41 research outputs found

    Big data analyses reveal patterns and drivers of the movements of southern elephant seals

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    The growing number of large databases of animal tracking provides an opportunity for analyses of movement patterns at the scales of populations and even species. We used analytical approaches, developed to cope with big data, that require no a priori assumptions about the behaviour of the target agents, to analyse a pooled tracking dataset of 272 elephant seals (Mirounga leonina) in the Southern Ocean, that was comprised of >500,000 location estimates collected over more than a decade. Our analyses showed that the displacements of these seals were described by a truncated power law distribution across several spatial and temporal scales, with a clear signature of directed movement. This pattern was evident when analysing the aggregated tracks despite a wide diversity of individual trajectories. We also identified marine provinces that described the migratory and foraging habitats of these seals. Our analysis provides evidence for the presence of intrinsic drivers of movement, such as memory, that cannot be detected using common models of movement behaviour. These results highlight the potential for big data techniques to provide new insights into movement behaviour when applied to large datasets of animal tracking.Comment: 18 pages, 5 figures, 6 supplementary figure

    Circumpolar habitat use in the southern elephant seal : implications for foraging success and population trajectories

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    In the Southern Ocean, wide-ranging predators offer the opportunity to quantify how animals respond to differences in the environment because their behavior and population trends are an integrated signal of prevailing conditions within multiple marine habitats. Southern elephant seals in particular, can provide useful insights due to their circumpolar distribution, their long and distant migrations and their performance of extended bouts of deep diving. Furthermore, across their range, elephant seal populations have very different population trends. In this study, we present a data set from the International Polar Year project; Marine Mammals Exploring the Oceans Pole to Pole for southern elephant seals, in which a large number of instruments (N = 287) deployed on animals, encompassing a broad circum-Antarctic geographic extent, collected in situ ocean data and at-sea foraging metrics that explicitly link foraging behavior and habitat structure in time and space. Broadly speaking, the seals foraged in two habitats, the relatively shallow waters of the Antarctic continental shelf and the Kerguelen Plateau and deep open water regions. Animals of both sexes were more likely to exhibit area-restricted search (ARS) behavior rather than transit in shelf habitats. While Antarctic shelf waters can be regarded as prime habitat for both sexes, female seals tend to move northwards with the advance of sea ice in the late autumn or early winter. The water masses used by the seals also influenced their behavioral mode, with female ARS behavior being most likely in modified Circumpolar Deepwater or northerly Modified Shelf Water, both of which tend to be associated with the outer reaches of the Antarctic Continental Shelf. The combined effects of (1) the differing habitat quality, (2) differing responses to encroaching ice as the winter progresses among colonies, (3) differing distances between breeding and haul-out sites and high quality habitats, and (4) differing long-term regional trends in sea ice extent can explain the differing population trends observed among elephant seal colonies.Publisher PDFPeer reviewe

    Utilising IPCC assessments to support the ecosystem approach to fisheries management within a warming Southern Ocean

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    Southern Ocean marine ecosystems are highly vulnerable to climate-driven change, the impacts of which must be factored into conservation and management. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is aware of the urgent need to develop climate-responsive options within its ecosystem approach to management. However, limited capacity as well as political differences have meant that little progress has been made. Strengthening scientific information flow to inform CCAMLR’s decision-making on climate change may help to remove some of these barriers. On this basis, this study encourages the utilisation of outputs from the United Nations’ Intergovernmental Panel on Climate Change (IPCC). The IPCC’s 2019 Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) constitutes the most rigorous and up-to-date assessment of how oceans and the cryosphere are changing, how they are projected to change, and the consequences of those changes, together with a range of response options. To assist CCAMLR to focus on what is most useful from this extensive global report, SROCC findings that have specific relevance to the management of Southern Ocean ecosystems are extracted and summarised here. These findings are translated into recommendations to CCAMLR, emphasising the need to reduce and manage the risks that climate change presents to harvested species and the wider ecosystem of which they are part. Improved linkages between IPCC, CCAMLR and other relevant bodies may help overcome existing impediments to progress, enabling climate change to become fully integrated into CCAMLR’s policy and decision-making

    Developing priority variables ("ecosystem Essential Ocean Variables" — eEOVs) for observing dynamics and change in Southern Ocean ecosystems

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    Reliable statements about variability and change in marine ecosystems and their underlying causes are needed to report on their status and to guide management. Here we use the Framework on Ocean Observing (FOO) to begin developing ecosystem Essential Ocean Variables (eEOVs) for the Southern Ocean Observing System (SOOS). An eEOV is a defined biological or ecological quantity, which is derived from field observations, and which contributes significantly to assessments of Southern Ocean ecosystems. Here, assessments are concerned with estimating status and trends in ecosystem properties, attribution of trends to causes, and predicting future trajectories. eEOVs should be feasible to collect at appropriate spatial and temporal scales and are useful to the extent that they contribute to direct estimation of trends and/or attribution, and/or development of ecological (statistical or simulation) models to support assessments. In this paper we outline the rationale, including establishing a set of criteria, for selecting eEOVs for the SOOS and develop a list of candidate eEOVs for further evaluation. Other than habitat variables, nine types of eEOVs for Southern Ocean taxa are identified within three classes: state (magnitude, genetic/species, size spectrum), predator–prey (diet, foraging range), and autecology (phenology, reproductive rate, individual growth rate, detritus). Most candidates for the suite of Southern Ocean taxa relate to state or diet. Candidate autecological eEOVs have not been developed other than for marine mammals and birds. We consider some of the spatial and temporal issues that will influence the adoption and use of eEOVs in an observing system in the Southern Ocean, noting that existing operations and platforms potentially provide coverage of the four main sectors of the region — the East and West Pacific, Atlantic and Indian. Lastly, we discuss the importance of simulation modelling in helping with the design of the observing system in the long term. Regional boundary: south of 30°S

    Convergence of marine megafauna movement patterns in coastal and open oceans

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    Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 115 (2018): 3072-3077, doi:10.1073/pnas.1716137115.The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals’ movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyse a global dataset of 2.8 million locations from > 2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared to more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal micro-habitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise and declining oxygen content.Workshops funding granted by the UWA Oceans Institute, AIMS, and KAUST. AMMS was supported by an ARC Grant DE170100841 and an IOMRC (UWA, AIMS, CSIRO) fellowship; JPR by MEDC (FPU program, Spain); DWS by UK NERC and Save Our Seas Foundation; NQ by FCT (Portugal); MMCM by a CAPES fellowship (Ministry of Education)

    Marine mammals exploring the oceans pole to pole

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    Polar oceans are poorly monitored despite the important role they play in regulating Earth’s climate system. Marine mammals equipped with biologging devices are now being used to fill the data gaps in these logistically difficult to sample regions. Since 2002, instrumented animals have been generating exceptionally large data sets of oceanographic CTD casts (>500,000 profiles), which are now freely available to the scientific community through the MEOP data portal (http://meop.net). MEOP (Marine Mammals Exploring the Oceans Pole to Pole) is a consortium of international researchers dedicated to sharing animal-derived data and knowledge about the polar oceans. Collectively, MEOP demonstrates the power and cost-effectiveness of using marine mammals as data-collection platforms that can dramatically improve the ocean observing system for biological and physical oceanographers. Here, we review the MEOP program and database to bring it to the attention of the international community.http://www.tos.org/oceanographyam2017Mammal Research InstituteZoology and Entomolog

    The retrospective analysis of Antarctic tracking data project

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    The Retrospective Analysis of Antarctic Tracking Data (RAATD) is a Scientific Committee for Antarctic Research project led jointly by the Expert Groups on Birds and Marine Mammals and Antarctic Biodiversity Informatics, and endorsed by the Commission for the Conservation of Antarctic Marine Living Resources. RAATD consolidated tracking data for multiple species of Antarctic meso- and top-predators to identify Areas of Ecological Significance. These datasets and accompanying syntheses provide a greater understanding of fundamental ecosystem processes in the Southern Ocean, support modelling of predator distributions under future climate scenarios and create inputs that can be incorporated into decision making processes by management authorities. In this data paper, we present the compiled tracking data from research groups that have worked in the Antarctic since the 1990s. The data are publicly available through biodiversity.aq and the Ocean Biogeographic Information System. The archive includes tracking data from over 70 contributors across 12 national Antarctic programs, and includes data from 17 predator species, 4060 individual animals, and over 2.9 million observed locations

    Distribution and Cconnection to other Plant-Communities of Genista radiata (L.) Scop in the South Tyrol (Italy)

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    Es werden die Genista radiata-BestĂ€nde an der Mendel in SĂŒdtirol (Italien) beschrieben und ihr Gesellschaftsanschluß diskutiert. Das Genisto-Festucetum alpestris Peer 83 besidelt steile sĂŒdexponierte KalkhĂ€nge der hochmontanen und subalpinen Stufe und ersetzt z.T. den ZwergstrauchgĂŒrtel mit Pinus mugo. Ähnlich zusammengesetzt ist das Genisto-Festucetum alpestris pinetosum Peer 83, das in den ÂĄlockeren Erika-KiefernwĂ€ldern auftritt und bis in die tiefmontane Stufe hinunterreicht. Keinerlei syntaxonomische Bedeutung besitzt Genista radiata in den thermophilen Buschwaldgesellschaften, in denen die Pflanze lediglich eine Variante zum Orno-Ostryetum seslerietosum Peer 81 darstellt und speziell in der Saumzone anzutreffen ist. Auch in den LĂ€rchenwiesen der Kammlagen kommt Genista radiata nur sporadisch vor. Sie ist hier mit dem Festucetum nigrescentis laricetosum subass. prov. verzahnt.IstraĆŸene su vegetacijske sastojine vrste Genista radiata u juĆŸnom Tirolu i razmatrana njihova fitocenoloĆĄka pripadnost. Asocijacija Genisto-Festucetum alpestris Peer 83 nastava strme, juĆŸne vapnenačke obronke visokobrdskog i subalpskog pojasa. Subasocijacija Genisto-Festucetum alpestris pinetosum Peer 83 dolazi u rijetkim borovim ĆĄumama s crnjuĆĄom i spuĆĄta se do u niĆŸi brdski pojas. Termofilne niske ĆĄume, u kojima Genista radiata nema posebno sintaksonomsko značenje, označene su samo kao varijanta zajednice Orno-Ostryetum seslerietosum Peer 81. Genista radiata dolazi također na travnjacima s ariĆĄem, ali samo sporadično i to u mjeĆĄavini sa zajednicom Festucetum nigrescentis laricetosnm subass. prov.The Genista radiata-communities of the Mendel in the South Tyrol (Italy) are described and their connection to other plant-communities is discussed. Genisto-Festucetum alpestris Peer 83 settles on steep, south- exposed colcareous slopes of high-mountain and subalpine altitudes and replaces particularly the dwarf-shrub-belt with Firms mugo. Similar contents aire found in Genisto-F estucetum alpestris pinetasum Peer 83, which occurs in undensed Erico-Pinetum-communities and reaches down to the low-mountain-altitude. In the thermophilic bush-communities, in which Genista radiata is found only as a variant of Orneto-Ostryetum seslerie- tosum (Peer 81), the plant has no syntaxonomic importance. Genista radiata especially is found in the edge-zone. In the grassland of the larch- communities of the ridges Genista radiata appears only sporadically. Here the plant appeals in Festucetum nigrescentis laricetosum subass. prov

    The retrospective analysis of Antarctic tracking data project

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    The Retrospective Analysis of Antarctic Tracking Data (RAATD) is a Scientific Committee for Antarctic Research project led jointly by the Expert Groups on Birds and Marine Mammals and Antarctic Biodiversity Informatics, and endorsed by the Commission for the Conservation of Antarctic Marine Living Resources. RAATD consolidated tracking data for multiple species of Antarctic meso- and top-predators to identify Areas of Ecological Significance. These datasets and accompanying syntheses provide a greater understanding of fundamental ecosystem processes in the Southern Ocean, support modelling of predator distributions under future climate scenarios and create inputs that can be incorporated into decision making processes by management authorities. In this data paper, we present the compiled tracking data from research groups that have worked in the Antarctic since the 1990s. The data are publicly available through biodiversity.aq and the Ocean Biogeographic Information System. The archive includes tracking data from over 70 contributors across 12 national Antarctic programs, and includes data from 17 predator species, 4060 individual animals, and over 2.9 million observed locations.Supplementary Figure S1: Filtered location data (black) and tag deployment locations (red) for each species. Maps are Lambert Azimuthal projections extending from 90° S to 20° S.Supplementary Table S1: Names and coordinates of the major study sites in the Southern Ocean and on the Antarctic Continent where tracking devices were deployed on the selected species (indicated by their 4-letter codes in the last column).Online Table 1: Description of fields (column names) in the metadata and data files.Supranational committees and organisations including the Scientific Committee on Antarctic Research Life Science Group and BirdLife International. National institutions and foundations, including but not limited to Argentina (Dirección Nacional del Antártico), Australia (Australian Antarctic program; Australian Research Council; Sea World Research and Rescue Foundation Inc., IMOS is a national collaborative research infrastructure, supported by the Australian Government and operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent), Belgium (Belgian Science Policy Office, EU Lifewatch ERIC), Brazil (Brazilian Antarctic Programme; Brazilian National Research Council (CNPq/MCTI) and CAPES), France (Agence Nationale de la Recherche; Centre National d’Etudes Spatiales; Centre National de la Recherche Scientifique; the French Foundation for Research on Biodiversity (FRB; www.fondationbiodiversite.fr) in the context of the CESAB project “RAATD”; Fondation Total; Institut Paul-Emile Victor; Programme Zone Atelier de Recherches sur l’Environnement Antarctique et Subantarctique; Terres Australes et Antarctiques Françaises), Germany (Deutsche Forschungsgemeinschaft, Hanse-Wissenschaftskolleg - Institute for Advanced Study), Italy (Italian National Antarctic Research Program; Ministry for Education University and Research), Japan (Japanese Antarctic Research Expedition; JSPS Kakenhi grant), Monaco (Fondation Prince Albert II de Monaco), New Zealand (Ministry for Primary Industries - BRAG; Pew Charitable Trusts), Norway (Norwegian Antarctic Research Expeditions; Norwegian Research Council), Portugal (Foundation for Science and Technology), South Africa (Department of Environmental Affairs; National Research Foundation; South African National Antarctic Programme), UK (Darwin Plus; Ecosystems Programme at the British Antarctic Survey; Natural Environment Research Council; WWF), and USA (U.S. AMLR Program of NOAA Fisheries; US Office of Polar Programs).http://www.nature.com/sdataam2021Mammal Research Institut
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