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Oliveira-Rodrigues C, Correia AM, Valente R, Gil Á, Gandra M, Liberal M, Rosso M, Pierce G, Sousa-Pinto I. Assessing data bias in visual surveys from a cetacean monitoring programme. Sci Data 2022; 9:682. [DOI: 10.1038/s41597-022-01803-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 10/25/2022] [Indexed: 11/12/2022] Open
Abstract
AbstractLong-term monitoring datasets are fundamental to understand physical and ecological responses to environmental changes, supporting management and conservation. The data should be reliable, with the sources of bias identified and quantified. CETUS Project is a cetacean monitoring programme in the Eastern North Atlantic, based on visual methods of data collection. This study aims to assess data quality and bias in the CETUS dataset, by 1) applying validation methods, through photographic confirmation of species identification; 2) creating data quality criteria to evaluate the observer’s experience; and 3) assessing bias to the number of sightings collected and to the success in species identification. Through photographic validation, the species identification of 10 sightings was corrected and a new species was added to the CETUS dataset. The number of sightings collected was biased by external factors, mostly by sampling effort but also by weather conditions. Ultimately, results highlight the importance of identifying and quantifying data bias, while also yielding guidelines for data collection and processing, relevant for species monitoring programmes based on visual methods.
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Campbell E, Alfaro-Shigueto J, Aliaga-Rossel E, Beasley I, Briceño Y, Caballero S, da Silva VMF, Gilleman C, Gravena W, Hines E, Shahnawaz Khan M, Khan U, Kreb D, Mangel JC, Marmontel M, Mei Z, Mintzer VJ, Mosquera-Guerra F, Oliveira-da_Costa MO, Paschoalini Frias M, Paudel S, Sinha RK, Smith BD, Turvey ST, Utreras V, Van Damme PA, Wang D, Sayuri Whitty T, Thurstan RH, Godley BJ. Challenges and priorities for river cetacean conservation. ENDANGER SPECIES RES 2022. [DOI: 10.3354/esr01201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Chhaya V, Lahiri S, Jagan MA, Mohan R, Pathaw NA, Krishnan A. Community Bioacoustics: Studying Acoustic Community Structure for Ecological and Conservation Insights. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.706445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The diversity of animal acoustic signals has evolved due to multiple ecological processes, both biotic and abiotic. At the level of communities of signaling animals, these processes may lead to diverse outcomes, including partitioning of acoustic signals along multiple axes (divergent signal parameters, signaling locations, and timing). Acoustic data provides information on the organization, diversity and dynamics of an acoustic community, and thus enables study of ecological change and turnover in a non-intrusive way. In this review, we lay out how community bioacoustics (the study of acoustic community structure and dynamics), has value in ecological monitoring and conservation of diverse landscapes and taxa. First, we review the concepts of signal space, signal partitioning and their effects on the structure of acoustic communities. Next, we highlight how spatiotemporal ecological change is reflected in acoustic community structure, and the potential this presents in monitoring and conservation. As passive acoustic monitoring gains popularity worldwide, we propose that the analytical framework of community bioacoustics has promise in studying the response of entire suites of species (from insects to large whales) to rapid anthropogenic change.
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Seasonal flow dynamics exacerbate overlap between artisanal fisheries and imperiled Ganges River dolphins. Sci Rep 2020; 10:18798. [PMID: 33139770 PMCID: PMC7608554 DOI: 10.1038/s41598-020-75997-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 10/22/2020] [Indexed: 11/29/2022] Open
Abstract
Here we quantify the effects of artisanal fisheries on the ecology of a small cetacean, the Ganges River dolphin (Platanista gangetica gangetica, GRD), in a large river system of Nepal. We examine the size-classes of fisheries’ catches, behavioural changes in GRD in response to fishing activities, and diel overlap between GRD and fishing activity. We observed high human exploitation rates (> 60% of the total catch per effort) of GRD-preferred prey sizes, indicating risks of high resource competition and dietary overlap, especially during the low water season when resource availability is reduced. Competitive interactions in the feeding niches during the low water season, plus temporal overlap between the peak exploitation and critical life-history events (e.g., reproduction), likely have ecological consequences. Furthermore, we detected 48% (95% CI 43–52%) increase in the chance of behavioural changes among dolphins exposed to anthropopressure (fishing activity), risking social behaviour impairment in exposed dolphins. The higher diel overlap and increased diel coefficient as the surveys progressed towards the monsoon season suggest temporal shifts in GRD socio-behavioural states and seasonal effects on resource partitioning, respectively. This work identifies drivers of small cetaceans-fisheries interactions and their consequences, and can be used to help reduce biologically significant fishing impacts on small cetaceans. Mitigation strategies, together with river sanctuary and distanced-based approaches, should be urgently included in a framework of ecosystem-based management.
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Mooney TA, Di Iorio L, Lammers M, Lin TH, Nedelec SL, Parsons M, Radford C, Urban E, Stanley J. Listening forward: approaching marine biodiversity assessments using acoustic methods. ROYAL SOCIETY OPEN SCIENCE 2020; 7:201287. [PMID: 32968541 PMCID: PMC7481698 DOI: 10.1098/rsos.201287] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 08/05/2020] [Indexed: 05/08/2023]
Abstract
Ecosystems and the communities they support are changing at alarmingly rapid rates. Tracking species diversity is vital to managing these stressed habitats. Yet, quantifying and monitoring biodiversity is often challenging, especially in ocean habitats. Given that many animals make sounds, these cues travel efficiently under water, and emerging technologies are increasingly cost-effective, passive acoustics (a long-standing ocean observation method) is now a potential means of quantifying and monitoring marine biodiversity. Properly applying acoustics for biodiversity assessments is vital. Our goal here is to provide a timely consideration of emerging methods using passive acoustics to measure marine biodiversity. We provide a summary of the brief history of using passive acoustics to assess marine biodiversity and community structure, a critical assessment of the challenges faced, and outline recommended practices and considerations for acoustic biodiversity measurements. We focused on temperate and tropical seas, where much of the acoustic biodiversity work has been conducted. Overall, we suggest a cautious approach to applying current acoustic indices to assess marine biodiversity. Key needs are preliminary data and sampling sufficiently to capture the patterns and variability of a habitat. Yet with new analytical tools including source separation and supervised machine learning, there is substantial promise in marine acoustic diversity assessment methods.
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Affiliation(s)
- T. Aran Mooney
- Biology Department, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543, USA
- Author for correspondence: T. Aran Mooney e-mail:
| | - Lucia Di Iorio
- CHORUS Institute, Phelma Minatec, 3 parvis Louis Néel, 38000 Grenoble, France
| | - Marc Lammers
- Hawaiian Islands Humpback Whale National Marine Sanctuary, 726 South Kihei Road, Kihei, HI 96753, USA
| | - Tzu-Hao Lin
- Biodiversity Research Center, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Sophie L. Nedelec
- Biosciences, College of Life and Environmental Sciences, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter EX4 4PS, UK
| | - Miles Parsons
- Australian Institute of Marine Science, Perth, Western Australia 6009, Australia
| | - Craig Radford
- Institute of Marine Science, Leigh Marine Laboratory, University of Auckland, PO Box 349, Warkworth 0941, New Zealand
| | - Ed Urban
- Scientific Committee on Oceanic Research, University of Delaware, Newark, DE 19716, USA
| | - Jenni Stanley
- Biology Department, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543, USA
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Couet P, Gally F, Canonne C, Besnard A. Joint estimation of survival and breeding probability in female dolphins and calves with uncertainty in state assignment. Ecol Evol 2019; 9:13043-13055. [PMID: 31871628 PMCID: PMC6912916 DOI: 10.1002/ece3.5693] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/06/2019] [Accepted: 09/06/2019] [Indexed: 12/01/2022] Open
Abstract
While the population growth rate in long-lived species is highly sensitive to adult survival, reproduction can also significantly drive population dynamics. Reproductive parameters can be challenging to estimate as breeders and nonbreeders may vary in resighting probability and reproductive status may be difficult to assess. We extended capture-recapture (CR) models previously fitted for data on other long-lived marine mammals to estimate demographic parameters while accounting for detection heterogeneity between individuals and state uncertainty regarding reproductive status. We applied this model to data on 106 adult female bottlenose dolphins observed over 13 years. The detection probability differed depending on breeding status. Concerning state uncertainty, offspring were not always sighted with their mother, and older calves were easier to detect than young-of-the-year (YOY), respectively, 0.79 (95% CI 0.59-0.90) and 0.58 (95% CI 0.46-0.68). This possibly led to inaccurate reproductive status assignment of females. Adult female survival probability was high (0.97 CI 95% 0.96-0.98) and did not differ according to breeding status. Young-of-the-year and 1-year-old calves had a significantly higher survival rate than 2-year-old (respectively, 0.66 CI 95% 0.50-0.78 and 0.45 CI 95% 0.29-0.61). This reduced survival is probably related to weaning, a period during which young are exposed to more risks since they lose protection and feeding from the mother. The probability of having a new YOY was high for breeding females that had raised a calf to the age of 3 or lost a 2-year-old calf (0.71, CI 95% 0.45-0.88). Yet, this probability was much lower for nonbreeding females and breeding females that had lost a YOY or a 1-year-old calf (0.33, 95% CI 0.26-0.42). The multievent CR framework we used is highly flexible and could be easily modified for other study questions or taxa (marine or terrestrial) aimed at modeling reproductive parameters.
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Affiliation(s)
- Pauline Couet
- CNRSUMSupAgroIRDINRAUMR 5175 CEFEEPHEPSL Research UniversityMontpellierFrance
- Groupe d'Etude des Cétacés du CotentinCherbourg‐OctevilleFrance
| | - François Gally
- Groupe d'Etude des Cétacés du CotentinCherbourg‐OctevilleFrance
| | - Coline Canonne
- CNRSUMSupAgroIRDINRAUMR 5175 CEFEEPHEPSL Research UniversityMontpellierFrance
- Direction Recherche et ExpertiseONCFSSaint‐BenoitAuffargisFrance
| | - Aurélien Besnard
- CNRSUMSupAgroIRDINRAUMR 5175 CEFEEPHEPSL Research UniversityMontpellierFrance
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Dewhurst‐Richman NI, Jones JPG, Northridge S, Ahmed B, Brook S, Freeman R, Jepson P, Mahood SP, Turvey ST. Fishing for the facts: river dolphin bycatch in a small‐scale freshwater fishery in Bangladesh. Anim Conserv 2019. [DOI: 10.1111/acv.12523] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- N. I. Dewhurst‐Richman
- Institute of Zoology Zoological Society of London Outer Circle, Regent's Park London NW1 4RY United Kingdom
- School of Environment, Natural Resources and Geography Bangor University Bangor LL57 2UW UK
- Department of Geography Department of GeographyUniversity College London Gower Street LondonWC1E 6BT
| | - J. P. G. Jones
- School of Environment, Natural Resources and Geography Bangor University Bangor LL57 2UW UK
| | - S. Northridge
- School of Biology University of St. Andrews St. AndrewsKY16 9TSUK
| | - B. Ahmed
- 7 B‐C, Ka 39‐A Dream Valley North Baridhara, Gulshan 2 Dhaka1212Bangladesh
| | - S. Brook
- Wildlife Conservation Society #21, Street 21 Phnom PenhPO Box 1620Cambodia
| | - R. Freeman
- Institute of Zoology Zoological Society of London Outer Circle, Regent's Park London NW1 4RY United Kingdom
| | - P. Jepson
- Institute of Zoology Zoological Society of London Outer Circle, Regent's Park London NW1 4RY United Kingdom
| | - S. P. Mahood
- 7 B‐C, Ka 39‐A Dream Valley North Baridhara, Gulshan 2 Dhaka1212Bangladesh
- Wildlife Conservation Society #21, Street 21 Phnom PenhPO Box 1620Cambodia
- Research Institute for the Environment and Livelihoods Charles Darwin University Ellengowan Drive, Casuarina NT 081 Australia
| | - S. T. Turvey
- Institute of Zoology Zoological Society of London Outer Circle, Regent's Park London NW1 4RY United Kingdom
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Fürstenau Oliveira JS, Georgiadis G, Campello S, Brandão RA, Ciuti S. Improving river dolphin monitoring using aerial surveys. Ecosphere 2017. [DOI: 10.1002/ecs2.1912] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Julia S. Fürstenau Oliveira
- Department of Biometry and Environmental System Analysis; University of Freiburg; Tennenbacher Straße 4 79106 Freiburg Germany
| | - George Georgiadis
- Instituto Araguaia de Proteção Ambiental; Parque Estadual do Cantão, Rodovia TO-080 Caseara Tocantins CEP 77680-000 Brazil
| | - Silvana Campello
- Instituto Araguaia de Proteção Ambiental; Parque Estadual do Cantão, Rodovia TO-080 Caseara Tocantins CEP 77680-000 Brazil
| | - Reuber A. Brandão
- Laboratório de Fauna e Unidades de Conservação; Departamento de Engenharia Florestal; Universidade de Brasília; Brasilia - DF CEP 70910-900 Brazil
| | - Simone Ciuti
- Department of Biometry and Environmental System Analysis; University of Freiburg; Tennenbacher Straße 4 79106 Freiburg Germany
- School of Biology and Environmental Science; University College Dublin; Belfield Dublin 4 Ireland
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Erbs F, Elwen SH, Gridley T. Automatic classification of whistles from coastal dolphins of the southern African subregion. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 141:2489. [PMID: 28464668 DOI: 10.1121/1.4978000] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Passive acoustic monitoring (PAM) is commonly used to generate information on the distribution, abundance, and behavior of cetacean species. In African waters, the utilization of PAM lags behind most other continents. This study examines whether the whistles of three coastal delphinid species (Delphinus delphis, Tursiops truncatus, and Tursiops aduncus) commonly encountered in the southern African subregion can be readily distinguished using both statistical analysis of standard whistle parameters and the automated detection and classification software PAMGuard. A first account of whistles recorded from D. delphis from South Africa is included. Using PAMGuard, classification to species was high with an overall mean correct classification rate of 87.3%. Although lower, high rates of correct classification were also found (78.4%) when the two T. aduncus populations were included separately. Classification outcomes reflected patterns observed in standard whistle parameters. Such acoustic discrimination may be useful for confirmation of morphologically similar species in the field. Classification success was influenced by training and testing the classifier with data from different populations, highlighting the importance of locally collected acoustic data to inform classifiers. The small number of sampling populations may have inflated the classification success, therefore, classification trials using a greater number of species are recommended.
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Affiliation(s)
- Florence Erbs
- Sea Search Africa, 4 Bath Road, Muizenberg, Cape Town 7945, South Africa
| | - Simon H Elwen
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, South Africa
| | - Tess Gridley
- Centre for Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences, University of Cape Town, South Africa
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Heenehan HL, Tyne JA, Bejder L, Van Parijs SM, Johnston DW. Passive acoustic monitoring of coastally associated Hawaiian spinner dolphins, Stenella longirostris, ground-truthed through visual surveys. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:206. [PMID: 27475147 DOI: 10.1121/1.4955094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Effective decision making to protect coastally associated dolphins relies on monitoring the presence of animals in areas that are critical to their survival. Hawaiian spinner dolphins forage at night and rest during the day in shallow bays. Due to their predictable presence, they are targeted by dolphin-tourism. In this study, comparisons of presence were made between passive acoustic monitoring (PAM) and vessel-based visual surveys in Hawaiian spinner dolphin resting bays. DSG-Ocean passive acoustic recording devices were deployed in four bays along the Kona Coast of Hawai'i Island between January 8, 2011 and August 30, 2012. The devices sampled at 80 kHz, making 30-s recordings every four minutes. Overall, dolphins were acoustically detected on 37.1% to 89.6% of recording days depending on the bay. Vessel-based visual surveys overlapped with the PAM surveys on 202 days across the four bays. No significant differences were found between visual and acoustic detections suggesting acoustic surveys can be used as a proxy for visual surveys. Given the need to monitor dolphin presence across sites, PAM is the most suitable and efficient tool for monitoring long-term presence/absence. Concomitant photo-identification surveys are necessary to address changes in abundance over time.
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Affiliation(s)
- Heather L Heenehan
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke, University Marine Laboratory, 135 Duke Marine Lab Road, Beaufort, North Carolina 28516, USA
| | - Julian A Tyne
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
| | - Lars Bejder
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
| | - Sofie M Van Parijs
- Passive Acoustic Research Group, Northeast Fisheries Science Center, 166 Water Street, Woods Hole, Massachusetts 02543, USA
| | - David W Johnston
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke, University Marine Laboratory, 135 Duke Marine Lab Road, Beaufort, North Carolina 28516, USA
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Paudel S, Pal P, Cove MV, Jnawali SR, Abel G, Koprowski JL, Ranabhat R. The Endangered Ganges River dolphin Platanista gangetica gangetica in Nepal: abundance, habitat and conservation threats. ENDANGER SPECIES RES 2015. [DOI: 10.3354/esr00702] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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