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Swadling KM, Constable AJ, Fraser AD, Massom RA, Borup MD, Ghigliotti L, Granata A, Guglielmo L, Johnston NM, Kawaguchi S, Kennedy F, Kiko R, Koubbi P, Makabe R, Martin A, McMinn A, Moteki M, Pakhomov EA, Peeken I, Reimer J, Reid P, Ryan KG, Vacchi M, Virtue P, Weldrick CK, Wongpan P, Wotherspoon SJ. Biological responses to change in Antarctic sea ice habitats. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2022.1073823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Sea ice is a key habitat in the high latitude Southern Ocean and is predicted to change in its extent, thickness and duration in coming decades. The sea-ice cover is instrumental in mediating ocean–atmosphere exchanges and provides an important substrate for organisms from microbes and algae to predators. Antarctic krill, Euphausia superba, is reliant on sea ice during key phases of its life cycle, particularly during the larval stages, for food and refuge from their predators, while other small grazers, including copepods and amphipods, either live in the brine channel system or find food and shelter at the ice-water interface and in gaps between rafted ice blocks. Fish, such as the Antarctic silverfish Pleuragramma antarcticum, use platelet ice (loosely-formed frazil crystals) as an essential hatching and nursery ground. In this paper, we apply the framework of the Marine Ecosystem Assessment for the Southern Ocean (MEASO) to review current knowledge about relationships between sea ice and associated primary production and secondary consumers, their status and the drivers of sea-ice change in this ocean. We then use qualitative network modelling to explore possible responses of lower trophic level sea-ice biota to different perturbations, including warming air and ocean temperatures, increased storminess and reduced annual sea-ice duration. This modelling shows that pelagic algae, copepods, krill and fish are likely to decrease in response to warming temperatures and reduced sea-ice duration, while salp populations will likely increase under conditions of reduced sea-ice duration and increased number of days of >0°C. Differences in responses to these pressures between the five MEASO sectors were also explored. Greater impacts of environmental pressures on ice-related biota occurring presently were found for the West and East Pacific sectors (notably the Ross Sea and western Antarctic Peninsula), with likely flow-on effects to the wider ecosystem. All sectors are expected to be impacted over coming decades. Finally, we highlight priorities for future sea ice biological research to address knowledge gaps in this field.
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McCormack SA, Melbourne-Thomas J, Trebilco R, Griffith G, Hill SL, Hoover C, Johnston NM, Marina TI, Murphy EJ, Pakhomov EA, Pinkerton M, Plagányi É, Saravia LA, Subramaniam RC, Van de Putte AP, Constable AJ. Southern Ocean Food Web Modelling: Progress, Prognoses, and Future Priorities for Research and Policy Makers. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.624763] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Graphical AbstractGraphical summary of multiple aspects of Southern Ocean food web structure and function including alternative energy pathways through pelagic food webs, climate change and fisheries impacts and the importance of microbial networks and benthic systems.
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3
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Lowther AD, Staniland I, Lydersen C, Kovacs KM. Male Antarctic fur seals: neglected food competitors of bioindicator species in the context of an increasing Antarctic krill fishery. Sci Rep 2020; 10:18436. [PMID: 33116190 PMCID: PMC7595138 DOI: 10.1038/s41598-020-75148-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 10/07/2020] [Indexed: 11/25/2022] Open
Abstract
The fishery for Antarctic krill is currently managed using a precautionary, ecosystem-based approach to limiting catch, with performance indices from a long-term monitoring program focused on several krill-dependent predators that are used to track ecosystem health. Concerns over increased fishing in concentrated areas and ongoing efforts to establish a Marine Protected Area along the Peninsula, a key fishing region, is driving the development of an adaptive management system for the fishery. The cumulative effects of fishing effort and interactions among krill-dependent predators and their performance is at present neglected in the CCAMLR Ecosystem Monitoring Program. However, we show considerable overlap between male Antarctic fur seals and the krill fishery in a complex mosaic, suggesting potential for cumulative impacts on other krill dependent predators. A holistic view is required as part of future efforts to manage the krill fishery that incorporates various sources of potential impacts on the performance of bioindicator species, including the fishery and its interactions with various krill dependent predators.
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Affiliation(s)
| | | | - C Lydersen
- Norwegian Polar Institute, Tromsö, Norway
| | - K M Kovacs
- Norwegian Polar Institute, Tromsö, Norway
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Han Y, Kristensen NP, Buckley YM, Maple DJ, West J, McDonald-Madden E. Predicting the ecosystem-wide impacts of eradication with limited information using a qualitative modelling approach. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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5
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Jansen J, Dunstan PK, Hill NA, Koubbi P, Melbourne-Thomas J, Causse R, Johnson CR. Integrated assessment of the spatial distribution and structural dynamics of deep benthic marine communities. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02065. [PMID: 31872512 DOI: 10.1002/eap.2065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 08/15/2019] [Accepted: 11/11/2019] [Indexed: 06/10/2023]
Abstract
Characterizing the spatial distribution and variation of species communities and validating these characteristics with data from the field are key elements for an ecosystem-based approach to management. However, models of species distributions that yield community structure are usually not linked to models of community dynamics, constraining understanding and management of the ecosystem, particularly in data-poor regions. Here we use a qualitative network model to predict changes in Antarctic benthic community structure between major marine habitats characterized largely by seafloor depth and slope, and use multivariate mixture models of species distributions to validate the community dynamics. We then assess how future increases in primary production associated with anticipated loss of sea-ice may affect the ecosystem. Our study shows how both spatial and structural features of ecosystems in data-poor regions can be analyzed and possible futures assessed, with direct relevance for ecosystem-based management.
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Affiliation(s)
- Jan Jansen
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, Tasmania, 7004, Australia
| | | | - Nicole A Hill
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, Tasmania, 7004, Australia
| | - Philippe Koubbi
- UFR 918 Terre Environnement Biodiversité, Sorbonne Université, Paris, France
- Channel and North Sea Fisheries Research Unit, IFREMER, Boulogne-sur-Mer, France
| | | | - Romain Causse
- Unité Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Muséum National d'Histoire Naturelle, Sorbonne Université, Université de Caen Normandie, Université des Antilles, CNRS, IRD, Paris, France
| | - Craig R Johnson
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, Tasmania, 7004, Australia
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6
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Calizza E, Careddu G, Sporta Caputi S, Rossi L, Costantini ML. Time- and depth-wise trophic niche shifts in Antarctic benthos. PLoS One 2018; 13:e0194796. [PMID: 29570741 PMCID: PMC5865725 DOI: 10.1371/journal.pone.0194796] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 03/09/2018] [Indexed: 01/30/2023] Open
Abstract
Climate change is expected to affect resource-consumer interactions underlying stability in polar food webs. Polar benthic organisms have adapted to the marked seasonality characterising their habitats by concentrating foraging and reproductive activity in summer months, when inputs from sympagic and pelagic producers increase. While this enables the persistence of biodiverse food webs, the mechanisms underlying changes in resource use and nutrient transfer are poorly understood. Thus, our understanding of how temporal and spatial variations in the supply of resources may affect food web structure and functioning is limited. By means of C and N isotopic analyses of two key Antarctic benthic consumers (Adamussium colbecki, Bivalvia, and Sterechinus neumayeri, Echinoidea) and Bayesian mixing models, we describe changes in trophic niche and nutrient transfer across trophic levels associated with the long- and short-term diet and body size of specimens sampled in midsummer in both shallow and deep waters. Samplings occurred soon after the sea-ice broke up at Tethys Bay, an area characterised by extreme seasonality in sea-ice coverage and productivity in the Ross Sea. In the long term, the trophic niche was broader and variation between specimens was greater, with intermediate-size specimens generally consuming a higher number of resources than small and large specimens. The coupling of energy channels in the food web was consequently more direct than in the short term. Sediment and benthic algae were more frequently consumed in the long term, before the sea-ice broke up, while consumers specialised on sympagic algae and plankton in the short term. Regardless of the time scale, sympagic algae were more frequently consumed in shallow waters, while plankton was more frequently consumed in deep waters. Our results suggest a strong temporal relationship between resource availability and the trophic niche of benthic consumers in Antarctica. Potential climate-driven changes in the timing and quality of nutrient inputs may have profound implications for the structure of polar food webs and the persistence of their constituent species, which have adapted their trophic niches to a highly predictable schedule of resource inputs.
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Affiliation(s)
- Edoardo Calizza
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
- CoNISMa-Consorzio Nazionale Interuniversitario per le Scienze del Mare, Rome, Italy
| | - Giulio Careddu
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
| | | | - Loreto Rossi
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
- CoNISMa-Consorzio Nazionale Interuniversitario per le Scienze del Mare, Rome, Italy
- * E-mail:
| | - Maria Letizia Costantini
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
- CoNISMa-Consorzio Nazionale Interuniversitario per le Scienze del Mare, Rome, Italy
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7
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Hindell MA, Sumner M, Bestley S, Wotherspoon S, Harcourt RG, Lea MA, Alderman R, McMahon CR. Decadal changes in habitat characteristics influence population trajectories of southern elephant seals. GLOBAL CHANGE BIOLOGY 2017; 23:5136-5150. [PMID: 28590592 DOI: 10.1111/gcb.13776] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 04/30/2017] [Indexed: 06/07/2023]
Abstract
Understanding divergent biological responses to climate change is important for predicting ecosystem level consequences. We use species habitat models to predict the winter foraging habitats of female southern elephant seals and investigate how changes in environmental variables within these habitats may be related to observed decreases in the Macquarie Island population. There were three main groups of seals that specialized in different ocean realms (the sub-Antarctic, the Ross Sea and the Victoria Land Coast). The physical and climate attributes (e.g. wind strength, sea surface height, ocean current strength) varied amongst the realms and also displayed different temporal trends over the last two to four decades. Most notably, sea ice extent increased on average in the Victoria Land realm while it decreased overall in the Ross Sea realm. Using a species distribution model relating mean residence times (time spent in each 50 × 50 km grid cell) to 9 climate and physical co-variates, we developed spatial predictions of residence time to identify the core regions used by the seals across the Southern Ocean from 120°E to 120°W. Population size at Macquarie Island was negatively correlated with ice concentration within the core habitat of seals using the Victoria Land Coast and the Ross Sea. Sea ice extent and concentration is predicted to continue to change in the Southern Ocean, having unknown consequences for the biota of the region. The proportion of Macquarie Island females (40%) utilizing the relatively stable sub-Antarctic region, may buffer this population against longer-term regional changes in habitat quality, but the Macquarie Island population has persistently decreased (-1.45% per annum) over seven decades indicating that environmental changes in the Antarctic are acting on the remaining 60% of the population to impose a long-term population decline in a top Southern Ocean predator.
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Affiliation(s)
- Mark A Hindell
- Institute for Marine & Antarctic Studies, Hobart, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart, Australia
| | - Michael Sumner
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart, Australia
- Australian Antarctic Division, Kingston, Australia
| | - Sophie Bestley
- Institute for Marine & Antarctic Studies, Hobart, Australia
- Australian Antarctic Division, Kingston, Australia
| | - Simon Wotherspoon
- Institute for Marine & Antarctic Studies, Hobart, Australia
- Australian Antarctic Division, Kingston, Australia
| | - Robert G Harcourt
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, Australia
| | - Mary-Anne Lea
- Institute for Marine & Antarctic Studies, Hobart, Australia
| | - Rachael Alderman
- Department of Primary Industries, Parks, Water and Environment, Hobart, Australia
| | - Clive R McMahon
- Institute for Marine & Antarctic Studies, Hobart, Australia
- Sydney Institute of Marine Science, Mosman, Australia
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8
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Subramaniam RC, Melbourne-Thomas J, Davidson AT, Corney SP. Mechanisms driving Antarctic microbial community responses to ocean acidification: a network modelling approach. Polar Biol 2017. [DOI: 10.1007/s00300-016-1989-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Fulton EA, Bax NJ, Bustamante RH, Dambacher JM, Dichmont C, Dunstan PK, Hayes KR, Hobday AJ, Pitcher R, Plagányi ÉE, Punt AE, Savina-Rolland M, Smith ADM, Smith DC. Modelling marine protected areas: insights and hurdles. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0278. [PMID: 26460131 DOI: 10.1098/rstb.2014.0278] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Models provide useful insights into conservation and resource management issues and solutions. Their use to date has highlighted conditions under which no-take marine protected areas (MPAs) may help us to achieve the goals of ecosystem-based management by reducing pressures, and where they might fail to achieve desired goals. For example, static reserve designs are unlikely to achieve desired objectives when applied to mobile species or when compromised by climate-related ecosystem restructuring and range shifts. Modelling tools allow planners to explore a range of options, such as basing MPAs on the presence of dynamic oceanic features, and to evaluate the potential future impacts of alternative interventions compared with 'no-action' counterfactuals, under a range of environmental and development scenarios. The modelling environment allows the analyst to test if indicators and management strategies are robust to uncertainties in how the ecosystem (and the broader human-ecosystem combination) operates, including the direct and indirect ecological effects of protection. Moreover, modelling results can be presented at multiple spatial and temporal scales, and relative to ecological, economic and social objectives. This helps to reveal potential 'surprises', such as regime shifts, trophic cascades and bottlenecks in human responses. Using illustrative examples, this paper briefly covers the history of the use of simulation models for evaluating MPA options, and discusses their utility and limitations for informing protected area management in the marine realm.
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Affiliation(s)
- Elizabeth A Fulton
- CSIRO Oceans and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia Centre for Marine Socioecology, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
| | - Nicholas J Bax
- CSIRO Oceans and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
| | | | - Jeffrey M Dambacher
- CSIRO Digital Productivity, GPO Box 1538, Hobart, Tasmania 7001, Australia Centre for Marine Socioecology, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
| | - Catherine Dichmont
- CSIRO Oceans and Atmosphere, PO Box 2583, Brisbane, Queensland 4001, Australia
| | - Piers K Dunstan
- CSIRO Oceans and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia
| | - Keith R Hayes
- CSIRO Digital Productivity, GPO Box 1538, Hobart, Tasmania 7001, Australia
| | - Alistair J Hobday
- CSIRO Oceans and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia Centre for Marine Socioecology, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
| | - Roland Pitcher
- CSIRO Oceans and Atmosphere, PO Box 2583, Brisbane, Queensland 4001, Australia
| | - Éva E Plagányi
- CSIRO Oceans and Atmosphere, PO Box 2583, Brisbane, Queensland 4001, Australia
| | - André E Punt
- CSIRO Oceans and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195-5020, USA
| | - Marie Savina-Rolland
- Laboratoire Ressources Halieutiques, Centre Manche - Mer du Nord, 150, quai Gambetta, BP 699, 62321 Boulogne sur Mer Cedex, France
| | - Anthony D M Smith
- CSIRO Oceans and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia Centre for Marine Socioecology, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
| | - David C Smith
- CSIRO Oceans and Atmosphere, GPO Box 1538, Hobart, Tasmania 7001, Australia Centre for Marine Socioecology, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
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11
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Marzloff MP, Melbourne-Thomas J, Hamon KG, Hoshino E, Jennings S, van Putten IE, Pecl GT. Modelling marine community responses to climate-driven species redistribution to guide monitoring and adaptive ecosystem-based management. GLOBAL CHANGE BIOLOGY 2016; 22:2462-2474. [PMID: 26990671 DOI: 10.1111/gcb.13285] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 03/08/2016] [Accepted: 03/08/2016] [Indexed: 06/05/2023]
Abstract
As a consequence of global climate-driven changes, marine ecosystems are experiencing polewards redistributions of species - or range shifts - across taxa and throughout latitudes worldwide. Research on these range shifts largely focuses on understanding and predicting changes in the distribution of individual species. The ecological effects of marine range shifts on ecosystem structure and functioning, as well as human coastal communities, can be large, yet remain difficult to anticipate and manage. Here, we use qualitative modelling of system feedback to understand the cumulative impacts of multiple species shifts in south-eastern Australia, a global hotspot for ocean warming. We identify range-shifting species that can induce trophic cascades and affect ecosystem dynamics and productivity, and evaluate the potential effectiveness of alternative management interventions to mitigate these impacts. Our results suggest that the negative ecological impacts of multiple simultaneous range shifts generally add up. Thus, implementing whole-of-ecosystem management strategies and regular monitoring of range-shifting species of ecological concern are necessary to effectively intervene against undesirable consequences of marine range shifts at the regional scale. Our study illustrates how modelling system feedback with only limited qualitative information about ecosystem structure and range-shifting species can predict ecological consequences of multiple co-occurring range shifts, guide ecosystem-based adaptation to climate change and help prioritise future research and monitoring.
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Affiliation(s)
- Martin Pierre Marzloff
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, Tas., 7001, Australia
| | - Jessica Melbourne-Thomas
- Department of the Environment, Australian Antarctic Division, Channel Highway, Kingston, Tas., 7005, Australia
- Antarctic Climate and Ecosystems Cooperative Research Centre, Private Bag 80, Hobart, Tas., 7001, Australia
| | - Katell G Hamon
- LEI - Wageningen UR, PO Box 29703, 2502 LS, 'S Gravenhage, The Netherlands
| | - Eriko Hoshino
- Tasmanian School of Business and Economics, University of Tasmania, Private Bag 84, Hobart, Tas., 7001, Australia
- CSIRO Oceans and Atmosphere, Castray Esplanade, Hobart, Tas., 7001, Australia
| | - Sarah Jennings
- Tasmanian School of Business and Economics, University of Tasmania, Private Bag 84, Hobart, Tas., 7001, Australia
- Centre for Marine Socioecology, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Ingrid E van Putten
- CSIRO Oceans and Atmosphere, Castray Esplanade, Hobart, Tas., 7001, Australia
- Centre for Marine Socioecology, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Gretta T Pecl
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, Tas., 7001, Australia
- Centre for Marine Socioecology, University of Tasmania, Hobart, Tas., 7001, Australia
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12
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Hindell MA, McMahon CR, Bester MN, Boehme L, Costa D, Fedak MA, Guinet C, Herraiz‐Borreguero L, Harcourt RG, Huckstadt L, Kovacs KM, Lydersen C, McIntyre T, Muelbert M, Patterson T, Roquet F, Williams G, Charrassin J. Circumpolar habitat use in the southern elephant seal: implications for foraging success and population trajectories. Ecosphere 2016. [DOI: 10.1002/ecs2.1213] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Affiliation(s)
- Mark A. Hindell
- Institute for Marine and Antarctic Studies University of Tasmania Hobart Tasmania 7001 Australia
- Antarctic Climate & Ecosystem Cooperative Research Centre University of Tasmania Hobart Tasmania 7001 Australia
| | - Clive R. McMahon
- Institute for Marine and Antarctic Studies University of Tasmania Hobart Tasmania 7001 Australia
- Sydney Institute of Marine Science 19 Chowder Bay Road Mosman New South Wales 2088 Australia
| | - Marthán N. Bester
- Department of Zoology and Entomology Mammal Research Institute University of Pretoria Private Bag X20 Hatfield 0028 South Africa
| | - Lars Boehme
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews UK
| | - Daniel Costa
- Department of Ecology and Evolutionary Biology University of California Santa Cruz California USA
| | - Mike A. Fedak
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews UK
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé Centre National de la Recherche Scientifique Villiers en Bois France
| | - Laura Herraiz‐Borreguero
- Antarctic Climate & Ecosystem Cooperative Research Centre University of Tasmania Hobart Tasmania 7001 Australia
- Centre for Ice and Climate Niels Bohr Institute University of Copenhagen Copenhagen Denmark
| | - Robert G. Harcourt
- Department of Biological Sciences Macquarie University Sydney New South Wales 2109 Australia
| | - Luis Huckstadt
- Department of Ecology and Evolutionary Biology University of California Santa Cruz California USA
| | - Kit M. Kovacs
- Norwegian Polar Institute Fram Centre Tromsø N‐9296 Norway
| | | | - Trevor McIntyre
- Department of Zoology and Entomology Mammal Research Institute University of Pretoria Private Bag X20 Hatfield 0028 South Africa
| | - Monica Muelbert
- Instituto de Oceanografia Universidade Federal do Rio Grande Porto Alegre Brazil
| | - Toby Patterson
- CSIRO Wealth from Oceans Research Flagship and Marine & Atmospheric Research GPO Box 1538 Hobart Tasmania 7001 Australia
| | - Fabien Roquet
- Department of Meteorology Stockholm University Stockholm Sweden
| | - Guy Williams
- Antarctic Climate & Ecosystem Cooperative Research Centre University of Tasmania Hobart Tasmania 7001 Australia
| | - Jean‐Benoit Charrassin
- Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques Paris France
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13
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Valenti D, Denaro G, Spagnolo B, Conversano F, Brunet C. How diffusivity, thermocline and incident light intensity modulate the dynamics of deep chlorophyll maximum in Tyrrhenian Sea. PLoS One 2015; 10:e0115468. [PMID: 25629963 PMCID: PMC4309620 DOI: 10.1371/journal.pone.0115468] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 11/23/2014] [Indexed: 11/22/2022] Open
Abstract
During the last few years theoretical works have shed new light and proposed new hypotheses on the mechanisms which regulate the spatio-temporal behaviour of phytoplankton communities in marine pelagic ecosystems. Despite this, relevant physical and biological issues, such as effects of the time-dependent mixing in the upper layer, competition between groups, and dynamics of non-stationary deep chlorophyll maxima, are still open questions. In this work, we analyze the spatio-temporal behaviour of five phytoplankton populations in a real marine ecosystem by using a one-dimensional reaction-diffusion-taxis model. The study is performed, taking into account the seasonal variations of environmental variables, such as light intensity, thickness of upper mixed layer and profiles of vertical turbulent diffusivity, obtained starting from experimental findings. Theoretical distributions of phytoplankton cell concentration was converted in chlorophyll concentration, and compared with the experimental profiles measured in a site of the Tyrrhenian Sea at four different times (seasons) of the year, during four different oceanographic cruises. As a result we find a good agreement between theoretical and experimental distributions of chlorophyll concentration. In particular, theoretical results reveal that the seasonal changes of environmental variables play a key role in the phytoplankton distribution and determine the properties of the deep chlorophyll maximum. This study could be extended to other marine ecosystems to predict future changes in the phytoplankton biomass due to global warming, in view of devising strategies to prevent the decline of the primary production and the consequent decrease of fish species.
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Affiliation(s)
- Davide Valenti
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
- * E-mail:
| | - Giovanni Denaro
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Bernardo Spagnolo
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Catania, Italy
- Radiophysics Department, Lobachevsky State University, Nizhniy Novgorod, Russia
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14
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Denaro G, Valenti D, Spagnolo B, Basilone G, Mazzola S, Zgozi SW, Aronica S, Bonanno A. Dynamics of two picophytoplankton groups in mediterranean sea: analysis of the deep chlorophyll maximum by a stochastic advection-reaction-diffusion model. PLoS One 2013; 8:e66765. [PMID: 23826130 PMCID: PMC3691268 DOI: 10.1371/journal.pone.0066765] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/13/2013] [Indexed: 11/25/2022] Open
Abstract
A stochastic advection-reaction-diffusion model with terms of multiplicative white Gaussian noise, valid for weakly mixed waters, is studied to obtain the vertical stationary spatial distributions of two groups of picophytoplankton, i.e., picoeukaryotes and Prochlorococcus, which account about for 60% of total chlorophyll on average in Mediterranean Sea. By numerically solving the equations of the model, we analyze the one-dimensional spatio-temporal dynamics of the total picophytoplankton biomass and nutrient concentration along the water column at different depths. In particular, we integrate the equations over a time interval long enough, obtaining the steady spatial distributions for the cell concentrations of the two picophytoplankton groups. The results are converted into chlorophyll a and divinil chlorophyll a concentrations and compared with experimental data collected in two different sites of the Sicily Channel (southern Mediterranean Sea). The comparison shows that real distributions are well reproduced by theoretical profiles. Specifically, position, shape and magnitude of the theoretical deep chlorophyll maximum exhibit a good agreement with the experimental values.
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Affiliation(s)
- Giovanni Denaro
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Davide Valenti
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Bernardo Spagnolo
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Gualtiero Basilone
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | - Salvatore Mazzola
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | | | - Salvatore Aronica
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | - Angelo Bonanno
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
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