity in the ecosystem. The comparison of the habitat suitability model with species absence and human use maps indicated the impact of direct human activities as potential inhibitors of coral development. Results reinforce the importance of the establishment of no-take zones and other protective measures for maintaining local biodiversity.
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11
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Lazarus M, Belmaker J. A review of seascape complexity indices and their performance in coral and rocky reefs. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mai Lazarus
- School of Zoology George S. Wise Faculty of Life Sciences Tel Aviv University Tel Aviv Israel
| | - Jonathan Belmaker
- School of Zoology George S. Wise Faculty of Life Sciences Tel Aviv University Tel Aviv Israel
- The Steinhardt Museum of Natural History Tel Aviv University Tel Aviv Israel
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12
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Foo SA, Walsh WJ, Lecky J, Marcoux S, Asner GP. Impacts of pollution, fishing pressure, and reef rugosity on resource fish biomass in West Hawaii. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e2213. [PMID: 32750738 DOI: 10.1002/eap.2213] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/27/2020] [Accepted: 06/19/2020] [Indexed: 06/11/2023]
Abstract
Human activities and land-use drivers combine in complex ways to affect coral reef health and, in turn, the diversity and abundance of reef fauna. Here we examine the impacts of different marine protected area (MPA) types, and various human and habitat drivers, on resource fish functional groups (i.e., total fish, herbivore, grazer, scraper, and browser biomass) along the 180 km west coast of Hawaii Island. Across survey years from 2008 to 2018, we observed an overall decrease in total fish biomass of 45%, with similar decreases in biomass seen across most fish functional groups. MPAs that prohibited a combination of lay nets, aquarium collection, and spear fishing were most effective in maintaining and/or increasing fish biomass across all functional groups. We also found that pollution, fishing, and habitat drivers all contributed to changes in total fish biomass, where the most negative impact was nitrogen input from land-based sewage disposal. Fish biomass relationships with our study drivers depended on fish functional grouping. For surgeonfish (grazers), changes in biomass linked most strongly to changes in reef rugosity. For parrotfish (scrapers), biomass was better explained by changes in commercial catch where current commercial fishing levels are negatively affecting scraper populations. Our observations suggest that regional management of multiple factors, including habitat, pollution, and fisheries, will benefit resource fish biomass off Hawaii Island.
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Affiliation(s)
- Shawna A Foo
- Center for Global Discovery and Conservation Science, Arizona State University, Tempe, Arizona, 85287, USA
| | - William J Walsh
- Hawaii Division of Aquatic Resources, 74-380B Kealakehe Parkway, Kailua Kona, Hawaii, 96740, USA
| | - Joey Lecky
- Lynker Technologies LLC, Marine, Ocean, and Coastal Science and Information Group, 202 Church Street, SE/Suite 536, Leesburg, Virginia, 20175, USA
| | - Stacia Marcoux
- Pacific Cooperative Studies Unit, Hawaii Division of Aquatic Resources, 75-308B Kealakehe Parkway, Kailua Kona, Hawaii, 96740, USA
| | - Gregory P Asner
- Center for Global Discovery and Conservation Science, Arizona State University, Tempe, Arizona, 85287, USA
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Carr H, Abas M, Boutahar L, Caretti ON, Chan WY, Chapman ASA, de Mendonça SN, Engleman A, Ferrario F, Simmons KR, Verdura J, Zivian A. The Aichi Biodiversity Targets: achievements for marine conservation and priorities beyond 2020. PeerJ 2020; 8:e9743. [PMID: 33391861 PMCID: PMC7759131 DOI: 10.7717/peerj.9743] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 07/27/2020] [Indexed: 11/20/2022] Open
Abstract
In 2010 the Conference of the Parties (COP) for the Convention on Biological Diversity revised and updated a Strategic Plan for Biodiversity 2011–2020, which included the Aichi Biodiversity Targets. Here a group of early career researchers mentored by senior scientists, convened as part of the 4th World Conference on Marine Biodiversity, reflects on the accomplishments and shortfalls under four of the Aichi Targets considered highly relevant to marine conservation: target 6 (sustainable fisheries), 11 (protection measures), 15 (ecosystem restoration and resilience) and 19 (knowledge, science and technology). We conclude that although progress has been made towards the targets, these have not been fully achieved for the marine environment by the 2020 deadline. The progress made, however, lays the foundations for further work beyond 2020 to work towards the 2050 Vision for Biodiversity. We identify key priorities that must be addressed to better enable marine biodiversity conservation efforts moving forward.
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Affiliation(s)
- Hannah Carr
- The Joint Nature Conservation Committee, Peterborough, Cambridgeshire, UK
| | - Marina Abas
- Departamento de Ciencias Marinas y Costeras, Universidad Autónoma de Baja California Sur, La Paz, Baja California Sur, Mexico
| | - Loubna Boutahar
- BioBio Research Center, BioEcoGen Laboratory, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco.,Laboratorío de Biología Marina, Departamento de Zoología, Universidad de Sevilla, Sevilla, Spain
| | - Olivia N Caretti
- Department of Marine, Earth, & Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
| | - Wing Yan Chan
- Australian Institute of Marine Science, Townsville, QLD, Australia.,School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
| | - Abbie S A Chapman
- School of Ocean and Earth Science, University of Southampton, Southampton, Hampshire, UK.,Centre for Biodiversity and Environment Research, University College London, London, UK
| | | | - Abigail Engleman
- Department of Biological Sciences, Florida State University, Tallahassee, FL, USA
| | - Filippo Ferrario
- Québec-Ocean and Département de Biologie, Université Laval, Québec, QC, Canada
| | - Kayelyn R Simmons
- Department of Marine, Earth, & Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
| | - Jana Verdura
- Institut d'Ecologia Aquàtica, Facultat de Ciències, Universitat de Girona, Girona, Spain
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14
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Sandin SA, Edwards CB, Pedersen NE, Petrovic V, Pavoni G, Alcantar E, Chancellor KS, Fox MD, Stallings B, Sullivan CJ, Rotjan RD, Ponchio F, Zgliczynski BJ. Considering the rates of growth in two taxa of coral across Pacific islands. ADVANCES IN MARINE BIOLOGY 2020; 87:167-191. [PMID: 33293010 DOI: 10.1016/bs.amb.2020.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Reef-building coral taxa demonstrate considerable flexibility and diversity in reproduction and growth mechanisms. Corals take advantage of this flexibility to increase or decrease size through clonal expansion and loss of live tissue area (i.e. via reproduction and mortality of constituent polyps). The biological lability of reef-building corals may be expected to map onto varying patterns of demography across environmental contexts which can contribute to geographic variation in population dynamics. Here we explore the patterns of growth of two common coral taxa, corymbose Pocillopora and massive Porites, across seven islands in the central and south Pacific. The islands span a natural gradient of environmental conditions, including a range of pelagic primary production, a metric linked to the relative availability of inorganic nutrients and heterotrophic resources for mixotrophic corals, and sea surface temperature and thermal histories. Over a multi-year sampling interval, most coral colonies experienced positive growth (greater planar area of live tissue in second relative to first time point), though the distributions of growth varied across islands. Island-level median growth did not relate simply to estimated pelagic primary productivity or temperature. However, at locations that experienced an extreme warm-water event during the sampling interval, most Porites colonies experienced net losses of live tissue and nearly all Pocillopora colonies experienced complete mortality. While descriptive statistics of demographics offer valuable insights into trends and variability in colony change through time, simplified models predicting growth patterns based on summarized oceanographic metrics appear inadequate for robust demographic prediction. We propose that the complexity of life history strategies among colonial reef-building corals introduces unique demographic flexibility for colonies to respond to a wide breadth of environmental conditions.
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Affiliation(s)
- Stuart A Sandin
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, United States.
| | - Clinton B Edwards
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, United States
| | - Nicole E Pedersen
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, United States
| | - Vid Petrovic
- Department of Computer Science and Engineering, UC San Diego, La Jolla, CA, United States
| | - Gaia Pavoni
- Visual Computing Lab, Istituto di Scienza e Tecnologie dell'Informazione "A. Faedo", Consiglio Nazionale delle Ricerche, Pisa, Italy
| | - Esmeralda Alcantar
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, United States
| | | | - Michael D Fox
- Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Brenna Stallings
- Department of Biology, Boston University, Boston, MA, United States
| | | | - Randi D Rotjan
- Department of Biology, Boston University, Boston, MA, United States
| | - Federico Ponchio
- Visual Computing Lab, Istituto di Scienza e Tecnologie dell'Informazione "A. Faedo", Consiglio Nazionale delle Ricerche, Pisa, Italy
| | - Brian J Zgliczynski
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, United States
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15
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Bayley DTI, Mogg AOM. A protocol for the large‐scale analysis of reefs using Structure from Motion photogrammetry. Methods Ecol Evol 2020. [DOI: 10.1111/2041-210x.13476] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel T. I. Bayley
- Centre for Biodiversity and Environment Research University College London London UK
| | - Andrew O. M. Mogg
- Tritonia Scientific Ltd.Dunstaffnage Marine Laboratories Oban UK
- National Facility for Scientific DivingScottish Association of Marine Science Oban UK
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16
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Tebbett SB, Goatley CHR, Streit RP, Bellwood DR. Algal turf sediments limit the spatial extent of function delivery on coral reefs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 734:139422. [PMID: 32460082 DOI: 10.1016/j.scitotenv.2020.139422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 05/07/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
The presence of key organisms is frequently associated with the delivery of specific ecosystem functions. Areas with such organisms are therefore often considered to have greater levels of these functions. While this assumption has been the backbone of coral reef ecosystem-based management approaches for decades, we currently have only a limited understanding of how fish presence equates to function on coral reefs and whether this relationship is susceptible to stressors. To assess the capacity of a stressor to shape function delivery we used a multi-scale approach ranging from tens of kilometres across the continental shelf of Australia's Great Barrier Reef, down to centimetres within a reef habitat. At each scale, we quantified the spatial extent of a model function (detritivory) by a coral reef surgeonfish (Ctenochaetus striatus) and its potential to be shaped by sediments. At broad spatial scales, C. striatus presence was correlated strongly with algal turf sediment loads, while at smaller spatial scales, function delivery appears to be constrained by algal turf sediment distributions. In all cases, sediment loads above ~250-500 g m-2 were associated with a marked decrease in fish abundance or feeding activity, suggesting that a common ecological threshold lies within this range. Our results reveal a complex functional dynamic between proximate agents of function delivery (fish) and the ultimate drivers of function delivery (sediments), which emphasizes: a) weaknesses in the assumed links between fish presence and function, and b) the multi-scale capacity of algal turf sediments to shape reef processes. Unless direct extractive activities (e.g. fishing) are the main driver of function loss on coral reefs, managing to conserve fish abundance is unlikely to yield the desired outcomes. It only addresses one potential driver. Instead, management of both the agents that deliver functions (e.g. fishes), and the drivers that modify functions (e.g. sediments), is needed.
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Affiliation(s)
- Sterling B Tebbett
- ARC Centre of Excellence for Coral Reef Studies and College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia.
| | - Christopher H R Goatley
- Function, Evolution and Anatomy Research Lab and Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia; Australian Museum Research Institute, Australian Museum, Sydney, New South Wales 2010, Australia
| | - Robert P Streit
- ARC Centre of Excellence for Coral Reef Studies and College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - David R Bellwood
- ARC Centre of Excellence for Coral Reef Studies and College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
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17
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Metrics of Coral Reef Structural Complexity Extracted from 3D Mesh Models and Digital Elevation Models. REMOTE SENSING 2020. [DOI: 10.3390/rs12172676] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Underwater photogrammetry has been increasingly used in coral-reef research in recent years. Habitat metrics extracted from resulting three-dimensional (3D) reconstructions can be used to examine associations between the structural complexity of the reef habitats and the distribution of reef organisms. We created simulated 3D models of bare surface structures and 3D reconstructions of coral morphologies to investigate the behavior of various habitat metrics that were extracted from both Digital Elevation Models (DEMs) and 3D mesh models. Analyzing the resulting values provided us with important insights into how these metrics would compare with one another in the characterization of coral-reef habitats. Surface complexity (i.e., reef rugosity), fractal dimension extracted from DEMs and vector dispersion obtained from 3D mesh models exhibited consistent patterns in the ranking of structural complexity among the simulated bare surfaces and coral morphologies. The vector ruggedness measure obtained from DEMs at three different resolutions of 1, 2, and 4 cm effectively captured differences in the structural complexity among different coral morphologies. Profile curvature and planform curvature, on the other hand, were better suited to capture the structural complexity derived from surface topography such as walls and overhanging ledges. Our results indicate that habitat metrics extracted from DEMs are generally suitable when characterizing a relatively large plot of a coral reef captured from an overhead planar angle, while the 3D metric of vector dispersion is suitable when characterizing a coral colony or a relatively small plot methodically captured from various angles.
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18
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Habitat zonation on coral reefs: Structural complexity, nutritional resources and herbivorous fish distributions. PLoS One 2020; 15:e0233498. [PMID: 32497043 PMCID: PMC7272040 DOI: 10.1371/journal.pone.0233498] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 05/06/2020] [Indexed: 11/20/2022] Open
Abstract
Distinct zonation of community assemblages among habitats is a ubiquitous feature of coral reefs. The distribution of roving herbivorous fishes (parrotfishes, surgeonfishes and rabbitfishes) is a particularly clear example, with the abundance of these fishes generally peaking in shallow-water, high-energy habitats, regardless of the biogeographic realm. Yet, our understanding of the factors which structure this habitat partitioning, especially with regards to different facets of structural complexity and nutritional resource availability, is limited. To address this issue, we used three-dimensional photogrammetry and structure-from-motion technologies to describe five components of structural complexity (rugosity, coral cover, verticality, refuge density and field-of-view) and nutritional resource availability (grazing surface area) among habitats and considered how these factors are related to herbivorous fish distributions. All complexity metrics (including coral cover) were highest on the slope and crest. Nutritional resource availability differed from this general pattern and peaked on the outer-flat. Unexpectedly, when compared to the distribution of herbivorous fishes, none of the complexity metrics had a marked influence in the models. However, grazing surface area was a strong predictor of both the abundance and biomass of herbivorous fishes. The strong relationship between grazing surface area and herbivorous fish distributions indicates that nutritional resource availability may be one of the primary factors driving the distribution of roving herbivorous fishes. The lack of a relationship between complexity and herbivorous fishes, and a strong affinity of herbivorous fishes for low-complexity, algal turf-dominated outer-flat habitats, offers some cautious optimism that herbivory may be sustained on future, low-complexity, algal turf-dominated reef configurations.
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19
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Hernández-Landa RC, Barrera-Falcon E, Rioja-Nieto R. Size-frequency distribution of coral assemblages in insular shallow reefs of the Mexican Caribbean using underwater photogrammetry. PeerJ 2020; 8:e8957. [PMID: 32337105 PMCID: PMC7169971 DOI: 10.7717/peerj.8957] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 03/22/2020] [Indexed: 01/07/2023] Open
Abstract
The characterisation of changes in coral communities depends heavily on systematic monitoring programs and the collection of necessary metrics to assess reef health. Coral cover is the most used metric to determine reef health. The current organizational shift in coral requires the evaluation of complementary metrics, such as colony size and frequency distributions, which help to infer the responses of the coral populations to local stress or larger scale environmental changes. In this study, underwater digital photogrammetry techniques were used to assess the live cover of all coral colonies ≥3 cm2 and determine the size-frequency distribution of the dominant species in the shallow reefs of the Cozumel Reefs National Park (CRNP). In addition, the minimum sampling area (m2) needed to obtain a representative sample of the local species pool was estimated. Areas between 550 and 825 m2 per reef were photographed to generate high-resolution digital ortho-mosaics. The live area of the colonies was digitised to generate community matrices of species and abundance. EstimateS software was used to generate accumulation curves and diversity (Shannon H′) at increasing area intervals. Chi-Square tests (χ2, p = 0.05) were used to compare the observed vs estimated species richness. Spearman’s coefficients (rs), were calculated to correlate the increase in sampling area (m2) vs H′, and the Clench’s function was used to validate the observed richness (R2 = 1 and R > 90%). SIMPER analysis was performed to identify dominant species. Comparisons in terms of abundance, coral cover and size-frequencies were performed with Kruskal-Wallis (H test, p = 0.05), and paired Mann-Whitney (U test, p = 0.05). In order to obtain 90% of the species richness, a minimum sampling area of 374 m2is needed. This sampling area could be used in shallow Caribbean reefs with similar characteristics. Twelve (mainly non-massive) species: Agaricia agaricites, A humilis, A. tenuifolia, Eusmilia fastigiata, Meandrina meandrites, Montastrea cavernosa, Orbicella annularis, Porites astreoides, P. porites, Pseudodiploria strigosa, Siderastrea radians andS. siderea, were dominant in terms of abundance and coral cover. A significant increase (p < 0.05) in the number of colonies and live coral (m2) was observed from north to south of the study area. Furthermore, a wide intraspecific variation of size-frequency, even between adjacent reefs, was also observed. The size-frequency distributions presented positive skewness and negative kurtosis, which are related to stable populations, with a greater number of young colonies and a constant input of recruits. Considering the increase in disturbances in the Caribbean and the appearance of a new coral disease, digital photogrammetry techniques allow coral community characteristics to be assessed at high spatial resolutions and over large scales, which would be complementary to conventional monitoring programs.
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Affiliation(s)
- Roberto C Hernández-Landa
- Laboratorio de Análisis Espacial de Zonas Costeras (COSTALAB), Unidad Multidisciplinaria de Docencia e Investigación-Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sierra Papacal, Yucatán, México
| | - Erick Barrera-Falcon
- Laboratorio de Análisis Espacial de Zonas Costeras (COSTALAB), Unidad Multidisciplinaria de Docencia e Investigación-Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sierra Papacal, Yucatán, México.,Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Mérida, Yucatán, México
| | - Rodolfo Rioja-Nieto
- Laboratorio de Análisis Espacial de Zonas Costeras (COSTALAB), Unidad Multidisciplinaria de Docencia e Investigación-Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sierra Papacal, Yucatán, México.,Escuela Nacional de Estudios Superiores, Unidad Mérida, Universidad Nacional Autónoma de México, Mérida, Yucatán, Mexico
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20
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Choi F, Gouhier T, Lima F, Rilov G, Seabra R, Helmuth B. Mapping physiology: biophysical mechanisms define scales of climate change impacts. CONSERVATION PHYSIOLOGY 2019; 7:coz028. [PMID: 31423312 PMCID: PMC6691486 DOI: 10.1093/conphys/coz028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 04/24/2019] [Accepted: 05/07/2019] [Indexed: 05/11/2023]
Abstract
The rocky intertidal zone is a highly dynamic and thermally variable ecosystem, where the combined influences of solar radiation, air temperature and topography can lead to differences greater than 15°C over the scale of centimetres during aerial exposure at low tide. For most intertidal organisms this small-scale heterogeneity in microclimates can have enormous influences on survival and physiological performance. However, the potential ecological importance of environmental heterogeneity in determining ecological responses to climate change remains poorly understood. We present a novel framework for generating spatially explicit models of microclimate heterogeneity and patterns of thermal physiology among interacting organisms. We used drone photogrammetry to create a topographic map (digital elevation model) at a resolution of 2 × 2 cm from an intertidal site in Massachusetts, which was then fed into to a model of incident solar radiation based on sky view factor and solar position. These data were in turn used to drive a heat budget model that estimated hourly surface temperatures over the course of a year (2017). Body temperature layers were then converted to thermal performance layers for organisms, using thermal performance curves, creating 'physiological landscapes' that display spatially and temporally explicit patterns of 'microrefugia'. Our framework shows how non-linear interactions between these layers lead to predictions about organismal performance and survivorship that are distinct from those made using any individual layer (e.g. topography, temperature) alone. We propose a new metric for quantifying the 'thermal roughness' of a site (RqT, the root mean square of spatial deviations in temperature), which can be used to quantify spatial and temporal variability in temperature and performance at the site level. These methods facilitate an exploration of the role of micro-topographic variability in driving organismal vulnerability to environmental change using both spatially explicit and frequency-based approaches.
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Affiliation(s)
- Francis Choi
- Marine Science Center, Department of Marine and Environmental Sciences, Northeastern University, 430 Nahant Rd, Nahant, MA, USA
| | - Tarik Gouhier
- Marine Science Center, Department of Marine and Environmental Sciences, Northeastern University, 430 Nahant Rd, Nahant, MA, USA
| | - Fernando Lima
- CIBIO, Research Center in Biodiversity and Genetic Resources, University of Porto, Campus de Vairão, Vairão, Portugal
| | - Gil Rilov
- National Institute of Oceanography, Israel Oceanography and Limnology Research Institute, Haifa, Israel
| | - Rui Seabra
- CIBIO, Research Center in Biodiversity and Genetic Resources, University of Porto, Campus de Vairão, Vairão, Portugal
| | - Brian Helmuth
- Marine Science Center, Department of Marine and Environmental Sciences, Northeastern University, 430 Nahant Rd, Nahant, MA, USA
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21
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Loh T, Archer SK, Dunham A. Monitoring program design for data-limited marine biogenic habitats: A structured approach. Ecol Evol 2019; 9:7346-7359. [PMID: 31380055 PMCID: PMC6662303 DOI: 10.1002/ece3.5261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/16/2019] [Accepted: 04/23/2019] [Indexed: 11/07/2022] Open
Abstract
Marine biogenic habitats-habitats created by living organisms-provide essential ecosystem functions and services, such as physical structuring, nutrient cycling, biodiversity support, and increases in primary, secondary, and tertiary production. With the growing trend toward ecosystem approaches to marine conservation and fisheries management, there is greater emphasis on rigorously designed habitat monitoring programs. However, such programs are challenging to design for data-limited habitats for which underlying ecosystem processes are poorly understood. To provide guidance in this area, we reviewed approaches to benthic assessments across well-studied marine biogenic habitats and identified common themes related to indicator selection, sampling methods, and survey design. Biogenic habitat monitoring efforts largely focus on the characteristics, distribution, and ecological function of foundation species, but may target other habitat-forming organisms, especially when community shifts are observed or expected, as well as proxies of habitat status, such as indicator species. Broad-scale methods cover large spatial areas and are typically used to examine the spatial configuration of habitats, whereas fine-scale methods tend to be laborious and thus restricted to small survey areas, but provide high-resolution data. Recent, emerging methods enhance the capabilities of surveying large areas at high spatial resolution and improve data processing efficiency, bridging the gap between broad- and fine-scale methods. Although sampling design selection may be limited by habitat characteristics and available resources, it is critically important to ensure appropriate matching of ecological, observational, and analytical scales. Drawing on these common themes, we propose a structured, iterative approach to designing monitoring programs for marine biogenic habitats that allows for rigorous data collection to inform management strategies, even when data and resource limitations are present. A practical application of this approach is illustrated using glass sponge reefs-a recently discovered and data-limited habitat type-as a case study.
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Affiliation(s)
- Tse‐Lynn Loh
- Quest University CanadaSquamishBritish ColumbiaCanada
| | - Stephanie K. Archer
- Fisheries and Oceans Canada, Pacific Biological StationNanaimoBritish ColumbiaCanada
| | - Anya Dunham
- Fisheries and Oceans Canada, Pacific Biological StationNanaimoBritish ColumbiaCanada
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22
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Brito-Millán M, Werner BT, Sandin SA, McNamara DE. Influence of aggregation on benthic coral reef spatio-temporal dynamics. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181703. [PMID: 30891282 PMCID: PMC6408412 DOI: 10.1098/rsos.181703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/15/2019] [Indexed: 06/09/2023]
Abstract
Spatial patterning of coral reef sessile benthic organisms can constrain competitive and demographic rates, with implications for dynamics over a range of time scales. However, techniques for quantifying and analysing reefscape behaviour, particularly at short to intermediate time scales (weeks to decades), are lacking. An analysis of the dynamics of coral reefscapes simulated with a lattice model shows consistent trends that can be categorized into four stages: a repelling stage that moves rapidly away from an unstable initial condition, a transient stage where spatial rearrangements bring key competitors into contact, an attracting stage where the reefscape decays to a steady-state attractor, and an attractor stage. The transient stage exhibits nonlinear dynamics, whereas the other stages are linear. The relative durations of the stages are affected by the initial spatial configuration as characterized by coral aggregation-a measure of spatial clumpiness, which together with coral and macroalgae fractional cover, more completely describe modelled reefscape dynamics. Incorporating diffusional processes results in aggregated patterns persisting in the attractor. Our quantitative characterization of reefscape dynamics has possible applications to other spatio-temporal systems and implications for reef restoration: high initial aggregation patterns slow losses in herbivore-limited systems and low initial aggregation configurations accelerate growth in herbivore-dominated systems.
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Affiliation(s)
- Marlene Brito-Millán
- Complex Systems Laboratory, Climate, Atmospheric Sciences, and Physical Oceanography, and University of California - San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0230, USA
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110-2492, USA
- Environmental and Ocean Sciences Department, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110-2492, USA
| | - B. T. Werner
- Complex Systems Laboratory, Climate, Atmospheric Sciences, and Physical Oceanography, and University of California - San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0230, USA
| | - Stuart A. Sandin
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110-2492, USA
| | - Dylan E. McNamara
- Department of Physics and Physical Oceanography/Center for Marine Sciences, University of North Carolina, Wilmington, 601 South College Road, Wilmington, NC 28403, USA
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23
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Aggregating behaviour in invasive Caribbean lionfish is driven by habitat complexity. Sci Rep 2019; 9:783. [PMID: 30692608 PMCID: PMC6349842 DOI: 10.1038/s41598-018-37459-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 11/30/2018] [Indexed: 01/04/2023] Open
Abstract
Caribbean lionfish (Pterois spp.) are considered the most heavily impacting invasive marine vertebrate ever recorded. However, current management is largely inadequate, relying on opportunistic culling by recreational SCUBA divers. Culling efficiency could be greatly improved by exploiting natural aggregations, but to date this behaviour has only been recorded anecdotally, and the drivers are unknown. We found aggregations to be common in situ, but detected no conspecific attraction through visual or olfactory cues in laboratory experiments. Aggregating individuals were on average larger, but showed no further differences in morphology or life history. However, using visual assessments and 3D modelling we show lionfish prefer broad-scale, but avoid fine-scale, habitat complexity. We therefore suggest that lionfish aggregations are coincidental based on individuals’ mutual attraction to similar reef structure to maximise hunting efficiency. Using this knowledge, artificial aggregation devices might be developed to concentrate lionfish densities and thus improve culling efficiency.
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24
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Abstract
Dense 3D point clouds were generated from Structure-from-Motion Multiview Stereo (SFM-MVS) photogrammetry for five representative freshwater fish habitats in the Xingu river basin, Brazil. The models were constructed from Unmanned Aerial Vehicle (UAV) photographs collected in 2016 and 2017. The Xingu River is one of the primary tributaries of the Amazon River. It is known for its exceptionally high aquatic biodiversity. The dense 3D point clouds were generated in the dry season when large areas of aquatic substrate are exposed due to the low water level. The point clouds were generated at ground sampling distances of 1.20–2.38 cm. These data are useful for studying the habitat characteristics and complexity of several fish species in a spatially explicit manner, such as calculation of metrics including rugosity and the Minkowski–Bouligand fractal dimension (3D complexity). From these dense 3D point clouds, substrate complexity can be determined more comprehensively than from conventional arbitrary cross sections.
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25
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Freshwater Fish Habitat Complexity Mapping Using Above and Underwater Structure-From-Motion Photogrammetry. REMOTE SENSING 2018. [DOI: 10.3390/rs10121912] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Substrate complexity is strongly related to biodiversity in aquatic habitats. We illustrate a novel framework, based on Structure-from-Motion photogrammetry (SfM) and Multi-View Stereo (MVS) photogrammetry, to quantify habitat complexity in freshwater ecosystems from Unmanned Aerial Vehicle (UAV) and underwater photography. We analysed sites in the Xingu river basin, Brazil, to reconstruct the 3D structure of the substrate and identify and map habitat classes important for maintaining fish assemblage biodiversity. From the digital models we calculated habitat complexity metrics including rugosity, slope and 3D fractal dimension. The UAV based SfM-MVS products were generated at a ground sampling distance (GSD) of 1.20–2.38 cm while the underwater photography produced a GSD of 1 mm. Our results show how these products provide spatially explicit complexity metrics, which are more comprehensive than conventional arbitrary cross sections. Shallow neural network classification of SfM-MVS products of substrate exposed in the dry season resulted in high accuracies across classes. UAV and underwater SfM-MVS is robust for quantifying freshwater habitat classes and complexity and should be chosen whenever possible over conventional methods (e.g., chain-and-tape) because of the repeatability, scalability and multi-dimensional nature of the products. The SfM-MVS products can be used to identify high priority freshwater sectors for conservation, species occurrences and diversity studies to provide a broader indication for overall fish species diversity and provide repeatability for monitoring change over time.
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