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Waller MJ, Humphries NE, Womersley FC, Loveridge A, Jeffries AL, Watanabe Y, Payne N, Semmens J, Queiroz N, Southall EJ, Sims DW. The vulnerability of sharks, skates, and rays to ocean deoxygenation: Physiological mechanisms, behavioral responses, and ecological impacts. JOURNAL OF FISH BIOLOGY 2024; 105:482-511. [PMID: 38852616 DOI: 10.1111/jfb.15830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/08/2024] [Accepted: 05/20/2024] [Indexed: 06/11/2024]
Abstract
Levels of dissolved oxygen in open ocean and coastal waters are decreasing (ocean deoxygenation), with poorly understood effects on marine megafauna. All of the more than 1000 species of elasmobranchs (sharks, skates, and rays) are obligate water breathers, with a variety of life-history strategies and oxygen requirements. This review demonstrates that although many elasmobranchs typically avoid hypoxic water, they also appear capable of withstanding mild to moderate hypoxia with changes in activity, ventilatory responses, alterations to circulatory and hematological parameters, and morphological alterations to gill structures. However, such strategies may be insufficient to withstand severe, progressive, or prolonged hypoxia or anoxia where anaerobic metabolic pathways may be used for limited periods. As water temperatures increase with climate warming, ectothermic elasmobranchs will exhibit elevated metabolic rates and are likely to be less able to tolerate the effects of even mild hypoxia associated with deoxygenation. As a result, sustained hypoxic conditions in warmer coastal or surface-pelagic waters are likely to lead to shifts in elasmobranch distributions. Mass mortalities of elasmobranchs linked directly to deoxygenation have only rarely been observed but are likely underreported. One key concern is how reductions in habitat volume as a result of expanding hypoxia resulting from deoxygenation will influence interactions between elasmobranchs and industrial fisheries. Catch per unit of effort of threatened pelagic sharks by longline fisheries, for instance, has been shown to be higher above oxygen minimum zones compared to adjacent, normoxic regions, and attributed to vertical habitat compression of sharks overlapping with increased fishing effort. How a compound stressor such as marine heatwaves alters vulnerability to deoxygenation remains an open question. With over a third of elasmobranch species listed as endangered, a priority for conservation and management now lies in understanding and mitigating ocean deoxygenation effects in addition to population declines already occurring from overfishing.
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Affiliation(s)
- Matt J Waller
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
| | | | | | | | - Amy L Jeffries
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
| | - Yuuki Watanabe
- Research Center for Integrative Evolutionary Science, The Graduate University for Advanced Studies, SOKENDAI, Kanagawa, Japan
| | - Nicholas Payne
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Jayson Semmens
- Institue for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Nuno Queiroz
- CIBIO/InBIO, Universidade do Porto, Vairão, Portugal
- BIOPOLIS, Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | | | - David W Sims
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
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Chen C, Jefferson TA, Chen B, Wang Y. Geographic range size, water temperature, and extrinsic threats predict the extinction risk in global cetaceans. GLOBAL CHANGE BIOLOGY 2022; 28:6541-6555. [PMID: 36008887 DOI: 10.1111/gcb.16385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 08/03/2022] [Accepted: 08/07/2022] [Indexed: 06/15/2023]
Abstract
Despite the fact that cetaceans provide significant ecological contributions to the health and stability of aquatic ecosystems, many are highly endangered with nearly one-third of species assessed as threatened with extinction. Nevertheless, to date, few studies have explicitly examined the patterns and processes of extinction risk and threats for this taxon, and even less between the two subclades (Mysticeti and Odontoceti). To fill this gap, we compiled a dataset of six intrinsic traits (active region, geographic range size, body weight, diving depth, school size, and reproductive cycle), six environmental factors relating to sea surface temperature and chlorophyll concentration, and two human-related threat indices that are commonly recognized for cetaceans. We then employed phylogenetic generalized least squares models and model selection to identify the key predictors of extinction risk in all cetaceans, as well as in the two subclades. We found that geographic range size, sea surface temperature, and human threat index were the most important predictors of extinction risk in all cetaceans and in odontocetes. Interestingly, maximum body weight was positively associated with the extinction risk in mysticetes, but negatively related to that for odontocetes. By linking seven major threat types to extinction risk, we further revealed that fisheries bycatch was the most common threat, yet the impacts of certain threats could be overestimated when considering all species rather than just threatened ones. Overall, we suggest that conservation efforts should focus on small-ranged cetaceans and species living in warmer waters or under strong anthropogenic pressures. Moreover, further studies should consider the threatened status of species when superimposing risk maps and quantifying risk severity. Finally, we emphasize that mysticetes and odontocetes should be conserved with different strategies, because their extinction risk patterns and major threat types are considerably different. For instance, large-bodied mysticetes and small-ranged odontocetes require special conservation priority.
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Affiliation(s)
- Chuanwu Chen
- Laboratory of Island Biogeography and Conservation Biology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | | | - Bingyao Chen
- Laboratory of Island Biogeography and Conservation Biology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Yanping Wang
- Laboratory of Island Biogeography and Conservation Biology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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Global collision-risk hotspots of marine traffic and the world's largest fish, the whale shark. Proc Natl Acad Sci U S A 2022; 119:e2117440119. [PMID: 35533277 PMCID: PMC9171791 DOI: 10.1073/pnas.2117440119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Marine traffic is increasing globally yet collisions with endangered megafauna such as whales, sea turtles, and planktivorous sharks go largely undetected or unreported. Collisions leading to mortality can have population-level consequences for endangered species. Hence, identifying simultaneous space use of megafauna and shipping throughout ranges may reveal as-yet-unknown spatial targets requiring conservation. However, global studies tracking megafauna and shipping occurrences are lacking. Here we combine satellite-tracked movements of the whale shark, Rhincodon typus, and vessel activity to show that 92% of sharks’ horizontal space use and nearly 50% of vertical space use overlap with persistent large vessel (>300 gross tons) traffic. Collision-risk estimates correlated with reported whale shark mortality from ship strikes, indicating higher mortality in areas with greatest overlap. Hotspots of potential collision risk were evident in all major oceans, predominantly from overlap with cargo and tanker vessels, and were concentrated in gulf regions, where dense traffic co-occurred with seasonal shark movements. Nearly a third of whale shark hotspots overlapped with the highest collision-risk areas, with the last known locations of tracked sharks coinciding with busier shipping routes more often than expected. Depth-recording tags provided evidence for sinking, likely dead, whale sharks, suggesting substantial “cryptic” lethal ship strikes are possible, which could explain why whale shark population declines continue despite international protection and low fishing-induced mortality. Mitigation measures to reduce ship-strike risk should be considered to conserve this species and other ocean giants that are likely experiencing similar impacts from growing global vessel traffic.
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Reisinger RR, Corney S, Raymond B, Lombard AT, Bester MN, Crawford RJM, Davies D, Bruyn PJN, Dilley BJ, Kirkman SP, Makhado AB, Ryan PG, Schoombie S, Stevens KL, Tosh CA, Wege M, Whitehead TO, Sumner MD, Wotherspoon S, Friedlaender AS, Cotté C, Hindell MA, Ropert‐Coudert Y, Pistorius PA. Habitat model forecasts suggest potential redistribution of marine predators in the southern Indian Ocean. DIVERS DISTRIB 2021. [DOI: 10.1111/ddi.13447] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Ryan R. Reisinger
- School of Ocean and Earth Science University of SouthamptonNational Oceanography Centre Southampton Southampton UK
- Institute for Marine Sciences University of California Santa Cruz Santa Cruz California USA
- Centre d’Etudes Biologiques de Chizé UMR 7372 du CNRS‐La Rochelle Université Villiers‐en‐Bois France
- Sorbonne UniversitésUPMC University, UMR 7159 CNRS‐IRD‐MNHN, LOCEAN‐IPSL Paris France
- Department of Zoology and Institute for Coastal and Marine Research DST/NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology Nelson Mandela University Gqeberha South Africa
| | - Stuart Corney
- Institute for Marine and Antarctic Studies University of Tasmania Hobart Tasmania Australia
| | - Ben Raymond
- Institute for Marine and Antarctic Studies University of Tasmania Hobart Tasmania Australia
- Australian Antarctic DivisionDepartment of Agriculture, Water and the Environment Kingston Tasmania Australia
| | - Amanda T. Lombard
- Institute for Coastal and Marine ResearchNelson Mandela University Gqeberha South Africa
| | - Marthán N. Bester
- Department of Zoology and Entomology Mammal Research Institute University of Pretoria Hatfield South Africa
| | | | - Delia Davies
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Rondebosch South Africa
| | - P. J. Nico Bruyn
- Department of Zoology and Entomology Mammal Research Institute University of Pretoria Hatfield South Africa
| | - Ben J. Dilley
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Rondebosch South Africa
| | - Stephen P. Kirkman
- Institute for Coastal and Marine ResearchNelson Mandela University Gqeberha South Africa
- Department of Forestry, Fisheries and the Environment Cape Town South Africa
| | - Azwianewi B. Makhado
- Department of Forestry, Fisheries and the Environment Cape Town South Africa
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Rondebosch South Africa
| | - Peter G. Ryan
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Rondebosch South Africa
| | - Stefan Schoombie
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Rondebosch South Africa
| | - Kim L. Stevens
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Rondebosch South Africa
| | - Cheryl A. Tosh
- Research Office Faculty of Health Sciences University of Pretoria Pretoria South Africa
| | - Mia Wege
- Department of Zoology and Entomology Mammal Research Institute University of Pretoria Hatfield South Africa
| | - T. Otto Whitehead
- FitzPatrick Institute of African Ornithology DST‐NRF Centre of Excellence University of Cape Town Rondebosch South Africa
| | - Michael D. Sumner
- Australian Antarctic DivisionDepartment of Agriculture, Water and the Environment Kingston Tasmania Australia
| | - Simon Wotherspoon
- Institute for Marine and Antarctic Studies University of Tasmania Hobart Tasmania Australia
- Australian Antarctic DivisionDepartment of Agriculture, Water and the Environment Kingston Tasmania Australia
| | - Ari S. Friedlaender
- Institute for Marine Sciences University of California Santa Cruz Santa Cruz California USA
| | - Cedric Cotté
- Sorbonne UniversitésUPMC University, UMR 7159 CNRS‐IRD‐MNHN, LOCEAN‐IPSL Paris France
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies University of Tasmania Hobart Tasmania Australia
| | - Yan Ropert‐Coudert
- Centre d’Etudes Biologiques de Chizé UMR 7372 du CNRS‐La Rochelle Université Villiers‐en‐Bois France
| | - Pierre A. Pistorius
- Department of Zoology and Institute for Coastal and Marine Research DST/NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology Nelson Mandela University Gqeberha South Africa
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Valsecchi S, Lanfredi C, Azzellino A, Savini A, Bracchi VA, Marchese F, Hancock J, Rees R, Cánovas Pérez C. Analysis of the temporal and spatial variability of whale shark ( Rhincodon typus) aggregation in the South Ari Marine Protected Area, Maldives, Indian Ocean. THE EUROPEAN ZOOLOGICAL JOURNAL 2021. [DOI: 10.1080/24750263.2021.1922523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- S. Valsecchi
- Department of Earth and Environmental Sciences (DISAT), University of Milano Bicocca, Milano, Italy
| | | | - A. Azzellino
- Milan DICA Civil and Environmental Engineering Department, Politecnico di Milano University of Technology, Milano, Italy
| | - A. Savini
- Department of Earth and Environmental Sciences (DISAT), University of Milano Bicocca, Milano, Italy
| | - V. A. Bracchi
- Department of Earth and Environmental Sciences (DISAT), University of Milano Bicocca, Milano, Italy
| | - F. Marchese
- Habitat and Benthic Biodiversity Laboratory, Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - J. Hancock
- Maldives Whale Shark Research Programme (MWSRP), South Ari Atoll, Maldives
| | - R. Rees
- Maldives Whale Shark Research Programme (MWSRP), South Ari Atoll, Maldives
| | - C. Cánovas Pérez
- Maldives Whale Shark Research Programme (MWSRP), South Ari Atoll, Maldives
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Womersley F, Hancock J, Perry CT, Rowat D. Wound-healing capabilities of whale sharks ( Rhincodon typus) and implications for conservation management. CONSERVATION PHYSIOLOGY 2021; 9:coaa120. [PMID: 33569175 PMCID: PMC7859907 DOI: 10.1093/conphys/coaa120] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 10/08/2020] [Accepted: 12/03/2020] [Indexed: 05/03/2023]
Abstract
Wound healing is important for marine taxa such as elasmobranchs, which can incur a range of natural and anthropogenic wounds throughout their life history. There is evidence that this group shows a high capacity for external wound healing. However, anthropogenic wounds may become more frequent due to increasing commercial and recreational marine activities. Whale sharks are particularly at risk of attaining injuries given their use of surface waters and wildlife tourism interest. There is limited understanding as to how whale sharks recover from injuries, and often insights are confined to singular opportunistic observations. The present study makes use of a unique and valuable photographic data source from two whale shark aggregation sites in the Indian Ocean. Successional injury-healing progression cases were reviewed to investigate the characteristics of injuries and quantify a coarse healing timeframe. Wounds were measured over time using an image standardization method. This work shows that by Day 25 major injury surface area decreased by an average of 56% and the most rapid healing case showed a surface area reduction of 50% in 4 days. All wounds reached a point of 90% surface area closure by Day 35. There were differences in healing rate based on wound type, with lacerations and abrasions taking 50 and 22 days to reach 90% healing, respectively. This study provides baseline information for wound healing in whale sharks and the methods proposed could act as a foundation for future research. Use of a detailed classification system, as presented here, may also assist in ocean scale injury comparisons between research groups and aid reliable descriptive data. Such findings can contribute to discussions regarding appropriate management in aggregation areas with an aim to reduce the likelihood of injuries, such as those resulting from vessel collisions, in these regions or during movements between coastal waters.
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Affiliation(s)
- Freya Womersley
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, SO17 1BJ, UK
- Marine Conservation Society Seychelles, Mahé, PO Box 384, Seychelles
- Corresponding author: Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK.
| | - James Hancock
- Maldives Whale Shark Research Programme, Popeshead Court Offices, Peter Lane, York, Yorkshire, Y01 8SU, UK
| | - Cameron T Perry
- Maldives Whale Shark Research Programme, Popeshead Court Offices, Peter Lane, York, Yorkshire, Y01 8SU, UK
| | - David Rowat
- Marine Conservation Society Seychelles, Mahé, PO Box 384, Seychelles
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Lezama-Ochoa N, Lopez J, Hall M, Bach P, Abascal F, Murua H. Spatio-temporal distribution of spinetail devil ray Mobula mobular in the eastern tropical Atlantic Ocean. ENDANGER SPECIES RES 2020. [DOI: 10.3354/esr01082] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The distribution of the spinetail devil ray Mobula mobular in the eastern tropical Atlantic remains poorly known compared to the Pacific and Indian Oceans. We used fishery-dependent data and generalized additive models to examine the environmental characteristics associated with the presence of M. mobular in the eastern Atlantic Ocean. Results revealed that the distribution of M. mobular is significantly associated with seasonal upwelling systems in coastal and pelagic areas. Our model predicted the presence of the species in areas where there is evidence of its occurrence, such as the Angolan upwelling system and the coast of Ghana. In addition, our model predicted new hotspot areas, including locations around the Mauritanian upwelling system, the Guinea coast, offshore Ghana and the south coast of Angola and Brazil, where sample sizes are limited. Those areas, as well as the environmental preferences depicted by the model, provide valuable information about the habitat and ecology of the spinetail devil ray. Future research lines derived from this study, as well as its limitations, are discussed. Furthermore, in light of our results we discuss the improvements that are needed to contribute to the conservation and management of this vulnerable species.
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Affiliation(s)
- N Lezama-Ochoa
- Inter-American Tropical Tuna Commission, Bycatch Program, San Diego, CA 92037, USA
- AZTI-Tecnalia, Marine Research Division, Pasaia 20110, Spain
| | - J Lopez
- Inter-American Tropical Tuna Commission, Bycatch Program, San Diego, CA 92037, USA
| | - M Hall
- Inter-American Tropical Tuna Commission, Bycatch Program, San Diego, CA 92037, USA
| | - P Bach
- Institut de Recherche pour le Développement (IRD), Séte 34200, France
| | - F Abascal
- Instituto Español de Oceanografía (IEO), Canary Islands 38180, Spain
| | - H Murua
- International Seafood Sustainability Foundation (ISSF), Washington, DC 20005, USA
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Báez JC, Barbosa AM, Pascual P, Ramos ML, Abascal F. Ensemble modeling of the potential distribution of the whale shark in the Atlantic Ocean. Ecol Evol 2020; 10:175-184. [PMID: 31988721 PMCID: PMC6972796 DOI: 10.1002/ece3.5884] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/11/2019] [Accepted: 11/10/2019] [Indexed: 11/22/2022] Open
Abstract
The whale shark (Rhincodon typus) is an endangered marine fish species which can be adversely affected by the fishing activities of the industrial purse seine fleet targeting tropical tuna. Tuna tend to aggregate around all types of floating objects, including whale sharks. We analyzed and modeled the spatial distribution and environmental preferences of whale sharks based on the presence and absence data from fishing observations in the Atlantic Ocean. We used a thorough multialgorithm analysis, based on a new presence-absence dataset, and endeavored to follow the most recent recommendations on best practices in species distribution modeling. First, we selected a subset of relevant variables using a generalized linear model that addressed multicollinearity, statistical errors, and information criteria. We then used the selected variables to build a model ensemble including 19 different algorithms. After eliminating models with insufficient performance, we assessed the potential distribution of whale sharks using the mean of the predictions of the selected models. We also assessed the variance among the predictions of different algorithms, in order to identify areas with the highest model consensus. The results show that several coastal regions and warm shallow currents, such as the Gulf Stream and the Canary and Benguela currents, are the most suitable areas for whale sharks under current environmental conditions. Future environmental projections for the Atlantic Ocean suggest that some of the suitable regions will shift northward, but current concentration areas will continue to be suitable for whale shark, although with less productivity, which could have negative consequences for conservation of the species. We discuss the implications of these predictions for the conservation and management of this charismatic marine species.
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Affiliation(s)
- José C. Báez
- Instituto Español de OceanografíaCentro Oceanográfico de MálagaFuengirolaMálagaSpain
- Facultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiago de ChileChile
| | - Ana Márcia Barbosa
- Faculdade de CiênciasCICGE ‐ Centro de Investigação em Ciências Geo‐EspaciaisObservatório Astronómico Prof. Manuel de BarrosUniversidade do PortoVila Nova de GaiaPortugal
| | - Pedro Pascual
- Instituto Español de OceanografíaCentro Oceanográfico de CanariasSanta Cruz de TenerifeSpain
| | - María Lourdes Ramos
- Instituto Español de OceanografíaCentro Oceanográfico de CanariasSanta Cruz de TenerifeSpain
| | - Francisco Abascal
- Instituto Español de OceanografíaCentro Oceanográfico de CanariasSanta Cruz de TenerifeSpain
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Copping JP, Stewart BD, McClean CJ, Hancock J, Rees R. Does bathymetry drive coastal whale shark ( Rhincodon typus) aggregations? PeerJ 2018; 6:e4904. [PMID: 29900072 PMCID: PMC5995094 DOI: 10.7717/peerj.4904] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 05/13/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The whale shark (Rhincodon typus) is known to aggregate in a number of coastal locations globally, however what causes these aggregations to form where they do is largely unknown. This study examines whether bathymetry is an important driver of coastal aggregation locations for R. typus through bathymetry's effect on primary productivity and prey availability. This is a global study taking into account all coastal areas within R. typus' range. METHODS R. typus aggregation locations were identified through an extensive literature review. Global bathymetric data were compared at R. typus aggregation locations and a large random selection of non-aggregation areas. Generalised linear models were used to assess which bathymetric characteristic had the biggest influence on aggregation presence. RESULTS Aggregation sites were significantly shallower than non-aggregation sites and in closer proximity to deep water (the mesopelagic zone) by two orders of magnitude. Slope at aggregation sites was significantly steeper than non-aggregation sites. These three bathymetric variables were shown to have the biggest association with aggregation sites, with up to 88% of deviation explained by the GLMs. DISCUSSION The three key bathymetric characteristics similar at the aggregation sites are known to induce upwelling events, increase primary productivity and consequently attract numerous other filter feeding species. The location of aggregation sites in these key areas can be attributed to this increased prey availability, thought to be the main reason R. typus aggregations occur, extensively outlined in the literature. The proximity of aggregations to shallow areas such as reefs could also be an important factor why whale sharks thermoregulate after deep dives to feed. These findings increase our understanding of whale shark behaviour and may help guide the identification and conservation of further aggregation sites.
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Affiliation(s)
- Joshua P. Copping
- School of Environment and Life Sciences, University of Salford, Manchester, United Kingdom
| | - Bryce D. Stewart
- Environment Department, University of York, York, United Kingdom
| | - Colin J. McClean
- Environment Department, University of York, York, United Kingdom
| | - James Hancock
- Maldives Whale Shark Research Programme, York, United Kingdom
| | - Richard Rees
- Maldives Whale Shark Research Programme, York, United Kingdom
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Sequeira AMM, Bouchet PJ, Yates KL, Mengersen K, Caley MJ. Transferring biodiversity models for conservation: Opportunities and challenges. Methods Ecol Evol 2018. [DOI: 10.1111/2041-210x.12998] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ana M. M. Sequeira
- IOMRC and Australian Institute of Marine Science The UWA Oceans Institute and School of Biological Sciences The University of Western Australia Crawley Western Australia Australia
| | - Phil J. Bouchet
- Marine Futures Lab School of Biological Sciences The University of Western Australia Crawley Western Australia Australia
| | - Katherine L. Yates
- School of Environment and Life Sciences University of Salford Manchester UK
- School of Mathematical Sciences Queensland University of Technology Brisbane Queensland Australia
| | - Kerrie Mengersen
- School of Mathematical Sciences Queensland University of Technology Brisbane Queensland Australia
- Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers (ACEMS), Queensland University of Technology Brisbane Queensland Australia
| | - M. Julian Caley
- School of Mathematical Sciences Queensland University of Technology Brisbane Queensland Australia
- Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers (ACEMS), Queensland University of Technology Brisbane Queensland Australia
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12
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Reynolds SD, Norman BM, Beger M, Franklin CE, Dwyer RG. Movement, distribution and marine reserve use by an endangered migratory giant. DIVERS DISTRIB 2017. [DOI: 10.1111/ddi.12618] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Samantha D. Reynolds
- Franklin Eco-Laboratory; The School of Biological Sciences; The University of Queensland; St Lucia QLD Australia
- ECOCEAN Inc.; 102/72 Marine Terrace; Fremantle WA Australia
| | | | - Maria Beger
- ARC Centre of Excellence for Environmental Decisions; The School of Biological Sciences; The University of Queensland; St Lucia QLD Australia
- School of Biology; University of Leeds; Leeds UK
| | - Craig E. Franklin
- Franklin Eco-Laboratory; The School of Biological Sciences; The University of Queensland; St Lucia QLD Australia
| | - Ross G. Dwyer
- Franklin Eco-Laboratory; The School of Biological Sciences; The University of Queensland; St Lucia QLD Australia
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13
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Hays GC, Ferreira LC, Sequeira AMM, Meekan MG, Duarte CM, Bailey H, Bailleul F, Bowen WD, Caley MJ, Costa DP, Eguíluz VM, Fossette S, Friedlaender AS, Gales N, Gleiss AC, Gunn J, Harcourt R, Hazen EL, Heithaus MR, Heupel M, Holland K, Horning M, Jonsen I, Kooyman GL, Lowe CG, Madsen PT, Marsh H, Phillips RA, Righton D, Ropert-Coudert Y, Sato K, Shaffer SA, Simpfendorfer CA, Sims DW, Skomal G, Takahashi A, Trathan PN, Wikelski M, Womble JN, Thums M. Key Questions in Marine Megafauna Movement Ecology. Trends Ecol Evol 2016; 31:463-475. [PMID: 26979550 DOI: 10.1016/j.tree.2016.02.015] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 02/16/2016] [Accepted: 02/17/2016] [Indexed: 02/03/2023]
Abstract
It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology.
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Affiliation(s)
- Graeme C Hays
- Deakin University, Geelong, Australia, School of Life and Environmental Sciences, Centre for Integrative Ecology, Warrnambool, VIC 3280, Australia.
| | - Luciana C Ferreira
- IOMRC and The UWA Oceans Institute, School of Animal Biology and Centre for Marine Futures, The University of Western Australia, Crawley, WA 6009, Australia; Australian Institute of Marine Science, c/o The UWA Oceans Institute, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Ana M M Sequeira
- IOMRC and The UWA Oceans Institute, School of Animal Biology and Centre for Marine Futures, The University of Western Australia, Crawley, WA 6009, Australia
| | - Mark G Meekan
- Australian Institute of Marine Science, c/o The UWA Oceans Institute, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Carlos M Duarte
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center (RSRC), Thuwal, 23955-6900, Saudi Arabia
| | - Helen Bailey
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD 20688, USA
| | - Fred Bailleul
- South Australian Research and Development Institute (Aquatic Sciences), 2 Hamra Avenue, West Beach, Adelaide, SA 5024, Australia
| | - W Don Bowen
- Population Ecology Division, Bedford Institute of Oceanography, Dartmouth, NS, B2Y 4A2, Canada
| | - M Julian Caley
- Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers, Australia; Australian Institute of Marine Science, PMB No. 3, Townsville, QLD 4810, Australia
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA
| | - Victor M Eguíluz
- Instituto de Física Interdisciplinar y Sistemas Complejos IFISC (CSIC-UIB), E-07122 Palma de Mallorca, Spain
| | - Sabrina Fossette
- School of Animal Biology, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Ari S Friedlaender
- Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, 2030 Marine Science Drive, Newport, OR 97365, USA
| | - Nick Gales
- Australian Antarctic Division, Department of the Environment, Australian Government, Kingston, TAS 7050, Australia
| | - Adrian C Gleiss
- Centre for Fish and Fisheries Research, School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
| | - John Gunn
- Australian Institute of Marine Science, PMB No. 3, Townsville, QLD 4810, Australia
| | - Rob Harcourt
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Elliott L Hazen
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, 99 Pacific St, Suite 255A, Monterey, CA 93940, USA
| | - Michael R Heithaus
- Department of Biological Sciences, Florida International University, Miami, FL 33174, USA
| | - Michelle Heupel
- Australian Institute of Marine Science, PMB No. 3, Townsville, QLD 4810, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, and College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - Kim Holland
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, PO Box 1346, Kaneohe, HI 98744, USA
| | - Markus Horning
- Science Department, Alaska SeaLife Center, Seward, AK 99664, USA
| | - Ian Jonsen
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Gerald L Kooyman
- Scripps Institute of Oceanography, University of California San Diego, San Diego, CA 92093, USA
| | - Christopher G Lowe
- Department of Biological Sciences, California State University, Long Beach, Long Beach, CA 90840, USA
| | - Peter T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, DK 8000, Denmark; Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, Perth, WA 6150, Australia
| | - Helene Marsh
- College of Marine and Environmental Science, James Cook University, Townsville, QLD 4810, Australia
| | - Richard A Phillips
- British Antarctic Survey, Natural Environment Research Council, Cambridge, CB3 0ET, UK
| | - David Righton
- Fisheries and Ecosystems Division, Cefas Laboratory, Pakefield Road, Lowestoft, NR34 7RU, UK
| | - Yan Ropert-Coudert
- Centre d'Etudes Biologiques de Chizé, Station d'Écologie de Chizé-Université de La Rochelle, CNRS UMR 7372, 79360 Villiers-en-Bois, France
| | - Katsufumi Sato
- Atmosphere and Ocean Research Institute, The University of Tokyo 5-1-5 Kashiwanoha, Kashiwa City, Chiba Prefecture, 277-8564, Japan
| | - Scott A Shaffer
- Department of Biological Sciences, San Jose State University, San Jose, CA 95192-0100, USA
| | - Colin A Simpfendorfer
- Centre for Sustainable Tropical Fisheries and Aquaculture, and College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - David W Sims
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK; Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH, UK; Centre for Biological Sciences, Building 85, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Gregory Skomal
- Massachusetts Shark Research Project, Division of Marine Fisheries, 1213 Purchase St, New Bedford, MA 02740, USA
| | - Akinori Takahashi
- National Institute of Polar Research, Tachikawa, Tokyo 190-8518, Japan
| | - Philip N Trathan
- British Antarctic Survey, Natural Environment Research Council, Cambridge, CB3 0ET, UK
| | - Martin Wikelski
- Department of Migration and ImmunoEcology, Max-Planck Institute for Ornithology, Am Obstberg 1, 78315 Radolfzell, Germany; Konstanz University, Department of Biology, 78457 Konstanz, Germany
| | - Jamie N Womble
- National Park Service, Glacier Bay Field Station, 3100 National Park Road, Juneau, AK 99801, USA
| | - Michele Thums
- Australian Institute of Marine Science, c/o The UWA Oceans Institute, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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14
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Sequeira AMM, Thums M, Brooks K, Meekan MG. Error and bias in size estimates of whale sharks: implications for understanding demography. ROYAL SOCIETY OPEN SCIENCE 2016; 3:150668. [PMID: 27069656 PMCID: PMC4821267 DOI: 10.1098/rsos.150668] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 02/18/2016] [Indexed: 05/30/2023]
Abstract
Body size and age at maturity are indicative of the vulnerability of a species to extinction. However, they are both difficult to estimate for large animals that cannot be restrained for measurement. For very large species such as whale sharks, body size is commonly estimated visually, potentially resulting in the addition of errors and bias. Here, we investigate the errors and bias associated with total lengths of whale sharks estimated visually by comparing them with measurements collected using a stereo-video camera system at Ningaloo Reef, Western Australia. Using linear mixed-effects models, we found that visual lengths were biased towards underestimation with increasing size of the shark. When using the stereo-video camera, the number of larger individuals that were possibly mature (or close to maturity) that were detected increased by approximately 10%. Mean lengths calculated by each method were, however, comparable (5.002 ± 1.194 and 6.128 ± 1.609 m, s.d.), confirming that the population at Ningaloo is mostly composed of immature sharks based on published lengths at maturity. We then collated data sets of total lengths sampled from aggregations of whale sharks worldwide between 1995 and 2013. Except for locations in the East Pacific where large females have been reported, these aggregations also largely consisted of juveniles (mean lengths less than 7 m). Sightings of the largest individuals were limited and occurred mostly prior to 2006. This result highlights the urgent need to locate and quantify the numbers of mature male and female whale sharks in order to ascertain the conservation status and ensure persistence of the species.
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Affiliation(s)
- Ana M. M. Sequeira
- IOMRC and The UWA Oceans Institute, School of Animal Biology and Centre for Marine Futures, University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Michele Thums
- School of Civil, Environmental and Mining Engineering and UWA Oceans Institute, University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
- Australian Institute of Marine Science, c/o UWA Oceans Institute (MO96), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Kim Brooks
- Australian Institute of Marine Science, c/o UWA Oceans Institute (MO96), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Mark G. Meekan
- Australian Institute of Marine Science, c/o UWA Oceans Institute (MO96), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
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15
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Sequeira AMM, Mellin C, Lozano‐Montes HM, Vanderklift MA, Babcock RC, Haywood MDE, Meeuwig JJ, Caley MJ. Transferability of predictive models of coral reef fish species richness. J Appl Ecol 2015. [DOI: 10.1111/1365-2664.12578] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ana M. M. Sequeira
- IOMRC and The UWA Oceans Institute School of Animal Biology and Centre for Marine Futures The University of Western Australia M470, 35 Stirling Highway Crawley WA 6009 Australia
| | - Camille Mellin
- Australian Institute of Marine Science PMB No. 3, Townsville MC Townsville Qld 4810 Australia
- The Environment Institute and School of Biological Sciences The University of Adelaide Adelaide SA 5005 Australia
| | | | | | - Russ C. Babcock
- Oceans and Atmosphere Flagship CSIRO Underwood Avenue Floreat WA 6014 Australia
| | | | - Jessica J. Meeuwig
- IOMRC and The UWA Oceans Institute School of Animal Biology and Centre for Marine Futures The University of Western Australia M470, 35 Stirling Highway Crawley WA 6009 Australia
| | - M. Julian Caley
- Australian Institute of Marine Science PMB No. 3, Townsville MC Townsville Qld 4810 Australia
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16
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Afonso P, McGinty N, Machete M. Dynamics of whale shark occurrence at their fringe oceanic habitat. PLoS One 2014; 9:e102060. [PMID: 25028929 PMCID: PMC4100814 DOI: 10.1371/journal.pone.0102060] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 06/13/2014] [Indexed: 11/18/2022] Open
Abstract
Studies have shown that the whale shark (Rhincodon typus), a vulnerable large filter feeder, seasonally aggregates at highly productive coastal sites and that individuals can perform large, trans-boundary migrations to reach these locations. Yet, the whereabouts of the whale shark when absent from these sites and the potential oceanographic and biological drivers involved in shaping their present and future habitat use, including that located at the fringes of their suitable oceanic habitat, are largely unknown. We analysed a 16-year (1998-2013) observer dataset from the pole-and-line tuna fishery across the Azores (mid-North Atlantic) and used GAM models to investigate the spatial and temporal patterns of whale shark occurrence in relation to oceanographic features. Across this period, the whale shark became a regular summer visitor to the archipelago after a sharp increase in sighting frequency seen in 2008. We found that SST helps predicting their occurrence in the region associated to the position of the seasonal 22°C isotherm, showing that the Azores are at a thermal boundary for this species and providing an explanation for the post 2007 increase. Within the region, whale shark detections were also higher in areas of increased bathymetric slope and closer to the seamounts, coinciding with higher chl-a biomass, a behaviour most probably associated to increased feeding opportunities. They also showed a tendency to be clustered around the southernmost island of Santa Maria. This study shows that the region integrates the oceanic habitat of adult whale shark and suggests that an increase in its relative importance for the Atlantic population might be expected in face of climate change.
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Affiliation(s)
- Pedro Afonso
- IMAR - Institute of Marine Research. Department of Oceanography and Fisheries, University of the Azores, Horta, Portugal
| | - Niall McGinty
- IMAR - Institute of Marine Research. Department of Oceanography and Fisheries, University of the Azores, Horta, Portugal
- MARICE - Marine Academic Research in Iceland. Department of Life and Health sciences, University of Iceland, Reykjavik, Iceland
| | - Miguel Machete
- LARSyS - Laboratory of Robotics and Systems in Engineering and Science, Lisbon, Portugal
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