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Ruiz MB, Servetto N, Alurralde G, Abele D, Harms L, Sahade R, Held C. Molecular responses of a key Antarctic species to sedimentation due to rapid climate change. MARINE ENVIRONMENTAL RESEARCH 2022; 180:105720. [PMID: 35987040 DOI: 10.1016/j.marenvres.2022.105720] [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: 04/08/2022] [Revised: 07/30/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Rapid regional warming causing glacial retreat and melting of ice caps in Antarctica leads benthic filter-feeders to be exposed to periods of food shortage and high respiratory impairment as a consequence of seasonal sediment discharge in the West Antarctic Peninsula coastal areas. The molecular physiological response and its fine-tuning allow species to survive acute environmental stress and are thus a prerequisite to longer-term adaptation to changing environments. Under experimental conditions, we analyzed here the metabolic response to changes in suspended sediment concentrations, through transcriptome sequencing and enzymatic measurements in a highly abundant Antarctic ascidian. We found that the mechanisms underlying short-term response to sedimentation in Cnemidocarpa verrucosa sp. A involved apoptosis, immune defense, and general metabolic depression. These mechanisms may be understood as an adaptive protection against sedimentation caused by glacial retreat. This process can strongly contribute to the structuring of future benthic filter-feeder communities in the face of climate change.
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Affiliation(s)
- Micaela B Ruiz
- Instituto de Diversidad y Ecología Animal (IDEA) CONICET, Córdoba, Argentina; Universidad Nacional de Córdoba, Facultad de Ciencias Exactas Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Ecología Marina, Córdoba, Argentina.
| | - Natalia Servetto
- Instituto de Diversidad y Ecología Animal (IDEA) CONICET, Córdoba, Argentina; Universidad Nacional de Córdoba, Facultad de Ciencias Exactas Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Ecología Marina, Córdoba, Argentina.
| | - Gastón Alurralde
- Department of Environmental Science, Stockholm University, Stockholm, Sweden.
| | - Doris Abele
- Alfred Wegener Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Section Functional Ecology, Evolutionary Macroecology, Bremerhaven, Germany
| | - Lars Harms
- Alfred Wegener Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Computing and data center, Data Science Support, Bremerhaven, Germany.
| | - Ricardo Sahade
- Instituto de Diversidad y Ecología Animal (IDEA) CONICET, Córdoba, Argentina; Universidad Nacional de Córdoba, Facultad de Ciencias Exactas Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Ecología Marina, Córdoba, Argentina.
| | - Christoph Held
- Alfred Wegener Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Section Functional Ecology, Evolutionary Macroecology, Bremerhaven, Germany.
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Torre L, Alurralde G, Lagger C, Abele D, Schloss IR, Sahade R. Antarctic ascidians under increasing sedimentation: Physiological thresholds and ecosystem hysteresis. MARINE ENVIRONMENTAL RESEARCH 2021; 167:105284. [PMID: 33730611 DOI: 10.1016/j.marenvres.2021.105284] [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: 12/05/2020] [Revised: 02/11/2021] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
Glacier melting sediment inputs affect coastal ecosystems on the Antarctic Peninsula. In Potter Cove (South Shetland Islands, Antarctica), the shift from an "ascidian dominated" to a "mixed" assemblage has been linked to sedimentation. However, in recently described newly ice-free areas ascidians became dominant in spite of total suspended particulate matter (TSPM) concentrations, which are the highest measured in Potter Cove. Here, we compared the gut content and energy reserve of three ascidian species at three stations under different TSPM regimes. All analysed species had a higher gut content with lower %OM at these newly areas. A theoretical relationship between the scope for growth for the targeted ascidians and TSPM explained assemblages' recorded change but failed to explain current ascidians distribution. The results may indicate the existence of a TSPM threshold that allows the spatial coexistence of alternative stable states at benthic Potter Cove system.
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Affiliation(s)
- L Torre
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Av. Vélez Sarsfield 299, 5000, Córdoba, Argentina; Instituto de Diversidad y Ecología Animal (Consejo Nacional de Investigaciones Científicas y Técnicas), Córdoba, Argentina.
| | - G Alurralde
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Av. Vélez Sarsfield 299, 5000, Córdoba, Argentina; Instituto de Diversidad y Ecología Animal (Consejo Nacional de Investigaciones Científicas y Técnicas), Córdoba, Argentina
| | - C Lagger
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Av. Vélez Sarsfield 299, 5000, Córdoba, Argentina; Instituto de Diversidad y Ecología Animal (Consejo Nacional de Investigaciones Científicas y Técnicas), Córdoba, Argentina
| | - D Abele
- Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research. Bremerhaven, Germany
| | - I R Schloss
- Instituto Antártico Argentino, San Martín, Provincia de Buenos Aires, Argentina; Centro Austral de Investigaciones Científicas, CONICET, Ushuaia, Argentina; Universidad Nacional de Tierra del Fuego, Ushuaia, Argentina
| | - R Sahade
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Av. Vélez Sarsfield 299, 5000, Córdoba, Argentina; Instituto de Diversidad y Ecología Animal (Consejo Nacional de Investigaciones Científicas y Técnicas), Córdoba, Argentina.
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3
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Glycoside hydrolases from the tunics of two Antarctic ascidians (Ascidia challengeri and Pyura bouvetensis) and the tropical species Phallusia nigra. Polar Biol 2021. [DOI: 10.1007/s00300-021-02837-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Default versus Configured-Geostatistical Modeling of Suspended Particulate Matter in Potter Cove, West Antarctic Peninsula. FLUIDS 2020. [DOI: 10.3390/fluids5040235] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The glacier retreat observed during the last decades at Potter Cove (PC) causes an increasing amount of suspended particulate matter (SPM) in the water column, which has a high impact on sessile filter feeder’ species at PC located at the West Antarctic Peninsula. SPM presents a highly-fluctuating dynamic pattern on a daily, monthly, seasonal, and interannual basis. Geostatistical interpolation techniques are widely used by default to generate reliable spatial information and thereby to improve the ecological understanding of environmental variables, which is often fundamental for guiding decision-makers and scientists. In this study, we compared the results of default and configured settings of three geostatistical algorithms (Simple Kriging, Ordinary Kriging, and Empirical Bayesian) and developed a performance index. In order to interpolate SPM data from the summer season 2010/2011 at PC, the best performance was obtained with Empirical Bayesian Kriging (standard mean = −0.001 and root mean square standardized = 0.995). It showed an excellent performance (performance index = 0.004), improving both evaluation parameters when radio and neighborhood were configured. About 69% of the models showed improved standard means when configured compared to the default settings following a here proposed guideline.
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Schack CR, Gordon DP, Ryan KG. Community assembly in a modular organism: the impact of environmental filtering on bryozoan colony form and polymorphism. Ecology 2020; 101:e03106. [DOI: 10.1002/ecy.3106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 04/02/2020] [Accepted: 04/14/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Carolann R. Schack
- School of Biological Sciences Victoria University of Wellington Kelburn Wellington 6012 New Zealand
- New Zealand Institute of Marine and Atmospheric Science 301 Evans Bay Parade Hataitai Wellington 6021 New Zealand
| | - Dennis P. Gordon
- New Zealand Institute of Marine and Atmospheric Science 301 Evans Bay Parade Hataitai Wellington 6021 New Zealand
| | - Ken G. Ryan
- School of Biological Sciences Victoria University of Wellington Kelburn Wellington 6012 New Zealand
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Alurralde G, Fuentes VL, Maggioni T, Movilla J, Olariaga A, Orejas C, Schloss IR, Tatián M. Role of suspension feeders in antarctic pelagic-benthic coupling: Trophic ecology and potential carbon sinks under climate change. MARINE ENVIRONMENTAL RESEARCH 2019; 152:104790. [PMID: 31537412 DOI: 10.1016/j.marenvres.2019.104790] [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: 06/12/2019] [Revised: 09/02/2019] [Accepted: 09/07/2019] [Indexed: 06/10/2023]
Abstract
Sea-ice and coastal glacier loss in the Western Antarctic Peninsula open new ice-free areas. They allowing primary production and providing new seabed for colonisation, both acting as a negative feedback of climate change. However, the injection of sediment-laden runoff from the melting of land-terminating glaciers may reduce this feedback. Changes in particulate matter will affect nutrition and excretion (faeces stoichiometry and properties) of suspension feeders, reshaping coastal carbon dynamics and pelagic-benthic coupling. Absorption efficiency and biodeposition of Euphausia superba and Cnemidocarpa verrucosa were quantified for different food treatments and varying sediment concentrations. Both species showed high overall absorption efficiency for free-sediment diets, but were negatively affected by sediment addition. High sediment conditions increased krill biodeposition, while it decreased in ascidians. Energy balance estimation indicated high carbon sink potential in ascidians, but it is modulated by food characteristics and negatively affected by sediment inputs in the water column.
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Affiliation(s)
- Gastón Alurralde
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Ecología Marina, Córdoba, Argentina; Instituto de Diversidad y Ecología Animal (IDEA) CONICET, Córdoba, Argentina.
| | | | - Tamara Maggioni
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Ecología Marina, Córdoba, Argentina; Instituto de Diversidad y Ecología Animal (IDEA) CONICET, Córdoba, Argentina
| | - Juancho Movilla
- Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain; Instituto Español de Oceanografía, Centro Oceanográfico de Baleares, Estación de Investigación Jaume Ferrer, Mahón, Spain
| | | | - Covadonga Orejas
- Instituto Español de Oceanografía, Centro Oceanográfico de Baleares, Palma, Mallorca, Spain
| | - Irene R Schloss
- Instituto Antártico Argentino, Ciudad de Buenos Aires, Argentina; Centro Austral de Investigaciones Científicas, CONICET, Ushuaia, Argentina; Universidad Nacional de Tierra del Fuego, Ushuaia, Argentina
| | - Marcos Tatián
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Ecología Marina, Córdoba, Argentina; Instituto de Diversidad y Ecología Animal (IDEA) CONICET, Córdoba, Argentina
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7
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Alternative NAD(P)H dehydrogenase and alternative oxidase: Proposed physiological roles in animals. Mitochondrion 2019; 45:7-17. [DOI: 10.1016/j.mito.2018.01.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 11/01/2017] [Accepted: 01/26/2018] [Indexed: 12/12/2022]
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8
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Jerosch K, Pehlke H, Monien P, Scharf F, Weber L, Kuhn G, Braun MH, Abele D. Benthic meltwater fjord habitats formed by rapid glacier recession on King George Island, Antarctica. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0178. [PMID: 29760120 PMCID: PMC5954476 DOI: 10.1098/rsta.2017.0178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/29/2018] [Indexed: 05/05/2023]
Abstract
The coasts of the West Antarctic Peninsula are strongly influenced by glacier meltwater discharge. The spatial structure and biogeochemical composition of inshore habitats are shaped by large quantities of terrigenous particulate material deposited in the vicinity of the coast, which impacts the pelagic and benthic ecosystems. We used a multitude of geochemical and environmental variables to identify the radius extension of the meltwater impact from the Fourcade Glacier into the fjord system of Potter Cove, King George Island. The k-means cluster algorithm, canonical correspondence analysis, variance analysis and Tukey's post hoc multiple comparison tests were applied to define and cluster coastal meltwater habitats. A minimum of 10 clusters were needed to classify the 8 km2 study area into meltwater fjord habitats (MFHs), fjord habitats and marine habitats. Strontium content in surface sediments is the main geochemical indicator for lithogenic creek discharge in Potter Cove. Furthermore, bathymetry, glacier distance and geomorphic positioning are the essential habitats explaining variables. The mean and maximum MFH extent amounted to 1 km and 2 km, respectively. Extrapolation of the identified meltwater impact ranges to King George Island coastlines, which are presently ice-covered bays and fjord areas, indicated an overall coverage of 200-400 km2 MFH, underpinning the importance of better understanding the biology and biogeochemistry in terrestrial marine transition zones.This article is part of the theme issue 'The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change'.
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Affiliation(s)
- Kerstin Jerosch
- Bio- and Geosciences Divisions, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity, University of Oldenburg, Carl-von-Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Hendrik Pehlke
- Bio- and Geosciences Divisions, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity, University of Oldenburg, Carl-von-Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Patrick Monien
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Carl-von-Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
- Faculty of Geosciences, University of Bremen, Klagenfurter Strasse 2-4, 28359 Bremen, Germany
| | - Frauke Scharf
- Bio- and Geosciences Divisions, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Lukas Weber
- Information Management and Media, Karlsruhe University of Applied Sciences, Moltkestraße 30, 76133 Karlsruhe, Germany
| | - Gerhard Kuhn
- Bio- and Geosciences Divisions, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Matthias H Braun
- Institute for Geography, Friedrich-Alexander-Universität Erlangen-Nürnberg, Wetterkreuz 15, 91058 Erlangen, Germany
| | - Doris Abele
- Bio- and Geosciences Divisions, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
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Lagger C, Servetto N, Torre L, Sahade R. Benthic colonization in newly ice-free soft-bottom areas in an Antarctic fjord. PLoS One 2017; 12:e0186756. [PMID: 29117262 PMCID: PMC5695587 DOI: 10.1371/journal.pone.0186756] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 10/06/2017] [Indexed: 12/04/2022] Open
Abstract
Extended glacier retreat is among the main consequences of the rapid warming of the West Antarctic Peninsula. Particularly, in the inner part of Potter Cove (South Shetland Islands, Antarctica) large areas are now exposed to open sea conditions owing to the retreat of Fourcade glacier. During the 2010 austral summer, underwater photographic surveys were undertaken by SCUBA diving up to 30 m in these new ice-free areas 80 m from the glacier front. Our main aim was to investigate colonization and early succession of the benthic assemblages on soft-bottom areas. Here, we reported a total of 1,146 animals belonging to 13 taxa. Filter-feeders comprised the largest trophic group and sessile fauna showed much higher coverages and densities than mobile fauna at all depths. The most abundant groups were ascidians and bryozoans, which together comprised ~90% of all taxa documented. In a region where most of marine-terminating glaciers are in retreat, these results are an important contribution to improve our knowledge on colonization in the newly ice-free areas.
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Affiliation(s)
- Cristian Lagger
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Laboratorio de Ecología Marina, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
- * E-mail:
| | - Natalia Servetto
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Laboratorio de Ecología Marina, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
| | - Luciana Torre
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Laboratorio de Ecología Marina, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
| | - Ricardo Sahade
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Laboratorio de Ecología Marina, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
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Campana GL, Zacher K, Deregibus D, Momo FR, Wiencke C, Quartino ML. Succession of Antarctic benthic algae (Potter Cove, South Shetland Islands): structural patterns and glacial impact over a four-year period. Polar Biol 2017. [DOI: 10.1007/s00300-017-2197-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Husmann G, Philipp EER, Abele D. Seasonal proliferation rates and the capacity to express genes involved in cell cycling and maintenance in response to seasonal and experimental food shortage in Laternula elliptica from King George Island. MARINE ENVIRONMENTAL RESEARCH 2016; 118:57-68. [PMID: 27180267 DOI: 10.1016/j.marenvres.2016.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 04/23/2016] [Accepted: 05/01/2016] [Indexed: 06/05/2023]
Abstract
Melting of coastal glaciers at the West Antarctic Peninsula (WAP) causes shorter winter sea ice duration, intensified ice scouring, sediment erosion and surface freshening in summer, which alters coastal productivity and feeding conditions for the benthos. The soft shell clam Laternula elliptica is a fast growing and abundant filter feeder in coastal Antarctica and a key element for bentho-pelagic carbon recycling. Our aim was to assess the cellular growth and maintenance capacity of small and large clams during natural winter food shortage (seasonal sampling) and in response to experimental starvation exposure. We measured tissue specific proliferation rates, the expression of cell cycling genes, and the iron binding protein Le-ferritin in freshly collected specimens in spring (Nov 2008) and at the end of summer (March 2009). For the experimental approach, we focused on 14 cell cycling and metabolic genes using the same animal size groups. Mantle tissue of young bivalves was the only tissue showing accelerated proliferation in summer (1.7% of cells dividing per day in March) compared to 0.4% dividing cells in animals collected in November. In mantle, siphon and adductor muscle proliferation rates were higher in younger compared to older individuals. At transcript level, Le-cyclin D was upregulated in digestive gland of older animals collected in spring (Nov) compared to March indicating initiation of cell proliferation. Likewise, during experimental starvation Le-cyclin D expression increased in large clam digestive gland, whereas Le-cyclin D and the autophagic factor beclin1 decreased in digestive gland of smaller starved clams. The paper corroborates earlier findings of size and age dependent differences in the metabolic response and gene expression patterns in L. elliptica under energetic deprivation. Age structure of shallow water populations can potentially change due to differences in cellular response between young and old animals as environmental stress levels increase.
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Affiliation(s)
- G Husmann
- Institute of Clinical Molecular Biology, Christian-Albrechts University Kiel, Germany
| | - E E R Philipp
- Institute of Clinical Molecular Biology, Christian-Albrechts University Kiel, Germany
| | - D Abele
- Alfred-Wegener-Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany.
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Pasotti F, Saravia LA, De Troch M, Tarantelli MS, Sahade R, Vanreusel A. Benthic Trophic Interactions in an Antarctic Shallow Water Ecosystem Affected by Recent Glacier Retreat. PLoS One 2015; 10:e0141742. [PMID: 26559062 PMCID: PMC4641631 DOI: 10.1371/journal.pone.0141742] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 10/12/2015] [Indexed: 12/03/2022] Open
Abstract
The western Antarctic Peninsula is experiencing strong environmental changes as a consequence of ongoing regional warming. Glaciers in the area are retreating rapidly and increased sediment-laden meltwater runoff threatens the benthic biodiversity at shallow depths. We identified three sites with a distinct glacier-retreat related history and different levels of glacial influence in the inner part of Potter Cove (King George Island, South Shetland Islands), a fjord-like embayment impacted since the 1950s by a tidewater glacier retreat. We compared the soft sediment meio- and macrofauna isotopic niche widths (δ13C and δ15N stable isotope analysis) at the three sites to investigate possible glacier retreat-related influences on benthic trophic interactions. The isotopic niches were locally shaped by the different degrees of glacier retreat-related disturbance within the Cove. Wider isotopic niche widths were found at the site that has become ice-free most recently, and narrower niches at the older ice-free sites. At an intermediate state of glacier retreat-related disturbance (e.g. via ice-growler scouring) species with different strategies could settle. The site at the earliest stage of post-retreat development was characterized by an assemblage with lower trophic redundancy. Generally, the isotopic niche widths increased with increasing size spectra of organisms within the community, excepting the youngest assemblage, where the pioneer colonizer meiofauna size class displayed the highest isotopic niche width. Meiofauna at all sites generally occupied positions in the isotopic space that suggested a detrital-pool food source and/or the presence of predatory taxa. In general ice scour and glacial impact appeared to play a two-fold role within the Cove: i) either stimulating trophic diversity by allowing continuous re-colonization of meiofaunal species or, ii) over time driving the benthic assemblages into a more compact trophic structure with increased connectedness and resource recycling.
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Affiliation(s)
- Francesca Pasotti
- Marine Biology Laboratory, Ghent University, Krijgslaan 281/S8, B-9000, Ghent, Belgium
- * E-mail:
| | - Leonardo Ariel Saravia
- Institute of Sciences, National University of General Sarmiento, Juan María Gutierrez 1150, C.P.1613, Los Polvorines, Buenos Aires, Argentina
| | - Marleen De Troch
- Marine Biology Laboratory, Ghent University, Krijgslaan 281/S8, B-9000, Ghent, Belgium
| | - Maria Soledad Tarantelli
- Institute of Animal Diversity and Ecology, CONICET, Fac.Cs. E.F. y Nat. National University of Cordoba, Av. Vélez Sársfield 299, 5000, Córdoba, Argentina
| | - Ricardo Sahade
- Institute of Animal Diversity and Ecology, CONICET, Fac.Cs. E.F. y Nat. National University of Cordoba, Av. Vélez Sársfield 299, 5000, Córdoba, Argentina
| | - Ann Vanreusel
- Marine Biology Laboratory, Ghent University, Krijgslaan 281/S8, B-9000, Ghent, Belgium
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Sahade R, Lagger C, Torre L, Momo F, Monien P, Schloss I, Barnes DKA, Servetto N, Tarantelli S, Tatián M, Zamboni N, Abele D. Climate change and glacier retreat drive shifts in an Antarctic benthic ecosystem. SCIENCE ADVANCES 2015; 1:e1500050. [PMID: 26702429 PMCID: PMC4681327 DOI: 10.1126/sciadv.1500050] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 10/09/2015] [Indexed: 05/19/2023]
Abstract
The Antarctic Peninsula (AP) is one of the three places on Earth that registered the most intense warming in the last 50 years, almost five times the global mean. This warming has strongly affected the cryosphere, causing the largest ice-shelf collapses ever observed and the retreat of 87% of glaciers. Ecosystem responses, although increasingly predicted, have been mainly reported for pelagic systems. However, and despite most Antarctic species being benthic, responses in the Antarctic benthos have been detected in only a few species, and major effects at assemblage level are unknown. This is probably due to the scarcity of baselines against which to assess change. We performed repeat surveys of coastal benthos in 1994, 1998, and 2010, analyzing community structure and environmental variables at King George Island, Antarctica. We report a marked shift in an Antarctic benthic community that can be linked to ongoing climate change. However, rather than temperature as the primary factor, we highlight the resulting increased sediment runoff, triggered by glacier retreat, as the potential causal factor. The sudden shift from a "filter feeders-ascidian domination" to a "mixed assemblage" suggests that thresholds (for example, of tolerable sedimentation) and alternative equilibrium states, depending on the reversibility of the changes, could be possible traits of this ecosystem. Sedimentation processes will be increasing under the current scenario of glacier retreat, and attention needs to be paid to its effects along the AP.
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Affiliation(s)
- Ricardo Sahade
- Instituto de Diversidad y Ecología Animal [Consejo Nacional de Investigaciones Científicas y Técnicas–Universidad Nacional de Córdoba (CONICET-UNC)], Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Avenida Vélez Sarsfield 299, 5000 Córdoba, Argentina
- Corresponding author. E-mail:
| | - Cristian Lagger
- Instituto de Diversidad y Ecología Animal [Consejo Nacional de Investigaciones Científicas y Técnicas–Universidad Nacional de Córdoba (CONICET-UNC)], Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Avenida Vélez Sarsfield 299, 5000 Córdoba, Argentina
| | - Luciana Torre
- Instituto de Diversidad y Ecología Animal [Consejo Nacional de Investigaciones Científicas y Técnicas–Universidad Nacional de Córdoba (CONICET-UNC)], Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Avenida Vélez Sarsfield 299, 5000 Córdoba, Argentina
| | - Fernando Momo
- Instituto de Ciencias, Universidad Nacional de General Sarmiento, Juan M. Gutiérrez 1150, B1613GSX Los Polvorines, Argentina
- Instituto de Ecología y Desarrollo Sustentable, Universidad Nacional de Luján, Luján 6700, Argentina
| | - Patrick Monien
- Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky Straße 9-11, 26129 Oldenburg, Germany
- Department of Geosciences, University of Bremen, Klagenfurter Straße (GEO), 28359 Bremen, Germany
| | - Irene Schloss
- Instituto Antártico Argentino, Balcarce 290, Ciudad Autónoma de Buenos Aires C1064AAF, Argentina
| | - David K. A. Barnes
- British Antarctic Survey, Natural Environment Research Council, Madingley, Road, Cambridge CB3 0ET, UK
| | - Natalia Servetto
- Instituto de Diversidad y Ecología Animal [Consejo Nacional de Investigaciones Científicas y Técnicas–Universidad Nacional de Córdoba (CONICET-UNC)], Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Avenida Vélez Sarsfield 299, 5000 Córdoba, Argentina
| | - Soledad Tarantelli
- Instituto de Diversidad y Ecología Animal [Consejo Nacional de Investigaciones Científicas y Técnicas–Universidad Nacional de Córdoba (CONICET-UNC)], Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Avenida Vélez Sarsfield 299, 5000 Córdoba, Argentina
| | - Marcos Tatián
- Instituto de Diversidad y Ecología Animal [Consejo Nacional de Investigaciones Científicas y Técnicas–Universidad Nacional de Córdoba (CONICET-UNC)], Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Avenida Vélez Sarsfield 299, 5000 Córdoba, Argentina
| | - Nadia Zamboni
- Instituto de Diversidad y Ecología Animal [Consejo Nacional de Investigaciones Científicas y Técnicas–Universidad Nacional de Córdoba (CONICET-UNC)], Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Avenida Vélez Sarsfield 299, 5000 Córdoba, Argentina
| | - Doris Abele
- Alfred Wegener Institut for Polar and Marine Research, Columbusstraße, 27568 Bremerhaven, Germany
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