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Li G, Li T, Liu Y, Zheng Y. A new Mach-Zehnder interference temperature measuring sensor based on silica-based chip. Sci Rep 2024; 14:8657. [PMID: 38622209 PMCID: PMC11018610 DOI: 10.1038/s41598-024-59447-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 04/10/2024] [Indexed: 04/17/2024] Open
Abstract
A new type of silicon-based Mach-Zehnder interference (MZI) temperature sensor chip with "mosquito coil" structure was designed. The sensor chip used a new MZI interference structure. After the light entered the chip, it split and interfered in the combiner of the chip. The change in the surrounding temperature will cause the refractive index of the waveguide to change, which will cause the output light intensity to change. The sensor used a frequency stabilized laser that was based on a Bragg grating fiber. The experimental results showed that this structure could achieve a resolution of 0.002 °C and measuring range of 30 °C.
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Affiliation(s)
- Guoqiang Li
- School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore, 639798, Singapore
| | - Tao Li
- Institute of Novel Semiconductors, Institute of Crystal Materials, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Yongfang Liu
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China.
| | - Yuanjin Zheng
- School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore, 639798, Singapore.
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2
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Bayley DTI, Brewin PE, James R, McCarthy AH, Brickle P. Identifying marine invasion threats and management priorities through introduction pathway analysis in a remote sub-Antarctic ecosystem. Ecol Evol 2024; 14:e11299. [PMID: 38654709 PMCID: PMC11036081 DOI: 10.1002/ece3.11299] [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: 12/05/2023] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/26/2024] Open
Abstract
The threat from novel marine species introductions is a global issue. When non-native marine species are introduced to novel environments and become invasive, they can affect biodiversity, industry, ecosystem function, and both human and wildlife health. Isolated areas with sensitive or highly specialised endemic species can be particularly impacted. The global increase in the scope of tourism and other human activities, together with a rapidly changing climate, now put these remote ecosystems under threat. In this context, we analyse invasion pathways into South Georgia and the South Sandwich Islands (SGSSI) for marine non-native species via vessel biofouling. The SGSSI archipelago has high biodiversity and endemism, and has historically been highly isolated from the South American mainland. The islands sit just below the Polar Front temperature boundary, affording some protection against introductions. However, the region is now warming and SGSSI increasingly acts as a gateway port for vessel traffic into the wider Antarctic, amplifying invasion likelihood. We use remote Automatic Identification System vessel-tracking data over a 2-year period to map vessel movement and behaviour around South Georgia, and across the 'Scotia Sea', 'Magellanic' and northern 'Continental High Antarctic' ecoregions. We find multiple vessel types from locations across the globe frequently now enter shallow inshore waters and stop for prolonged periods (weeks/months) at anchor. Vessels are active throughout the year and stop at multiple port hubs, frequently crossing international waters and ecoregions. Management recommendations to reduce marine invasion likelihood within SGSSI include initiating benthic and hull monitoring at the identified activity/dispersion hubs of King Edward Point, Bay of Isles, Gold Harbour, St Andrews Bay and Stromness Bay. More broadly, regional collaboration and coordination is necessary at neighbouring international ports. Here vessels need increased pre- and post-arrival biosecurity assessment following set protocols, and improved monitoring of hulls for biofouling to pre-emptively mitigate this threat.
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Affiliation(s)
- Daniel T. I. Bayley
- South Atlantic Environment Research InstituteStanleyFalkland Islands
- Centre for Biodiversity and Environment ResearchUniversity College LondonLondonUK
| | - Paul E. Brewin
- South Atlantic Environment Research InstituteStanleyFalkland Islands
- Shallow Marine Surveys GroupStanleyFalkland Islands
| | - Ross James
- Government of South Georgia & the South Sandwich IslandsStanleyFalkland Islands
| | - Arlie H. McCarthy
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB)OldenburgGermany
- Alfred‐Wegener‐InstitutHelmholtz‐Zentrum für Polar‐ Und MeeresforschungBremerhavenGermany
| | - Paul Brickle
- South Atlantic Environment Research InstituteStanleyFalkland Islands
- Shallow Marine Surveys GroupStanleyFalkland Islands
- School of Biological Sciences (Zoology)University of AberdeenAberdeenUK
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3
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Low vulnerability of the Mediterranean antipatharian Antipathella subpinnata (Ellis & Solander, 1786) to ocean warming. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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4
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Dawson W, Peyton JM, Pescott OL, Adriaens T, Cottier‐Cook EJ, Frohlich DS, Key G, Malumphy C, Martinou AF, Minchin D, Moore N, Rabitsch W, Rorke SL, Tricarico E, Turvey KMA, Winfield IJ, Barnes DKA, Baum D, Bensusan K, Burton FJ, Carr P, Convey P, Copeland AI, Fa DA, Fowler L, García‐Berthou E, Gonzalez A, González‐Moreno P, Gray A, Griffiths RW, Guillem R, Guzman AN, Haakonsson J, Hughes KA, James R, Linares L, Maczey N, Mailer S, Manco BN, Martin S, Monaco A, Moverley DG, Rose‐Smyth C, Shanklin J, Stevens N, Stewart AJ, Vaux AGC, Warr SJ, Werenkaut V, Roy HE. Horizon scanning for potential invasive non‐native species across the United Kingdom Overseas Territories. Conserv Lett 2022. [DOI: 10.1111/conl.12928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Wayne Dawson
- Department of Biosciences Durham University Durham UK
| | | | | | - Tim Adriaens
- Research Institute for Nature and Forest (INBO) Herman Teirlinckgebouw Brussels Belgium
| | | | | | - Gillian Key
- GB Non‐Native Species Secretariat Animal and Plant Health Agency York UK
| | | | - Angeliki F. Martinou
- Joint Services Health Unit, British Forces Cyprus Nicosia Cyprus
- The Cyprus Institute Nicosia Cyprus
| | - Dan Minchin
- Marine Research Institute Klaipėda University Klaipėda Lithuania
- Marine Organism Investigations Co Clare Ireland
| | - Niall Moore
- GB Non‐Native Species Secretariat Animal and Plant Health Agency York UK
| | | | | | - Elena Tricarico
- Department of Biology University of Florence Sesto Fiorentino Italy
| | | | - Ian J. Winfield
- UK Centre for Ecology & Hydrology Lancaster Environment Centre Lancaster UK
| | | | - Diane Baum
- Ascension Island Government Ascension Island South Atlantic Ocean
| | - Keith Bensusan
- Gibraltar Botanic Gardens Campus, ‘The Alameda’ University of Gibraltar Gibraltar Gibraltar
| | - Frederic J. Burton
- Department of Environment Cayman Islands Government Grand Cayman Cayman Islands
| | - Peter Carr
- Institute of Zoology Zoological Society of London London UK
| | | | - Alison I. Copeland
- Department of Biosciences Durham University Durham UK
- Department of Environment and Natural Resources Government of Bermuda Hamilton Parish Bermuda
| | - Darren A. Fa
- Natural Sciences and Environment Hub, Research Office University of Gibraltar, Europa Point Campus Gibraltar Gibraltar
| | - Liza Fowler
- St Helena National Trust Jamestown South Atlantic Ocean
| | | | | | - Pablo González‐Moreno
- Department of Forest Engineering, ERSAF University of Cordoba Córdoba Spain
- CABI Egham UK
| | - Alan Gray
- UK Centre for Ecology and Hydrology Penicuik UK
| | | | | | - Antenor N. Guzman
- U.S. Navy Support Facility Diego Garcia Diego Garcia British Indian Ocean Territory
| | - Jane Haakonsson
- Gibraltar Botanic Gardens Campus, ‘The Alameda’ University of Gibraltar Gibraltar Gibraltar
| | | | - Ross James
- Government of South Georgia & the South Sandwich Islands Government House Stanley Falkland Islands
| | - Leslie Linares
- Field Centre, Jews’ Gate Gibraltar Ornithological & Natural History Society Gibraltar Gibraltar
| | | | | | - Bryan Naqqi Manco
- Department of Environment and Coastal Resources National Environmental Centre Providenciales Turks and Caicos Islands
| | - Stephanie Martin
- Government of Tristan da Cunha Edinburgh of the Seven Seas Tristan da Cunha
| | - Andrea Monaco
- Department of Life Sciences University of Siena Siena Italy
| | - David G. Moverley
- Secretariat of the Pacific Regional Environment Programme Apia Samoa
| | | | | | | | | | | | - Stephen J. Warr
- Department of the Environment HM Government of Gibraltar Gibraltar Gibraltar
| | - Victoria Werenkaut
- Laboratorio Ecotono INIBIOMA‐CONICET – Universidad Nacional del Comahue San Carlos de Bariloche Argentina
| | - Helen E. Roy
- UK Centre for Ecology & Hydrology Crowmarsh Gifford UK
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Effects of seawater temperature and seasonal irradiance on growth, reproduction, and survival of the endemic Antarctic brown alga Desmarestia menziesii (Phaeophyceae). Polar Biol 2022. [DOI: 10.1007/s00300-021-02991-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractEndemic Antarctic macroalgae are especially adapted to live in extreme Antarctic conditions. Their potential biogeographic distribution niche is primarily controlled by the photoperiodic regime and seawater temperatures, since these parameters regulate growth, reproduction, and survival during the entire life cycle. Here we analyzed the upper survival temperature (UST) of juvenile sporophytes and the temperature range for sporophyte formation from gametophytes of Desmarestia menziesii, one of the dominant endemic Antarctic brown algal species. This process is a missing link to better evaluate the full biogeographical niche of this species. Two laboratory experiments were conducted. First, growth and maximum quantum yield of juvenile sporophytes were analyzed under a temperature gradient (0, 5, 10, 12, 13, 14, 15, and 16 °C) in a 16:8 h light:dark (LD) regime (Antarctic spring condition) for 2 weeks. Second, the formation of sporophytes from gametophytes (as a proxy of gametophyte reproduction) was evaluated during a 7 weeks period under a temperature gradient (0, 4, 8, 12, and 16 °C), and two different photoperiods: 6:18 h LD regime simulating winter conditions and a light regime simulating the Antarctic shift from winter to spring by gradually increasing the light period from 7.5:16.5 h LD (late winter) to 18.5:5.5 h LD (late spring). Sporophytes of D. menziesii were able to grow and survive up to 14 °C for 2 weeks without visible signs of morphological damage. Thus, this species shows the highest UST of all endemic Antarctic Desmarestiales species. In turn, gametophyte reproduction solely took place at 0 °C but not at 4–8 °C. The number of emerging sporophytes was six times higher under the light regime simulating the transition from winter to spring than under constant short day winter conditions. There was a negative relationship between the number of sporophytes formed and the gametophyte density at the beginning of the experiment, which provides evidence that gametophyte density exerts some control upon reproduction in D. menziesii. Results strongly indicate that although sporophytes and gametophytes may survive in warmer temperatures, the northernmost distribution limit of D. menziesii in South Georgia Islands is set by the low temperature requirements for gametophyte reproduction. Hence, global warming could have an impact on the distribution of this and other Antarctic species, by influencing their growth and reproduction.
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Calderan SV, Black A, Branch TA, Collins MA, Kelly N, Leaper R, Lurcock S, Miller BS, Moore M, Olson PA, Širović A, Wood AG, Jackson JA. South Georgia blue whales five decades after the end of whaling. ENDANGER SPECIES RES 2020. [DOI: 10.3354/esr01077] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Blue whales Balaenoptera musculus at South Georgia were heavily exploited during 20th century industrial whaling, to the point of local near-extirpation. Although legal whaling for blue whales ceased in the 1960s, and there were indications of blue whale recovery across the wider Southern Ocean area, blue whales were seldom seen in South Georgia waters in subsequent years. We collated 30 yr of data comprising opportunistic sightings, systematic visual and acoustic surveys and photo-identification to assess the current distribution of blue whales in the waters surrounding South Georgia. Over 34000 km of systematic survey data between 1998 and 2018 resulted in only a single blue whale sighting, although opportunistic sightings were reported over that time period. However, since 2018 there have been increases in both sightings of blue whales and detections of their vocalisations. A survey in 2020 comprising visual line transect surveys and directional frequency analysis and recording (DIFAR) sonobuoy deployments resulted in 58 blue whale sightings from 2430 km of visual effort, including the photo-identification of 23 individual blue whales. Blue whale vocalisations were detected on all 31 sonobuoys deployed (114 h). In total, 41 blue whales were photo-identified from South Georgia between 2011 and 2020, none of which matched the 517 whales in the current Antarctic catalogue. These recent data suggest that blue whales have started to return to South Georgia waters, but continued visual and acoustic surveys are required to monitor any future changes in their distribution and abundance.
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Affiliation(s)
- SV Calderan
- Scottish Association for Marine Science (SAMS), Argyll PA37 1QA, UK
| | - A Black
- Government of South Georgia and South Sandwich Islands, Government House, Stanley FIQQ 1ZZ, Falkland Islands
| | - TA Branch
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, USA
| | - MA Collins
- British Antarctic Survey, NERC, High Cross, Cambridge CB3 0ET, UK
| | - N Kelly
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, Tasmania 7050, Australia
| | - R Leaper
- International Fund for Animal Welfare, London SE1 8NL, UK
| | - S Lurcock
- South Georgia Heritage Trust, Dundee DD1 5BT, UK
| | - BS Miller
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, Tasmania 7050, Australia
| | - M Moore
- Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - PA Olson
- Southwest Fisheries Science Center, NMFS/NOAA, La Jolla, CA 92037, USA
| | - A Širović
- Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - AG Wood
- British Antarctic Survey, NERC, High Cross, Cambridge CB3 0ET, UK
| | - JA Jackson
- British Antarctic Survey, NERC, High Cross, Cambridge CB3 0ET, UK
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Jackson JA, Kennedy A, Moore M, Andriolo A, Bamford CCG, Calderan S, Cheeseman T, Gittins G, Groch K, Kelly N, Leaper R, Leslie MS, Lurcock S, Miller BS, Richardson J, Rowntree V, Smith P, Stepien E, Stowasser G, Trathan P, Vermeulen E, Zerbini AN, Carroll EL. Have whales returned to a historical hotspot of industrial whaling? The pattern of southern right whale Eubalaena australis recovery at South Georgia. ENDANGER SPECIES RES 2020. [DOI: 10.3354/esr01072] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Around 176500 whales were killed in the sub-Antarctic waters off South Georgia (South Atlantic) between 1904 and 1965. In recent decades, whales have once again become summer visitors, with the southern right whale (SRW) the most commonly reported species until 2011. Here, we assess the distribution, temporal pattern, health status and likely prey of SRWs in these waters, combining observations from a summertime vessel-based expedition to South Georgia, stable isotope data collected from SRWs and putative prey and sightings reports collated by the South Georgia Museum. The expedition used directional acoustics and visual surveys to localise whales and collected skin biopsies and photo-IDs. During 76 h of visual observation effort over 19 expedition days, SRWs were encountered 15 times (~31 individuals). Photo-IDs, combined with publicly contributed images from commercial vessels, were reconciled and quality-controlled to form a catalogue of 6 fully (i.e. both sides) identified SRWs and 26 SRWs identified by either left or right sides. No photo-ID matches were found with lower-latitude calving grounds, but 3 whales had gull lesions supporting a direct link with Península Valdés, Argentina. The isotopic position of SRWs in the South Georgia food web suggests feeding on a combination of copepod and krill species. Opportunistic reports of SRW sightings and associated group sizes remain steady over time, while humpback whales provide a strong contrast, with increased sighting rates and group sizes seen since 2013. These data suggest a plateau in SRWs and an increasing humpback whale presence in South Georgia waters following the cessation of whaling.
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Affiliation(s)
- JA Jackson
- British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK For a full list of affiliations see Supplement 1 at www.int-res.com/articles/suppl/n043p323_supp1.pdf
| | | | | | | | - CCG Bamford
- British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK For a full list of affiliations see Supplement 1 at www.int-res.com/articles/suppl/n043p323_supp1.pdf
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - G Stowasser
- British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK For a full list of affiliations see Supplement 1 at www.int-res.com/articles/suppl/n043p323_supp1.pdf
| | - P Trathan
- British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK For a full list of affiliations see Supplement 1 at www.int-res.com/articles/suppl/n043p323_supp1.pdf
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8
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Matias RS, Seco J, Gregory S, Belchier M, Pereira ME, Bustamante P, Xavier JC. Antarctic octopod beaks as proxy for mercury concentrations in soft tissues. MARINE POLLUTION BULLETIN 2020; 158:111447. [PMID: 32753223 DOI: 10.1016/j.marpolbul.2020.111447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 07/05/2020] [Accepted: 07/05/2020] [Indexed: 06/11/2023]
Abstract
As the role of mercury is poorly known in Southern Ocean biota, the total mercury (T-Hg) concentrations were evaluated in upper/lower beaks, digestive gland, gills and mantle muscle of Adelieledone polymorpha and Pareledone turqueti, two of the most abundant octopod species around South Georgia. Beaks had the lowest T-Hg concentrations (A. polymorpha: [T-Hg]Upper = 27.2 ± 12.9 ng∙g-1 and [T-Hg]Lower = 27.5 ± 20.0 ng∙g-1; P. turqueti: [T-Hg]Upper = 34.6 ± 13.9 ng∙g-1 and [T-Hg]Lower = 56.8 ± 42.0 ng∙g-1), followed by gills and muscle. The highest values were recorded in the digestive gland (A. polymorpha: 251.6 ± 69.7 ng∙g-1; P. turqueti: 347.0 ± 177.0 ng∙g-1). Significant relationships were found between the concentrations of T-Hg in the beaks and muscle of A. polymorpha (T-Hg in muscle is 10 times higher than in beaks). This study shows that beaks can be used as proxy for T-Hg in muscle for some octopod species, and a helpful tool for estimating total Hg body burden from beaks.
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Affiliation(s)
- Ricardo S Matias
- Marine and Environmental Sciences Centre (MARE), Department of Life Sciences, Faculty of Sciences and Technology of the University of Coimbra, 3000-456 Coimbra, Portugal.
| | - José Seco
- Department of Chemistry and CESAM/REQUIMTE, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; School of Biology, University of St Andrews, KY16 9ST, Scotland, United Kingdom.
| | - Susan Gregory
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom; Government of South Georgia and the South Sandwich Islands, Stanley, Falkland Islands
| | - Mark Belchier
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom
| | - Maria E Pereira
- Department of Chemistry and CESAM/REQUIMTE, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Paco Bustamante
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, 2 rue Olympe de Gouges, 17000 La Rochelle, France; Institut Universitaire de France (IUF), 1 rue Descartes 75005 Paris, France
| | - José C Xavier
- Marine and Environmental Sciences Centre (MARE), Department of Life Sciences, Faculty of Sciences and Technology of the University of Coimbra, 3000-456 Coimbra, Portugal; British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom
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Rogers AD, Frinault BAV, Barnes DKA, Bindoff NL, Downie R, Ducklow HW, Friedlaender AS, Hart T, Hill SL, Hofmann EE, Linse K, McMahon CR, Murphy EJ, Pakhomov EA, Reygondeau G, Staniland IJ, Wolf-Gladrow DA, Wright RM. Antarctic Futures: An Assessment of Climate-Driven Changes in Ecosystem Structure, Function, and Service Provisioning in the Southern Ocean. ANNUAL REVIEW OF MARINE SCIENCE 2020; 12:87-120. [PMID: 31337252 DOI: 10.1146/annurev-marine-010419-011028] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this article, we analyze the impacts of climate change on Antarctic marine ecosystems. Observations demonstrate large-scale changes in the physical variables and circulation of the Southern Ocean driven by warming, stratospheric ozone depletion, and a positive Southern Annular Mode. Alterations in the physical environment are driving change through all levels of Antarctic marine food webs, which differ regionally. The distributions of key species, such as Antarctic krill, are also changing. Differential responses among predators reflect differences in species ecology. The impacts of climate change on Antarctic biodiversity will likely vary for different communities and depend on species range. Coastal communities and those of sub-Antarctic islands, especially range-restricted endemic communities, will likely suffer the greatest negative consequences of climate change. Simultaneously, ecosystem services in the Southern Ocean will likely increase. Such decoupling of ecosystem services and endemic species will require consideration in the management of human activities such as fishing in Antarctic marine ecosystems.
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Affiliation(s)
- A D Rogers
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom;
- REV Ocean, 1366 Lysaker, Norway
| | - B A V Frinault
- School of Geography and the Environment, University of Oxford, Oxford OX1 3QY, United Kingdom
| | - D K A Barnes
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - N L Bindoff
- Antarctic Climate and Ecosystems Cooperative Research Centre and CSIRO Oceans and Atmospheres, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - R Downie
- WWF, Living Planet Centre, Surrey GU21 4LL, United Kingdom
| | - H W Ducklow
- Lamont-Doherty Earth Observatory and Department of Earth and Environmental Sciences, Columbia University, Palisades, New York 10964-8000, USA
| | - A S Friedlaender
- Institute for Marine Sciences, University of California, Santa Cruz, California 95060, USA
| | - T Hart
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom;
| | - S L Hill
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - E E Hofmann
- Center for Coastal Physical Oceanography, Old Dominion University, Norfolk, Virginia 23508, USA
| | - K Linse
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - C R McMahon
- Integrated Marine Observing System Animal Tracking Facility, Sydney Institute of Marine Science, Sydney, New South Wales 2088, Australia
| | - E J Murphy
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - E A Pakhomov
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Aquatic Ecosystems Research Lab, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - G Reygondeau
- Aquatic Ecosystems Research Lab, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - I J Staniland
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - D A Wolf-Gladrow
- Alfred-Wegener-Institut Helmholtz Zentrum für Polar- und Meeresforschung (AWI), 27570 Bremerhaven, Germany
| | - R M Wright
- Tyndall Centre, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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Hogg OT, Huvenne VAI, Griffiths HJ, Linse K. On the ecological relevance of landscape mapping and its application in the spatial planning of very large marine protected areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 626:384-398. [PMID: 29353784 DOI: 10.1016/j.scitotenv.2018.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/01/2018] [Accepted: 01/02/2018] [Indexed: 06/07/2023]
Abstract
In recent years very large marine protected areas (VLMPAs) have become the dominant form of spatial protection in the marine environment. Whilst seen as a holistic and geopolitically achievable approach to conservation, there is currently a mismatch between the size of VLMPAs, and the data available to underpin their establishment and inform on their management. Habitat mapping has increasingly been adopted as a means of addressing paucity in biological data, through use of environmental proxies to estimate species and community distribution. Small-scale studies have demonstrated environmental-biological links in marine systems. Such links, however, are rarely demonstrated across larger spatial scales in the benthic environment. As such, the utility of habitat mapping as an effective approach to the ecosystem-based management of VLMPAs remains, thus far, largely undetermined. The aim of this study was to assess the ecological relevance of broadscale landscape mapping. Specifically we test the relationship between broad-scale marine landscapes and the structure of their benthic faunal communities. We focussed our work at the sub-Antarctic island of South Georgia, site of one of the largest MPAs in the world. We demonstrate a statistically significant relationship between environmentally derived landscape mapping clusters, and the composition of presence-only species data from the region. To demonstrate this relationship required specific re-sampling of historical species occurrence data to balance biological rarity, biological cosmopolitism, range-restricted sampling and fine-scale heterogeneity between sampling stations. The relationship reveals a distinct biological signature in the faunal composition of individual landscapes, attributing ecological relevance to South Georgia's environmentally derived marine landscape map. We argue therefore, that landscape mapping represents an effective framework for ensuring representative protection of habitats in management plans. Such scientific underpinning of marine spatial planning is critical in balancing the needs of multiple stakeholders whilst maximising conservation payoff.
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Affiliation(s)
- Oliver T Hogg
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 OET, UK; National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, Southampton, UK; University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK.
| | - Veerle A I Huvenne
- National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, Southampton, UK
| | - Huw J Griffiths
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 OET, UK
| | - Katrin Linse
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 OET, UK
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11
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Taverna A, Lagger C, Maggioni T, Reyna P, Lovrich G, Tatián M. Ascidian distribution provides new insights to help define the biogeographic provinces in the South American Region. Polar Biol 2018. [DOI: 10.1007/s00300-018-2272-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Functional group diversity is key to Southern Ocean benthic carbon pathways. PLoS One 2017; 12:e0179735. [PMID: 28654664 PMCID: PMC5487044 DOI: 10.1371/journal.pone.0179735] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/02/2017] [Indexed: 11/19/2022] Open
Abstract
High latitude benthos are globally important in terms of accumulation and storage of ocean carbon, and the feedback this is likely to have on regional warming. Understanding this ecosystem service is important but difficult because of complex taxonomic diversity, history and geography of benthic biomass. Using South Georgia as a model location (where the history and geography of benthic biology is relatively well studied) we investigated whether the composition of functional groups were critical to benthic accumulation, immobilization and burial pathway to sequestration–and also aid their study through simplification of identification. We reclassified [1], [2]) morphotype and carbon mass data to 13 functional groups, for each sample of 32 sites around the South Georgia continental shelf. We investigated the influence on carbon accumulation, immobilization and sequestration estimate by multiple factors including the compositions of functional groups. Functional groups showed high diversity within and between sites, and within and between habitat types. Carbon storage was not linked to a functional group in particular but accumulation and immobilization increased with the number of functional groups present and the presence of hard substrata. Functional groups were also important to carbon burial rate, which increased with the presence of mixed (hard and soft substrata). Functional groups showed high surrogacy for taxonomic composition and were useful for examining contrasting habitat categorization. Functional groups not only aid marine carbon storage investigation by reducing time and the need for team size and speciality, but also important to benthic carbon pathways per se. There is a distinct geography to seabed carbon storage; seabed boulder-fields are hotspots of carbon accumulation and immobilization, whilst the interface between such boulder-fields and sediments are key places for burial and sequestration.
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Figuerola B, Barnes DKA, Brickle P, Brewin PE. Bryozoan diversity around the Falkland and South Georgia Islands: Overcoming Antarctic barriers. MARINE ENVIRONMENTAL RESEARCH 2017; 126:81-94. [PMID: 28258012 DOI: 10.1016/j.marenvres.2017.02.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/16/2017] [Accepted: 02/17/2017] [Indexed: 06/06/2023]
Abstract
There are a number of remote archipelagos distributed between 45 and 60 °S. The biota of these islands provide useful information to describe and understand patterns in biodiversity and biogeography as well as potential impacts of climate change on marine ecosystems. They are in key locations either side of the Polar Front but also have limited influence from human activities. Here we investigate one taxon, bryozoans, on South Atlantic shelf habitats of the Falkland (FI) and the sub-Antarctic island of South Georgia (SG). We present new data on spatial distribution in these islands, as well as an analysis of the bryozoological similarities between these and neighbouring regions. A total of 85 species of cheilostome bryozoans (351 samples) were found, belonging to 33 genera, including 18 potentially new genera and 23 new species. Remarkably 65% and 41% of species were reported for the first time at FI and SG, respectively. The highest and the lowest value of species richness and species/genus ratio were found at East (EFI) and West Falkland (WFI), respectively, likely showing a tendency for stronger intrageneric competition. New data from this study were jointly analysed with data from the literature and existing databases, revealing new bathymetric ranges in 32 species. The biogeographic affinities of the bryozoans found give further evidence of the hypothesis of sequential separation of Gondwana and support the changing concept that although the Polar Front acts as a circumpolar biogeographic barrier it is not as impermeable as originally thought. Potential dispersal mechanisms are also discussed.
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Affiliation(s)
- Blanca Figuerola
- Biodiversity Research Institute (IRBio), Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028 Barcelona, Catalonia, Spain.
| | - David K A Barnes
- British Antarctic Survey (BAS), Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Paul Brickle
- South Atlantic Environmental Research Institute (SAERI), Box 609, Stanley, FIQQ 1ZZ, South Atlantic, Falkland Islands; Shallow Marine Surveys Group (SMSG), 2 Philomel Pl, Stanley, FIQQ 1ZZ, South Atlantic, Falkland Islands; School of Biological Sciences (Zoology), University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Paul E Brewin
- Shallow Marine Surveys Group (SMSG), 2 Philomel Pl, Stanley, FIQQ 1ZZ, South Atlantic, Falkland Islands; Directorate of Natural Resources - Fisheries, Falklands Islands Government, PO Box 598, Stanley, South Atlantic, FIQQ 1ZZ, Falkland Islands; Government of South Georgia & the South Sandwich Islands, Government House, Stanley, FIQQ 1ZZ, South Atlantic, Falkland Islands
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Major advance of South Georgia glaciers during the Antarctic Cold Reversal following extensive sub-Antarctic glaciation. Nat Commun 2017; 8:14798. [PMID: 28303885 PMCID: PMC5357866 DOI: 10.1038/ncomms14798] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 02/01/2017] [Indexed: 01/29/2023] Open
Abstract
The history of glaciations on Southern Hemisphere sub-polar islands is unclear. Debate surrounds the extent and timing of the last glacial advance and termination on sub-Antarctic South Georgia in particular. Here, using sea-floor geophysical data and marine sediment cores, we resolve the record of glaciation offshore of South Georgia through the transition from the Last Glacial Maximum to Holocene. We show a sea-bed landform imprint of a shelf-wide last glacial advance and progressive deglaciation. Renewed glacier resurgence in the fjords between c. 15,170 and 13,340 yr ago coincided with a period of cooler, wetter climate known as the Antarctic Cold Reversal, revealing a cryospheric response to an Antarctic climate pattern extending into the Atlantic sector of the Southern Ocean. We conclude that the last glaciation of South Georgia was extensive, and the sensitivity of its glaciers to climate variability during the last termination more significant than implied by previous studies. The glaciated history of South Georgia is debated, with many suggesting a coastal limit to the island's ice cap during the last glaciation. Here, the authors show extensive ice-cap cover of the continental block during this time and a readvance of glaciers to fjord mouths during the Antarctic Cold Reversal.
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Goodwin CE, Berman J, Downey RV, Hendry KR. Carnivorous sponges (Porifera : Demospongiae : Poecilosclerida : Cladorhizidae) from the Drake Passage (Southern Ocean) with a description of eight new species and a review of the family Cladorhizidae in the Southern Ocean. INVERTEBR SYST 2017. [DOI: 10.1071/is16020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study reviews the taxonomy and biogeography of carnivorous sponges (family Cladorhizidae) in the Southern Ocean. Specimens were collected from seamounts in the Drake Passage by dredging and trawling and biogeographical information from other sources was compiled and reviewed. Eight new species of carnivorous sponges are described: Abyssocladia leverhulmei, sp. nov., Asbestopluma (Asbestopluma) sarsensis, sp. nov., A. (A.) gemmae, sp. nov., A. (A.) rhaphidiophorus, sp. nov., Asbestopluma (Helophloeina) keraia, sp. nov., Chondrocladia (Chondrocladia) saffronae, sp. nov., Cladorhiza scanlonae, sp. nov. and Lycopodina drakensis, sp. nov. Specimens of three previously described species, L. callithrix, L. calyx and A. (A.) bitrichela, were also found. These new records increase the number of known carnivorous sponge species in the Southern Ocean by more than a third. We demonstrate that the Cladorhizidae is the second most species-rich family of Demospongiae in the Southern Ocean and many of its species are highly endemic, with 70% found only in this region. Southern Ocean species represent close to 20% of all known carnivorous sponges. This study highlights the importance of seamount and bathyal benthic habitats for supporting the rich and endemic carnivorous sponge fauna of the Southern Ocean.
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Cryptic species diversity in sub-Antarctic islands: A case study of Lepidonotothen. Mol Phylogenet Evol 2016; 104:32-43. [DOI: 10.1016/j.ympev.2016.07.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/20/2016] [Accepted: 07/11/2016] [Indexed: 12/28/2022]
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Landscape mapping at sub-Antarctic South Georgia provides a protocol for underpinning large-scale marine protected areas. Sci Rep 2016; 6:33163. [PMID: 27694889 PMCID: PMC5046182 DOI: 10.1038/srep33163] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 08/18/2016] [Indexed: 01/30/2023] Open
Abstract
Global biodiversity is in decline, with the marine environment experiencing significant and increasing anthropogenic pressures. In response marine protected areas (MPAs) have increasingly been adopted as the flagship approach to marine conservation, many covering enormous areas. At present, however, the lack of biological sampling makes prioritising which regions of the ocean to protect, especially over large spatial scales, particularly problematic. Here we present an interdisciplinary approach to marine landscape mapping at the sub-Antarctic island of South Georgia as an effective protocol for underpinning large-scale (105–106 km2) MPA designations. We have developed a new high-resolution (100 m) digital elevation model (DEM) of the region and integrated this DEM with bathymetry-derived parameters, modelled oceanographic data, and satellite primary productivity data. These interdisciplinary datasets were used to apply an objective statistical approach to hierarchically partition and map the benthic environment into physical habitats types. We assess the potential application of physical habitat classifications as proxies for biological structuring and the application of the landscape mapping for informing on marine spatial planning.
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Barnes DKA, Ireland L, Hogg OT, Morley S, Enderlein P, Sands CJ. Why is the South Orkney Island shelf (the world's first high seas marine protected area) a carbon immobilization hotspot? GLOBAL CHANGE BIOLOGY 2016; 22:1110-20. [PMID: 26682944 DOI: 10.1111/gcb.13157] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 10/10/2015] [Accepted: 11/02/2015] [Indexed: 05/21/2023]
Abstract
The Southern Ocean archipelago, the South Orkney Islands (SOI), became the world's first entirely high seas marine protected area (MPA) in 2010. The SOI continental shelf (~44 000 km(2) ), was less than half covered by grounded ice sheet during glaciations, is biologically rich and a key area of both sea surface warming and sea-ice losses. Little was known of the carbon cycle there, but recent work showed it was a very important site of carbon immobilization (net annual carbon accumulation) by benthos, one of the few demonstrable negative feedbacks to climate change. Carbon immobilization by SOI bryozoans was higher, per species, unit area and ice-free day, than anywhere-else polar. Here, we investigate why carbon immobilization has been so high at SOI, and whether this is due to high density, longevity or high annual production in six study species of bryozoans (benthic suspension feeders). We compared benthic carbon immobilization across major regions around West Antarctica with sea-ice and primary production, from remotely sensed and directly sampled sources. Lowest carbon immobilization was at the northernmost study regions (South Georgia) and southernmost Amundsen Sea. However, data standardized for age and density showed that only SOI was anomalous (high). High immobilization at SOI was due to very high annual production of bryozoans (rather than high densities or longevity), which were 2x, 3x and 5x higher than on the Bellingshausen, South Georgia and Amundsen shelves, respectively. We found that carbon immobilization correlated to the duration (but not peak or integrated biomass) of phytoplankton blooms, both in directly sampled, local scale data and across regions using remote-sensed data. The long bloom at SOI seems to drive considerable carbon immobilization, but sea-ice losses across West Antarctica mean that significant carbon sinks and negative feedbacks to climate change could also develop in the Bellingshausen and Amundsen seas.
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Affiliation(s)
- David K A Barnes
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, UK
| | - Louise Ireland
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, UK
| | - Oliver T Hogg
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, UK
- National Oceanography Centre Southampton, University of Southampton, European Way, Southampton, SO14 3ZH, UK
| | - Simon Morley
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, UK
| | - Peter Enderlein
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, UK
| | - Chester J Sands
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, UK
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Rogers AD, Yesson C, Gravestock P. A Biophysical and Economic Profile of South Georgia and the South Sandwich Islands as Potential Large-Scale Antarctic Protected Areas. ADVANCES IN MARINE BIOLOGY 2015; 70:1-286. [PMID: 26296718 DOI: 10.1016/bs.amb.2015.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The current hiatus in the establishment of a network of marine protected areas (MPAs) in the Antarctic means that other routes to conservation are required. The protection of overseas territories in the Antarctic and sub-Antarctic represents one way to advance the initiation of such a network. This review of the physical and biological features of the United Kingdom (U.K.) overseas territories of South Georgia and South Sandwich Islands (SGSSI) is undertaken to estimate the importance of the islands in terms of marine conservation in the Southern Ocean and globally. The economy and management of SGSSI are also analysed, and the question of whether the islands already have sufficient protection to constitute part of an Antarctic network of MPAs is assessed. The SGSSI comprise unique geological and physical features, a diverse marine biota, including a significant proportion of endemic species and globally important breeding populations of marine predators. Regardless of past exploitation of biotic resources, such as seals, whales and finfish, SGSSI would make a significant contribution to biological diversity in an Antarctic network of MPAs. At present, conservation measures do not adequately protect all of the biological features that render the islands so important in terms of conservation at a regional and global level. However, a general lack of data on Antarctic marine ecosystems (particularly needed for SGSSSI) makes it difficult to assess this fully. One barrier to achieving more complete protection is the continuing emphasis on fishing effort in these waters by U.K. government. Other non-U.K. Antarctic overseas territories of conservation importance are also compromised as MPAs because of the exploitation of fisheries resources in their waters. The possible non-use values of SGSSI as well as the importance of ecosystem services that are indirectly used by people are outlined in this review. Technology is improving the potential for management of remote MPAs, particularly in the context of incursion by illegal fishing activities and use of satellite surveillance for enforcement of fisheries and conservation regulations. The conflict between commercial exploitation and conservation of Antarctic marine living resources is explored.
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Affiliation(s)
- Alex D Rogers
- Department of Zoology, University of Oxford, Oxford, United Kingdom.
| | - Christopher Yesson
- Institute of Zoology, Zoological Society of London, London, United Kingdom
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Trathan PN, Collins MA, Grant SM, Belchier M, Barnes DKA, Brown J, Staniland IJ. The South Georgia and the South Sandwich Islands MPA: protecting a biodiverse oceanic island chain situated in the flow of the antarctic circumpolar current. ADVANCES IN MARINE BIOLOGY 2014; 69:15-78. [PMID: 25358297 DOI: 10.1016/b978-0-12-800214-8.00002-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
South Georgia and the South Sandwich Islands (SGSSI) are surrounded by oceans that are species-rich, have high levels of biodiversity, important endemism and which also support large aggregations of charismatic upper trophic level species. Spatial management around these islands is complex, particularly in the context of commercial fisheries that exploit some of these living resources. Furthermore, management is especially complicated as local productivity relies fundamentally upon biological production transported from outside the area. The MPA uses practical management boundaries, allowing access for the current legal fisheries for Patagonian toothfish, mackerel icefish and Antarctic krill. Management measures developed as part of the planning process designated the whole SGSSI Maritime Zone as an IUCN Category VI reserve, within which a number of IUCN Category I reserves were identified. Multiple-use zones and temporal closures were also designated. A key multiple-use principle was to identify whether the ecological impacts of a particular fishery threatened either the pelagic or benthic domain.
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Affiliation(s)
- Philip N Trathan
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom.
| | - Martin A Collins
- Government of South Georgia and the South Sandwich Islands, Government House, Stanley, Falkland Islands
| | - Susie M Grant
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - Mark Belchier
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - David K A Barnes
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - Judith Brown
- Government of South Georgia and the South Sandwich Islands, Government House, Stanley, Falkland Islands
| | - Iain J Staniland
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
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Griffiths HJ, Whittle RJ, Roberts SJ, Belchier M, Linse K. Antarctic crabs: invasion or endurance? PLoS One 2013; 8:e66981. [PMID: 23843974 PMCID: PMC3700924 DOI: 10.1371/journal.pone.0066981] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 05/10/2013] [Indexed: 11/28/2022] Open
Abstract
Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the "invasion hypothesis".
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Wilkins D, Yau S, Williams TJ, Allen MA, Brown MV, DeMaere MZ, Lauro FM, Cavicchioli R. Key microbial drivers in Antarctic aquatic environments. FEMS Microbiol Rev 2013; 37:303-35. [DOI: 10.1111/1574-6976.12007] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 08/11/2012] [Accepted: 10/01/2012] [Indexed: 11/27/2022] Open
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Downey RV, Griffiths HJ, Linse K, Janussen D. Diversity and distribution patterns in high southern latitude sponges. PLoS One 2012; 7:e41672. [PMID: 22911840 PMCID: PMC3404021 DOI: 10.1371/journal.pone.0041672] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 06/24/2012] [Indexed: 11/29/2022] Open
Abstract
Sponges play a key role in Antarctic marine benthic community structure and dynamics and are often a dominant component of many Southern Ocean benthic communities. Understanding the drivers of sponge distribution in Antarctica enables us to understand many of general benthic biodiversity patterns in the region. The sponges of the Antarctic and neighbouring oceanographic regions were assessed for species richness and biogeographic patterns using over 8,800 distribution records. Species-rich regions include the Antarctic Peninsula, South Shetland Islands, South Georgia, Eastern Weddell Sea, Kerguelen Plateau, Falkland Islands and north New Zealand. Sampling intensity varied greatly within the study area, with sampling hotspots found at the Antarctic Peninsula, South Georgia, north New Zealand and Tierra del Fuego, with limited sampling in the Bellingshausen and Amundsen seas in the Southern Ocean. In contrast to previous studies we found that eurybathy and circumpolar distributions are important but not dominant characteristics in Antarctic sponges. Overall Antarctic sponge species endemism is ∼43%, with a higher level for the class Hexactinellida (68%). Endemism levels are lower than previous estimates, but still indicate the importance of the Polar Front in isolating the Southern Ocean fauna. Nineteen distinct sponge distribution patterns were found, ranging from regional endemics to cosmopolitan species. A single, distinct Antarctic demosponge fauna is found to encompass all areas within the Polar Front, and the sub-Antarctic regions of the Kerguelen Plateau and Macquarie Island. Biogeographical analyses indicate stronger faunal links between Antarctica and South America, with little evidence of links between Antarctica and South Africa, Southern Australia or New Zealand. We conclude that the biogeographic and species distribution patterns observed are largely driven by the Antarctic Circumpolar Current and the timing of past continent connectivity.
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Affiliation(s)
- Rachel V. Downey
- British Antarctic Survey, Natural Environmental Research Council, Cambridge, United Kingdom
| | - Huw J. Griffiths
- British Antarctic Survey, Natural Environmental Research Council, Cambridge, United Kingdom
- * E-mail:
| | - Katrin Linse
- British Antarctic Survey, Natural Environmental Research Council, Cambridge, United Kingdom
| | - Dorte Janussen
- Sektion Marine Evertebraten I, Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt am Main, Germany
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