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Helias M, Grall J, Jardim VL, Toumi C, Burel T. Changes in maerl-associated macroalgal community dynamics as evidence of anthropogenic pressure. ANNALS OF BOTANY 2024; 133:1025-1040. [PMID: 38502708 PMCID: PMC11089261 DOI: 10.1093/aob/mcae042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 03/18/2024] [Indexed: 03/21/2024]
Abstract
BACKGROUND AND AIMS Maerl-associated communities have received considerable attention due to their uniqueness, biodiversity and functional importance. Although the impacts of human activities are well documented for maerl-associated macrofauna, the spatio-temporal variations of macroalgae have comparatively been neglected, and the drivers that influence their dynamics are poorly known. We investigate the links between maerl-associated macroalgal communities, anthropogenic pressures and environmental conditions, and hypothesize that sites under human pressure would exhibit different dynamics when compared to reference sites. METHODS To better understand community variation through space and time, four subtidal maerl beds under different pressures were consistently monitored over one year in the bay of Brest, Brittany, France. Both macroalgae community monitoring and environmental data were acquired through field sampling and available models. KEY RESULTS Higher macroalgal biomass was observed within eutrophic sites, especially in summer (more than ten times higher than in the Unimpacted site), caused by free-living forms of opportunistic red macroalgae. The Dredged site also exhibited distinct macroalgal communities during summer from the Unimpacted site. Nutrient concentrations and seasonality proved to be key factors affecting the macroalgal community composition, although dredging and its effects on granulometry also had a strong influence. Over the long term, fewer than half of the species identified during historical surveys were found, indicating major temporal changes. CONCLUSIONS Human pressures have strong impacts on maerl-associated macroalgal communities. Nutrient concentrations and dredging pressure appear as the main anthropogenic factors shaping maerl-associated macroalgal communities. Additionally, our results suggest historical changes in maerl-associated macroalgal communities over 25 years in response to changes in local human pressure management. This study suggests that maerl-associated macroalgal communities could be used as indicators of anthropogenically driven changes in this habitat.
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Affiliation(s)
- Mathieu Helias
- UMS 3113, Observatoire Marin, Université de Brest, Plouzané, Brittany, France
| | - Jacques Grall
- Université de Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, Brittany, France
- UMS 3113, Observatoire Marin, Université de Brest, Plouzané, Brittany, France
| | - Victor L Jardim
- Université de Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, Brittany, France
| | - Chirine Toumi
- Université de Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, Brittany, France
| | - Thomas Burel
- Université de Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, Brittany, France
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2
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Teichert S, Reddin CJ, Wisshak M. In situ decrease in rhodolith growth associated with Arctic climate change. GLOBAL CHANGE BIOLOGY 2024; 30:e17300. [PMID: 38738563 DOI: 10.1111/gcb.17300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 03/12/2024] [Accepted: 04/05/2024] [Indexed: 05/14/2024]
Abstract
Rhodoliths built by crustose coralline algae (CCA) are ecosystem engineers of global importance. In the Arctic photic zone, their three-dimensional growth emulates the habitat complexity of coral reefs but with a far slower growth rate, growing at micrometers per year rather than millimeters. While climate change is known to exert various impacts on the CCA's calcite skeleton, including geochemical and structural alterations, field observations of net growth over decade-long timescales are lacking. Here, we use a temporally explicit model to show that rising ocean temperatures over nearly 100 years were associated with reduced rhodolith growth at different depths in the Arctic. Over the past 90 years, the median growth rate was 85 μm year-1 but each °C increase in summer seawater temperature decreased growth by a mean of 8.9 μm (95% confidence intervals = 1.32-16.60 μm °C-1, p < .05). The decrease was expressed for rhodolith occurrences in 11 and 27 m water depth but not at 46 m, also having the shortest time series (1991-2015). Although increasing temperatures can spur plant growth, we suggest anthropogenic climate change has either exceeded the population thermal optimum for these CCA, or synergistic effects of warming, ocean acidification, and/or increasing turbidity impair rhodolith growth. Rhodoliths built by calcitic CCA are important habitat providers worldwide, so decreased growth would lead to yet another facet of anthropogenic habitat loss.
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Affiliation(s)
- Sebastian Teichert
- Lehrstuhl für Paläoumwelt, GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Carl J Reddin
- Lehrstuhl für Paläoumwelt, GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Integrative Ecophysiology Section, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
| | - Max Wisshak
- Marine Research Department, Senckenberg am Meer, Wilhelmshaven, Germany
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3
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Wernberg T, Thomsen MS, Baum JK, Bishop MJ, Bruno JF, Coleman MA, Filbee-Dexter K, Gagnon K, He Q, Murdiyarso D, Rogers K, Silliman BR, Smale DA, Starko S, Vanderklift MA. Impacts of Climate Change on Marine Foundation Species. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:247-282. [PMID: 37683273 DOI: 10.1146/annurev-marine-042023-093037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
Marine foundation species are the biotic basis for many of the world's coastal ecosystems, providing structural habitat, food, and protection for myriad plants and animals as well as many ecosystem services. However, climate change poses a significant threat to foundation species and the ecosystems they support. We review the impacts of climate change on common marine foundation species, including corals, kelps, seagrasses, salt marsh plants, mangroves, and bivalves. It is evident that marine foundation species have already been severely impacted by several climate change drivers, often through interactive effects with other human stressors, such as pollution, overfishing, and coastal development. Despite considerable variation in geographical, environmental, and ecological contexts, direct and indirect effects of gradual warming and subsequent heatwaves have emerged as the most pervasive drivers of observed impact and potent threat across all marine foundation species, but effects from sea level rise, ocean acidification, and increased storminess are expected to increase. Documented impacts include changes in the genetic structures, physiology, abundance, and distribution of the foundation species themselves and changes to their interactions with other species, with flow-on effects to associated communities, biodiversity, and ecosystem functioning. We discuss strategies to support marine foundation species into the Anthropocene, in order to increase their resilience and ensure the persistence of the ecosystem services they provide.
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Affiliation(s)
- Thomas Wernberg
- Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia;
- Flødevigen Research Station, Institute of Marine Research, His, Norway
| | - Mads S Thomsen
- Marine Ecology Research Group, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Department of Ecoscience, Aarhus University, Roskilde, Denmark
| | - Julia K Baum
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Melanie J Bishop
- School of Natural Sciences, Macquarie University, Macquarie Park, New South Wales, Australia
| | - John F Bruno
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Melinda A Coleman
- National Marine Science Centre, New South Wales Department of Primary Industries, Coffs Harbour, New South Wales, Australia
| | - Karen Filbee-Dexter
- Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia;
- Flødevigen Research Station, Institute of Marine Research, His, Norway
| | - Karine Gagnon
- Flødevigen Research Station, Institute of Marine Research, His, Norway
| | - Qiang He
- Coastal Ecology Lab, MOE Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Daniel Murdiyarso
- Center for International Forestry Research-World Agroforestry (CIFOR-ICRAF), Bogor, Indonesia
- Department of Geophysics and Meteorology, IPB University, Bogor, Indonesia
| | - Kerrylee Rogers
- School of Earth, Atmospheric, and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Brian R Silliman
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Dan A Smale
- Marine Biological Association of the United Kingdom, Plymouth, United Kingdom
| | - Samuel Starko
- Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia;
| | - Mathew A Vanderklift
- Indian Ocean Marine Research Centre, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Crawley, Western Australia, Australia
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4
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Jardim VL, Gauthier O, Toumi C, Grall J. Quantifying maerl (rhodolith) habitat complexity along an environmental gradient at regional scale in the Northeast Atlantic. MARINE ENVIRONMENTAL RESEARCH 2022; 181:105768. [PMID: 36240648 DOI: 10.1016/j.marenvres.2022.105768] [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: 06/08/2022] [Revised: 09/19/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Maerl beds are ecologically important marine biogenic habitats founded on a few species of free-living coralline algae that aggregate and form highly complex rhodoliths. The high biodiversity found in these habitats have been mainly justified by the structural complexity that they provide. However, few attempts to quantify this complexity have been made. Maerl species distribution, density, rhodolith growth forms, and shapes vary with environmental conditions. Hydrodynamics and depth have been shown to drive morphology. Using species-specific metrics such as sphericity and branching density, as well as diameter and fractal dimension at the rhodolith level, and maerl density at the habitat level, we quantified the habitat complexity within ten maerl beds at a regional scale (along ∼400 km of the coastline of Brittany in Western France). Using both long-term monitoring data and environmental models, we investigated how maerl habitat complexity varies among beds and which environmental conditions drive those differences. The effects of currents, exposure to wind-generated waves, temperature and sediment granulometry were evaluated. We confirmed variations in complexity in maerl beds at the habitat and rhodolith levels at local and regional scales, which might have ecological and conservational implications for their associated biodiversity. The analysed environmental conditions drive around a third of the variance in habitat complexity. Sediment granulometry is the main driver of maerl habitat complexity in Brittany, while the isolated effects of depth and hydrodynamics accounted for less than 5% of the variability each. Our results have important implications for paleoecology, and we suggest that maerl facies should be interpreted carefully. Our study provides a first attempt at explicitly quantifying maerl habitat complexity, and further contributes to the understanding of this fundamental ecological question.
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Affiliation(s)
- Victor L Jardim
- LEMAR, Univ Brest, CNRS, IRD, Ifremer, 29280, Plouzané, France.
| | - Olivier Gauthier
- LEMAR, Univ Brest, CNRS, IRD, Ifremer, 29280, Plouzané, France; OSU IUEM, Univ Brest, CNRS, IRD, 29280, Plouzané, France
| | - Chirine Toumi
- LEMAR, Univ Brest, CNRS, IRD, Ifremer, 29280, Plouzané, France
| | - Jacques Grall
- LEMAR, Univ Brest, CNRS, IRD, Ifremer, 29280, Plouzané, France; OSU IUEM, Univ Brest, CNRS, IRD, 29280, Plouzané, France
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5
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Cornwall CE, Harvey BP, Comeau S, Cornwall DL, Hall-Spencer JM, Peña V, Wada S, Porzio L. Understanding coralline algal responses to ocean acidification: Meta-analysis and synthesis. GLOBAL CHANGE BIOLOGY 2022; 28:362-374. [PMID: 34689395 DOI: 10.1111/gcb.15899] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Ocean acidification (OA) is a major threat to the persistence of biogenic reefs throughout the world's ocean. Coralline algae are comprised of high magnesium calcite and have long been considered one of the most susceptible taxa to the negative impacts of OA. We summarize these impacts and explore the causes of variability in coralline algal responses using a review/qualitative assessment of all relevant literature, meta-analysis, quantitative assessment of critical responses, and a discussion of physiological mechanisms and directions for future research. We find that most coralline algae experienced reduced abundance, calcification rates, recruitment rates, and declines in pH within the site of calcification in laboratory experiments simulating OA or at naturally elevated CO2 sites. There were no other consistent physiological responses of coralline algae to simulated OA (e.g., photo-physiology, mineralogy, and survival). Calcification/growth was the most frequently measured parameters in coralline algal OA research, and our meta-analyses revealed greater declines in seawater pH were associated with significant decreases in calcification in adults and similar but nonsignificant trends for juveniles. Adults from the family Mesophyllumaceae also tended to be more robust to OA, though there was insufficient data to test similar trends for juveniles. OA was the dominant driver in the majority of laboratory experiments where other local or global drivers were assessed. The interaction between OA and any other single driver was often additive, though factors that changed pH at the surface of coralline algae (light, water motion, epiphytes) acted antagonistically or synergistically with OA more than any other drivers. With advances in experimental design and methodological techniques, we now understand that the physiology of coralline algal calcification largely dictates their responses to OA. However, significant challenges still remain, including improving the geographic and life-history spread of research effort and a need for holistic assessments of physiology.
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Affiliation(s)
- Christopher E Cornwall
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Ben P Harvey
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Steeve Comeau
- Laboratoire d'Océanographie de Villefranche, Sorbonne Université, CNRS-INSU, Villefranche-sur-mer, France
| | - Daniel L Cornwall
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Jason M Hall-Spencer
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, UK
| | - Viviana Peña
- BioCost Research Group, Facultad de Ciencias, Universidade da Coruña, Coruña, Spain
| | - Shigeki Wada
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Lucia Porzio
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
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6
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Qui-Minet ZN, Davoult D, Grall J, Delaunay C, Six C, Cariou T, Martin S. Physiology of maerl algae: Comparison of inter- and intraspecies variations. JOURNAL OF PHYCOLOGY 2021; 57:831-848. [PMID: 33316844 DOI: 10.1111/jpy.13119] [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: 07/17/2020] [Revised: 10/09/2020] [Accepted: 11/08/2020] [Indexed: 06/12/2023]
Abstract
Free-living red coralline algae play an important role in the carbon and carbonate cycles of coastal environments. In this study, we examined the physiology of free-living coralline algae-forming maerl beds in the Bay of Brest (Brittany, France), where Lithothamnion corallioides is the dominant maerl (i.e., rhodolith) species. Phymatolithon calcareum and Lithophyllum incrustans are also present (in lower abundances) at a specific site in the bay. We aimed to assess how maerl physiology is affected by seasonality and/or local environmental variations at the inter- and intraspecific levels. Physiological measurements (respiration, photosynthetic, and calcification rates) were performed using incubation chambers in winter and summer to compare (1) the dominant maerl species at three sites and (2) three coexisting maerl species at one site. Comparison of the three coexisting maerl species suggests that L. corallioides is the best adapted to the current environmental conditions in the Bay of Brest, because this species is the most robust to dissolution in the dark in winter and has the highest calcification efficiency in the light. Comparisons of L. corallioides metabolic rates between stations showed that morphological variations within this species are the main factor affecting its photosynthetic and calcification rates. Environmental factors such as freshwater inputs also affect its calcification rates in the dark. In addition to interspecies variation in maerl physiology, there were intraspecific variations associated with direct (water physico-chemistry) or indirect (morphology) local environmental conditions. This study demonstrates the plasticity of maerl physiology in response to environmental changes, which is fundamental for maerl persistence.
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Affiliation(s)
- Zujaila Nohemy Qui-Minet
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
| | - Dominique Davoult
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
| | - Jacques Grall
- IUEM, Université de Bretagne Occidentale, Place Nicolas Copernic, 29280, Plouzané, France
| | - Coralie Delaunay
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
| | - Christophe Six
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
| | - Thierry Cariou
- CNRS, Fédération de Recherche FR2424, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29680, Roscoff, France
| | - Sophie Martin
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
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7
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Calcification in free-living coralline algae is strongly influenced by morphology: Implications for susceptibility to ocean acidification. Sci Rep 2021; 11:11232. [PMID: 34045570 PMCID: PMC8160205 DOI: 10.1038/s41598-021-90632-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 05/12/2021] [Indexed: 11/13/2022] Open
Abstract
Rhodolith beds built by free-living coralline algae are important ecosystems for marine biodiversity and carbonate production. Yet, our mechanistic understanding regarding rhodolith physiology and its drivers is still limited. Using three rhodolith species with different branching morphologies, we investigated the role of morphology in species’ physiology and the implications for their susceptibility to ocean acidification (OA). For this, we determined the effects of thallus topography on diffusive boundary layer (DBL) thickness, the associated microscale oxygen and pH dynamics and their relationship with species’ metabolic and light and dark calcification rates, as well as species’ responses to short-term OA exposure. Our results show that rhodolith branching creates low-flow microenvironments that exhibit increasing DBL thickness with increasing branch length. This, together with species’ metabolic rates, determined the light-dependent pH dynamics at the algal surface, which in turn dictated species’ calcification rates. While these differences did not translate in species-specific responses to short-term OA exposure, the differences in the magnitude of diurnal pH fluctuations (~ 0.1–1.2 pH units) between species suggest potential differences in phenotypic plasticity to OA that may result in different susceptibilities to long-term OA exposure, supporting the general view that species’ ecomechanical characteristics must be considered for predicting OA responses.
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8
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Rastelli E, Petani B, Corinaldesi C, Dell'Anno A, Lo Martire M, Cerrano C, Danovaro R. A high biodiversity mitigates the impact of ocean acidification on hard-bottom ecosystems. Sci Rep 2020; 10:2948. [PMID: 32076065 PMCID: PMC7031329 DOI: 10.1038/s41598-020-59886-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 02/05/2020] [Indexed: 02/04/2023] Open
Abstract
Biodiversity loss and climate change simultaneously threaten marine ecosystems, yet their interactions remain largely unknown. Ocean acidification severely affects a wide variety of marine organisms and recent studies have predicted major impacts at the pH conditions expected for 2100. However, despite the renowned interdependence between biodiversity and ecosystem functioning, the hypothesis that the species’ response to ocean acidification could differ based on the biodiversity of the natural multispecies assemblages in which they live remains untested. Here, using experimentally controlled conditions, we investigated the impact of acidification on key habitat-forming organisms (including corals, sponges and macroalgae) and associated microbes in hard-bottom assemblages characterised by different biodiversity levels. Our results indicate that, at higher biodiversity, the impact of acidification on otherwise highly vulnerable key organisms can be reduced by 50 to >90%, depending on the species. Here we show that such a positive effect of a higher biodiversity can be associated with higher availability of food resources and healthy microbe-host associations, overall increasing host resistance to acidification, while contrasting harmful outbreaks of opportunistic microbes. Given the climate change scenarios predicted for the future, we conclude that biodiversity conservation of hard-bottom ecosystems is fundamental also for mitigating the impacts of ocean acidification.
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Affiliation(s)
- Eugenio Rastelli
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy.
| | - Bruna Petani
- Department of Ecology, Agronomy and Aquaculture, University of Zadar, 23000, Zadar, Croatia
| | - Cinzia Corinaldesi
- Department of Materials, Environmental Sciences and Urban Planning, Polytechnic University of Marche, 60131, Ancona, Italy
| | - Antonio Dell'Anno
- Department of Life and Environmental Sciences, Polytechnic University of Marche, 60131, Ancona, Italy
| | - Marco Lo Martire
- Department of Life and Environmental Sciences, Polytechnic University of Marche, 60131, Ancona, Italy
| | - Carlo Cerrano
- Department of Life and Environmental Sciences, Polytechnic University of Marche, 60131, Ancona, Italy
| | - Roberto Danovaro
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy. .,Department of Life and Environmental Sciences, Polytechnic University of Marche, 60131, Ancona, Italy.
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9
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Gong S, Jin X, Xiao Y, Li Z. Ocean Acidification and Warming Lead to Increased Growth and Altered Chloroplast Morphology in the Thermo-Tolerant Alga Symbiochlorum hainanensis. FRONTIERS IN PLANT SCIENCE 2020; 11:585202. [PMID: 33281847 PMCID: PMC7705064 DOI: 10.3389/fpls.2020.585202] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/21/2020] [Indexed: 05/03/2023]
Abstract
Ocean acidification and warming affect the growth and predominance of algae. However, the effects of ocean acidification and warming on the growth and gene transcription of thermo-tolerant algae are poorly understood. Here we determined the effects of elevated temperature (H) and acidification (A) on a recently discovered coral-associated thermo-tolerant alga Symbiochlorum hainanensis by culturing it under two temperature settings (26.0 and 32.0°C) crossed with two pH levels (8.16 and 7.81). The results showed that the growth of S. hainanensis was positively affected by H, A, and the combined treatment (AH). However, no superimposition effect of H and A on the growth of S. hainanensis was observed under AH. The analysis of chlorophyll fluorescence, pigment content, and subcellular morphology indicated that the chloroplast morphogenesis (enlargement) along with the increase of chlorophyll fluorescence and pigment content of S. hainanensis might be a universal mechanism for promoting the growth of S. hainanensis. Transcriptomic profiles revealed the effect of elevated temperature on the response of S. hainanensis to acidification involved in the down-regulation of photosynthesis- and carbohydrate metabolism-related genes but not the up-regulation of genes related to antioxidant and ubiquitination processes. Overall, this study firstly reports the growth, morphology, and molecular response of the thermo-tolerant alga S. hainanensis to future climate changes, suggesting the predominance of S. hainanensis in its associated corals and/or coral reefs in the future.
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Affiliation(s)
- Sanqiang Gong
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Xuejie Jin
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
| | - Yilin Xiao
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhiyong Li
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Zhiyong Li,
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10
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Qui-Minet ZN, Coudret J, Davoult D, Grall J, Mendez‐Sandin M, Cariou T, Martin S. Combined effects of global climate change and nutrient enrichment on the physiology of three temperate maerl species. Ecol Evol 2019; 9:13787-13807. [PMID: 31938482 PMCID: PMC6953553 DOI: 10.1002/ece3.5802] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 01/20/2023] Open
Abstract
Made up of calcareous coralline algae, maerl beds play a major role as ecosystem engineers in coastal areas throughout the world. They undergo strong anthropogenic pressures, which may threaten their survival. The aim of this study was to gain insight into the future of maerl beds in the context of global and local changes. We examined the effects of rising temperatures (+3°C) and ocean acidification (-0.3 pH units) according to temperature and pH projections (i.e., the RCP 8.5 scenario), and nutrient (N and P) availability on three temperate maerl species (Lithothamnion corallioides, Phymatolithon calcareum, and Lithophyllum incrustans) in the laboratory in winter and summer conditions. Physiological rates of primary production, respiration, and calcification were measured on all three species in each treatment and season. The physiological response of maerl to global climate change was species-specific and influenced by seawater nutrient concentrations. Future temperature-pH scenario enhanced maximal gross primary production rates in P. calcareum in winter and in L. corallioides in both seasons. Nevertheless, both species suffered an impairment of light harvesting and photoprotective mechanisms in winter. Calcification rates at ambient light intensity were negatively affected by the future temperature-pH scenario in winter, with net dissolution observed in the dark in L. corallioides and P. calcareum under low nutrient concentrations. Nutrient enrichment avoided dissolution under future scenarios in winter and had a positive effect on L. incrustans calcification rate in the dark in summer. In winter conditions, maximal calcification rates were enhanced by the future temperature-pH scenario on the three species, but P. calcareum suffered inhibition at high irradiances. In summer conditions, the maximal calcification rate dropped in L. corallioides under the future global climate change scenario, with a potential negative impact on CaCO3 budget for maerl beds in the Bay of Brest where this species is dominant. Our results highlight how local changes in nutrient availability or irradiance levels impact the response of maerl species to global climate change and thus point out how it is important to consider other abiotic parameters in order to develop management policies capable to increase the resilience of maerl beds under the future global climate change scenario.
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Affiliation(s)
- Zujaila Nohemy Qui-Minet
- Sorbonne UniversitésCNRSUMR 7144 Adaptation et Diversité en Milieu MarinStation Biologique de RoscoffRoscoffFrance
| | - Jérôme Coudret
- Sorbonne UniversitésCNRSUMR 7144 Adaptation et Diversité en Milieu MarinStation Biologique de RoscoffRoscoffFrance
| | - Dominique Davoult
- Sorbonne UniversitésCNRSUMR 7144 Adaptation et Diversité en Milieu MarinStation Biologique de RoscoffRoscoffFrance
| | - Jacques Grall
- Université de Bretagne OccidentaleIUEMPlouzanéFrance
| | - Miguel Mendez‐Sandin
- Sorbonne UniversitésCNRSUMR 7144 Adaptation et Diversité en Milieu MarinStation Biologique de RoscoffRoscoffFrance
| | - Thierry Cariou
- Sorbonne UniversitésCNRS, FR2424Station Biologique de RoscoffRoscoffFrance
| | - Sophie Martin
- Sorbonne UniversitésCNRSUMR 7144 Adaptation et Diversité en Milieu MarinStation Biologique de RoscoffRoscoffFrance
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Sordo L, Santos R, Barrote I, Silva J. Temperature amplifies the effect of high CO 2 on the photosynthesis, respiration, and calcification of the coralline algae Phymatolithon lusitanicum. Ecol Evol 2019; 9:11000-11009. [PMID: 31641450 PMCID: PMC6802031 DOI: 10.1002/ece3.5560] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 06/17/2019] [Accepted: 07/25/2019] [Indexed: 01/13/2023] Open
Abstract
The combination of ocean acidification (OA) and global warming is expected to have a significant effect on the diversity and functioning of marine ecosystems, particularly on calcifying algae such as rhodoliths (maërl) that form extensive beds worldwide, from polar to tropical regions. In addition, the increasing frequency of extreme events, such as heat waves, threatens coastal ecosystems and may affect their capacity to fix blue carbon. The few studies where the simultaneous effects of both temperature and CO2 were investigated have revealed contradictory results. To assess the effect that high temperature spells can have on the maërl beds under OA, we tested the short-time effects of temperature and CO2 on the net photosynthesis, respiration, and calcification of the recently described species Phymatolithon lusitanicum, the most common maërl species of southern Portugal. Photosynthesis, calcification, and respiration increased with temperature, and the differences among treatments were enhanced under high CO2. We found that in the short term, the metabolic rates of Phymatolithon lusitanicum will increase with CO2 and temperature as will the coupling between calcification and photosynthesis. However, under high CO2, this coupling will favor photosynthesis over calcification, which, in the long term, can have a negative effect on the blue carbon fixing capacity of the maërl beds from southern Portugal.
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Affiliation(s)
- Laura Sordo
- Marine Plant Ecology Research Group, Centre of Marine Sciences (CCMAR)University of AlgarveFaroPortugal
- Portuguese Institute of Ocean and Atmosphere (IPMA)OlhãoPortugal
| | - Rui Santos
- Marine Plant Ecology Research Group, Centre of Marine Sciences (CCMAR)University of AlgarveFaroPortugal
| | - Isabel Barrote
- Marine Plant Ecology Research Group, Centre of Marine Sciences (CCMAR)University of AlgarveFaroPortugal
| | - João Silva
- Marine Plant Ecology Research Group, Centre of Marine Sciences (CCMAR)University of AlgarveFaroPortugal
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Sordo L, Santos R, Barrote I, Silva J. High CO 2 decreases the long-term resilience of the free-living coralline algae Phymatolithon lusitanicum. Ecol Evol 2018; 8:4781-4792. [PMID: 29876057 PMCID: PMC5980507 DOI: 10.1002/ece3.4020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 02/04/2018] [Accepted: 02/25/2018] [Indexed: 01/10/2023] Open
Abstract
Mäerl/rhodolith beds are protected habitats that may be affected by ocean acidification (OA), but it is still unclear how the availability of CO 2 will affect the metabolism of these organisms. Some of the inconsistencies found among OA experimental studies may be related to experimental exposure time and synergetic effects with other stressors. Here, we investigated the long-term (up to 20 months) effects of OA on the production and calcification of the most common mäerl species of southern Portugal, Phymatolithon lusitanicum. Both the photosynthetic and calcification rates increased with CO 2 after the first 11 months of the experiment, whereas respiration slightly decreased with CO 2. After 20 months, the pattern was reversed. Acidified algae showed lower photosynthetic and calcification rates, as well as lower accumulated growth than control algae, suggesting that a metabolic threshold was exceeded. Our results indicate that long-term exposure to high CO 2 will decrease the resilience of Phymatolithon lusitanicum. Our results also show that shallow communities of these rhodoliths may be particularly at risk, while deeper rhodolith beds may become ocean acidification refuges for this biological community.
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Affiliation(s)
- Laura Sordo
- Marine Plant Ecology Research GroupCentre of Marine Sciences (CCMAR)University of AlgarveFaroPortugal
| | - Rui Santos
- Marine Plant Ecology Research GroupCentre of Marine Sciences (CCMAR)University of AlgarveFaroPortugal
| | - Isabel Barrote
- Marine Plant Ecology Research GroupCentre of Marine Sciences (CCMAR)University of AlgarveFaroPortugal
| | - João Silva
- Marine Plant Ecology Research GroupCentre of Marine Sciences (CCMAR)University of AlgarveFaroPortugal
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