23 research outputs found
Convergence of marine megafauna movement patterns in coastal and open oceans
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 animalsâ 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)
Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries
Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management
Diving into the vertical dimension of elasmobranch movement ecology
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
Distribution and Cconnection to other Plant-Communities of Genista radiata (L.) Scop in the South Tyrol (Italy)
Es werden die Genista radiata-BestĂ€nde an der Mendel in SĂŒdtirol (Italien) beschrieben und ihr GesellschaftsanschluĂ 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. Ăhnlich 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 vapnenaÄke 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 znaÄenje, oznaÄene su samo kao varijanta zajednice Orno-Ostryetum seslerietosum Peer 81. Genista radiata dolazi takoÄer na travnjacima s ariĆĄem, ali samo sporadiÄno 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
Animal-borne telemetry: An integral component of the ocean observing toolkit
Animal telemetry is a powerful tool for observing marine animals and the physical environments that they inhabit, from coastal and continental shelf ecosystems to polar seas and open oceans. Satellite-linked biologgers and networks of acoustic receivers allow animals to be reliably monitored over scales of tens of meters to thousands of kilometers, giving insight into their habitat use, home range size, the phenology of migratory patterns and the biotic and abiotic factors that drive their distributions. Furthermore, physical environmental variables can be collected using animals as autonomous sampling platforms, increasing spatial and temporal coverage of global oceanographic observation systems. The use of animal telemetry, therefore, has the capacity to provide measures from a suite of essential ocean variables (EOVs) for improved monitoring of Earth's oceans. Here we outline the design features of animal telemetry systems, describe current applications and their benefits and challenges, and discuss future directions. We describe new analytical techniques that improve our ability to not only quantify animal movements but to also provide a powerful framework for comparative studies across taxa. We discuss the application of animal telemetry and its capacity to collect biotic and abiotic data, how the data collected can be incorporated into ocean observing systems, and the role these data can play in improved ocean management