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Raudino HC, Bouchet PJ, Douglas C, Douglas R, Waples K. Aerial abundance estimates for two sympatric dolphin species at a regional scale using distance sampling and density surface modeling. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2022.1086686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Monitoring wildlife populations over scales relevant to management is critical to supporting conservation decision-making in the face of data deficiency, particularly for rare species occurring across large geographic ranges. The Pilbara region of Western Australia is home to two sympatric and morphologically similar species of coastal dolphins—the Indo-pacific bottlenose dolphin (Tursiops aduncus) and Australian humpback dolphin (Sousa sahulensis)—both of which are believed to be declining in numbers and facing increasing pressures from the combined impacts of environmental change and extensive industrial activities. The aim of this study was to develop spatially explicit models of bottlenose and humpback dolphin abundance in Pilbara waters that could inform decisions about coastal development at a regional scale. Aerial line transect surveys were flown from a fixed-wing aircraft in the austral winters of 2015, 2016, and 2017 across a total area of 33,420 km2. Spatio-temporal patterns in dolphin density were quantified using a density surface modeling (DSM) approach, accounting for imperfect detection as well as both perception and availability bias. We estimated the abundance of bottlenose dolphins at 3,713 (95% CI = 2,679–5,146; average density of 0.189 ± 0.046 SD individuals per km2) in 2015, 2,638 (95% CI = 1,670–4,168; 0.159 ± 0.135 individuals per km2) in 2016 and 1,635 (95% CI = 1,031–2,593; 0.101 ± 0.103 individuals per km2) in 2017. Too few humpback dolphins were detected in 2015 to model abundance, but their estimated abundance was 1,546 (95% CI = 942–2,537; 0.097 ± 0.03 individuals per km2) and 2,690 (95% CI = 1,792–4,038; 0.169 ± 0.064 individuals per km2) in 2016 and 2017, respectively. Dolphin densities were greatest in nearshore waters, with hotspots in Exmouth Gulf, the Dampier Archipelago, and Great Sandy Islands. Our results provide a benchmark on which future risk assessments can be based to better understand the overlap between pressures and important dolphin habitats in tropical northwestern Australia.
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Rexstad E, Buckland S, Marshall L, Borchers D. Pooling robustness in distance sampling: Avoiding bias when there is unmodelled heterogeneity. Ecol Evol 2023; 13:e9684. [PMID: 36620408 PMCID: PMC9817188 DOI: 10.1002/ece3.9684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/25/2022] [Accepted: 12/06/2022] [Indexed: 01/08/2023] Open
Abstract
The pooling robustness property of distance sampling results in unbiased abundance estimation even when sources of variation in detection probability are not modeled. However, this property cannot be relied upon to produce unbiased subpopulation abundance estimates when using a single pooled detection function that ignores subpopulations. We investigate by simulation the effect of differences in subpopulation detectability upon bias in subpopulation abundance estimates. We contrast subpopulation abundance estimates using a pooled detection function with estimates derived using a detection function model employing a subpopulation covariate. Using point transect survey data from a multispecies songbird study, species-specific abundance estimates are compared using pooled detection functions with and without a small number of adjustment terms, and a detection function with species as a covariate. With simulation, we demonstrate the bias of subpopulation abundance estimates when a pooled detection function is employed. The magnitude of the bias is positively related to the magnitude of disparity between the subpopulation detection functions. However, the abundance estimate for the entire population remains unbiased except when there is extreme heterogeneity in detection functions. Inclusion of a detection function model with a subpopulation covariate essentially removes the bias of the subpopulation abundance estimates. The analysis of the songbird point count surveys shows some bias in species-specific abundance estimates when a pooled detection function is used. Pooling robustness is a unique property of distance sampling, producing unbiased abundance estimates at the level of the study area even in the presence of large differences in detectability between subpopulations. In situations where subpopulation abundance estimates are required for data-poor subpopulations and where the subpopulations can be identified, we recommend the use of subpopulation as a covariate to reduce bias induced in subpopulation abundance estimates.
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Affiliation(s)
- Eric Rexstad
- Center for Research into Ecological and Environmental ModellingUniversity of St AndrewsSt AndrewsUK
| | - Steve Buckland
- Center for Research into Ecological and Environmental ModellingUniversity of St AndrewsSt AndrewsUK
| | - Laura Marshall
- Center for Research into Ecological and Environmental ModellingUniversity of St AndrewsSt AndrewsUK
| | - David Borchers
- Center for Research into Ecological and Environmental ModellingUniversity of St AndrewsSt AndrewsUK
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3
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Lauret V, Labach H, Turek D, Laran S, Gimenez O. Integrated spatial models foster complementarity between monitoring programmes in producing large‐scale bottlenose dolphin indicators. Anim Conserv 2022. [DOI: 10.1111/acv.12815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- V. Lauret
- CEFE, Université Montpellier, CNRS, EPHE, IRD Montpellier France
| | - H. Labach
- CEFE, Université Montpellier, CNRS, EPHE, IRD Montpellier France
- MIRACETI, Connaissance et conservation des cétacés Place des traceurs de pierres La Couronne France
| | - D. Turek
- Department of Mathematics and Statistics Williams College Williamstown MA USA
| | - S. Laran
- Observatoire PELAGIS UMS 3462 CNRS‐La Rochelle Université La Rochelle France
| | - O. Gimenez
- CEFE, Université Montpellier, CNRS, EPHE, IRD Montpellier France
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The Seabed Makes the Dolphins: Physiographic Features Shape the Size and Structure of the Bottlenose Dolphin Geographical Units. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10081036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The common bottlenose dolphin (Tursiops truncatus) is a cosmopolitan delphinid, regularly present in the Mediterranean Sea. According to previous studies, this dolphin tends to form resident geographical units scattered on the continental shelf. We investigated how the physiographic characteristics of the area of residence, with special reference to the size and shape of the continental shelf, affect the home range and the group size of the local units. We analysed and compared data collected between 2004–2016 by 15 research groups operating in different study areas of the Mediterranean Sea: the Alboran Sea, in the South-Western Mediterranean, the Gulf of Lion and the Pelagos Sanctuary for the marine mammals, in the North-Western Mediterranean, and the Gulf of Ambracia, in the North-Central Mediterranean Sea. We have found that in areas characterised by a wide continental platform, dolphins have wider home ranges and aggregate into larger groups. In areas characterized by a narrow continental platform, dolphins show much smaller home ranges and aggregate into smaller groups. The results obtained from this collective research effort highlight the importance of data sharing to improve our scientific knowledge in the field of cetaceans and beyond.
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Audino T, Grattarola C, Centelleghe C, Peletto S, Giorda F, Florio CL, Caramelli M, Bozzetta E, Mazzariol S, Di Guardo G, Lauriano G, Casalone C. SARS-CoV-2, a Threat to Marine Mammals? A Study from Italian Seawaters. Animals (Basel) 2021; 11:1663. [PMID: 34204885 PMCID: PMC8226612 DOI: 10.3390/ani11061663] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/26/2021] [Accepted: 05/29/2021] [Indexed: 02/07/2023] Open
Abstract
Zoonotically transmitted coronaviruses were responsible for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), causing the dramatic Coronavirus Disease-2019 (CoViD-19) pandemic, which affected public health, the economy, and society on a global scale. The impact of the SARS-CoV-2 pandemic permeated into our environment and wildlife as well; in particular, concern has been raised about the viral occurrence and persistence in aquatic and marine ecosystems. The discharge of untreated wastewaters carrying infectious SARS-CoV-2 into natural water systems that are home to sea mammals may have dramatic consequences on vulnerable species. The efficient transmission of coronaviruses raises questions regarding the contributions of virus-receptor interactions. The main receptor of SARS-CoV-2 is Angiotensin Converting Enzyme-2 (ACE-2), serving as a functional receptor for the viral spike (S) protein. This study aimed, through the comparative analysis of the ACE-2 receptor with the human one, at assessing susceptibility to SARS-CoV-2 for different species of marine mammals living in Italian waters. We also determined, by means of immunohistochemistry, ACE-2 receptor localization in the lung tissue from different cetacean species, in order to provide a preliminary characterization of ACE-2 expression in the marine mammal respiratory tracts. Furthermore, to evaluate if and how Italian wastewater management and coastal exposition to extreme weather events may led to susceptible marine mammal populations being exposed to SARS-CoV-2, geomapping data were carried out and overlapped. The results showed the potential SARS-CoV-2 exposure for marine mammals inhabiting Italian coastal waters, putting them at risk when swimming and feeding in specific risk areas. Thus, we highlighted the potential hazard of the reverse zoonotic transmission of SARS-CoV-2 infection, along with its impact on marine mammals regularly inhabiting the Mediterranean Sea, while also stressing the need for appropriate action in order to prevent further damage to specific vulnerable populations.
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Affiliation(s)
- Tania Audino
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy; (T.A.); (C.G.); (S.P.); (F.G.); (C.L.F.); (M.C.); (E.B.)
| | - Carla Grattarola
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy; (T.A.); (C.G.); (S.P.); (F.G.); (C.L.F.); (M.C.); (E.B.)
| | - Cinzia Centelleghe
- Department of Comparative Biomedicine and Food Science, University of Padua, Legnaro, 35020 Padua, Italy; (C.C.); (S.M.)
| | - Simone Peletto
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy; (T.A.); (C.G.); (S.P.); (F.G.); (C.L.F.); (M.C.); (E.B.)
| | - Federica Giorda
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy; (T.A.); (C.G.); (S.P.); (F.G.); (C.L.F.); (M.C.); (E.B.)
- Institute for Animal Health and Food Safety (IUSA), Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, 35416 Canary Islands, Spain
| | - Caterina Lucia Florio
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy; (T.A.); (C.G.); (S.P.); (F.G.); (C.L.F.); (M.C.); (E.B.)
| | - Maria Caramelli
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy; (T.A.); (C.G.); (S.P.); (F.G.); (C.L.F.); (M.C.); (E.B.)
| | - Elena Bozzetta
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy; (T.A.); (C.G.); (S.P.); (F.G.); (C.L.F.); (M.C.); (E.B.)
| | - Sandro Mazzariol
- Department of Comparative Biomedicine and Food Science, University of Padua, Legnaro, 35020 Padua, Italy; (C.C.); (S.M.)
| | - Giovanni Di Guardo
- Faculty of Veterinary Medicine, University of Teramo, Strada Provinciale 18 Località Piano d’Accio, 64100 Teramo, Italy;
| | - Giancarlo Lauriano
- Italian National Institute for Environmental Protection and Research (ISPRA), via Vitaliano Brancati 60, 00144 Rome, Italy
| | - Cristina Casalone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy; (T.A.); (C.G.); (S.P.); (F.G.); (C.L.F.); (M.C.); (E.B.)
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6
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Dolphins Stranded along the Tuscan Coastline (Central Italy) of the "Pelagos Sanctuary": A Parasitological Investigation. Pathogens 2020; 9:pathogens9080612. [PMID: 32727040 PMCID: PMC7459703 DOI: 10.3390/pathogens9080612] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/13/2022] Open
Abstract
Parasite monitoring is considered a necessary step for cetacean management and conservation. Between February 2013 and July 2015, 26 dolphins (15 Stenella coeruleoalba, 10 Tursiops truncatus, and one Grampus griseus) stranded along the Tuscan coastline of the protected marine area "Pelagos Sanctuary", were examined. Organs, tissues, and faecal and blood samples taken from all animals were analysed by parasitological, immunological, and molecular techniques. Twenty-one out of 26 dolphins (80.77%) tested positive for at least one parasite species, and 13/15 (86.7%) S. coeruleoalba, 7/10 (70%) T. truncatus, and the single G. griseus were found positive. Identified parasites included the nematodes Skrjabinalius guevarai (7.69%, 2/26), Halocercus lagenorhynchi (3.85%, 1/26), Halocercus delphini (7.69%, 2/26), Stenurus ovatus (7.69%, 2/26), Crassicauda spp. (7.69%, 2/26); the trematodes Pholeter gastrophilus (26.92%, 7/26), Campula palliata (3.85%, 1/26); the cestodes Phyllobothrium delphini (42.31%, 11/26), Monorygma grimaldii (23.08%, 6/26), Tetrabothrium forsteri (7.69%, 2/26), Strobilocephalus triangularis (7.69%, 2/26), and the acanthocephalan Bolbosoma vasculosum (7.69%, 2/26). Moreover, 6/26 (23%) animals scored positive to Toxoplasma gondii at serology, but PCR confirmed the infection (T. gondii Type II genotype) in a single animal. In examined dolphins, obtained results showed a high prevalence of endoparasites, which included species considered as a cause of severe debilitation or death.
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7
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Abundance estimates and habitat preferences of bottlenose dolphins reveal the importance of two gulfs in South Australia. Sci Rep 2019; 9:8044. [PMID: 31142765 PMCID: PMC6541621 DOI: 10.1038/s41598-019-44310-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 04/29/2019] [Indexed: 11/08/2022] Open
Abstract
Informed conservation management of marine mammals requires an understanding of population size and habitat preferences. In Australia, such data are needed for the assessment and mitigation of anthropogenic impacts, including fisheries interactions, coastal zone developments, oil and gas exploration and mining activities. Here, we present large-scale estimates of abundance, density and habitat preferences of southern Australian bottlenose dolphins (Tursiops sp.) over an area of 42,438km2 within two gulfs of South Australia. Using double-observer platform aerial surveys over four strata and mark-recapture distance sampling analyses, we estimated 3,493 (CV = 0.21; 95%CI = 2,327-5,244) dolphins in summer/autumn, and 3,213 (CV = 0.20; 95%CI = 2,151-4,801) in winter/spring of 2011. Bottlenose dolphin abundance and density was higher in gulf waters across both seasons (0.09-0.24 dolphins/km2) compared to adjacent shelf waters (0.004-0.04 dolphins/km2). The high densities of bottlenose dolphins in the two gulfs highlight the importance of these gulfs as a habitat for the species. Habitat modelling associated bottlenose dolphins with shallow waters, flat seafloor topography, and higher sea surface temperatures (SSTs) in summer/autumn and lower SSTs in winter/spring. Spatial predictions showed high dolphin densities in northern and coastal gulf sections. Distributional data should inform management strategies, marine park planning and environmental assessments of potential anthropogenic threats to this protected species.
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Claro F, Fossi MC, Ioakeimidis C, Baini M, Lusher AL, Mc Fee W, McIntosh RR, Pelamatti T, Sorce M, Galgani F, Hardesty BD. Tools and constraints in monitoring interactions between marine litter and megafauna: Insights from case studies around the world. MARINE POLLUTION BULLETIN 2019; 141:147-160. [PMID: 30955719 DOI: 10.1016/j.marpolbul.2019.01.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/22/2018] [Accepted: 01/09/2019] [Indexed: 06/09/2023]
Abstract
Adverse impacts of marine litter is documented on >1400 species, including marine megafauna (fish, birds, sea turtles and mammals). The primary impacts include ingestion and entanglement, and there is increasing concern about chemical contamination via ingestion. Numerous survey approaches and monitoring programs have been developed and implemented around the world. They may aim to provide data about parameters such as species distribution and interactions with anthropogenic activities. During the Sixth International Marine Debris Conference, a session was dedicated to the tools and constraints in monitoring interactions between litter and megafauna. In the present paper, we summarize 7 case studies which discuss entanglement and ingestion including macro- and micro-debris in several taxa and across multiple geographic regions. We then discusses the importance of tools and standardizing methods for assessment and management purposes, in the context of international environmental policies and marine litter strategies.
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Affiliation(s)
- F Claro
- Museum national d'Histoire naturelle, UMS 2006 AFB MNHN CNRS CP41, 57 rue Cuvier, 75231 Paris cedex 05, France.
| | - M C Fossi
- Department of Physical Sciences, Earth and Environment, University of Siena, Via P.A. Mattioli, 4, 53100 Siena, Italy
| | - C Ioakeimidis
- Mediterranean Pollution Assessment and Control Programme (MED POL), UN Environment/Mediterranean Action Plan Coordinating Unit, Barcelona Convention Secretariat, Vas. Konstantinou 48, Athens 11635, Greece
| | - M Baini
- Department of Physical Sciences, Earth and Environment, University of Siena, Via P.A. Mattioli, 4, 53100 Siena, Italy
| | - A L Lusher
- Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349 Oslo, Norway
| | - W Mc Fee
- National Oceanic and Atmospheric Administration, National Ocean Service, Charleston, SC, USA
| | - R R McIntosh
- Research Department, Phillip Island Nature Parks, P.O. Box 97, Cowes, VIC 3922, Australia
| | - T Pelamatti
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas (CICIMAR-IPN), Av. IPN s/n, Colonia Playa Palo de Santa Rita, C.P. 23096 La Paz, Baja California Sur, Mexico; Pelagios Kakunja A.C., Sinaloa 1540, Las Garzas, 23070 La Paz, Baja California Sur, Mexico
| | - M Sorce
- Harvard University, 15 Sanger Street, Medford, MA 02155, USA
| | - F Galgani
- IFREMER, Immeuble Agostini, ZI Furiani, 20600 Bastia, France
| | - B D Hardesty
- CSIRO Oceans and Atmosphere, GPO Box 1538, Hobart, TAS, 7001, Australia
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Mannocci L, Roberts JJ, Halpin PN, Authier M, Boisseau O, Bradai MN, Cañadas A, Chicote C, David L, Di-Méglio N, Fortuna CM, Frantzis A, Gazo M, Genov T, Hammond PS, Holcer D, Kaschner K, Kerem D, Lauriano G, Lewis T, Notarbartolo di Sciara G, Panigada S, Raga JA, Scheinin A, Ridoux V, Vella A, Vella J. Assessing cetacean surveys throughout the Mediterranean Sea: a gap analysis in environmental space. Sci Rep 2018; 8:3126. [PMID: 29449646 PMCID: PMC5814436 DOI: 10.1038/s41598-018-19842-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 01/09/2018] [Indexed: 11/20/2022] Open
Abstract
Heterogeneous data collection in the marine environment has led to large gaps in our knowledge of marine species distributions. To fill these gaps, models calibrated on existing data may be used to predict species distributions in unsampled areas, given that available data are sufficiently representative. Our objective was to evaluate the feasibility of mapping cetacean densities across the entire Mediterranean Sea using models calibrated on available survey data and various environmental covariates. We aggregated 302,481 km of line transect survey effort conducted in the Mediterranean Sea within the past 20 years by many organisations. Survey coverage was highly heterogeneous geographically and seasonally: large data gaps were present in the eastern and southern Mediterranean and in non-summer months. We mapped the extent of interpolation versus extrapolation and the proportion of data nearby in environmental space when models calibrated on existing survey data were used for prediction across the entire Mediterranean Sea. Using model predictions to map cetacean densities in the eastern and southern Mediterranean, characterised by warmer, less productive waters, and more intense eddy activity, would lead to potentially unreliable extrapolations. We stress the need for systematic surveys of cetaceans in these environmentally unique Mediterranean waters, particularly in non-summer months.
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Affiliation(s)
- Laura Mannocci
- Marine Geospatial Ecology Laboratory, Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA.
- UMR MARBEC (IRD, Ifremer, Université de Montpellier, CNRS), Institut Français de Recherche pour l'Exploitation de la Mer, Avenue Jean Monnet, CS 30171, 34203, Sète, France.
| | - Jason J Roberts
- Marine Geospatial Ecology Laboratory, Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Patrick N Halpin
- Marine Geospatial Ecology Laboratory, Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Matthieu Authier
- Observatoire PELAGIS UMS 3462 Université de La Rochelle/CNRS, 5 allées de l'Océan, 17 000, La Rochelle, France
| | - Oliver Boisseau
- Marine Conservation Research (MCR), 94 High Street, Kelvedon, CO5 9AA, UK
- Song of the Whale research team, International Fund for Animal Welfare (IFAW), 87-90 Albert Embankment, London, SE1 7UD, UK
| | - Mohamed Nejmeddine Bradai
- Institut National des Sciences et Technologies de la Mer (INSTM), Centre de Sfax, B.P. 1035, Sfax, 3018, Tunisia
| | - Ana Cañadas
- Alnilam Research and Conservation, Pradillos 29, 28491, Navacerrada, Madrid, Spain
| | - Carla Chicote
- SUBMON - Marine Environmental Services, Rabassa, 49, 08024, Barcelona, Spain
| | - Léa David
- EcoOcéan Institut, 18 rue des Hospices, 34090, Montpellier, France
| | | | - Caterina M Fortuna
- Italian National Institute for Environmental Protection and Research (ISPRA), via Vitaliano Brancati 60, 00144, Rome, Italy
| | - Alexandros Frantzis
- Pelagos Cetacean Research Institute, Terpsichoris 21, 16671, Vouliagmeni, Greece
| | - Manel Gazo
- SUBMON - Marine Environmental Services, Rabassa, 49, 08024, Barcelona, Spain
| | - Tilen Genov
- Morigenos - Slovenian Marine Mammal Society, Kidričevo nabrežje 4, 6330, Piran, Slovenia
- Department of Biodiversity, Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000, Koper, Slovenia
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, KY16 8LB, Scotland, UK
| | - Philip S Hammond
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, KY16 8LB, Scotland, UK
| | - Draško Holcer
- Blue World Institute of Marine Research and Conservation, Kaštel 24, HR-51551, Veli Lošinj, Croatia
- Croatian Natural History Museum, Demetrova 1, 10000, Zagreb, Croatia
| | - Kristin Kaschner
- Department of Biometry and Environmental Systems Analysis, Albert-Ludwigs University Freiburg, Tennenbacher Straße 4, 79106, Freiburg i. Br., Germany
| | - Dani Kerem
- Israel Marine Mammal Research & Assistance Center, Institute of Maritime Studies, School of Marine Sciences, The University of Haifa, Mt Carmel, 31095, Haifa, Israel
| | - Giancarlo Lauriano
- Italian National Institute for Environmental Protection and Research (ISPRA), via Vitaliano Brancati 60, 00144, Rome, Italy
| | - Tim Lewis
- Marine Conservation Research (MCR), 94 High Street, Kelvedon, CO5 9AA, UK
- Song of the Whale research team, International Fund for Animal Welfare (IFAW), 87-90 Albert Embankment, London, SE1 7UD, UK
- North Atlantic & Mediterranean Sperm Whale Catalogue (NAMSC), London, United Kingdom
| | | | - Simone Panigada
- Tethys Research Institute, Acquario Civico, Viale G.B. Gadio 2, 20121, Milano, Italy
| | - Juan Antonio Raga
- Unidad de Zoología Marina, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, University of Valencia, Aptdo 22085, 46071, Valencia, Spain
| | - Aviad Scheinin
- Israel Marine Mammal Research & Assistance Center, Institute of Maritime Studies, School of Marine Sciences, The University of Haifa, Mt Carmel, 31095, Haifa, Israel
- The Morris Kahn Marine Research Centre, The University of Haifa, Haifa, Israel
| | - Vincent Ridoux
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 Université de La Rochelle/CNRS, 2 avenue Olympe de Gouges, 17000, La Rochelle, France
| | - Adriana Vella
- Conservation Biology Research Group, Department of Biology, University of Malta, Msida, MSD2080, Malta
- The Biological Conservation Research Foundation, BICREF, PO BOX 30, Hamrun, Malta
| | - Joseph Vella
- The Biological Conservation Research Foundation, BICREF, PO BOX 30, Hamrun, Malta
- Department of Computer Information Systems, University of Malta, Msida, MSD2080, Malta
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10
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Allen SJ, Pollock KH, Bouchet PJ, Kobryn HT, McElligott DB, Nicholson KE, Smith JN, Loneragan NR. Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery. Sci Rep 2017; 7:4995. [PMID: 28694444 PMCID: PMC5503993 DOI: 10.1038/s41598-017-05189-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 06/13/2017] [Indexed: 11/11/2022] Open
Abstract
The incidental capture of wildlife in fishing gear presents a global conservation challenge. As a baseline to inform assessments of the impact of bycatch on bottlenose dolphins (Tursiops truncatus) interacting with an Australian trawl fishery, we conducted an aerial survey to estimate dolphin abundance across the fishery. Concurrently, we carried out boat-based dolphin photo-identification to assess short-term fidelity to foraging around trawlers, and used photographic and genetic data to infer longer-term fidelity to the fishery. We estimated abundance at ≈ 2,300 dolphins (95% CI = 1,247–4,214) over the ≈ 25,880-km2 fishery. Mark-recapture estimates yielded 226 (SE = 38.5) dolphins associating with one trawler and some individuals photographed up to seven times over 12 capture periods. Moreover, photographic and genetic re-sampling over three years confirmed that some individuals show long-term fidelity to trawler-associated foraging. Our study presents the first abundance estimate for any Australian pelagic dolphin community and documents individuals associating with trawlers over days, months and years. Without trend data or correction factors for dolphin availability, the impact of bycatch on this dolphin population’s conservation status remains unknown. These results should be taken into account by management agencies assessing the impact of fisheries-related mortality on this protected species.
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Affiliation(s)
- Simon J Allen
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia. .,School of Biological Sciences and Oceans Institute, University of Western Australia, Crawley, Western Australia, 6009, Australia. .,Evolutionary Genetics Group, Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
| | - Kenneth H Pollock
- Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, 27695-7617, United States of America
| | - Phil J Bouchet
- School of Biological Sciences and Oceans Institute, University of Western Australia, Crawley, Western Australia, 6009, Australia
| | - Halina T Kobryn
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia
| | | | - Krista E Nicholson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia
| | - Joshua N Smith
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia
| | - Neil R Loneragan
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, 6150, Australia
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Panigada S, Donovan GP, Druon JN, Lauriano G, Pierantonio N, Pirotta E, Zanardelli M, Zerbini AN, di Sciara GN. Satellite tagging of Mediterranean fin whales: working towards the identification of critical habitats and the focussing of mitigation measures. Sci Rep 2017; 7:3365. [PMID: 28611466 PMCID: PMC5469747 DOI: 10.1038/s41598-017-03560-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 05/01/2017] [Indexed: 11/09/2022] Open
Abstract
Mediterranean fin whales comprise a genetically distinct population, listed as Vulnerable (VU) in the IUCN Red List. Collisions with vessels are believed to represent the main cause of human-induced mortality. The identification of critical habitats (including migration routes) incorporating satellite telemetry data is therefore crucial to develop focussed conservation efforts. Between 2012 and 2015 thirteen fin whales were equipped with satellite transmitters, 8 in the Pelagos Sanctuary (although two ceased within two days) and 5 in the Strait of Sicily, to evaluate movements and habitat use. A hierarchical switching state-space model was used to identify transiting and area-restricted search (ARS) behaviours, believed to indicate foraging activities. All whales undertook mid- to long-distance migrations, crossing some of the world's busiest maritime routes. Areas where the animals predominantly engaged in ARS behaviour were identified in both study areas. The telemetry data were compared with results from ecosystem niche modelling, and showed that 80% of tagged whale positions was near (<7 km) the closest suitable habitat. The results contribute to the view that precautionary management should include establishment of a coordinated and dynamic basin-wide management scheme; if appropriate, this may include the establishment of protected areas by specific regional Conventions.
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Affiliation(s)
- Simone Panigada
- Tethys Research Institute, c/o Acquario Civico, Viale G.B. Gadio 2, 20121, Milan, Italy.
| | - Gregory P Donovan
- International Whaling Commission, The Red House, 135 Station Road, Impington, CB24 9NP, Cambridge, United Kingdom
| | - Jean-Noël Druon
- European Commission, DG Joint Research Centre, Directorate D - Sustainable Resources, Unit D.02 Water and Marine Resources, Via Fermi, TP 051, 21027, Ispra, (VA), Italy
| | - Giancarlo Lauriano
- Institute for Environmental Protection and Research - ISPRA, Via V. Brancati 60, 00144, Rome, Italy
| | - Nino Pierantonio
- Tethys Research Institute, c/o Acquario Civico, Viale G.B. Gadio 2, 20121, Milan, Italy
| | - Enrico Pirotta
- School of Mathematics, Washington State University, 14204 NE Salmon Creek Ave, Vancouver, WA, 98686, USA
| | - Margherita Zanardelli
- Tethys Research Institute, c/o Acquario Civico, Viale G.B. Gadio 2, 20121, Milan, Italy
| | - Alexandre N Zerbini
- National Marine Mammal Laboratory, Alaska Fisheries Science Center - NOAA, 7600 Sand Point Way N.E., Seattle, WA, 98115-6349, USA
- Cascadia Research Collective, Olympia, WA, USA
- Instituto Aqualie, Juiz de Fora, Minas Gerais, Brazil
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Abundance and Summer Distribution of a Local Stock of Black Sea Bottlenose Dolphins, Tursiops truncatus (Cetacea, Delphinidae), in Coastal Waters near Sudak (Ukraine, Crimea). VESTNIK ZOOLOGII 2016. [DOI: 10.1515/vzoo-2016-0006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
The first assessment of abundance of a local population of bottlenose dolphins in the Black Sea (near the Sudak coast) in 2011–2012 has been conducted: the results of a mark-recapture study of photo identified animals were complemented by a vessel line transect survey. The overall abundance of a population was estimated at between 621 ± 198 and 715 ± 267 animals (Chapman and Petersen estimates), and the majority of members of the population were recorded in the surveyed area. The summer range covered the area of a few hundred square kilometers, similar to migrating coastal stocks in other world regions. The greatest density of distribution was observed in August in sea 45–60 m deep; in addition, frequent approaches to the coastline are usual for dolphins of this stock. These trends in distribution may be partly explained by distribution of prey. Interaction with sprat trawling fisheries can be a factor shaping the local population structure. Coastal waters of Sudak and adjoining sea areas are an important habitat for bottlenose dolphins in the northern Black Sea, significant for their conservation.
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Notarbartolo di Sciara G, Lauriano G, Pierantonio N, Cañadas A, Donovan G, Panigada S. The Devil We Don't Know: Investigating Habitat and Abundance of Endangered Giant Devil Rays in the North-Western Mediterranean Sea. PLoS One 2015; 10:e0141189. [PMID: 26580814 PMCID: PMC4651356 DOI: 10.1371/journal.pone.0141189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 10/05/2015] [Indexed: 12/03/2022] Open
Abstract
The giant devil ray Mobula mobular, the only Mediterranean mobulid, is subject to mortality caused by directed and accidental captures in fisheries throughout the region. Whilst the combination of human impacts, limited range and a low reproductive potential is not inconsistent with its endangered listing, there are insufficient data to enable a quantitative assessment of trends. Without this, it is difficult to assess and prioritise threats and develop effective conservation actions. Using results from aerial surveys conducted between 2009 and 2014 over the Ligurian, Corsican, Sardinian, northern and central Tyrrhenian seas (626,228 km2), this study provides the first quantitative information on giant devil ray abundance and habitat choice in the western Mediterranean. Devil rays were observed in all seasons except winter, with their estimated abundance in the study area peaking in summer. The overall uncorrected mean density in the study area during summer was estimated at 0.0257 individuals km-2 (range: 0.017–0.044), resulting in a total abundance estimate of 6,092 (12.7%CV) individuals at the surface; once corrected for availability bias, this estimate indicates a summer presence of >12,700 devil rays in the study area. Rays were mostly observed alone even if occasionally, larger aggregations up to a maximum of 18 individuals were observed. Although observed throughout the study area, spatial modelling identified their preferred habitat to be over a broad strip connecting the Tuscan Archipelago to Eastern Sardinia, over a wide range of water depths ranging from 10 to 2000m. The observed seasonal changes in giant devil ray distribution in this study, combined with similar evidence from other areas in the Mediterranean, support the hypothesis that the species undertakes latitudinal migrations across the region, taking advantage of highly productive waters in the north during summer, and warmer southern waters during winter.
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Affiliation(s)
| | - Giancarlo Lauriano
- Istituto Superiore per la Protezione e la Ricerca Ambientale, Via Vitaliano Brancati 48, 00144, Roma, Italy
| | - Nino Pierantonio
- Tethys Research Institute, Viale G.B. Gadio 2, 20121, Milano, Italy
| | - Ana Cañadas
- ALNILAM Research and Conservation Ltd, Cándamo 116, 28240 Hoyo de Manzanares, Madrid, Spain
| | - Greg Donovan
- The International Whaling Commission, The Red House, 135 Station Road, Impington, Cambridge, Cambridgeshire, CB24 9NP, United Kingdom
| | - Simone Panigada
- Tethys Research Institute, Viale G.B. Gadio 2, 20121, Milano, Italy
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