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Strader ME, Wright RM, Pezner AK, Nuttall MF, Aichelman HE, Davies SW. Intersection of coral molecular responses to a localized mortality event and ex situ deoxygenation. Ecol Evol 2024; 14:e11275. [PMID: 38654712 PMCID: PMC11036075 DOI: 10.1002/ece3.11275] [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: 03/13/2024] [Revised: 03/22/2024] [Accepted: 04/01/2024] [Indexed: 04/26/2024] Open
Abstract
In July 2016, East Bank of Flower Garden Banks (FGB) National Marine Sanctuary experienced a localized mortality event (LME) of multiple invertebrate species that ultimately led to reductions in coral cover. Abiotic data taken directly after the event suggested that acute deoxygenation contributed to the mortality. Despite the large impact of this event on the coral community, there was no direct evidence that this LME was driven by acute deoxygenation, and thus we explored whether gene expression responses of corals to the LME would indicate what abiotic factors may have contributed to the LME. Gene expression of affected and unaffected corals sampled during the mortality event revealed evidence of the physiological consequences of the LME on coral hosts and their algal symbionts from two congeneric species (Orbicella franksi and Orbicella faveolata). Affected colonies of both species differentially regulated genes involved in mitochondrial regulation and oxidative stress. To further test the hypothesis that deoxygenation led to the LME, we measured coral host and algal symbiont gene expression in response to ex situ experimental deoxygenation (control = 6.9 ± 0.08 mg L-1, anoxic = 0.083 ± 0.017 mg L-1) in healthy O. faveolata colonies from the FGB. However, this deoxygenation experiment revealed divergent gene expression patterns compared to the corals sampled during the LME and was more similar to a generalized coral environmental stress response. It is therefore likely that while the LME was connected to low oxygen, it was a series of interconnected stressors that elicited the unique gene expression responses observed here. These in situ and ex situ data highlight how field responses to stressors are unique from those in controlled laboratory conditions, and that the complexities of deoxygenation events in the field likely arise from interactions between multiple environmental factors simultaneously.
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Affiliation(s)
- Marie E. Strader
- Department of BiologyTexas A&M UniversityCollege StationTexasUSA
| | - Rachel M. Wright
- Department of Biological SciencesSouthern Methodist UniversityDallasTexasUSA
| | | | | | | | - Sarah W. Davies
- Department of BiologyBoston UniversityBostonMassachusettsUSA
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2
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Howard RD, Schul MD, Rodriguez Bravo LM, Altieri AH, Meyer JL. Shifts in the coral microbiome in response to in situ experimental deoxygenation. Appl Environ Microbiol 2023; 89:e0057723. [PMID: 37916820 PMCID: PMC10686059 DOI: 10.1128/aem.00577-23] [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: 04/06/2023] [Accepted: 09/12/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Marine hypoxia is a threat for corals but has remained understudied in tropical regions where coral reefs are abundant. Though microbial symbioses can alleviate the effects of ecological stress, we do not yet understand the taxonomic or functional response of the coral microbiome to hypoxia. In this study, we experimentally lowered oxygen levels around Siderastrea siderea and Agaricia lamarcki colonies in situ to observe changes in the coral microbiome in response to deoxygenation. Our results show that hypoxia triggers a stochastic change of the microbiome overall, with some bacterial families changing deterministically after just 48 hours of exposure. These families represent an increase in anaerobic and opportunistic taxa in the microbiomes of both coral species. Thus, marine deoxygenation destabilizes the coral microbiome and increases bacterial opportunism. This work provides novel and fundamental knowledge of the microbial response in coral during hypoxia and may provide insight into holobiont function during stress.
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Affiliation(s)
- Rachel D. Howard
- Department of Soil, Water, and Ecosystem Sciences, University of Florida, Gainesville, Florida, USA
| | - Monica D. Schul
- Department of Soil, Water, and Ecosystem Sciences, University of Florida, Gainesville, Florida, USA
| | - Lucia M. Rodriguez Bravo
- Smithsonian Tropical Research Institute, Balboa, Ancon, Panama
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Andrew H. Altieri
- Smithsonian Tropical Research Institute, Balboa, Ancon, Panama
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, Florida, USA
| | - Julie L. Meyer
- Department of Soil, Water, and Ecosystem Sciences, University of Florida, Gainesville, Florida, USA
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3
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Violette C, Le Gendre R, Chauveau M, Andréfouët S. A multivariate approach to synthetize large amount of connectivity matrices for management decisions: Application to oyster population restocking in the pearl farming context of Tuamotu Archipelago semi-closed atolls. MARINE POLLUTION BULLETIN 2023; 189:114748. [PMID: 36841211 DOI: 10.1016/j.marpolbul.2023.114748] [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: 11/24/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
In applied ecology, numerical biophysical modelling allows running numerous simulations of spatial connectivity between source and destination locations. To characterize population connectivity, larval dispersal and resulting connectivity matrices can be computed for various forcing conditions of wind, density of spawners, or pelagic larval durations. Here, we investigate a methodology to synthetize meaningfully all numerical experiments performed for three atoll lagoons in the Tuamotu Archipelago pearl farming context. The objective is to identify the best restocking locations that consistently maximize the spread of pearl oyster larval dispersal, considering all forcing conditions. A multivariate generic approach is used to process and synthesize time-series of connectivity matrices and identify afterward with contextual criteria the spawning locations that match a variety of specific connectivity, logistical and ecological criteria. Similar synthesis of large volume of connectivity matrices will likely gain momentum considering the increasing use of numerical models for applied science and population management.
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Affiliation(s)
- Clémentine Violette
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, IFREMER, CNRS, Université de la Nouvelle-Calédonie), BP 49 Vairao, Tahiti, French Polynesia; Bordeaux Sciences Agro, Gradignan 33170, France
| | - Romain Le Gendre
- UMR 9220 ENTROPIE (IFREMER, Institut de Recherche pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique, BP 32078, 98897 Noumea Cedex, New Caledonia
| | - Mathilde Chauveau
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, IFREMER, CNRS, Université de la Nouvelle-Calédonie), BP A5, 98848 Noumea Cedex, New Caledonia
| | - Serge Andréfouët
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, IFREMER, CNRS, Université de la Nouvelle-Calédonie), BP 49 Vairao, Tahiti, French Polynesia; UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, IFREMER, CNRS, Université de la Nouvelle-Calédonie), BP A5, 98848 Noumea Cedex, New Caledonia.
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4
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Bionaz O, Le Gendre R, Liao V, Andréfouët S. Natural stocks of Pinctada margaritifera pearl oysters in Tuamotu and Gambier lagoons: New assessments, temporal evolutions, and consequences for the French Polynesia pearl farming industry. MARINE POLLUTION BULLETIN 2022; 183:114055. [PMID: 36029582 DOI: 10.1016/j.marpolbul.2022.114055] [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: 06/17/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
Knowledge of the status of the black-lipped pearl oyster Pinctada margaritifera populations is critical for the sustainability of the French Polynesia black pearl farming industry. Indeed, this activity relies on collection of spat settling out of the water column, which is inherently related to the abundance of in situ benthic stocks and their reproductive capacities. From surveys performed between 2016 and 2021, we present new stock assessments of natural wild oyster populations from four contrasted pearl farming lagoons (Gambier, Takapoto, Raroia, Takume). Also using Ahe atoll historical data, we first highlight how results vary with the methods (Direct, Zonal and Cokriging) used to scale in situ density measurements to lagoon-scale stocks. Takapoto and Gambier populations were also previously surveyed at least twice since the 1980s, allowing to demonstrate with field data clear changes in stock distributions and population structures. The consequences of our findings are discussed to provide recommendations for stock monitoring and management in the future.
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Affiliation(s)
- Océane Bionaz
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, IFREMER, CNRS, Université de la Nouvelle-Calédonie), BP 49 Vairao, Tahiti, French Polynesia.
| | - Romain Le Gendre
- UMR 9220 ENTROPIE (IFREMER, Institut de Recherche pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP 32078, 98897 Noumea Cedex, New Caledonia
| | - Vetea Liao
- Direction des Ressources Marines, BP 20, 98713 Papeete, French Polynesia
| | - Serge Andréfouët
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, IFREMER, CNRS, Université de la Nouvelle-Calédonie), BP 49 Vairao, Tahiti, French Polynesia
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5
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Andréfouët S, Desclaux T, Buttin J, Jullien S, Aucan J, Le Gendre R, Liao V. Periodicity of wave-driven flows and lagoon water renewal for 74 Central Pacific Ocean atolls. MARINE POLLUTION BULLETIN 2022; 179:113748. [PMID: 35584571 DOI: 10.1016/j.marpolbul.2022.113748] [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: 05/31/2021] [Revised: 04/27/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
French Polynesia atolls are spread on a vast 2300 by 1200 km Central Pacific Ocean area exposed to spatially and temporally dependent wave forcing. They also have a wide range of closed to open morphologies and several have been suitable to develop from black-lipped pearl oysters a substantial pearl farming activity in the past 30 years, representing nowadays the 2nd source of income for French Polynesia. Considering here only the component of lagoon renewal that is driven by waves, we investigate for 74 atolls different lagoon renewal metrics using 20 years of wave model data at 0.05° spatial resolution. Wavelet spectral analyses highlight that atolls, even in close vicinity, can be exposed to different and characteristic periodicities in wave-driven flows and water renewal. These characteristics are discussed in relation to pearl farming atolls, including atolls known to be efficient oyster spat producers, a critical activity for pearl farming sustainability.
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Affiliation(s)
- Serge Andréfouët
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement), Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique, BP A5, 98848 Nouméa cedex, New Caledonia.
| | - Terence Desclaux
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement), Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique, BP A5, 98848 Nouméa cedex, New Caledonia
| | - Julie Buttin
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement), Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique, BP A5, 98848 Nouméa cedex, New Caledonia
| | - Swen Jullien
- Ifremer, Univ. Brest, CNRS, IRD, Laboratoire d'Océanographie Physique et Spatiale (LOPS), IUEM, Plouzané, France
| | - Jérôme Aucan
- IRD, LOCEAN (UMR 7159), BP A5, 98848 Nouméa cedex, New Caledonia
| | - Romain Le Gendre
- IFREMER, ENTROPIE, UMR 9220, Institut de Recherche pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique, BP 32078, 98897 Noumea Cedex, New Caledonia
| | - Vetea Liao
- Direction des Ressources Marines, BP 20, 98713 Papeete, French Polynesia
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Andréfouët S, Lo-Yat A, Lefebvre S, Bionaz O, Liao V. The MANA (MANagement of Atolls, 2017-2022) project for pearl oyster aquaculture management in the Central Pacific Ocean using modelling approaches: Overview of first results. MARINE POLLUTION BULLETIN 2022; 178:113649. [PMID: 35427816 DOI: 10.1016/j.marpolbul.2022.113649] [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: 03/06/2022] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
This editorial presents results of the MANA (MANagement of Atolls) project compiled in the form of a Marine Pollution Bulletin collection of 14 articles. MANA is a project funded by the French Agence National pour la Recherche that specifically addresses the development of knowledge and management tools for pearl farming atolls, with a focus on the spat collecting activity in French Polynesia. The 14 papers cover the range of thematic tasks described in the initial project, including atoll geomorphology and bathymetry, climate forcing, atoll lagoon and rim hydrodynamics, typology of atolls, evaluation of remote sensing data for monitoring atoll lagoons, and development of numerical models and spatially-explicit tools that altogether have contributed to the applied objectives. In addition, this editorial draws an update on the pearl farming industry in French Polynesia with the latest statistics, and discusses the next targeted priorities for research programs focusing on pearl farming atolls.
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Affiliation(s)
- Serge Andréfouët
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, Ifremer, CNRS, Université de la Nouvelle-Calédonie), 101, promenade Roger-Laroque Anse Vata, BP A5, 98848 Noumea, New Caledonia.
| | - Alain Lo-Yat
- UMR241 Ecosystèmes Insulaires Océaniens (EIO), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre du Pacifique, Unité Ressources Marines en Polynésie Française. BP. 49, 98725 Vairao, Tahiti, French Polynesia
| | - Sebastien Lefebvre
- Université de Lille/Station Marine de Wimereux, UMR LOG 'Laboratoire d'Océanologie et Géosciences'(Univ-Lille/CNRS/ULCO 8187), 28 avenue Foch, 62930 Wimereux, France
| | - Océane Bionaz
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, Ifremer, CNRS, Université de la Nouvelle-Calédonie), 101, promenade Roger-Laroque Anse Vata, BP A5, 98848 Noumea, New Caledonia
| | - Vetea Liao
- Direction des Ressources Marines, BP 20, 98713 Papeete, French Polynesia
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7
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Spatial Solutions and Their Impacts When Reshuffling Coastal Management Priorities in Small Islands with Limited Diversification Opportunities. SUSTAINABILITY 2022. [DOI: 10.3390/su14073871] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In small islands, the potential for new coastal activities and management options are often spatially limited. To reduce dependence on external factors and increase the resilience of populations to global changes and fluctuations in international markets, a recommended pathway is to diversify activities. We used a systematic prioritization tool with single and multiobjective zoning to explore the feasibility of scenarios at various levels of spatial diversification in the Gambier lagoon (French Polynesia), where black pearl culture is economically and spatially dominant. Local managers are committed to economic, livelihood, and environmental sustainability and agree that prioritizing both artisanal fisheries, which provide local food security, and ecosystem conservation should also be considered. Diversification options included the optimized reallocation of farming concessions and the identification of different types of conservation areas while taking into account traditional management areas. The scenarios were set to minimize surface areas and loss of access to existing fishing grounds. The solutions were compared between the scenarios with different cost metrics, allowing further discussions with stakeholders and managers. The Gambier case study shows that exploring diversification options in small islands using systematic prioritization tools can provide local managers with tailor-made plans adapted to island development questions.
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8
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André LV, Chinain M, Gatti CMI, Liao V, Van Wynsberge S, Tedesco P, Andréfouët S. A systematic prioritization approach for identifying suitable pearl oyster restocking zones following a mass mortality event in Takaroa Atoll, French Polynesia. MARINE POLLUTION BULLETIN 2022; 176:113472. [PMID: 35219077 DOI: 10.1016/j.marpolbul.2022.113472] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 05/28/2023]
Abstract
Oyster farming for black pearl production is central in French Polynesia. It is the second source of national income and provides substantial job opportunities, notably in remote atolls. However, this sector has been undermined by successive crises, such as mass-mortalities of wild and farmed oyster stocks that have impacted entire lagoons. An option to revive the activity consists of reintroducing oysters in strategic benthic locations selected to maximize reproduction and dispersal of larvae throughout the lagoon, hence promoting recolonization and spat collection for farming. For Takaroa, a Tuamotu atoll recently impacted by mortalities, a systematic prioritization approach identified these restocking sites, using environmental and socio-economic criteria such as: location of suitable habitats for oyster settlement, larval connectivity estimated from hydrodynamic circulation model, farming waste accumulation, and opportunity cost to fishers and farmers who lose access to restocking areas. This approach provides managers with a portfolio of restocking options.
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Affiliation(s)
- Laure Vaitiare André
- IRD Institut de Recherche pour le Développement - France, UMR 9220 Entropie, (Institut de Recherche pour le Développement - France, Université de la Réunion, Université de la Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia; SU Sorbonne Université, 21, rue de l'école de médecine, 75006 Paris, France.
| | - Mireille Chinain
- ILM Institut Louis Malardé, Laboratoire des Biotoxines Marines, UMR 241 EIO, (Ifremer, Institut Louis Malardé, Institut de Recherche pour le Développement, Université de la Polynésie française), BP 30, 98713 Papeete, Tahiti, French Polynesia
| | - Clémence M I Gatti
- ILM Institut Louis Malardé, Laboratoire des Biotoxines Marines, UMR 241 EIO, (Ifremer, Institut Louis Malardé, Institut de Recherche pour le Développement, Université de la Polynésie française), BP 30, 98713 Papeete, Tahiti, French Polynesia
| | - Vetea Liao
- DRM Direction des Ressources Marines, Fare Ute, BP 20, 98713 Papeete, Tahiti, French Polynesia
| | - Simon Van Wynsberge
- Ifremer Institut Français de Recherche pour l'Exploitation de la Mer, UMR 9220 Entropie, (Institut de Recherche pour le Développement - France, Université de la Réunion, Université de la Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
| | - Pauline Tedesco
- Ifremer Institut Français de Recherche pour l'Exploitation de la Mer, DYNECO/PHYSED, BP 70, 29280 Plouzané, France
| | - Serge Andréfouët
- IRD Institut de Recherche pour le Développement - France, UMR 9220 Entropie, (Institut de Recherche pour le Développement - France, Université de la Réunion, Université de la Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
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9
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Brahmi C, Chapron L, Le Moullac G, Soyez C, Beliaeff B, Lazareth CE, Gaertner-Mazouni N, Vidal-Dupiol J. Effects of elevated temperature and pCO 2 on the respiration, biomineralization and photophysiology of the giant clam Tridacna maxima. CONSERVATION PHYSIOLOGY 2021; 9:coab041. [PMID: 34150209 PMCID: PMC8208665 DOI: 10.1093/conphys/coab041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 01/18/2021] [Accepted: 05/22/2021] [Indexed: 06/12/2023]
Abstract
Many reef organisms, such as the giant clams, are confronted with global change effects. Abnormally high seawater temperatures can lead to mass bleaching events and subsequent mortality, while ocean acidification may impact biomineralization processes. Despite its strong ecological and socio-economic importance, its responses to these threats still need to be explored. We investigated physiological responses of 4-year-old Tridacna maxima to realistic levels of temperature (+1.5°C) and partial pressure of carbon dioxide (pCO2) (+800 μatm of CO2) predicted for 2100 in French Polynesian lagoons during the warmer season. During a 65-day crossed-factorial experiment, individuals were exposed to two temperatures (29.2°C, 30.7°C) and two pCO2 (430 μatm, 1212 μatm) conditions. The impact of each environmental parameter and their potential synergetic effect were evaluated based on respiration, biomineralization and photophysiology. Kinetics of thermal and/or acidification stress were evaluated by performing measurements at different times of exposure (29, 41, 53, 65 days). At 30.7°C, the holobiont O2 production, symbiont photosynthetic yield and density were negatively impacted. High pCO2 had a significant negative effect on shell growth rate, symbiont photosynthetic yield and density. No significant differences of the shell microstructure were observed between control and experimental conditions in the first 29 days; however, modifications (i.e. less-cohesive lamellae) appeared from 41 days in all temperature and pCO2 conditions. No significant synergetic effect was found. Present thermal conditions (29.2°C) appeared to be sufficiently stressful to induce a host acclimatization response. All these observations indicate that temperature and pCO2 are both forcing variables affecting T. maxima's physiology and jeopardize its survival under environmental conditions predicted for the end of this century.
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Affiliation(s)
- Chloé Brahmi
- Univ. Polynésie française, IFREMER, ILM, IRD, EIO UMR 241, F-98702 Faa’a, Tahiti, Polynésie française
| | - Leila Chapron
- School of Earth Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Gilles Le Moullac
- IFREMER, IRD, Institut Louis-Malardé, Univ. Polynésie française, EIO, F-98719 Taravao, Tahiti, Polynésie française, France
| | - Claude Soyez
- IFREMER, IRD, Institut Louis-Malardé, Univ. Polynésie française, EIO, F-98719 Taravao, Tahiti, Polynésie française, France
| | - Benoît Beliaeff
- IFREMER, IRD, Institut Louis-Malardé, Univ. Polynésie française, EIO, F-98719 Taravao, Tahiti, Polynésie française, France
| | - Claire E Lazareth
- Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA) MNHN, CNRS, IRD, SU, UCN, UA, Muséum National d'Histoire Naturelle, 61 Rue Buffon, CP53, 75231, Paris Cedex 05, France
| | - Nabila Gaertner-Mazouni
- Univ. Polynésie française, IFREMER, ILM, IRD, EIO UMR 241, F-98702 Faa’a, Tahiti, Polynésie française
| | - Jeremie Vidal-Dupiol
- IFREMER, IRD, Institut Louis-Malardé, Univ. Polynésie française, EIO, F-98719 Taravao, Tahiti, Polynésie française, France
- IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier France
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10
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Monaco CJ, Sangare N, Le Moullac G, Basset C, Belliard C, Mizuno K, Smith DL, Lo-Yat A. Dynamic Energy Budget model suggests feeding constraints and physiological stress in black-lip pearl oysters, 5 years post mass-mortality event. MARINE POLLUTION BULLETIN 2021; 167:112329. [PMID: 33862381 DOI: 10.1016/j.marpolbul.2021.112329] [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: 01/12/2021] [Revised: 03/03/2021] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
Mass-mortality events of marine species can disturb the structure of communities. While identifying the causes of mass-mortality events is crucial for implementing recovery strategies, monitoring is challenging in remote locations. Black-lip pearl oysters (Pinctada margaritifera) are farmed for producing black pearls within remote atolls of French Polynesia. Previous mass-mortality events have resulted in the collapse of oysters and other species; however, the causes and conditions that favour recovery are unclear. We investigated the potential for oyster population recovery 5 years after a mortality event at Takaroa Atoll (Tuamotu Archipelago). Temperature, food availability (total chlorophyll-a), growth and reproduction were monitored. Growth was also simulated using a Dynamic Energy Budget model. Despite favourable conditions, reduced growth and reproduction signalled an energetic deficit. The model overpredicted growth, and supported the hypotheses that individuals are unable to profit from the phytoplankton available and maintenance costs are high in Takaroa, ultimately explaining their poor physiological condition.
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Affiliation(s)
- Cristián J Monaco
- IFREMER, IRD, Institut Louis-Malardé, Univ Polynésie française, EIO, F-98719 Taravao, Tahiti, French Polynesia.
| | - Nathanael Sangare
- IFREMER, IRD, Institut Louis-Malardé, Univ Polynésie française, EIO, F-98719 Taravao, Tahiti, French Polynesia; UMR 9220 ENTROPIE, Institut de Recherche Pour le Développement (IRD, Université de la Réunion, Université de la Nouvelle-Calédonie, Ifremer, CNRS), B.P.A5, 98848 Nouméa, New Caledonia
| | - Gilles Le Moullac
- IFREMER, IRD, Institut Louis-Malardé, Univ Polynésie française, EIO, F-98719 Taravao, Tahiti, French Polynesia
| | - Caline Basset
- IFREMER, IRD, Institut Louis-Malardé, Univ Polynésie française, EIO, F-98719 Taravao, Tahiti, French Polynesia
| | - Corinne Belliard
- IFREMER, IRD, Institut Louis-Malardé, Univ Polynésie française, EIO, F-98719 Taravao, Tahiti, French Polynesia
| | - Keiichi Mizuno
- IFREMER, IRD, Institut Louis-Malardé, Univ Polynésie française, EIO, F-98719 Taravao, Tahiti, French Polynesia
| | | | - Alain Lo-Yat
- IFREMER, IRD, Institut Louis-Malardé, Univ Polynésie française, EIO, F-98719 Taravao, Tahiti, French Polynesia
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11
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André LV, Van Wynsberge S, Chinain M, Andréfouët S. An appraisal of systematic conservation planning for Pacific Ocean Tropical Islands coastal environments. MARINE POLLUTION BULLETIN 2021; 165:112131. [PMID: 33607453 DOI: 10.1016/j.marpolbul.2021.112131] [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: 03/19/2020] [Revised: 01/18/2021] [Accepted: 01/29/2021] [Indexed: 06/12/2023]
Abstract
Systematic Conservation Planning (SCP) offers concepts and toolboxes to make spatial decisions on where to focus conservation actions while minimizing a variety of costs to stakeholders. Thirty-four studies of Pacific Ocean Tropical Islands were scrutinized to categorize past and current types of applications. It appeared that scenarios were often built on a biodiversity representation objective, opportunity costs for fishers was the most frequent cost factor, and an evolution from simple to sophisticated scenarios followed the need to maximize resilience and connectivity while mitigating climate change impacts. However, proxies and models were often not validated, pointing to data quality issues. Customary management by local communities motivated applications specific to the Pacific region, but several island features remained ignored, including invertebrate fishing, ciguatera poisoning and mariculture. Fourteen recommendations are provided to enhance scenarios' robustness, island specificities integration, complex modelling accuracy, and better use of SCP for island management.
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Affiliation(s)
- Laure Vaitiare André
- IRD Institut de Recherche pour le Développement - France, UMR 9220 Entropie (Institut de Recherche pour le Développement - France, Université de la Réunion, Université de la Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia; SU Sorbonne Université, 21, rue de l'école de médecine, 75006 Paris, France.
| | - Simon Van Wynsberge
- Ifremer Institut Français de Recherche pour l'Exploitation de la Mer, UMR 9220 Entropie (Institut de Recherche pour le Développement - France, Université de la Réunion, Université de la Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
| | - Mireille Chinain
- ILM Institut Louis Malardé, UMR 241 EIO (Ifremer, Institut Louis Malardé, Institut de Recherche pour le Développement, Université de la Polynésie française), BP 30, 98713 Papeete, Tahiti, French Polynesia
| | - Serge Andréfouët
- IRD Institut de Recherche pour le Développement - France, UMR 9220 Entropie (Institut de Recherche pour le Développement - France, Université de la Réunion, Université de la Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
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12
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Resilience of Tropical Ecosystems to Ocean Deoxygenation. Trends Ecol Evol 2021; 36:227-238. [PMID: 33419595 DOI: 10.1016/j.tree.2020.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 01/18/2023]
Abstract
The impacts of ocean deoxygenation on biodiversity and ecosystem function are well established in temperate regions, and here we illustrate how the study of hypoxia in tropical ecosystems can offer insights of general importance. We first describe how mechanisms of resilience have developed in response to naturally occurring hypoxia across three tropical ecosystems: coral reefs, seagrass beds, and mangrove forests. We then suggest that the vulnerability of these systems to deoxygenation lies in interactions with other stressors that are increasing rapidly in the Anthropocene. Finally, we advocate for the adoption of a broader community- and ecosystem-level perspective that incorporates mutualisms, feedbacks, and mechanisms of self-rescue and recovery to develop a better predictive understanding of the effects of deoxygenation in coastal ecosystems.
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13
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Dutheil C, Jullien S, Aucan J, Menkes C, Le Gendre R, Andréfouët S. The wave regimes of the Central Pacific Ocean with a focus on pearl farming atolls. MARINE POLLUTION BULLETIN 2021; 162:111751. [PMID: 33162053 DOI: 10.1016/j.marpolbul.2020.111751] [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: 05/28/2020] [Revised: 10/04/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
Pearl farming sustainability in South Central Pacific (SCP) atolls strongly depends on water quality and renewal. These factors are partly controlled by the wave conditions that impact the lagoon circulation. To characterize the wave conditions around 83 SCP atolls including those hosting pearl farming activities, we used 18 years of WaveWatchIII simulation with a grid refined from 50 to 5 km resolution. Three regional wave regimes are statistically identified: two associated with long distant swells originating from mid-latitude storms, and one with local trade winds. All regimes occur with a relatively high frequency (22-44%), but with a marked seasonality. Wave conditions are also strongly modified locally during their propagation between the archipelagoes. Western and southern isolated atolls generally have a single regime all around their rims. In contrast, central Tuamotu atolls experience different regimes depending on their levels of protection. These results help understanding atoll hydrodynamics, which has implications for their management.
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Affiliation(s)
- Cyril Dutheil
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa Cedex, New Caledonia; IRD, LOCEAN (UMR 7159), BP A5, 98848 Nouméa Cedex, New Caledonia; Department of Physical Oceanography and Instrumentation, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany.
| | - S Jullien
- Ifremer, Univ. Brest, CNRS, IRD, Laboratoire d'Océanographie Physique et Spatiale (LOPS), IUEM, Plouzané, France
| | - J Aucan
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa Cedex, New Caledonia
| | - C Menkes
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa Cedex, New Caledonia
| | - R Le Gendre
- IFREMER, ENTROPIE (UMR 9220), Institut de Recherche pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Centre National de la Recherche Scientifique, BP 32078, 98897 Noumea Cedex, New Caledonia
| | - S Andréfouët
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa Cedex, New Caledonia
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14
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Van Wynsberge S, Le Gendre R, Sangare N, Aucan J, Menkes C, Liao V, Andréfouët S. Monitoring pearl farming lagoon temperature with global high resolution satellite-derived products: An evaluation using Raroia Atoll, French Polynesia. MARINE POLLUTION BULLETIN 2020; 160:111576. [PMID: 32861941 DOI: 10.1016/j.marpolbul.2020.111576] [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: 04/17/2020] [Revised: 08/13/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Temperature is important for pearl oyster reproduction, pelagic larval duration, and growth in the context of pearl farming, but has seldom been monitored over long periods in remote atolls. To test if satellite-derived Sea Surface Temperature (SST) could provide a solution, two daily global SST products were compared with 18 high-precision loggers deployed during 10-months in the wide Raroia atoll (Tuamotu Archipelago, French Polynesia). The Multi-scale-Ultra-high-Resolution (MUR) SST was better correlated with lagoon temperature (r > 0.97) than the Global-Foundation-Sea-Surface-Temperature-Analysis (G1SST) SST (r < 0.94). Differences between observations and MUR SST ranged between -0.75 °C and + 1.12 °C and were influenced by seasons and locations, depth, and hours of measurements. Within this uncertainty range, simulations using a Dynamic Energy Budget model predicted similar life traits of oysters. Therefore, MUR SST appears suitable to monitor lagoon temperature in wide atolls, model oyster population dynamics and assist pearl oyster research and management.
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Affiliation(s)
- Simon Van Wynsberge
- Ifremer, IRD, Univ Nouvelle-Calédonie, Univ LaRéunion, CNRS, ENTROPIE, F-98800 Nouméa, New Caledonia.
| | - Romain Le Gendre
- Ifremer, IRD, Univ Nouvelle-Calédonie, Univ LaRéunion, CNRS, ENTROPIE, F-98800 Nouméa, New Caledonia
| | - Nathanaël Sangare
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, IFREMER, Université de la Nouvelle-Calédonie, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia; Ifremer, IRD, Institut Louis-Malardé, Univ Polynésie française, EIO, F-98719 Taravao Tahiti, French Polynesia
| | - Jérôme Aucan
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, IFREMER, Université de la Nouvelle-Calédonie, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
| | - Christophe Menkes
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, IFREMER, Université de la Nouvelle-Calédonie, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
| | - Vetea Liao
- Direction des Ressources Marines, Papeete, French Polynesia
| | - Serge Andréfouët
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, IFREMER, Université de la Nouvelle-Calédonie, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
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15
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Dutheil C, Andrefouët S, Jullien S, Le Gendre R, Aucan J, Menkes C. Characterization of south central Pacific Ocean wind regimes in present and future climate for pearl farming application. MARINE POLLUTION BULLETIN 2020; 160:111584. [PMID: 32896714 DOI: 10.1016/j.marpolbul.2020.111584] [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: 02/10/2020] [Revised: 08/13/2020] [Accepted: 08/16/2020] [Indexed: 06/11/2023]
Abstract
In the South Pacific (SP) pearl farming atolls, wind is the main driver of lagoon water circulation, affecting dispersal and survival of pearl oyster larvae. To characterize typical wind conditions in the SP, wind regime classifications are performed from regional climate simulations using the WRF model, for present-day and for the end of the 21st century under RCP8.5 scenario conditions. At the daily time-scale, 4 regimes are identified: a trade-wind, a north-easterly, and two easterly regimes. Their characteristics are driven by large-scale circulation and climate modes of variability. In future projection, all regimes are characterized by a ~15% wind speed increase, while directions and occurrence frequencies undergo marginal changes. At the monthly time-scale that corresponds to pearl oyster pelagic larval duration, nine wind regimes are determined including three regimes with wind reversals. These regimes can be used to model typical lagoon conditions during larval dispersal.
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Affiliation(s)
- Cyril Dutheil
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia; IRD, LOCEAN (UMR 7159), BP A5, 98848 Nouméa cedex, New Caledonia.
| | - S Andrefouët
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
| | - S Jullien
- IFREMER, Univ. Brest, CNRS, IRD, Laboratoire d'Océanographie Physique et Spatiale (LOPS), IUEM, Plouzané, France
| | - R Le Gendre
- IFREMER, Unité de Recherche Lagons, Ecosystèmes et Aquaculture Durable, ENTROPIE (UMR 9220), BP 32078, 98897 Noumea Cedex, New Caledonia
| | - J Aucan
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
| | - C Menkes
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Université de Nouvelle-Calédonie, Ifremer, Centre National de la Recherche Scientifique), BP A5, 98848 Nouméa cedex, New Caledonia
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16
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Bellino A, Mangano MC, Baldantoni D, Russell BD, Mannino AM, Mazzola A, Vizzini S, Sarà G. Seasonal patterns of biodiversity in Mediterranean coastal lagoons. DIVERS DISTRIB 2019. [DOI: 10.1111/ddi.12942] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Alessandro Bellino
- Dipartimento di Chimica e Biologia “Adolfo Zambelli” (DCB) Università degli Studi di Salerno Fisciano (Salerno) Italy
| | - Maria Cristina Mangano
- Dipartimento di Scienze della Terra e del Mare (DISTEM) Università di Palermo Palermo Italy
| | - Daniela Baldantoni
- Dipartimento di Chimica e Biologia “Adolfo Zambelli” (DCB) Università degli Studi di Salerno Fisciano (Salerno) Italy
| | - Bayden Dwight Russell
- The Swire Institute of Marine Science and School of Biological Sciences The University of Hong Kong Hong Kong SAR China
| | - Anna Maria Mannino
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF) Università degli Studi di Palermo Palermo Italy
| | - Antonio Mazzola
- Dipartimento di Scienze della Terra e del Mare (DISTEM) Università di Palermo Palermo Italy
| | - Salvatrice Vizzini
- Dipartimento di Scienze della Terra e del Mare (DISTEM) Università di Palermo Palermo Italy
| | - Gianluca Sarà
- Dipartimento di Scienze della Terra e del Mare (DISTEM) Università di Palermo Palermo Italy
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17
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Nieder C, Liao CP, Chen CA, Liu SL. Filamentous calcareous alga provides substrate for coral-competitive macroalgae in the degraded lagoon of Dongsha Atoll, Taiwan. PLoS One 2019; 14:e0200864. [PMID: 31095566 PMCID: PMC6522048 DOI: 10.1371/journal.pone.0200864] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 05/05/2019] [Indexed: 12/11/2022] Open
Abstract
Background The chemically-rich seaweed Galaxaura is not only highly competitive with corals, but also provides substrate for other macroalgae. Its ecology and associated epiphytes remain largely unexplored. To fill this knowledge gap, we undertook an ecological assessment to explore the spatial variation, temporal dynamics, and diversity of epiphytic macroalgae of Galaxaura divaricata on patch reefs in the lagoon of Dongsha Atoll, a shallow coral reef ecosystem in the northern South China Sea that has been repeatedly impacted by mass coral bleaching events. Methods Twelve spatially independent patch reefs in the Dongsha lagoon were first surveyed to assess benthic composition in April 2016, and then revisited to determine G. divaricata cover in September 2017, with one additional Galaxaura-dominated reef (site 9). Four surveys over a period of 17 months were then carried out on a degraded patch reef site to assess the temporal variation in G. divaricata cover. Epiphytic macroalgae associated with G. divaricata were quantified and identified through the aid of DNA barcoding at this degraded site. Results Patch reefs in the Dongsha lagoon were degraded, exhibiting relatively low coral cover (5–43%), but high proportions of macroalgae (13–58%) and other substrate (rubble and dead corals; 23–69%). The distribution of G. divaricata was heterogeneous across the lagoon, with highest abundance (16–41%) in the southeast area. Temporal surveys showed consistently high covers (mean ± SD = 16.9 ± 1.21%) of G. divaricata for 17 months. Additional photographic evidence suggested that overgrowth of G. divaricata can persist for 3.5 years. Yet, G. divaricata provides substrate to other macroalgae (e.g., Lobophora sp.) that also limit the growth of corals. Conclusions Our study demonstrates that an allelopathic seaweed, such as G. divaricata, can overgrow degraded coral reefs for extended periods of time. By providing habitat for other harmful macroalgae, a prolonged Galaxaura overgrowth could further enhance the spread of macroalgae, and strengthen negative feedback loops, decreasing the recovery potential of degraded reefs.
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Affiliation(s)
- Carolin Nieder
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, Leigh, New Zealand
| | - Chen-Pan Liao
- Department of Life Science & Center for Ecology and Environment, Tunghai University, Taichung, Taiwan
- Department of Biology, National Museum of Natural Science, Taichung, Taiwan
| | - Chaolun Allen Chen
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Shao-Lun Liu
- Department of Life Science & Center for Ecology and Environment, Tunghai University, Taichung, Taiwan
- * E-mail:
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Wolfe K, Vidal-Ramirez F, Dove S, Deaker D, Byrne M. Altered sediment biota and lagoon habitat carbonate dynamics due to sea cucumber bioturbation in a high-pCO 2 environment. GLOBAL CHANGE BIOLOGY 2018; 24:465-480. [PMID: 28727218 DOI: 10.1111/gcb.13826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 07/06/2017] [Indexed: 06/07/2023]
Abstract
The effects of global change on biological systems and functioning are already measurable, but how ecological interactions are being altered is poorly understood. Ecosystem resilience is strengthened by ecological functionality, which depends on trophic interactions between key species and resilience generated through biogenic buffering. Climate-driven alterations to coral reef metabolism, structural complexity and biodiversity are well documented, but the feedbacks between ocean change and trophic interactions of non-coral invertebrates are understudied. Sea cucumbers, some of the largest benthic inhabitants of tropical lagoon systems, can influence diel changes in reef carbonate dynamics. Whether they have the potential to exacerbate or buffer ocean acidification over diel cycles depends on their relative production of total alkalinity (AT ) through the dissolution of ingested calcium carbonate (CaCO3 ) sediments and release of dissolved inorganic carbon (CT ) through respiration and trophic interactions. In this study, the potential for the sea cucumber, Stichopus herrmanni, a bêche-de-mer (fished) species listed as vulnerable to extinction, to buffer the impacts of ocean acidification on reef carbonate chemistry was investigated in lagoon sediment mesocosms across diel cycles. Stichopus herrmanni directly reduced the abundance of meiofauna and benthic primary producers through its deposit-feeding activity under present-day and near-future pCO2 . These changes in benthic community structure, as well as AT (sediment dissolution) and CT (respiration) production by S. herrmanni, played a significant role in modifying seawater carbonate dynamics night and day. This previously unappreciated role of tropical sea cucumbers, in support of ecosystem resilience in the face of global change, is an important consideration with respect to the bêche-de-mer trade to ensure sea cucumber populations are sustained in a future ocean.
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Affiliation(s)
- Kennedy Wolfe
- School of Medical Sciences, The University of Sydney, Sydney, NSW, Australia
| | | | - Sophie Dove
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Dione Deaker
- School of Medical Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Maria Byrne
- School of Medical Sciences, The University of Sydney, Sydney, NSW, Australia
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
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Van Wynsberge S, Andréfouët S, Gaertner-Mazouni N, Remoissenet G. Consequences of an uncertain mass mortality regime triggered by climate variability on giant clam population management in the Pacific Ocean. Theor Popul Biol 2017; 119:37-47. [PMID: 29158140 DOI: 10.1016/j.tpb.2017.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 08/18/2017] [Accepted: 10/26/2017] [Indexed: 10/18/2022]
Abstract
Despite actions to manage sustainably tropical Pacific Ocean reef fisheries, managers have faced failures and frustrations because of unpredicted mass mortality events triggered by climate variability. The consequences of these events on the long-term population dynamics of living resources need to be better understood for better management decisions. Here, we use a giant clam (Tridacna maxima) spatially explicit population model to compare the efficiency of several management strategies under various scenarios of natural mortality, including mass mortality due to climatic anomalies. The model was parameterized by in situ estimations of growth and mortality and fishing effort, and was validated by historical and new in situ surveys of giant clam stocks in two French Polynesia lagoons. Projections on the long run (100 years) suggested that the best management strategy was a decrease of fishing pressure through quota implementation, regardless of the mortality regime considered. In contrast, increasing the minimum legal size of catch and closing areas to fishing were less efficient. When high mortality occurred due to climate variability, the efficiency of all management scenarios decreased markedly. Simulating El Niño Southern Oscillation event by adding temporal autocorrelation in natural mortality rates increased the natural variability of stocks, and also decreased the efficiency of management. These results highlight the difficulties that managers in small Pacific islands can expect in the future in the face of global warming, climate anomalies and new mass mortalities.
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Affiliation(s)
- Simon Van Wynsberge
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Centre National de la Recherche Scientifique). Centre IRD de Tahiti, Chemin de l'Arahiri, pk 3.5, 98713 Arue, BP 529, 98713 Papeete, Tahiti, French Polynesia; Université de la Polynésie Française, UMR-241 EIO (Université de la Polynésie française, Institut Français de Recherche pour l'Exploitation de la MER, Institut de Recherche pour le Développement, Institut Louis Malardé), Laboratoire d'Excellence CORAIL, BP 6570, 98702 Faa'a, Tahiti, French Polynesia.
| | - Serge Andréfouët
- Institut de Recherche pour le Développement, UMR 9220 ENTROPIE (Institut de Recherche Pour le Développement, Université de la Réunion, Centre National de la Recherche Scientifique). Centre IRD de Nouméa, 101 Promenade Roger Laroque, 98848 Nouméa, New Caledonia
| | - Nabila Gaertner-Mazouni
- Université de la Polynésie Française, UMR-241 EIO (Université de la Polynésie française, Institut Français de Recherche pour l'Exploitation de la MER, Institut de Recherche pour le Développement, Institut Louis Malardé), Laboratoire d'Excellence CORAIL, BP 6570, 98702 Faa'a, Tahiti, French Polynesia
| | - Georges Remoissenet
- Direction des Ressources Marines et Minières, Fare Ute, Immeuble Le caill, BP 20, 98713 Papeete, Tahiti, French Polynesia
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Abstract
Degradation of coastal water quality in the form of low dissolved oxygen levels (hypoxia) can harm biodiversity, ecosystem function, and human wellbeing. Extreme hypoxic conditions along the coast, leading to what are often referred to as "dead zones," are known primarily from temperate regions. However, little is known about the potential threat of hypoxia in the tropics, even though the known risk factors, including eutrophication and elevated temperatures, are common. Here we document an unprecedented hypoxic event on the Caribbean coast of Panama and assess the risk of dead zones to coral reefs worldwide. The event caused coral bleaching and massive mortality of corals and other reef-associated organisms, but observed shifts in community structure combined with laboratory experiments revealed that not all coral species are equally sensitive to hypoxia. Analyses of global databases showed that coral reefs are associated with more than half of the known tropical dead zones worldwide, with >10% of all coral reefs at elevated risk for hypoxia based on local and global risk factors. Hypoxic events in the tropics and associated mortality events have likely been underreported, perhaps by an order of magnitude, because of the lack of local scientific capacity for their detection. Monitoring and management plans for coral reef resilience should incorporate the growing threat of coastal hypoxia and include support for increased detection and research capacity.
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Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia. PLoS One 2017; 12:e0170565. [PMID: 28118406 PMCID: PMC5261826 DOI: 10.1371/journal.pone.0170565] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 01/08/2017] [Indexed: 11/20/2022] Open
Abstract
Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems.
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Heterotrophy promotes the re-establishment of photosynthate translocation in a symbiotic coral after heat stress. Sci Rep 2016; 6:38112. [PMID: 27917888 PMCID: PMC5137022 DOI: 10.1038/srep38112] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/04/2016] [Indexed: 12/20/2022] Open
Abstract
Symbiotic scleractinian corals are particularly affected by climate change stress and respond by bleaching (losing their symbiotic dinoflagellate partners). Recently, the energetic status of corals is emerging as a particularly important factor that determines the corals’ vulnerability to heat stress. However, detailed studies of coral energetic that trace the flow of carbon from symbionts to host are still sparse. The present study thus investigates the impact of heat stress on the nutritional interactions between dinoflagellates and coral Stylophora pistillata maintained under auto- and heterotrophy. First, we demonstrated that the percentage of autotrophic carbon retained in the symbionts was significantly higher during heat stress than under non-stressful conditions, in both fed and unfed colonies. This higher photosynthate retention in symbionts translated into lower rates of carbon translocation, which required the coral host to use tissue energy reserves to sustain its respiratory needs. As calcification rates were positively correlated to carbon translocation, a significant decrease in skeletal growth was observed during heat stress. This study also provides evidence that heterotrophic nutrient supply enhances the re-establishment of normal nutritional exchanges between the two symbiotic partners in the coral S. pistillata, but it did not mitigate the effects of temperature stress on coral calcification.
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Shuail D, Wiedenmann J, D'Angelo C, Baird AH, Pratchett MS, Riegl B, Burt JA, Petrov P, Amos C. Local bleaching thresholds established by remote sensing techniques vary among reefs with deviating bleaching patterns during the 2012 event in the Arabian/Persian Gulf. MARINE POLLUTION BULLETIN 2016; 105:654-659. [PMID: 26971815 DOI: 10.1016/j.marpolbul.2016.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/06/2016] [Accepted: 03/01/2016] [Indexed: 06/05/2023]
Abstract
A severe bleaching event affected coral communities off the coast of Abu Dhabi, UAE in August/September, 2012. In Saadiyat and Ras Ghanada reefs ~40% of the corals showed signs of bleaching. In contrast, only 15% of the corals were affected on Delma reef. Bleaching threshold temperatures for these sites were established using remotely sensed sea surface temperature (SST) data recorded by MODIS-Aqua. The calculated threshold temperatures varied between locations (34.48 °C, 34.55 °C, 35.05 °C), resulting in site-specific deviations in the numbers of days during which these thresholds were exceeded. Hence, the less severe bleaching of Delma reef might be explained by the lower relative heat stress experienced by this coral community. However, the dominance of Porites spp. that is associated with the long-term exposure of Delma reef to elevated temperatures, as well as the more pristine setting may have additionally contributed to the higher coral bleaching threshold for this site.
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Affiliation(s)
- Dawood Shuail
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, SO143ZH Southampton, UK
| | - Jörg Wiedenmann
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, SO143ZH Southampton, UK
| | - Cecilia D'Angelo
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, SO143ZH Southampton, UK
| | - Andrew H Baird
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Morgan S Pratchett
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Bernhard Riegl
- National Coral Reef Institute, Nova Southeastern University, Fort Lauderdale, Florida 33314-7796, USA
| | - John A Burt
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Peter Petrov
- Regional Organization for the Protection of the Marine Environment (ROPME), 13124 Safat, Kuwait
| | - Carl Amos
- Coral Reef Laboratory, Ocean and Earth Science, University of Southampton, SO143ZH Southampton, UK
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Velásquez J, Sánchez JA. Octocoral Species Assembly and Coexistence in Caribbean Coral Reefs. PLoS One 2015; 10:e0129609. [PMID: 26177191 PMCID: PMC4503594 DOI: 10.1371/journal.pone.0129609] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 05/11/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND What are the determinant factors of community assemblies in the most diverse ecosystem in the ocean? Coral reefs can be divided in continental (i.e., reefs that develop on the continental shelf, including siliciclastic reefs) and oceanic (i.e., far off the continental shelf, usually on volcanic substratum); whether or not these habitat differences impose community-wide ecological divergence or species exclusion/coexistence with evolutionary consequences, is unknown. METHODS Studying Caribbean octocorals as model system, we determined the phylogenetic community structure in a coral reef community, making emphasis on species coexistence evidenced on trait evolution and environmental feedbacks. Forty-nine species represented in five families constituted the species pool from which a phylogenetic tree was reconstructed using mtDNA. We included data from 11 localities in the Western Caribbean (Colombia) including most reef types. To test diversity-environment and phenotype-environment relationships, phylogenetic community structure and trait evolution we carried out comparative analyses implementing ecological and evolutionary approaches. RESULTS Phylogenetic inferences suggest clustering of oceanic reefs (e.g., atolls) contrasting with phylogenetic overdispersion of continental reefs (e.g., reefs banks). Additionally, atolls and barrier reefs had the highest species diversity (Shannon index) whereas phylogenetic diversity was higher in reef banks. The discriminant component analysis supported this differentiation between oceanic and continental reefs, where continental octocoral species tend to have greater calyx apertures, thicker branches, prominent calyces and azooxanthellate species. This analysis also indicated a clear separation between the slope and the remaining habitats, caused by the presence or absence of Symbiodinium. K statistic analysis showed that this trait is conserved as well as the branch shape. DISCUSSION There was strong octocoral community structure with opposite diversity and composition patterns between oceanic and continental reefs. Even habitats with similar depths and overall environmental conditions did not share similar communities between oceanic and continental reefs. This indicates a strong regional influence over the local communities, probably due to water transparency differences between major reef types, i.e., oceanic vs. continental shelf-neritic. This was supported by contrasting patterns found in morphology, composition and evolutionary history of the species between atolls and reef banks.
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Affiliation(s)
- Johanna Velásquez
- Departamento de Ciencias Biológicas-Facultad de Ciencias, Laboratorio de Biología Molecular Marina (BIOMMAR), Universidad de los Andes, Carrera 1E No 18A–10, Bogotá, 111711, Colombia
| | - Juan A. Sánchez
- Departamento de Ciencias Biológicas-Facultad de Ciencias, Laboratorio de Biología Molecular Marina (BIOMMAR), Universidad de los Andes, Carrera 1E No 18A–10, Bogotá, 111711, Colombia
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