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Fisher DN, Cheney BJ. Dolphin social phenotypes vary in response to food availability but not the North Atlantic Oscillation index. Proc Biol Sci 2023; 290:20231187. [PMID: 37817593 PMCID: PMC10565371 DOI: 10.1098/rspb.2023.1187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 09/18/2023] [Indexed: 10/12/2023] Open
Abstract
Social behaviours can allow individuals to flexibly respond to environmental change, potentially buffering adverse effects. However, individuals may respond differently to the same environmental stimulus, complicating predictions for population-level response to environmental change. Here, we show that bottlenose dolphins (Tursiops truncatus) alter their social behaviour at yearly and monthly scales in response to a proxy for food availability (salmon abundance) but do not respond to variation in a proxy for climate (the North Atlantic Oscillation index). There was also individual variation in plasticity for gregariousness and connectedness to distant parts of the social network, although these traits showed limited repeatability. By contrast, individuals showed consistent differences in clustering with their immediate social environment at the yearly scale but no individual variation in plasticity for this trait at either timescale. These results indicate that social behaviour in free-ranging cetaceans can be highly resource dependent with individuals increasing their connectedness over short timescales but possibly reducing their wider range of connection at longer timescales. Some social traits showed more individual variation in plasticity or mean behaviour than others, highlighting how predictions for the responses of populations to environmental variation must consider the type of individual variation present in the population.
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Affiliation(s)
- David N. Fisher
- School of Biological Sciences, University of Aberdeen, King's College, Aberdeen AB24 3FX, UK
| | - Barbara J. Cheney
- School of Biological Sciences, University of Aberdeen, Lighthouse Field Station, George Street, Cromarty IV11 8YL, UK
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2
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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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3
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Bossley MI, Steiner A, Parra GJ, Saltré F, Peters KJ. Dredging activity in a highly urbanised estuary did not affect the long-term occurrence of Indo-Pacific bottlenose dolphins and long-nosed fur seals. MARINE POLLUTION BULLETIN 2022; 184:114183. [PMID: 36307952 DOI: 10.1016/j.marpolbul.2022.114183] [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: 06/18/2022] [Revised: 09/18/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
Dredging is an excavation activity used worldwide in marine and freshwater environments to create, deepen, and maintain waterways, harbours, channels, locks, docks, berths, river entrances, and approaches to ports and boat ramps. However, dredging impacts on marine life, including marine mammals (cetaceans, pinnipeds, and sirenians), remain largely unknown. Here we quantified the effect of dredging operations in 2005 and 2019 on the occurrence of Indo-Pacific bottlenose dolphins (Tursiops aduncus) and long-nosed fur seals (Arctocephalus forsteri) in the Port River estuary, a highly urbanized estuary in Adelaide, South Australia. We applied generalised linear models to two long-term sighting datasets (dolphins: 1992-2020, fur seals: 2010-2020), to analyse changes in sighting rates as a function of dredging operations, season, rainfall, and sea surface temperature. We showed that the fluctuations in both dolphin and fur seal occurrences were not correlated with dredging operations, whereas sea surface temperature and season were stronger predictors of both species sighting rates (with seals more prevalent during the colder months, and dolphins in summer). Given the highly industrial environment of the Port River estuary, it is possible that animals in this area are habituated to high noise levels and therefore were not disturbed by dredging operations. Future research would benefit from analysing short-term effects of dredging operations on behaviour, movement patterns and habitat use to determine effects of possible habitat alteration caused by dredging.
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Affiliation(s)
- Mike I Bossley
- WDC, Whale and Dolphin Conservation Australasia, PO Box 720, Port Adelaide Business Centre, South Australia, 5015, Australia
| | - Aude Steiner
- Les Brussattes 1, 2904 Bressaucourt, Switzerland
| | - Guido J Parra
- Cetacean Ecology, Behaviour and Evolution Lab, College of Science and Engineering, Flinders University, Adelaide, South Australia 5001, Australia
| | - Frédérik Saltré
- Global Ecology, College of Science and Engineering, ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders University, Adelaide, South Australia 5001, Australia
| | - Katharina J Peters
- Global Ecology, College of Science and Engineering, ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders University, Adelaide, South Australia 5001, Australia; Evolutionary Genetics Group, Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland; School of Earth and Environment, University of Canterbury, 8041 Christchurch, New Zealand; Cetacean Ecology Research Group, School of Natural Sciences, Massey University, 0745 Auckland, New Zealand.
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4
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Ogilvy C, Constantine R, Bury SJ, Carroll EL. Diet variation in a critically endangered marine predator revealed with stable isotope analysis. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220470. [PMID: 35991335 PMCID: PMC9382206 DOI: 10.1098/rsos.220470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Understanding the foraging ecology of animals gives insights into their trophic relationships and habitat use. We used stable isotope analysis to understand the foraging ecology of a critically endangered marine predator, the Māui dolphin. We analysed carbon and nitrogen isotope ratios of skin samples (n = 101) collected from 1993 to 2021 to investigate temporal changes in diet and niche space. Genetic monitoring associated each sample with a DNA profile which allowed us to assess individual and population level changes in diet. Potential prey and trophic level indicator samples were also collected (n = 166; 15 species) and incorporated in Bayesian mixing models to estimate importance of prey types to Māui dolphin diet. We found isotopic niche space had decreased over time, particularly since the 2008 implementation of a Marine Mammal Sanctuary. We observed a decreasing trend in ∂13C and ∂15N values, but this was not linear and several fluctuations in isotope values occurred over time. The largest variation in isotope values occurred during an El Niño event, suggesting that prey is influenced by climate-driven oceanographic variables. Mixing models indicated relative importance of prey remained constant since 2008. The isotopic variability observed here is not consistent with individual specialization, rather it occurs at the population level.
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Affiliation(s)
- Courtney Ogilvy
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Rochelle Constantine
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
- Institute of Marine Science, University of Auckland, Auckland 1010, New Zealand
| | - Sarah J. Bury
- National Institute of Water and Atmospheric Research, Greta Point, Wellington 6021, New Zealand
| | - Emma L. Carroll
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
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5
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Sharp decline in humpback whale (Megaptera novaeangliae) survival and reproductive success in southeastern Alaska during and after the 2014–2016 Northeast Pacific marine heatwave. Mamm Biol 2022. [DOI: 10.1007/s42991-021-00187-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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6
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Cárdenas‐Alayza S, Torres DA, Gutiérrez D, Tremblay Y. Resource partitioning as a mechanism for trophic segregation in sympatric otariids from the productive upwelling Peruvian Humboldt Current System. AUSTRAL ECOL 2022. [DOI: 10.1111/aec.13158] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Susana Cárdenas‐Alayza
- Centro para la Sostenibilidad Ambiental Universidad Peruana Cayetano Heredia Lima 15074 Peru
- Laboratorio de Ciencias del Mar Universidad Peruana Cayetano Heredia Lima Peru
- UMR 248 MARBEC: IRD CNRS Ifremer Univ. Montpellier Sète cedex France
| | - Daniel A. Torres
- Centro para la Sostenibilidad Ambiental Universidad Peruana Cayetano Heredia Lima 15074 Peru
| | - Dimitri Gutiérrez
- Laboratorio de Ciencias del Mar Universidad Peruana Cayetano Heredia Lima Peru
- Programa Maestría en Ciencias del Mar Universidad Peruana Cayetano Heredia Lima Peru
| | - Yann Tremblay
- UMR 248 MARBEC: IRD CNRS Ifremer Univ. Montpellier Sète cedex France
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7
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Cárdenas-Alayza S, Gutiérrez D, Tremblay Y. Trends in sympatric otariid populations suggest resource limitations in the Peruvian Humboldt Current System. MARINE ENVIRONMENTAL RESEARCH 2021; 169:105349. [PMID: 34000662 DOI: 10.1016/j.marenvres.2021.105349] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 04/15/2021] [Accepted: 04/24/2021] [Indexed: 06/12/2023]
Abstract
Sympatric species evolve mechanisms to avoid competition and coexist. In the Humboldt Current System (HCS), populations of South American sea lions (SASL, Otaria byronia) and South American fur seals (SAFS, Arctocephalus australis) fluctuate mostly due to ENSO events and prey availability. We evaluate population trajectories of Peruvian sympatric otariids and discuss mechanisms for competition and/or resource limitation. For this purpose, we analyzed population trajectories of SASL and SAFS in a sympatric breeding site in Punta San Juan, Peru between 2001 and 2019. Wavelet analysis was used to extract trends and derivatives to estimate rates and turning points. Age-class proportions and biomass times series were constructed from weekly counts and evaluated. Both populations show a growth phase and subsequent decline. SAFS started to decline ~2.25 years before and at a rate 1.5 times faster than SASL. Decrease in juvenile age-class suggests that resource limitation is the main contributing factor for current population decline.
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Affiliation(s)
- Susana Cárdenas-Alayza
- Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Lima, 15074, Peru; Laboratorio de Ciencias Del Mar, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru; UMR 248 MARBEC: IRD - Univ. Montpellier - CNRS - Ifremer, Avenue Jean Monnet CS 30171, 34203, Sète Cedex, France.
| | - Dimitri Gutiérrez
- Laboratorio de Ciencias Del Mar, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru; Facultad de Ciencias y Filosofía, Programa Maestría en Ciencias Del Mar, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru.
| | - Yann Tremblay
- UMR 248 MARBEC: IRD - Univ. Montpellier - CNRS - Ifremer, Avenue Jean Monnet CS 30171, 34203, Sète Cedex, France.
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8
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van Weelden C, Towers JR, Bosker T. Impacts of climate change on cetacean distribution, habitat and migration. CLIMATE CHANGE ECOLOGY 2021. [DOI: 10.1016/j.ecochg.2021.100009] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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9
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Currie JJ, van Aswegen M, Stack SH, West KL, Vivier F, Bejder L. Rapid weight loss in free ranging pygmy killer whales (Feresa attenuata) and the implications for anthropogenic disturbance of odontocetes. Sci Rep 2021; 11:8181. [PMID: 33854117 PMCID: PMC8046785 DOI: 10.1038/s41598-021-87514-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/30/2021] [Indexed: 11/09/2022] Open
Abstract
Understanding the impacts of foraging disruptions to odontocete body condition is fundamental to quantifying biological effects of human disturbance and environmental changes on cetacean populations. Here, reductions in body volume of free-ranging pygmy killer whales (Feresa attenuata) were calculated using repeated measurements of the same individuals obtained through Unoccupied Aerial System (UAS)-photogrammetry during a prolonged disruption in foraging activity arising from a 21-day stranding event. Stranded individuals were used to verify UAS-derived volume and length estimates through 3D-imaging, water displacement, and post-mortem measurements. We show that (a) UAS estimates of length were within 1.5% of actual body length and UAS volume estimates were within 10-13% of actual volume, (b) foraging disruption resulted in a daily decrease of 2% of total body mass/day, and (c) pygmy killer whales can lose up to 27% of their total body weight within 17 days. These findings highlight the use of UAS as a promising new method to remotely monitor changes in body condition and animal health, which can be used to determine the potential effects of anthropogenic disturbance and environmental change on free-ranging odontocetes.
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Affiliation(s)
| | - Martin van Aswegen
- Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, HI, USA
| | | | - Kristi L West
- Hawaii Institute of Marine Biology, Kaneohe, HI, USA
- Human Nutrition Food and Animal Sciences, College of Tropical Agriculture and Human Resources, Honolulu, HI, USA
| | - Fabien Vivier
- Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, HI, USA
| | - Lars Bejder
- Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, HI, USA
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, WA, Australia
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10
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Forrest JAH, Bouchet PJ, Barley SC, McLennan AG, Meeuwig JJ. True blue: Temporal and spatial stability of pelagic wildlife at a submarine canyon. Ecosphere 2021. [DOI: 10.1002/ecs2.3423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- J. A. H. Forrest
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
| | - P. J. Bouchet
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
- School of Ocean Sciences Bangor University LL59 5AB Menai Bridge BangorUK
| | - S. C. Barley
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
| | - A. G. McLennan
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
| | - J. J. Meeuwig
- School of Biological Sciences University of Western Australia 35 Stirling Hwy Crawley Perth6009Australia
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11
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Perez‐Correa J, Carr P, Meeuwig JJ, Koldewey HJ, Letessier TB. Climate oscillation and the invasion of alien species influence the oceanic distribution of seabirds. Ecol Evol 2020; 10:9339-9357. [PMID: 32953065 PMCID: PMC7487247 DOI: 10.1002/ece3.6621] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/30/2020] [Accepted: 07/09/2020] [Indexed: 12/29/2022] Open
Abstract
Spatial and temporal distribution of seabird transiting and foraging at sea is an important consideration for marine conservation planning. Using at-sea observations of seabirds (n = 317), collected during the breeding season from 2012 to 2016, we built boosted regression tree (BRT) models to identify relationships between numerically dominant seabird species (red-footed booby, brown noddy, white tern, and wedge-tailed shearwater), geomorphology, oceanographic variability, and climate oscillation in the Chagos Archipelago. We documented positive relationships between red-footed booby and wedge-tailed shearwater abundance with the strength in the Indian Ocean Dipole, as represented by the Dipole Mode Index (6.7% and 23.7% contribution, respectively). The abundance of red-footed boobies, brown noddies, and white terns declined abruptly with greater distance to island (17.6%, 34.1%, and 41.1% contribution, respectively). We further quantified the effects of proximity to rat-free and rat-invaded islands on seabird distribution at sea and identified breaking point distribution thresholds. We detected areas of increased abundance at sea and habitat use-age under a scenario where rats are eradicated from invaded nearby islands and recolonized by seabirds. Following rat eradication, abundance at sea of red-footed booby, brown noddy, and white terns increased by 14%, 17%, and 3%, respectively, with no important increase detected for shearwaters. Our results have implication for seabird conservation and island restoration. Climate oscillations may cause shifts in seabird distribution, possibly through changes in regional productivity and prey distribution. Invasive species eradications and subsequent island recolonization can lead to greater access for seabirds to areas at sea, due to increased foraging or transiting through, potentially leading to distribution gains and increased competition. Our approach predicting distribution after successful eradications enables anticipatory threat mitigation in these areas, minimizing competition between colonies and thereby maximizing the risk of success and the conservation impact of eradication programs.
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Affiliation(s)
- Julian Perez‐Correa
- Zoological Society of LondonInstitute of ZoologyLondonUK
- Escuela de Ciencias AmbientalesFacultad de IngenieríaUniversidad Espíritu SantoSamborondónEcuador
- Imperial College LondonLondonUK
| | - Peter Carr
- Zoological Society of LondonInstitute of ZoologyLondonUK
- Centre for Ecology and ConservationUniversity of ExeterCornwallUK
| | - Jessica J. Meeuwig
- Centre for Marine Futures, Oceans Institute and School of Animal BiologyThe University of Western AustraliaCrawleyWAAustralia
| | - Heather J. Koldewey
- Centre for Ecology and ConservationUniversity of ExeterCornwallUK
- Conservation and PolicyZoological Society of LondonLondonUK
| | - Tom B. Letessier
- Zoological Society of LondonInstitute of ZoologyLondonUK
- Centre for Marine Futures, Oceans Institute and School of Animal BiologyThe University of Western AustraliaCrawleyWAAustralia
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12
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Tavares DC, Moura JF, Merico A, Siciliano S. Mortality of seabirds migrating across the tropical Atlantic in relation to oceanographic processes. Anim Conserv 2019. [DOI: 10.1111/acv.12539] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- D. C. Tavares
- Department of Theoretical Ecology and Modelling Leibniz Centre for Tropical Marine Research Bremen Germany
| | - J. F. Moura
- Department of Theoretical Ecology and Modelling Leibniz Centre for Tropical Marine Research Bremen Germany
| | - A. Merico
- Department of Theoretical Ecology and Modelling Leibniz Centre for Tropical Marine Research Bremen Germany
- Department of Physics & Earth Science Jacobs University Bremen Germany
| | - S. Siciliano
- Laboratório de Enterobactérias Instituto Oswaldo Cruz/Fiocruz Rio de Janeiro Brazil
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13
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van Aswegen M, Christiansen F, Symons J, Mann J, Nicholson K, Sprogis K, Bejder L. Morphological differences between coastal bottlenose dolphin (Tursiops aduncus) populations identified using non-invasive stereo-laser photogrammetry. Sci Rep 2019; 9:12235. [PMID: 31439909 PMCID: PMC6706378 DOI: 10.1038/s41598-019-48419-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 08/05/2019] [Indexed: 02/06/2023] Open
Abstract
Obtaining morphometric data on free-ranging marine megafauna is difficult, as traditional methods rely on post-mortem or live-capture techniques. We linked stereo-laser photogrammetry with long-term demographic data to compare length-at-age (LaA) growth curves of two well-studied populations of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in south-western (SW) and Shark Bay (SB), mid-western Australia. First, we determined the relationship between total length (TL) and blowhole-to-dorsal fin (BH-DF) length from post-mortem subjects (R2 = 0.99, n = 12). We then predicted TL from laser-derived BH-DF measurements of 129 and 74 known-age individuals in SW and SB, respectively. Richards growth models best described our LaA data. While birth length (103-110 cm) was similar between study regions, TL estimates at 1, 3, 12, and 25 years differed significantly (p < 0.001). Asymptotic length of adult males (SW = 246 cm, SB = 201 cm) and females (SW = 244 cm, SB = 200 cm) also differed significantly. Morphotypic variations likely reflect regional adaptations to local water temperatures, with the temperate SW having cooler waters than sub-tropical SB. We demonstrate the effectiveness of a non-invasive technique to understand ecological, demographic and life-history characteristics of long-lived marine megafauna, which are critical parameters for informing conservation and management actions.
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Affiliation(s)
- Martin van Aswegen
- Environmental and Conservation Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia. .,Aquatic Megafauna Research Unit, Harry Butler Institute, Murdoch University, South Street, Murdoch, WA, 6150, Australia. .,Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, 96744, Kaneohe, USA.
| | - Fredrik Christiansen
- Environmental and Conservation Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia.,Aquatic Megafauna Research Unit, Harry Butler Institute, Murdoch University, South Street, Murdoch, WA, 6150, Australia.,Aarhus Institute of Advanced Studies, Høegh-Guldbergs Gade 6B, 8000, Aarhus, Denmark.,Zoophysiology, Department of Bioscience, Aarhus University, 8000, Aarhus, Denmark
| | - John Symons
- Environmental and Conservation Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia.,Aquatic Megafauna Research Unit, Harry Butler Institute, Murdoch University, South Street, Murdoch, WA, 6150, Australia
| | - Janet Mann
- Department of Biology and Department of Psychology, Georgetown University, 20057, Washington, DC, USA
| | - Krista Nicholson
- Environmental and Conservation Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia.,Aquatic Megafauna Research Unit, Harry Butler Institute, Murdoch University, South Street, Murdoch, WA, 6150, Australia
| | - Kate Sprogis
- Environmental and Conservation Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia.,Aquatic Megafauna Research Unit, Harry Butler Institute, Murdoch University, South Street, Murdoch, WA, 6150, Australia.,Zoophysiology, Department of Bioscience, Aarhus University, 8000, Aarhus, Denmark
| | - Lars Bejder
- Environmental and Conservation Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia.,Aquatic Megafauna Research Unit, Harry Butler Institute, Murdoch University, South Street, Murdoch, WA, 6150, Australia.,Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, 96744, Kaneohe, USA
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14
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Food-provisioning negatively affects calf survival and female reproductive success in bottlenose dolphins. Sci Rep 2019; 9:8981. [PMID: 31222088 PMCID: PMC6586622 DOI: 10.1038/s41598-019-45395-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 06/03/2019] [Indexed: 11/08/2022] Open
Abstract
Food-provisioning of wildlife can facilitate reliable up-close encounters desirable by tourists and, consequently, tour operators. Food-provisioning can alter the natural behavior of an animal, encouraging adverse behavior (e.g. begging for food handouts), and affect the reproductive success and the viability of a population. Studies linking food-provisioning to reproductive success are limited due to the lack of long-term datasets available, especially for long-lived species such as marine mammals. In Bunbury, Western Australia, a state-licensed food-provisioning program offers fish handouts to a limited number of free-ranging bottlenose dolphins (Tursiops aduncus). Coupled with long-term historical data, this small (<200 individuals), resident dolphin population has been extensively studied for over ten years, offering an opportunity to examine the effect of food-provisioning on the reproductive success of females (ntotal = 63; nprovisioned females = 8). Female reproductive success was estimated as the number of weaned calves produced per reproductive years and calf survival at year one and three years old was investigated. The mean reproductive success of provisioned and non-provisioned females was compared using Bayes factor. We also used generalized linear models (GLMs) to examine female reproductive success in relation to the occurrence of food-provisioning, begging behavior and location (within the study area). Furthermore, we examined the influence of these variables and birth order and climatic fluctuations (e.g. El Niño Southern Oscillation) on calf survival. Bayes factor analyses (Bayes factor = 6.12) and results from the best fitting GLMs showed that female reproductive success and calf survival were negatively influenced by food-provisioning. The negative effects of food-provisioning, although only affecting a small proportion of the adult females’ population (13.2%), are of concern, especially given previous work showing that this population is declining.
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Manlik O, Krützen M, Kopps AM, Mann J, Bejder L, Allen SJ, Frère C, Connor RC, Sherwin WB. Is MHC diversity a better marker for conservation than neutral genetic diversity? A case study of two contrasting dolphin populations. Ecol Evol 2019; 9:6986-6998. [PMID: 31380027 PMCID: PMC6662329 DOI: 10.1002/ece3.5265] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 04/26/2019] [Accepted: 04/30/2019] [Indexed: 12/15/2022] Open
Abstract
Genetic diversity is essential for populations to adapt to changing environments. Measures of genetic diversity are often based on selectively neutral markers, such as microsatellites. Genetic diversity to guide conservation management, however, is better reflected by adaptive markers, including genes of the major histocompatibility complex (MHC). Our aim was to assess MHC and neutral genetic diversity in two contrasting bottlenose dolphin (Tursiops aduncus) populations in Western Australia-one apparently viable population with high reproductive output (Shark Bay) and one with lower reproductive output that was forecast to decline (Bunbury). We assessed genetic variation in the two populations by sequencing the MHC class II DQB, which encompasses the functionally important peptide binding regions (PBR). Neutral genetic diversity was assessed by genotyping twenty-three microsatellite loci. We confirmed that MHC is an adaptive marker in both populations. Overall, the Shark Bay population exhibited greater MHC diversity than the Bunbury population-for example, it displayed greater MHC nucleotide diversity. In contrast, the difference in microsatellite diversity between the two populations was comparatively low. Our findings are consistent with the hypothesis that viable populations typically display greater genetic diversity than less viable populations. The results also suggest that MHC variation is more closely associated with population viability than neutral genetic variation. Although the inferences from our findings are limited, because we only compared two populations, our results add to a growing number of studies that highlight the usefulness of MHC as a potentially suitable genetic marker for animal conservation. The Shark Bay population, which carries greater adaptive genetic diversity than the Bunbury population, is thus likely more robust to natural or human-induced changes to the coastal ecosystem it inhabits.
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Affiliation(s)
- Oliver Manlik
- Biology Department, College of ScienceUnited Arab Emirates UniversityAl AinUnited Arab Emirates
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyNew South WalesAustralia
| | - Michael Krützen
- Department of AnthropologyUniversity of ZurichZurichSwitzerland
| | - Anna M. Kopps
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyNew South WalesAustralia
| | - Janet Mann
- Department of Biology and Department of PsychologyGeorgetown UniversityWashingtonDistrict of Columbia
| | - Lars Bejder
- Marine Mammal Research Program, Hawai'i Institute of Marine BiologyUniversity of Hawai'i at ManoaKaneoheHonolulu
- Aquatic Megafauna Research Unit, School of Veterinary and Life SciencesMurdoch UniversityMurdochWestern AustraliaAustralia
| | - Simon J. Allen
- School of Biological SciencesUniversity of BristolBristolUnited Kingdom
| | - Celine Frère
- Faculty of Science, Health, Education and EngineeringUniversity of the Sunshine CoastSippy DownsQueenslandAustralia
| | | | - William B. Sherwin
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyNew South WalesAustralia
- Aquatic Megafauna Research Unit, School of Veterinary and Life SciencesMurdoch UniversityMurdochWestern AustraliaAustralia
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16
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Nowicki R, Heithaus M, Thomson J, Burkholder D, Gastrich K, Wirsing A. Indirect legacy effects of an extreme climatic event on a marine megafaunal community. ECOL MONOGR 2019. [DOI: 10.1002/ecm.1365] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Robert Nowicki
- International Center for Coral Reef Research and Restoration Mote Marine Laboratory 24244 Overseas Highway Summerland Key Florida 33042 USA
- Department of Biological Sciences and Marine Education and Research Initiative Florida International University Miami Florida 33199 USA
| | - Michael Heithaus
- Department of Biological Sciences and Marine Education and Research Initiative Florida International University Miami Florida 33199 USA
| | - Jordan Thomson
- School of Life and Environmental Sciences Deakin University Warrnambool Campus Warrnambool Victoria 3280 Australia
| | - Derek Burkholder
- Guy Harvey Research Institute Nova Southeastern University Ft Lauderdale Florida 33314 USA
| | - Kirk Gastrich
- Department of Biological Sciences and Marine Education and Research Initiative Florida International University Miami Florida 33199 USA
| | - Aaron Wirsing
- School of Environmental and Forest Sciences University of Washington Box 352100 Seattle Washington 98195 USA
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17
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Symons J, Sprogis KR, Bejder L. Implications of survey effort on estimating demographic parameters of a long-lived marine top predator. Ecol Evol 2018; 8:10470-10481. [PMID: 30464819 PMCID: PMC6238146 DOI: 10.1002/ece3.4512] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 03/19/2018] [Accepted: 03/29/2018] [Indexed: 12/30/2022] Open
Abstract
Effective management of wildlife populations rely on knowledge of their abundance, survival, and reproductive rates. Maintaining long‐term studies capable of estimating demographic parameters for long‐lived, slow‐reproducing species is challenging. Insights into the effects of research intensity on the statistical power to estimate demographic parameters are limited. Here, we investigate implications of survey effort on estimating abundance, home range sizes, and reproductive output of Indo‐Pacific bottlenose dolphins (Tursiops aduncus), using a 3‐year subsample of a long‐term, capture–recapture study off Bunbury, Western Australia. Photo‐identification on individual dolphins was collected following Pollock's Robust Design, where seasons were defined as “primary periods”, each consisting of multiple “secondary periods.” The full dataset consisted of 12 primary periods and 72 secondary periods, resulting in the study area being surveyed 24 times/year. We simulated reduced survey effort by randomly removing one, two, or three secondary periods per primary period. Capture–recapture models were used to assess the effect of survey intensity on the power to detect trends in population abundance, while individual dolphin sighting histories were used to assess the ability to conduct home range analyses. We used sighting records of adult females and their calving histories to assess survey effort on quantifying reproductive output. A 50% reduction in survey effort resulted in (a) up to a 36% decline in population abundance at the time of detection; (b) a reduced ability to estimate home range sizes, by increasing the time for individuals to be sighted on ≥30 occasions (an often‐used metric for home range analyses) from 7.74 to 14.32 years; and (c) 33%, 24%, and 33% of annual calving events across three years going undocumented, respectively. Results clearly illustrate the importance of survey effort on the ability to assess demographic parameters with clear implications for population viability analyses, population forecasting, and conservation efforts to manage human–wildlife interactions.
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Affiliation(s)
- John Symons
- Cetacean Research Unit School of Veterinary and Life Sciences Murdoch University Murdoch Western Australia Australia
| | - Kate R Sprogis
- Cetacean Research Unit School of Veterinary and Life Sciences Murdoch University Murdoch Western Australia Australia.,Zoophysiology Department of Bioscience Aarhus University Aarhus Denmark
| | - Lars Bejder
- Cetacean Research Unit School of Veterinary and Life Sciences Murdoch University Murdoch Western Australia Australia.,Marine Mammal Research Program Hawaii Institute of Marine Biology University of Hawaii at Manoa Honolulu Hawaii
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18
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Miloslavich P, Bax NJ, Simmons SE, Klein E, Appeltans W, Aburto-Oropeza O, Andersen Garcia M, Batten SD, Benedetti-Cecchi L, Checkley DM, Chiba S, Duffy JE, Dunn DC, Fischer A, Gunn J, Kudela R, Marsac F, Muller-Karger FE, Obura D, Shin YJ. Essential ocean variables for global sustained observations of biodiversity and ecosystem changes. GLOBAL CHANGE BIOLOGY 2018; 24:2416-2433. [PMID: 29623683 DOI: 10.1111/gcb.14108] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 05/21/2023]
Abstract
Sustained observations of marine biodiversity and ecosystems focused on specific conservation and management problems are needed around the world to effectively mitigate or manage changes resulting from anthropogenic pressures. These observations, while complex and expensive, are required by the international scientific, governance and policy communities to provide baselines against which the effects of human pressures and climate change may be measured and reported, and resources allocated to implement solutions. To identify biological and ecological essential ocean variables (EOVs) for implementation within a global ocean observing system that is relevant for science, informs society, and technologically feasible, we used a driver-pressure-state-impact-response (DPSIR) model. We (1) examined relevant international agreements to identify societal drivers and pressures on marine resources and ecosystems, (2) evaluated the temporal and spatial scales of variables measured by 100+ observing programs, and (3) analysed the impact and scalability of these variables and how they contribute to address societal and scientific issues. EOVs were related to the status of ecosystem components (phytoplankton and zooplankton biomass and diversity, and abundance and distribution of fish, marine turtles, birds and mammals), and to the extent and health of ecosystems (cover and composition of hard coral, seagrass, mangrove and macroalgal canopy). Benthic invertebrate abundance and distribution and microbe diversity and biomass were identified as emerging EOVs to be developed based on emerging requirements and new technologies. The temporal scale at which any shifts in biological systems will be detected will vary across the EOVs, the properties being monitored and the length of the existing time-series. Global implementation to deliver useful products will require collaboration of the scientific and policy sectors and a significant commitment to improve human and infrastructure capacity across the globe, including the development of new, more automated observing technologies, and encouraging the application of international standards and best practices.
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Affiliation(s)
- Patricia Miloslavich
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., Australia
- Departamento de Estudios Ambientales, Universidad Simón Bolívar, Caracas, Venezuela
- Australian Institute of Marine Science, Townsville, Qld, Australia
- Oceans Institute, University of Western Australia, Crawley, WA, Australia
| | - Nicholas J Bax
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., Australia
- CSIRO, Oceans and Atmosphere, Hobart, Tas., Australia
| | | | - Eduardo Klein
- Departamento de Estudios Ambientales, Universidad Simón Bolívar, Caracas, Venezuela
| | - Ward Appeltans
- Intergovernmental Oceanographic Commission of UNESCO, IOC Project Office for IODE, Oostende, Belgium
| | - Octavio Aburto-Oropeza
- Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, CA, USA
| | - Melissa Andersen Garcia
- National Oceanic and Atmospheric Administration (NOAA), Office of International Affairs, Washington, DC, USA
| | - Sonia D Batten
- Sir Alister Hardy Foundation for Ocean Science (SAHFOS), Nanaimo, BC, Canada
| | | | | | - Sanae Chiba
- UN Environment-World Conservation Monitoring Centre, Cambridge, UK
- Research and Development Center for Global Change (RCGC), JAMSTEC, Yokohama, Japan
| | - J Emmett Duffy
- Tennenbaum Marine Observatories Network, Smithsonian Institution, Edgewater, MD, USA
| | - Daniel C Dunn
- Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke University, Beaufort, NC, USA
| | - Albert Fischer
- Intergovermental Oceanographic Commission IOC/UNESCO, Paris, France
| | - John Gunn
- Australian Institute of Marine Science, Townsville, Qld, Australia
| | - Raphael Kudela
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Francis Marsac
- Institut de Recherche pour le Développement (IRD), UMR MARBEC 248, Université Montpellier, Montpellier, France
- Department of Oceanography, University of Cape Town, Rondebosch, South Africa
| | - Frank E Muller-Karger
- Institute for Marine Remote Sensing/IMaRS, College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | | | - Yunne-Jai Shin
- Institut de Recherche pour le Développement (IRD), UMR MARBEC 248, Université Montpellier, Montpellier, France
- Department of Biological Sciences, Ma-Re Institute, University of Cape Town, Rondebosch, South Africa
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