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Montes-Herrera JC, Cimoli E, Cummings VJ, D'Archino R, Nelson WA, Lucieer A, Lucieer V. Quantifying pigment content in crustose coralline algae using hyperspectral imaging: A case study with Tethysphytum antarcticum (Ross Sea, Antarctica). JOURNAL OF PHYCOLOGY 2024; 60:695-709. [PMID: 38558363 DOI: 10.1111/jpy.13449] [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: 04/28/2023] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 04/04/2024]
Abstract
Crustose coralline algae (CCA) are a highly diverse group of habitat-forming, calcifying red macroalgae (Rhodophyta) with unique adaptations to diverse irradiance regimes. A distinctive CCA phenotype adaptation, which allows them to maximize photosynthetic performance in low light, is their content of a specific group of light-harvesting pigments called phycobilins. In this study, we assessed the potential of noninvasive hyperspectral imaging (HSI) in the visible spectrum (400-800 nm) to describe the phenotypic variability in phycobilin content of an Antarctic coralline, Tethysphytum antarcticum (Hapalidiales), from two distinct locations. We validated our measurements with pigment extractions and spectrophotometry analysis, in addition to DNA barcoding using the psbA marker. Targeted spectral indices were developed and correlated with phycobilin content using linear mixed models (R2 = 0.64-0.7). Once applied to the HSI, the models revealed the distinct phycoerythrin spatial distribution in the two site-specific CCA phenotypes, with thin and thick crusts, respectively. This study advances the capabilities of hyperspectral imaging as a tool to quantitatively study CCA pigmentation in relation to their phenotypic plasticity, which can be applied in laboratory studies and potentially in situ surveys using underwater hyperspectral imaging systems.
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Affiliation(s)
- Juan C Montes-Herrera
- Institute for Marine and Antarctic Studies, College of Sciences and Engineering, University of Tasmania, Hobart, Tasmania, Australia
| | - Emiliano Cimoli
- Institute for Marine and Antarctic Studies, College of Sciences and Engineering, University of Tasmania, Hobart, Tasmania, Australia
| | - Vonda J Cummings
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
| | - Roberta D'Archino
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
| | - Wendy A Nelson
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
- Tāmaki Paenga Hira Auckland Museum & School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Arko Lucieer
- School of Geography, Planning, and Spatial Sciences, College of Sciences and Engineering, University of Tasmania, Hobart, Tasmania, Australia
| | - Vanessa Lucieer
- Institute for Marine and Antarctic Studies, College of Sciences and Engineering, University of Tasmania, Hobart, Tasmania, Australia
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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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Voerman SE, Marsh BC, Bahia RG, Pereira-Filho GH, Becker ACF, Amado-Filho GM, Ruseckas A, Turnbull GA, Samuel IDW, Burdett HL. Dominance of photo over chromatic acclimation strategies by habitat-forming mesophotic red algae. Proc Biol Sci 2023; 290:20231329. [PMID: 37788706 PMCID: PMC10547552 DOI: 10.1098/rspb.2023.1329] [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: 06/14/2023] [Accepted: 09/01/2023] [Indexed: 10/05/2023] Open
Abstract
Red coralline algae are the deepest living macroalgae, capable of creating spatially complex reefs from the intertidal to 100+ m depth with global ecological and biogeochemical significance. How these algae maintain photosynthetic function under increasingly limiting light intensity and spectral availability is key to explaining their large depth distribution. Here, we investigated the photo- and chromatic acclimation and morphological change of free-living red coralline algae towards mesophotic depths in the Fernando do Noronha archipelago, Brazil. From 13 to 86 m depth, thalli tended to become smaller and less complex. We observed a dominance of the photo-acclimatory response, characterized by an increase in photosynthetic efficiency and a decrease in maximum electron transport rate. Chromatic acclimation was generally stable across the euphotic-mesophotic transition with no clear depth trend. Taxonomic comparisons suggest these photosynthetic strategies are conserved to at least the Order level. Light saturation necessitated the use of photoprotection to 65 m depth, while optimal light levels were met at 86 m. Changes to the light environment (e.g. reduced water clarity) due to human activities therefore places these mesophotic algae at risk of light limitation, necessitating the importance of maintaining good water quality for the conservation and protection of mesophotic habitats.
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Affiliation(s)
- Sofie E. Voerman
- Lyell Centre for Earth and Marine Science and Technology, Edinburgh, UK
- School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, UK
| | - Beauregard C. Marsh
- Lyell Centre for Earth and Marine Science and Technology, Edinburgh, UK
- School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, UK
| | - Ricardo G. Bahia
- Botanical Garden Research Institute of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Guilherme H. Pereira-Filho
- Laboratório de Ecologia e Conservação Marinha, Instituto do Mar, Universidade Federal de São Paulo, Santos, São Paulo, Brazil
| | - Ana Clara F. Becker
- Laboratório de Ecologia e Conservação Marinha, Instituto do Mar, Universidade Federal de São Paulo, Santos, São Paulo, Brazil
| | | | - Arvydas Ruseckas
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK
| | - Graham A. Turnbull
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK
| | - Ifor D. W. Samuel
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK
| | - Heidi L. Burdett
- Umeå Marine Sciences Centre, Umeå University, Norrbyn, Sweden
- Department of Ecology & Environmental Science, Umeå University, Umeå, Sweden
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The Hidden Diversity of Temperate Mesophotic Ecosystems from Central Chile (Southeastern Pacific Ocean) Assessed through Towed Underwater Videos. DIVERSITY 2023. [DOI: 10.3390/d15030360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
The largely unexplored diversity in temperate mesophotic ecosystems (TME, ~30–150 m depth) has attracted much attention over the past years. However, the number of studies and knowledge of TME diversity and ecology remains limited and geographically restricted. The absence of information on how assemblages vary across environmental gradients and with depth for most regions also limits our capacity to delimit conservation areas and devise management plans effectively. This study focuses on TME from central Chile and describes the depth distribution of reef fishes and benthic invertebrates and algae for the first time. Through the analysis of towed underwater video surveys between 4.7–95.5 m in multiple sites, we show that total reef fish density and richness decrease with depth but increase with local topographic complexity. The depth-related density varies among fish species and trophic groups, and it reverses in the case of Sebastes oculatus, which increases in density with depth. Sponges and gorgonians dominate benthic assemblages below 20 m depth, and brachiopods and anemones increase below 40 and 60 m, respectively. Some of these species form animal forests which, to some extent, replace the shallow-water kelp forests as structural habitat providers. Nevertheless, the reef fish and benthic community do not show a clear structure with depth or across studied sites. We highlight the urgency to intensify and expand the quantitative characterization of these communities, through this and other methodologies, to better define ecological patterns and advance towards conservation plans for TME, including the Souteastern Pacific region.
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Voerman SE, Ruseckas A, Turnbull GA, Samuel IDW, Burdett HL. Red algae acclimate to low light by modifying phycobilisome composition to maintain efficient light harvesting. BMC Biol 2022; 20:291. [PMID: 36575464 PMCID: PMC9794408 DOI: 10.1186/s12915-022-01480-3] [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: 02/11/2022] [Accepted: 11/24/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Despite a global prevalence of photosynthetic organisms in the ocean's mesophotic zone (30-200+ m depth), the mechanisms that enable photosynthesis to proceed in this low light environment are poorly defined. Red coralline algae are the deepest known marine benthic macroalgae - here we investigated the light harvesting mechanism and mesophotic acclimatory response of the red coralline alga Lithothamnion glaciale. RESULTS Following initial absorption by phycourobilin and phycoerythrobilin in phycoerythrin, energy was transferred from the phycobilisome to photosystems I and II within 120 ps. This enabled delivery of 94% of excitations to reaction centres. Low light intensity, and to a lesser extent a mesophotic spectrum, caused significant acclimatory change in chromophores and biliproteins, including a 10% increase in phycoerythrin light harvesting capacity and a 20% reduction in chlorophyll-a concentration and photon requirements for photosystems I and II. The rate of energy transfer remained consistent across experimental treatments, indicating an acclimatory response that maintains energy transfer. CONCLUSIONS Our results demonstrate that responsive light harvesting by phycobilisomes and photosystem functional acclimation are key to red algal success in the mesophotic zone.
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Affiliation(s)
- Sofie E. Voerman
- Lyell Centre for Earth and Marine Science and Technology, Edinburgh, EH14 4BA UK ,grid.9531.e0000000106567444School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, EH14 4AS UK
| | - Arvydas Ruseckas
- grid.11914.3c0000 0001 0721 1626Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS UK
| | - Graham A. Turnbull
- grid.11914.3c0000 0001 0721 1626Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS UK
| | - Ifor D. W. Samuel
- grid.11914.3c0000 0001 0721 1626Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS UK
| | - Heidi L. Burdett
- Lyell Centre for Earth and Marine Science and Technology, Edinburgh, EH14 4BA UK ,grid.9531.e0000000106567444School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, EH14 4AS UK ,grid.12650.300000 0001 1034 3451Present Address: Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden ,grid.12650.300000 0001 1034 3451Umeå Marine Sciences Centre, Umeå University, Norrbyn, Sweden
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