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Crespo GO, Dunn DC, Reygondeau G, Boerder K, Worm B, Cheung W, Tittensor DP, Halpin PN. The environmental niche of the global high seas pelagic longline fleet. SCIENCE ADVANCES 2018; 4:eaat3681. [PMID: 30101192 PMCID: PMC6082651 DOI: 10.1126/sciadv.aat3681] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 07/14/2018] [Indexed: 05/09/2023]
Abstract
International interest in the protection and sustainable use of high seas biodiversity has grown in recent years. There is an opportunity for new technologies to enable improvements in management of these areas beyond national jurisdiction. We explore the spatial ecology and drivers of the global distribution of the high seas longline fishing fleet by creating predictive models of the distribution of fishing effort from newly available automatic identification system (AIS) data. Our results show how longline fishing effort can be predicted using environmental variables, many related to the expected distribution of the species targeted by longliners. We also find that the longline fleet has seasonal environmental preferences (for example, increased importance of cooler surface waters during boreal summer) and may only be using 38 to 64% of the available environmentally suitable fishing habitat. Possible explanations include misclassification of fishing effort, incomplete AIS coverage, or how potential range contractions of pelagic species may have reduced the abundance of fishing habitats in the open ocean.
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Affiliation(s)
- Guillermo Ortuño Crespo
- Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
- Corresponding author.
| | - Daniel C. Dunn
- Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Gabriel Reygondeau
- Nippon Foundation Nereus Program and Changing Ocean Research Unit, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Kristina Boerder
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada
| | - Boris Worm
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada
| | - William Cheung
- Nippon Foundation Nereus Program and Changing Ocean Research Unit, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Derek P. Tittensor
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada
- United Nations Environment Programme World Conservation Monitoring Centre, 219 Huntingdon Road, Cambridge CB3 0DL, UK
| | - Patrick N. Halpin
- Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
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52
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O'Leary BC, Roberts CM. Ecological connectivity across ocean depths: Implications for protected area design. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00431] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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53
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Fisheries bycatch risk to marine megafauna is intensified in Lagrangian coherent structures. Proc Natl Acad Sci U S A 2018; 115:7362-7367. [PMID: 29941592 DOI: 10.1073/pnas.1801270115] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Incidental catch of nontarget species (bycatch) is a major barrier to ecological and economic sustainability in marine capture fisheries. Key to mitigating bycatch is an understanding of the habitat requirements of target and nontarget species and the influence of heterogeneity and variability in the dynamic marine environment. While patterns of overlap among marine capture fisheries and habitats of a taxonomically diverse range of marine vertebrates have been reported, a mechanistic understanding of the real-time physical drivers of bycatch events is lacking. Moving from describing patterns toward understanding processes, we apply a Lagrangian analysis to a high-resolution ocean model output to elucidate the fundamental mechanisms that drive fisheries interactions. We find that the likelihood of marine megafauna bycatch is intensified in attracting Lagrangian coherent structures associated with submesoscale and mesoscale filaments, fronts, and eddies. These results highlight how the real-time tracking of dynamic structures in the oceans can support fisheries sustainability and advance ecosystem-based management.
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54
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Santos CC, Coelho R. Migrations and habitat use of the smooth hammerhead shark (Sphyrna zygaena) in the Atlantic Ocean. PLoS One 2018; 13:e0198664. [PMID: 29874297 PMCID: PMC5991395 DOI: 10.1371/journal.pone.0198664] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/23/2018] [Indexed: 11/18/2022] Open
Abstract
The smooth hammerhead shark, Sphyrna zygaena, is a cosmopolitan semipelagic shark captured as bycatch in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. From 2012 to 2016, eight smooth hammerheads were tagged with Pop-up Satellite Archival Tags in the inter-tropical region of the Northeast Atlantic Ocean, with successful transmissions received from seven tags (total of 319 tracking days). Results confirmed the smooth hammerhead is a highly mobile species, as the longest migration ever documented for this species (> 6600 km) was recorded. An absence of a diel vertical movement behavior was noted, with the sharks spending most of their time at surface waters (0–50 m) above 23°C. The operating depth of the pelagic longline gear was measured with Minilog Temperature and Depth Recorders, and the overlap with the species vertical distribution was calculated. The overlap is taking place mainly during the night and is higher for juveniles (~40% of overlap time). The novel information presented can now be used to contribute to the provision of sustainable management tools and serve as input for Ecological Risk Assessments for smooth hammerheads caught in Atlantic pelagic longline fisheries.
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Affiliation(s)
- Catarina C. Santos
- Portuguese Institute for the Ocean and Atmosphere, I.P., Olhão, Portugal
- * E-mail:
| | - Rui Coelho
- Portuguese Institute for the Ocean and Atmosphere, I.P., Olhão, Portugal
- Center of Marine Sciences (CCMAR), University of Algarve, Faro, Portugal
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55
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Bailleul D, Mackenzie A, Sacchi O, Poisson F, Bierne N, Arnaud‐Haond S. Large-scale genetic panmixia in the blue shark ( Prionace glauca): A single worldwide population, or a genetic lag-time effect of the "grey zone" of differentiation? Evol Appl 2018; 11:614-630. [PMID: 29875806 PMCID: PMC5978958 DOI: 10.1111/eva.12591] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/12/2017] [Indexed: 12/31/2022] Open
Abstract
The blue shark Prionace glauca, among the most common and widely studied pelagic sharks, is a top predator, exhibiting the widest distribution range. However, little is known about its population structure and spatial dynamics. With an estimated removal of 10-20 million individuals per year by fisheries, the species is classified as "Near Threatened" by International Union for Conservation of Nature. We lack the knowledge to forecast the long-term consequences of such a huge removal on this top predator itself and on its trophic network. The genetic analysis of more than 200 samples collected at broad scale (from Mediterranean Sea, North Atlantic and Pacific Oceans) using mtDNA and nine microsatellite markers allowed to detect signatures of genetic bottlenecks but a nearly complete genetic homogeneity across the entire studied range. This apparent panmixia could be explained by a genetic lag-time effect illustrated by simulations of demographic changes that were not detectable through standard genetic analysis before a long transitional phase here introduced as the "population grey zone." The results presented here can thus encompass distinct explanatory scenarios spanning from a single demographic population to several independent populations. This limitation prevents the genetic-based delineation of stocks and thus the ability to anticipate the consequences of severe depletions at all scales. More information is required for the conservation of population(s) and management of stocks, which may be provided by large-scale sampling not only of individuals worldwide, but also of loci genomewide.
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Affiliation(s)
- Diane Bailleul
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | - Alicia Mackenzie
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | - Olivier Sacchi
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
| | | | - Nicolas Bierne
- OREME – Station MarineUniversité MontpellierSèteFrance
- CNRS, Institut des Sciences de l'EvolutionUniversité MontpellierMontpellierFrance
| | - Sophie Arnaud‐Haond
- IFREMER, UMR MARBEC, Station de SèteSèteFrance
- OREME – Station MarineUniversité MontpellierSèteFrance
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56
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Mesoscale eddies influence the movements of mature female white sharks in the Gulf Stream and Sargasso Sea. Sci Rep 2018; 8:7363. [PMID: 29743492 PMCID: PMC5943458 DOI: 10.1038/s41598-018-25565-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 04/24/2018] [Indexed: 11/08/2022] Open
Abstract
Satellite-tracking of mature white sharks (Carcharodon carcharias) has revealed open-ocean movements spanning months and covering tens of thousands of kilometers. But how are the energetic demands of these active apex predators met as they leave coastal areas with relatively high prey abundance to swim across the open ocean through waters often characterized as biological deserts? Here we investigate mesoscale oceanographic variability encountered by two white sharks as they moved through the Gulf Stream region and Sargasso Sea in the North Atlantic Ocean. In the vicinity of the Gulf Stream, the two mature female white sharks exhibited extensive use of the interiors of clockwise-rotating anticyclonic eddies, characterized by positive (warm) temperature anomalies. One tagged white shark was also equipped with an archival tag that indicated this individual made frequent dives to nearly 1,000 m in anticyclones, where it was presumably foraging on mesopelagic prey. We propose that warm temperature anomalies in anticyclones make prey more accessible and energetically profitable to adult white sharks in the Gulf Stream region by reducing the physiological costs of thermoregulation in cold water. The results presented here provide valuable new insight into open ocean habitat use by mature, female white sharks that may be applicable to other large pelagic predators.
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Daly R, Smale MJ, Singh S, Anders D, Shivji M, K. Daly CA, Lea JSE, Sousa LL, Wetherbee BM, Fitzpatrick R, Clarke CR, Sheaves M, Barnett A. Refuges and risks: Evaluating the benefits of an expanded MPA network for mobile apex predators. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12758] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Ryan Daly
- Save Our Seas Foundation - D'Arros Research Centre (SOSF-DRC); Genève Switzerland
- Port Elizabeth Museum at Bayworld; Port Elizabeth South Africa
| | - Malcolm J. Smale
- Port Elizabeth Museum at Bayworld; Port Elizabeth South Africa
- Department of Zoology and Institute for Coastal and Marine Research; Nelson Mandela Metropolitan University; Port Elizabeth South Africa
| | - Sarika Singh
- Department of Environmental Affairs; Government of South Africa; Cape Town South Africa
| | - Darrell Anders
- Department of Environmental Affairs; Government of South Africa; Cape Town South Africa
| | - Mahmood Shivji
- Department of Biological Sciences; The Guy Harvey Research Institute; Nova Southeastern University; Dania Beach FL USA
| | - Clare A. K. Daly
- Save Our Seas Foundation - D'Arros Research Centre (SOSF-DRC); Genève Switzerland
| | | | - Lara L. Sousa
- Wildlife Conservation Research Unit; Department of Zoology; University of Oxford; Recanati-Kaplan Centre; Tubney UK
| | - Bradley M. Wetherbee
- Department of Biological Sciences; The Guy Harvey Research Institute; Nova Southeastern University; Dania Beach FL USA
- Department of Biological Sciences; University of Rhode Island; Kingston RI USA
| | - Richard Fitzpatrick
- College of Science & Engineering; James Cook University; Cairns QLD Australia
| | | | - Marcus Sheaves
- College of Science & Engineering; James Cook University; Cairns QLD Australia
| | - Adam Barnett
- College of Science & Engineering; James Cook University; Cairns QLD Australia
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58
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First quantification of subtidal community structure at Tristan da Cunha Islands in the remote South Atlantic: from kelp forests to the deep sea. PLoS One 2018; 13:e0195167. [PMID: 29596484 PMCID: PMC5875861 DOI: 10.1371/journal.pone.0195167] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 03/16/2018] [Indexed: 11/24/2022] Open
Abstract
Tristan da Cunha Islands, an archipelago of four rocky volcanic islands situated in the South Atlantic Ocean and part of the United Kingdom Overseas Territories (UKOTs), present a rare example of a relatively unimpacted temperate marine ecosystem. We conducted the first quantitative surveys of nearshore kelp forests, offshore pelagic waters and deep sea habitats. Kelp forests had very low biodiversity and species richness, but high biomass and abundance of those species present. Spatial variation in assemblage structure for both nearshore fish and invertebrates/algae was greatest between the three northern islands and the southern island of Gough, where sea temperatures were on average 3-4o colder. Despite a lobster fishery that provides the bulk of the income to the Tristan islands, lobster abundance and biomass are comparable to or greater than many Marine Protected Areas in other parts of the world. Pelagic camera surveys documented a rich biodiversity offshore, including large numbers of juvenile blue sharks, Prionace glauca. Species richness and abundance in the deep sea is positively related to hard rocky substrate and biogenic habitats such as sea pens, crinoids, whip corals, and gorgonians were present at 40% of the deep camera deployments. We observed distinct differences in the deep fish community above and below ~750 m depth. Concurrent oceanographic sampling showed a discontinuity in temperature and salinity at this depth. While currently healthy, Tristan’s marine ecosystem is not without potential threats: shipping traffic leading to wrecks and species introductions, pressure to increase fishing effort beyond sustainable levels and the impacts of climate change all could potentially increase in the coming years. The United Kingdom has committed to protection of marine environments across the UKOTs, including Tristan da Cunha and these results can be used to inform future management decisions as well as provide a baseline against which future monitoring can be based.
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59
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Affiliation(s)
- David W. Sims
- Marine Biological Association of the UK, Plymouth PL1 2PB, UK
- University of Southampton, Southampton SO14 3ZH, UK
| | | | - Nuno Queiroz
- CIBIO/InBIO–Universidade do Porto, 4485-668 Vairão, Portugal
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60
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Convergence of marine megafauna movement patterns in coastal and open oceans. Proc Natl Acad Sci U S A 2018; 115:3072-3077. [PMID: 29483242 DOI: 10.1073/pnas.1716137115] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
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 analyze 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 with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, 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.
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61
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Kroodsma DA, Mayorga J, Hochberg T, Miller NA, Boerder K, Ferretti F, Wilson A, Bergman B, White TD, Block BA, Woods P, Sullivan B, Costello C, Worm B. Tracking the global footprint of fisheries. Science 2018; 359:904-908. [PMID: 29472481 DOI: 10.1126/science.aao5646] [Citation(s) in RCA: 231] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 01/17/2018] [Indexed: 11/02/2022]
Abstract
Although fishing is one of the most widespread activities by which humans harvest natural resources, its global footprint is poorly understood and has never been directly quantified. We processed 22 billion automatic identification system messages and tracked >70,000 industrial fishing vessels from 2012 to 2016, creating a global dynamic footprint of fishing effort with spatial and temporal resolution two to three orders of magnitude higher than for previous data sets. Our data show that industrial fishing occurs in >55% of ocean area and has a spatial extent more than four times that of agriculture. We find that global patterns of fishing have surprisingly low sensitivity to short-term economic and environmental variation and a strong response to cultural and political events such as holidays and closures.
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Affiliation(s)
| | - Juan Mayorga
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106, USA.,Pristine Seas, National Geographic Society, Washington, DC 20036, USA
| | | | | | - Kristina Boerder
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H4R2, Canada
| | | | | | | | | | | | - Paul Woods
- Global Fishing Watch, Washington, DC 20036, USA
| | | | - Christopher Costello
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106, USA
| | - Boris Worm
- Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H4R2, Canada
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62
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Byrne ME, Cortés E, Vaudo JJ, Harvey GCM, Sampson M, Wetherbee BM, Shivji M. Satellite telemetry reveals higher fishing mortality rates than previously estimated, suggesting overfishing of an apex marine predator. Proc Biol Sci 2018; 284:rspb.2017.0658. [PMID: 28768885 DOI: 10.1098/rspb.2017.0658] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 06/23/2017] [Indexed: 11/12/2022] Open
Abstract
Overfishing is a primary cause of population declines for many shark species of conservation concern. However, means of obtaining information on fishery interactions and mortality, necessary for the development of successful conservation strategies, are often fisheries-dependent and of questionable quality for many species of commercially exploited pelagic sharks. We used satellite telemetry as a fisheries-independent tool to document fisheries interactions, and quantify fishing mortality of the highly migratory shortfin mako shark (Isurus oxyrinchus) in the western North Atlantic Ocean. Forty satellite-tagged shortfin mako sharks tracked over 3 years entered the Exclusive Economic Zones of 19 countries and were harvested in fisheries of five countries, with 30% of tagged sharks harvested. Our tagging-derived estimates of instantaneous fishing mortality rates (F = 0.19-0.56) were 10-fold higher than previous estimates from fisheries-dependent data (approx. 0.015-0.024), suggesting data used in stock assessments may considerably underestimate fishing mortality. Additionally, our estimates of F were greater than those associated with maximum sustainable yield, suggesting a state of overfishing. This information has direct application to evaluations of stock status and for effective management of populations, and thus satellite tagging studies have potential to provide more accurate estimates of fishing mortality and survival than traditional fisheries-dependent methodology.
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Affiliation(s)
- Michael E Byrne
- Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, FL 33004, USA
| | - Enric Cortés
- National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Panama City, FL 32408, USA
| | - Jeremy J Vaudo
- Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, FL 33004, USA
| | - Guy C McN Harvey
- Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, FL 33004, USA
| | - Mark Sampson
- Fish Finder Adventures, Ocean City, MD 21842, USA
| | - Bradley M Wetherbee
- Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, FL 33004, USA.,Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Mahmood Shivji
- Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, FL 33004, USA
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63
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Biton-Porsmoguer S, Bǎnaru D, Boudouresque CF, Dekeyser I, Bouchoucha M, Marco-Miralles F, Lebreton B, Guillou G, Harmelin-Vivien M. Mercury in blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus) from north-eastern Atlantic: Implication for fishery management. MARINE POLLUTION BULLETIN 2018; 127:131-138. [PMID: 29475644 DOI: 10.1016/j.marpolbul.2017.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 11/17/2017] [Accepted: 12/02/2017] [Indexed: 06/08/2023]
Abstract
Pelagic sharks (blue shark Prionace glauca and shortfin mako Isurus oxyrinchus) caught by long-line Spanish and Portuguese fleets in the NE Atlantic, were sampled at Vigo fish market (Spain) for total mercury (Hg) analysis. Hg concentration in white muscle increased with size and weight in both species, but at a higher rate in shortfin mako than in the blue shark. No difference was found with sex, year and season. Spatial variation was observed in the blue shark with higher Hg values in the North of the Azorean archipelago, but not in the shortfin mako. These high-level predators are particularly susceptible to bioaccumulate contaminants (Hg) in their tissues (muscle). However, a significant positive relationship between Hg concentration and trophic level (δ15N) of individuals was observed only in the shortfin mako. Most sharks landed were juveniles which presented Hg concentration lower than the maximum limit allowed by the European Union (1mgkg-1 wet weight) for marketing. However, concentrations above this threshold were most recorded in blue sharks larger than 250cm total length (TL) and in shortfin makos larger than 190cm TL, raising the question of the commercialization of large-sized individuals.
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Affiliation(s)
- Sebastián Biton-Porsmoguer
- Aix-Marseille University, CNRS/INSU, Toulon University, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Campus de Luminy, 13288 Marseille, France
| | - Daniela Bǎnaru
- Aix-Marseille University, CNRS/INSU, Toulon University, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Campus de Luminy, 13288 Marseille, France.
| | - Charles F Boudouresque
- Aix-Marseille University, CNRS/INSU, Toulon University, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Campus de Luminy, 13288 Marseille, France
| | - Ivan Dekeyser
- Aix-Marseille University, CNRS/INSU, Toulon University, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Campus de Luminy, 13288 Marseille, France
| | - Marc Bouchoucha
- Institut Français de Recherche pour l'Exploitation de la Mer (Ifremer), Z.P. Brégaillon, CS 20203, 83507 La Seyne-sur-Mer, France
| | - Françoise Marco-Miralles
- Institut Français de Recherche pour l'Exploitation de la Mer (Ifremer), Z.P. Brégaillon, CS 20203, 83507 La Seyne-sur-Mer, France
| | - Benoît Lebreton
- Littoral Environnement et Sociétés, UMR 7266 CNRS-Université de La Rochelle, 2 Rue Olympe de Gouges, 17000 La Rochelle, France
| | - Gaël Guillou
- Littoral Environnement et Sociétés, UMR 7266 CNRS-Université de La Rochelle, 2 Rue Olympe de Gouges, 17000 La Rochelle, France
| | - Mireille Harmelin-Vivien
- Aix-Marseille University, CNRS/INSU, Toulon University, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Campus de Luminy, 13288 Marseille, France
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64
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A global perspective on the trophic geography of sharks. Nat Ecol Evol 2018; 2:299-305. [DOI: 10.1038/s41559-017-0432-z] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 11/28/2017] [Indexed: 11/09/2022]
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65
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Scales KL, Hazen EL, Maxwell SM, Dewar H, Kohin S, Jacox MG, Edwards CA, Briscoe DK, Crowder LB, Lewison RL, Bograd SJ. Fit to predict? Eco-informatics for predicting the catchability of a pelagic fish in near real time. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:2313-2329. [PMID: 28833890 DOI: 10.1002/eap.1610] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 05/24/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
The ocean is a dynamic environment inhabited by a diverse array of highly migratory species, many of which are under direct exploitation in targeted fisheries. The timescales of variability in the marine realm coupled with the extreme mobility of ocean-wandering species such as tuna and billfish complicates fisheries management. Developing eco-informatics solutions that allow for near real-time prediction of the distributions of highly mobile marine species is an important step towards the maturation of dynamic ocean management and ecological forecasting. Using 25 yr (1990-2014) of NOAA fisheries' observer data from the California drift gillnet fishery, we model relative probability of occurrence (presence-absence) and catchability (total catch per gillnet set) of broadbill swordfish Xiphias gladius in the California Current System. Using freely available environmental data sets and open source software, we explore the physical drivers of regional swordfish distribution. Comparing models built upon remotely sensed data sets with those built upon a data-assimilative configuration of the Regional Ocean Modelling System (ROMS), we explore trade-offs in model construction, and address how physical data can affect predictive performance and operational capacity. Swordfish catchability was found to be highest in deeper waters (>1,500 m) with surface temperatures in the 14-20°C range, isothermal layer depth (ILD) of 20-40 m, positive sea surface height (SSH) anomalies, and during the new moon (<20% lunar illumination). We observed a greater influence of mesoscale variability (SSH, wind speed, isothermal layer depth, eddy kinetic energy) in driving swordfish catchability (total catch) than was evident in predicting the relative probability of presence (presence-absence), confirming the utility of generating spatiotemporally dynamic predictions. Data-assimilative ROMS circumvent the limitations of satellite remote sensing in providing physical data fields for species distribution models (e.g., cloud cover, variable resolution, subsurface data), and facilitate broad-scale prediction of dynamic species distributions in near real time.
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Affiliation(s)
- Kylie L Scales
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, California, 95064, USA
- Environmental Research Division, NOAA Southwest Fisheries Science Center, 99 Pacific Street, Suite #255A, Monterey, California, 93940, USA
- University of the Sunshine Coast, Maroochydore, Queensland, 4556, Australia
| | - Elliott L Hazen
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, California, 95064, USA
- Environmental Research Division, NOAA Southwest Fisheries Science Center, 99 Pacific Street, Suite #255A, Monterey, California, 93940, USA
| | - Sara M Maxwell
- Old Dominion University, 5115 Hampton Boulevard, Norfolk, Virginia, 23529, USA
| | - Heidi Dewar
- NOAA Southwest Fisheries Science Center, 8901 La Jolla Shores Drive, La Jolla, California, 92037, USA
| | - Suzanne Kohin
- NOAA Southwest Fisheries Science Center, 8901 La Jolla Shores Drive, La Jolla, California, 92037, USA
| | - Michael G Jacox
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, California, 95064, USA
- Environmental Research Division, NOAA Southwest Fisheries Science Center, 99 Pacific Street, Suite #255A, Monterey, California, 93940, USA
| | - Christopher A Edwards
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, California, 95064, USA
| | - Dana K Briscoe
- Hopkins Marine Station of Stanford University, 120 Ocean View Boulevard, Pacific Grove, California, 93950, USA
| | - Larry B Crowder
- Hopkins Marine Station of Stanford University, 120 Ocean View Boulevard, Pacific Grove, California, 93950, USA
| | - Rebecca L Lewison
- San Diego State University, 5500 Campanile Drive, San Diego, California, 92182, USA
| | - Steven J Bograd
- Environmental Research Division, NOAA Southwest Fisheries Science Center, 99 Pacific Street, Suite #255A, Monterey, California, 93940, USA
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Tiger sharks can connect equatorial habitats and fisheries across the Atlantic Ocean basin. PLoS One 2017; 12:e0184763. [PMID: 28926627 PMCID: PMC5604974 DOI: 10.1371/journal.pone.0184763] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 08/30/2017] [Indexed: 12/02/2022] Open
Abstract
Increasing our knowledge about the spatial ecology of apex predators and their interactions with diverse habitats and fisheries is necessary for understanding the trophic mechanisms that underlie several aspects of marine ecosystem dynamics and for guiding informed management policies. A preliminary assessment of tiger shark (Galeocerdo cuvier) population structure off the oceanic insular system of Fernando de Noronha (FEN) and the large-scale movements performed by this species in the equatorial Atlantic Ocean was conducted using longline and handline fishing gear and satellite telemetry. A total of 25 sharks measuring 175–372 cm in total length (TL) were sampled. Most sharks were likely immature females ranging between 200 and 260 cm TL, with few individuals < 200 cm TL being caught. This contrasts greatly with the tiger shark size-distribution previously reported for coastal waters off the Brazilian mainland, where most individuals measured < 200 cm TL. Also, the movements of 8 individuals measuring 202–310 cm TL were assessed with satellite transmitters for a combined total of 757 days (mean = 94.6 days∙shark-1; SD = 65.6). These sharks exhibited a considerable variability in their horizontal movements, with three sharks showing a mostly resident behavior around FEN during the extent of the respective tracks, two sharks traveling west to the South American continent, and two sharks moving mostly along the middle of the oceanic basin, one of which ending up in the northern hemisphere. Moreover, one shark traveled east to the African continent, where it was eventually caught by fishers from Ivory Coast in less than 474 days at liberty. The present results suggest that young tiger sharks measuring < 200 cm TL make little use of insular oceanic habitats from the western South Atlantic Ocean, which agrees with a previously-hypothesized ontogenetic habitat shift from coastal to oceanic habitats experienced by juveniles of this species in this region. In addition, this study adds evidence that tiger sharks are able to connect marine trophic webs from the neritic provinces of the eastern and western margins of the Atlantic Ocean across the equatorial basin and that they may experience mortality induced by remote fisheries. All this information is extremely relevant for understanding the energetic balance of marine ecosystems as much as the exposure of this species to fishing pressure in this yet poorly-known region.
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Howey LA, Wetherbee BM, Tolentino ER, Shivji MS. Biogeophysical and physiological processes drive movement patterns in a marine predator. MOVEMENT ECOLOGY 2017; 5:16. [PMID: 28725435 PMCID: PMC5514520 DOI: 10.1186/s40462-017-0107-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 06/11/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Blue sharks (Prionace glauca) are among the most abundant and widely distributed of oceanic elasmobranchs. Millions are taken annually in pelagic longline fisheries and comprise the highest component of auctioned fin weight in the international shark fin trade. Though studies of blue sharks outnumber those of other large pelagic sharks, the species' complicated and sexually segregated life history still confound current understanding of Atlantic movement patterns. Lack of detailed information regarding movement and vertical behavior continues to limit management efforts that require such data for stock assessment and sustainable catch modeling. Therefore, this study aims to describe behavioral and ecological patterns distinct to aggregating and migrating blue sharks, and compare the findings to existing Atlantic movement models. RESULTS Data collected from 23 blue sharks instrumented with pop-up satellite archival tags were used in statistical predictive regression models to investigate habitat use during a localized aggregation in the northwest Atlantic, while undergoing seasonal migrations, and with respect to environmental variables. Deployment durations ranged from 4 to 273 days, with sharks inhabiting both productive coastal waters and the open ocean, and exhibiting long-distance seasonal movements exceeding 3700 km. While aggregating on the continental shelf of the northwest Atlantic, blue sharks displayed consistent depth use independent of sex and life stage, and exhibited varied response to environmental (temperature and chlorophyll a) factors. As sharks dispersed from the aggregation site, depth use was influenced by bathymetry, latitude, demography, and presence in the Gulf Stream. Mature females were not observed at the New England tagging site, however, two mature females with recent mating wounds were captured and tagged opportunistically in The Bahamas, one of which migrated to the Mid-Atlantic Ridge. CONCLUSIONS Vertical behaviors displayed by blue sharks varied greatly among locales; depth use off the continental shelf was significantly greater, and individuals exhibited a greater frequency of deep-diving behavior, compared to periods of aggregation on the continental shelf. Sexual segregation was evident, suggesting mature and immature males, and immature females may be subjected to high levels of anthropogenic exploitation in this region during periods of aggregation. Analysis of the spatio-temporal tracks revealed that nine individuals traveled beyond the United States EEZ, including a mature female captured in The Bahamas that migrated to the Mid-Atlantic Ridge. These results reflect and augment existing Atlantic migration models, and highlight the complex, synergistic nature of factors affecting blue shark ecology and the need for a cooperative management approach in the North Atlantic.
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Affiliation(s)
- Lucy A. Howey
- Save Our Seas Shark Research Center and Guy Harvey Research Institute, Nova Southeastern University, Fort Lauderdale, Florida, USA
- Microwave Telemetry, Inc., 8835 Columbia 100 Parkway, Suites K & L, Columbia, MD USA
| | | | - Emily R. Tolentino
- Microwave Telemetry, Inc., 8835 Columbia 100 Parkway, Suites K & L, Columbia, MD USA
| | - Mahmood S. Shivji
- Save Our Seas Shark Research Center and Guy Harvey Research Institute, Nova Southeastern University, Fort Lauderdale, Florida, USA
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68
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Veríssimo A, Sampaio Í, McDowell JR, Alexandrino P, Mucientes G, Queiroz N, da Silva C, Jones CS, Noble LR. World without borders-genetic population structure of a highly migratory marine predator, the blue shark ( Prionace glauca). Ecol Evol 2017; 7:4768-4781. [PMID: 28690806 PMCID: PMC5496551 DOI: 10.1002/ece3.2987] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/10/2017] [Accepted: 03/21/2017] [Indexed: 01/21/2023] Open
Abstract
Highly migratory, cosmopolitan oceanic sharks often exhibit complex movement patterns influenced by ontogeny, reproduction, and feeding. These elusive species are particularly challenging to population genetic studies, as representative samples suitable for inferring genetic structure are difficult to obtain. Our study provides insights into the genetic population structure one of the most abundant and wide-ranging oceanic shark species, the blue shark Prionace glauca, by sampling the least mobile component of the populations, i.e., young-of-year and small juveniles (<2 year; N = 348 individuals), at three reported nursery areas, namely, western Iberia, Azores, and South Africa. Samples were collected in two different time periods (2002-2008 and 2012-2015) and were screened at 12 nuclear microsatellites and at a 899-bp fragment of the mitochondrial control region. Our results show temporally stable genetic homogeneity among the three Atlantic nurseries at both nuclear and mitochondrial markers, suggesting basin-wide panmixia. In addition, comparison of mtDNA CR sequences from Atlantic and Indo-Pacific locations also indicated genetic homogeneity and unrestricted female-mediated gene flow between ocean basins. These results are discussed in light of the species' life history and ecology, but suggest that blue shark populations may be connected by gene flow at the global scale. The implications of the present findings to the management of this important fisheries resource are also discussed.
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Affiliation(s)
- Ana Veríssimo
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
- Virginia Institute of Marine ScienceCollege of William and MaryGloucester PointVAUSA
| | - Íris Sampaio
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
| | - Jan R. McDowell
- Virginia Institute of Marine ScienceCollege of William and MaryGloucester PointVAUSA
| | - Paulo Alexandrino
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
| | - Gonzalo Mucientes
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
- Centro Tecnológico del MarFundación CETMARVigoSpain
| | - Nuno Queiroz
- CIBIO – U.P. – Research Center for Biodiversity and Genetic ResourcesVairãoPortugal
| | - Charlene da Silva
- Department of Agriculture, Forestry and FisheriesBranch FisheriesRogge BaySouth Africa
| | - Catherine S. Jones
- Institute of Biological and Environmental SciencesSchool of Biological SciencesUniversity of AberdeenAberdeenUK
| | - Leslie R. Noble
- Institute of Biological and Environmental SciencesSchool of Biological SciencesUniversity of AberdeenAberdeenUK
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69
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Ramírez-Macías D, Queiroz N, Pierce SJ, Humphries NE, Sims DW, Brunnschweiler JM. Oceanic adults, coastal juveniles: tracking the habitat use of whale sharks off the Pacific coast of Mexico. PeerJ 2017; 5:e3271. [PMID: 28484673 PMCID: PMC5420197 DOI: 10.7717/peerj.3271] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 04/04/2017] [Indexed: 11/23/2022] Open
Abstract
Eight whale sharks tagged with pop-up satellite archival tags off the Gulf of California, Mexico, were tracked for periods of 14–134 days. Five of these sharks were adults, with four females visually assessed to be pregnant. At least for the periods they were tracked, juveniles remained in the Gulf of California while adults moved offshore into the eastern Pacific Ocean. We propose that parturition occurs in these offshore waters. Excluding two juveniles that remained in the shallow tagging area for the duration of tracking, all sharks spent 65 ± 20.7% (SD) of their time near the surface, even over deep water, often in association with frontal zones characterized by cool-water upwelling. While these six sharks all made dives into the meso- or bathypelagic zones, with two sharks reaching the maximum depth recordable by the tags (1285.8 m), time spent at these depths represented a small proportion of the overall tracks. Most deep dives (72.7%) took place during the day, particularly during the early morning and late afternoon. Pronounced habitat differences by ontogenetic stage suggest that adult whale sharks are less likely to frequent coastal waters after the onset of maturity.
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Affiliation(s)
| | - Nuno Queiroz
- Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, CIBIO/InBIO-Universidade do Porto, Porto, Portugal.,The Laboratory, Marine Biological Association of the United Kingdom, Plymouth, United Kingdom
| | | | - Nicolas E Humphries
- The Laboratory, Marine Biological Association of the United Kingdom, Plymouth, United Kingdom
| | - David W Sims
- The Laboratory, Marine Biological Association of the United Kingdom, Plymouth, United Kingdom.,Ocean and Earth Science, National Oceanography Centre Southampton, Waterfront Campus, University of Southampton, Southampton, United Kingdom.,Center for Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
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Rangel BDS, Wosnick N, Hammerschlag N, Ciena AP, Kfoury Junior JR, Rici REG. A preliminary investigation into the morphology of oral papillae and denticles of blue sharks (Prionace glauca) with inferences about its functional significance across life stages. J Anat 2017; 230:389-397. [PMID: 28026018 PMCID: PMC5314393 DOI: 10.1111/joa.12574] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2016] [Indexed: 11/29/2022] Open
Abstract
Sensory organs in elasmobranchs (sharks, skates, rays) detect and respond to a different set of biotic and/or abiotic stimuli, through sight, smell, taste, hearing, mechanoreception and electroreception. Although gustation is crucial for survival and essential for growth, mobility, and maintenance of neural activity and the proper functioning of the immune system, comparatively little is known about this sensory system in elasmobranchs. Here we present a preliminary investigation into the structural and dimensional characteristics of the oral papillae and denticles found in the oropharyngeal cavity of the blue shark (Prionace glauca) during embryonic development through adulthood. Samples were obtained from the dorsal and ventral surface of the oropharyngeal cavity collected from embryos at different development stages as well as from adults. Our results suggest that development of papillae occurs early in ontogeny, before the formation of the oral denticles. The diameter of oral papillae gradually increases during development, starting from 25 μm in stage I embryos, to 110 μm in stage IV embryos and 272-300 μm in adults. Embryos exhibit papillae at early developmental stages, suggesting that these structures may be important during early in life. The highest density of papillae was observed in the maxillary and mandibular valve regions, possibly related to the ability to identify, capture and process prey. The oral denticles were observed only in the final embryonic stage as well as in adults. Accordingly, we suggest that oral denticles likely aid in ram ventilation (through reducing the hydrodynamic drag), to protect papillae from injury during prey consumption and assist in the retention and consumption of prey (through adhesion), since these processes are only necessary after birth.
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Affiliation(s)
- Bianca de S. Rangel
- Departamento de FisiologiaInstituto de BiociênciasUniversidade de São PauloSão PauloBrazil
- Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São PauloSão PauloBrazil
| | - Natascha Wosnick
- Departamento de FisiologiaSetor de Ciências BiológicasCentro PolitécnicoUniversidade Federal do ParanáCuritibaParanáBrazil
| | - Neil Hammerschlag
- Rosenstiel School of Marine and Atmospheric ScienceUniversity of MiamiMiamiFLUSA
- Abess Center for Ecosystem Science and PolicyUniversity of MiamiMiamiFLUSA
| | - Adriano P. Ciena
- Laboratório de MorfologiaInstituto de BiociênciasUniversidade Estadual PaulistaRio ClaroSão PauloBrazil
| | - José Roberto Kfoury Junior
- Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São PauloSão PauloBrazil
| | - Rose E. G. Rici
- Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São PauloSão PauloBrazil
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Vaudo JJ, Byrne ME, Wetherbee BM, Harvey GM, Shivji MS. Long-term satellite tracking reveals region-specific movements of a large pelagic predator, the shortfin mako shark, in the western North Atlantic Ocean. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.12852] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jeremy J. Vaudo
- The Guy Harvey Research Institute; Nova Southeastern University; Dania Beach FL USA
| | - Michael E. Byrne
- The Guy Harvey Research Institute; Nova Southeastern University; Dania Beach FL USA
| | - Bradley M. Wetherbee
- The Guy Harvey Research Institute; Nova Southeastern University; Dania Beach FL USA
- Department of Biological Sciences; University of Rhode Island; Kingston RI USA
| | - Guy M. Harvey
- The Guy Harvey Research Institute; Nova Southeastern University; Dania Beach FL USA
| | - Mahmood S. Shivji
- The Guy Harvey Research Institute; Nova Southeastern University; Dania Beach FL USA
- The Save Our Seas Shark Research Center; Nova Southeastern University; Dania Beach FL USA
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Adams GD, Flores D, Flores OG, Aarestrup K, Svendsen JC. Spatial ecology of blue shark and shortfin mako in southern Peru: local abundance, habitat preferences and implications for conservation. ENDANGER SPECIES RES 2016. [DOI: 10.3354/esr00744] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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