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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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Page TM, McDougall C, Bar I, Diaz-Pulido G. Transcriptomic stability or lability explains sensitivity to climate stressors in coralline algae. BMC Genomics 2022; 23:729. [PMID: 36303112 PMCID: PMC9615231 DOI: 10.1186/s12864-022-08931-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 10/10/2022] [Indexed: 08/30/2023] Open
Abstract
Background Crustose coralline algae (CCA) are calcifying red macroalgae that play important ecological roles including stabilisation of reef frameworks and provision of settlement cues for a range of marine invertebrates. Previous research into the responses of CCA to ocean warming (OW) and ocean acidification (OA) have found magnitude of effect to be species-specific. Response to OW and OA could be linked to divergent underlying molecular processes across species. Results Here we show Sporolithon durum, a species that exhibits low sensitivity to climate stressors, had little change in metabolic performance and did not significantly alter the expression of any genes when exposed to temperature and pH perturbations. In contrast, Porolithon onkodes, a major coral reef builder, reduced photosynthetic rates and had a labile transcriptomic response with over 400 significantly differentially expressed genes, with differential regulation of genes relating to physiological processes such as carbon acquisition and metabolism. The differential gene expression detected in P. onkodes implicates possible key metabolic pathways, including the pentose phosphate pathway, in the stress response of this species. Conclusions We suggest S. durum is more resistant to OW and OA than P. onkodes, which demonstrated a high sensitivity to climate stressors and may have limited ability for acclimatisation. Understanding changes in gene expression in relation to physiological processes of CCA could help us understand and predict how different species will respond to, and persist in, future ocean conditions predicted for 2100. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08931-9.
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Affiliation(s)
- Tessa M Page
- Griffth University School of Environment and Science Nathan Campus, Griffith University, Nathan, QLD, Australia. .,Australian Rivers Institute Nathan Campus, Griffith University, Nathan, QLD, Australia. .,Coastal and Marine Research Centre Nathan Campus, Griffith University, Gold Coast, QLD, Australia. .,School of Ocean and Earth Science University of Southampton Waterfront Campus, National Oceanography Centre, Southampton, UK.
| | - Carmel McDougall
- Griffth University School of Environment and Science Nathan Campus, Griffith University, Nathan, QLD, Australia.,Australian Rivers Institute Nathan Campus, Griffith University, Nathan, QLD, Australia.,Coastal and Marine Research Centre Nathan Campus, Griffith University, Gold Coast, QLD, Australia
| | - Ido Bar
- Griffth University School of Environment and Science Nathan Campus, Griffith University, Nathan, QLD, Australia.,Centre for Planetary Health and Food Security Nathan Campus, Griffith University, Nathan, QLD, Australia
| | - Guillermo Diaz-Pulido
- Griffth University School of Environment and Science Nathan Campus, Griffith University, Nathan, QLD, Australia. .,Australian Rivers Institute Nathan Campus, Griffith University, Nathan, QLD, Australia. .,Coastal and Marine Research Centre Nathan Campus, Griffith University, Gold Coast, QLD, Australia.
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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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Jenkins TL, Guillemin M, Simon‐Nutbrown C, Burdett HL, Stevens JR, Peña V. Whole genome genotyping reveals discrete genetic diversity in north-east Atlantic maerl beds. Evol Appl 2021; 14:1558-1571. [PMID: 34178104 PMCID: PMC8210795 DOI: 10.1111/eva.13219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 02/21/2021] [Accepted: 03/02/2021] [Indexed: 01/16/2023] Open
Abstract
Maerl beds are vital habitats for a diverse array of marine species across trophic levels, but they are increasingly threatened by human activities and climate change. Furthermore, little is known about the genetic diversity of maerl-forming species and the population structure of maerl beds, both of which are important for understanding the ability of these species to adapt to changing environments and for informing marine reserve planning. In this study, we used a whole genome genotyping approach to explore the population genomics of Phymatolithon calcareum, a maerl-forming red algal species, whose geographical distribution spans the north-east Atlantic, from Norway to Portugal. Our results, using 14,150 genome-wide SNPs (single nucleotide polymorphisms), showed that P. calcareum maerl beds across the north-east Atlantic are generally structured geographically, a pattern likely explained by low dispersal potential and limited connectivity between regions. Additionally, we found that P. calcareum from the Fal Estuary, south-west England, is genetically distinct from all other P. calcareum sampled, even from The Manacles, a site located only 13 km away. Further analysis revealed that this finding is not the result of introgression from two closely related species, Phymatolithon purpureum or Lithothamnion corallioides. Instead, this unique diversity may have been shaped over time by geographical isolation of the Fal Estuary maerl bed and a lack of gene flow with other P. calcareum populations. The genomic data presented in this study suggest that P. calcareum genetic diversity has accumulated over large temporal and spatial scales, the preservation of which will be important for maximizing the resilience of this species to changes in climate and the environment. Moreover, our findings underline the importance of managing the conservation of maerl beds across western Europe as distinct units, at a site-by-site level.
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Affiliation(s)
- Tom L. Jenkins
- Department of Biosciences, College of Life and Environmental SciencesUniversity of ExeterExeterUK
| | - Marie‐Laure Guillemin
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de CienciasUniversidad Austral de ChileValdiviaChile
- IRL EBEA 3614, Evolutionary Biology and Ecology of Algae, CNRS, UC, UACH, Station Biologique de RoscoffSorbonne UniversitéRoscoffFrance
| | - Cornelia Simon‐Nutbrown
- Lyell Centre for Earth and Marine Science and TechnologyEdinburghUK
- School of Energy, Geoscience, Infrastructure and SocietyHeriot‐Watt UniversityEdinburghUK
- Royal Botanic Garden EdinburghEdinburghUK
| | - Heidi L. Burdett
- Lyell Centre for Earth and Marine Science and TechnologyEdinburghUK
- School of Energy, Geoscience, Infrastructure and SocietyHeriot‐Watt UniversityEdinburghUK
| | - Jamie R. Stevens
- Department of Biosciences, College of Life and Environmental SciencesUniversity of ExeterExeterUK
| | - Viviana Peña
- BioCost Research Group, Facultad de Ciencias and Centro de Investigaciones Científicas Avanzadas (CICA)Universidade da Coruña, A CoruñaSpain
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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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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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