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Krisch S, Browning TJ, Graeve M, Ludwichowski KU, Lodeiro P, Hopwood MJ, Roig S, Yong JC, Kanzow T, Achterberg EP. The influence of Arctic Fe and Atlantic fixed N on summertime primary production in Fram Strait, North Greenland Sea. Sci Rep 2020; 10:15230. [PMID: 32943713 PMCID: PMC7499181 DOI: 10.1038/s41598-020-72100-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/25/2020] [Indexed: 11/14/2022] Open
Abstract
Climate change has led to a ~ 40% reduction in summer Arctic sea-ice cover extent since the 1970s. Resultant increases in light availability may enhance phytoplankton production. Direct evidence for factors currently constraining summertime phytoplankton growth in the Arctic region is however lacking. GEOTRACES cruise GN05 conducted a Fram Strait transect from Svalbard to the NE Greenland Shelf in summer 2016, sampling for bioessential trace metals (Fe, Co, Zn, Mn) and macronutrients (N, Si, P) at ~ 79°N. Five bioassay experiments were conducted to establish phytoplankton responses to additions of Fe, N, Fe + N and volcanic dust. Ambient nutrient concentrations suggested N and Fe were deficient in surface seawater relative to typical phytoplankton requirements. A west-to-east trend in the relative deficiency of N and Fe was apparent, with N becoming more deficient towards Greenland and Fe more deficient towards Svalbard. This aligned with phytoplankton responses in bioassay experiments, which showed greatest chlorophyll-a increases in + N treatment near Greenland and + N + Fe near Svalbard. Collectively these results suggest primary N limitation of phytoplankton growth throughout the study region, with conditions potentially approaching secondary Fe limitation in the eastern Fram Strait. We suggest that the supply of Atlantic-derived N and Arctic-derived Fe exerts a strong control on summertime nutrient stoichiometry and resultant limitation patterns across the Fram Strait region.
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Affiliation(s)
- Stephan Krisch
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Thomas J Browning
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Martin Graeve
- Alfred-Wegener-Institute for Polar and Marine Research, 27570, Bremerhaven, Germany
| | - Kai-Uwe Ludwichowski
- Alfred-Wegener-Institute for Polar and Marine Research, 27570, Bremerhaven, Germany
| | - Pablo Lodeiro
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Mark J Hopwood
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Stéphane Roig
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Jaw-Chuen Yong
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Torsten Kanzow
- Alfred-Wegener-Institute for Polar and Marine Research, 27570, Bremerhaven, Germany
| | - Eric P Achterberg
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany.
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Bascur M, Muñoz-Ramírez C, Román-González A, Sheen K, Barnes DKA, Sands CJ, Brante A, Urzúa Á. The influence of glacial melt and retreat on the nutritional condition of the bivalve Nuculana inaequisculpta (Protobranchia: Nuculanidae) in the West Antarctic Peninsula. PLoS One 2020; 15:e0233513. [PMID: 32437403 PMCID: PMC7241748 DOI: 10.1371/journal.pone.0233513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/06/2020] [Indexed: 01/09/2023] Open
Abstract
Due to climate change, numerous ice bodies have been lost in the West Antarctic Peninsula (WAP). As a consequence, deglaciation is expected to impact the marine environment and its biota at physiological and ecosystem levels. Nuculana inaequisculpta is a marine bivalve widely distributed around Antarctica that plays an important role for ecosystem functioning. Considering that N. inaequisculpta inhabits coastal areas under effect of glacial melt and retreat, impacts on its nutritional condition are expected due to alterations on its physiology and food availability. To test this hypothesis, biochemical composition (lipids, proteins, and fatty acids) and energy content were measured in individuals of N. inaequisculpta collected in a fjord at different distances to the retreating glacier in the WAP. Oceanographic parameters of the top and bottom-water layers (temperature, salinity, dissolved oxygen, and chlorophyll-a) were measured to investigate how the environment changes along the fjord. Results showed that surface oceanographic parameters displayed a lower temperature and dissolved oxygen, but a higher salinity and chlorophyll-a content at nearest compared to farthest sites to the glacier. In contrast, a lower temperature and chlorophyll-a, and a higher salinity and dissolved oxygen was measured in the bottom-water layer toward the glacier. N. inaequisculpta had a higher amount of lipids (17.42 ± 3.24 vs. 12.16 ± 3.46%), protein (24.34 ± 6.12 vs. 21.05 ± 2.46%) and energy content (50.57 ± 6.97 J vs. 39.14 ± 5.80 J) in the farthest compared to the nearest site to the glacier. No differences were found in total fatty acids among all sites. It seems likely that lower individual fitness related to proximity to the glacier would not be related to nutritional quality of sediment food, but rather to food quantity.
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Affiliation(s)
- Miguel Bascur
- Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción, Chile
- Programa de Magíster en Ecología Marina, Universidad Católica de la Santísima Concepción, Concepción, Chile
| | - Carlos Muñoz-Ramírez
- Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción, Chile
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Concepción, Chile
- Instituto de Entomología, Universidad Metropolitana de Ciencias de la Educación, Santiago, Chile
| | - Alejandro Román-González
- College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, England, United Kingdom
| | - Katy Sheen
- College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, England, United Kingdom
| | - David K. A. Barnes
- British Antarctic Survey, Natural Environment Research Council, Cambridge, England, United Kingdom
| | - Chester J. Sands
- British Antarctic Survey, Natural Environment Research Council, Cambridge, England, United Kingdom
| | - Antonio Brante
- Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción, Chile
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Concepción, Chile
| | - Ángel Urzúa
- Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción, Chile
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Concepción, Chile
- * E-mail:
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Hendry KR, Meredith MP, Ducklow HW. The marine system of the West Antarctic Peninsula: status and strategy for progress. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0179. [PMID: 29760121 PMCID: PMC5954477 DOI: 10.1098/rsta.2017.0179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/23/2018] [Indexed: 06/08/2023]
Affiliation(s)
- Katharine R Hendry
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
| | - Michael P Meredith
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Hugh W Ducklow
- Lamont-Doherty Earth Observatory, Columbia University, 61 US-9 W, Palisades, NY 10964, USA
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Sherrell RM, Annett AL, Fitzsimmons JN, Roccanova VJ, Meredith MP. A 'shallow bathtub ring' of local sedimentary iron input maintains the Palmer Deep biological hotspot on the West Antarctic Peninsula shelf. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0171. [PMID: 29760114 PMCID: PMC5954470 DOI: 10.1098/rsta.2017.0171] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/21/2018] [Indexed: 05/23/2023]
Abstract
Palmer Deep (PD) is one of several regional hotspots of biological productivity along the inner shelf of the West Antarctic Peninsula. The proximity of hotspots to shelf-crossing deep troughs has led to the 'canyon hypothesis', which proposes that circumpolar deep water flowing shoreward along the canyons is upwelled on the inner shelf, carrying nutrients including iron (Fe) to surface waters, maintaining phytoplankton blooms. We present here full-depth profiles of dissolved and particulate Fe and manganese (Mn) from eight stations around PD, sampled in January and early February of 2015 and 2016, allowing the first detailed evaluation of Fe sources to the area's euphotic zone. We show that upwelling of deep water does not control Fe flux to the surface; instead, shallow sediment-sourced Fe inputs are transported horizontally from surrounding coastlines, creating strong vertical gradients of dissolved Fe within the upper 100 m that supply this limiting nutrient to the local ecosystem. The supply of bioavailable Fe is, therefore, not significantly related to the canyon transport of deep water. Near shore time-series samples reveal that local glacial meltwater appears to be an important Mn source but, surprisingly, is not a large direct Fe input to this biological hotspot.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)
- Robert M Sherrell
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ, USA
| | - Amber L Annett
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
| | - Jessica N Fitzsimmons
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
| | - Vincent J Roccanova
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA
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