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Ehrie AJ, Iruri-Tucker AA, Lord YB, Williamson HG, Hunt KD, Polly PD, Fitzpatrick CL, Wasserman MD. Measuring mantled howler monkey (Alouatta palliata) testes via parallel laser photogrammetry: Expanding the use of noninvasive methods. Am J Primatol 2024; 86:e23616. [PMID: 38462743 DOI: 10.1002/ajp.23616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 02/20/2024] [Accepted: 02/24/2024] [Indexed: 03/12/2024]
Abstract
Parallel laser photogrammetry (PLP), which consists of attaching two or three parallel laser beams at a known inter-beam distance to a camera, can be used to collect morphological measurements of organisms noninvasively. The lasers project onto the photo being taken, and because the inter-beam distance is known, they act as a scale for image analysis programs like ImageJ. Traditionally, this method has been used to measure larger morphological traits (e.g., limb length, crown-rump length) to serve as proxies for overall body size, whereas applications to smaller anatomical features remain limited. To that end, we used PLP to measure the testes of 18 free-living mantled howler monkeys (Alouatta palliata) at La Selva Biological Station, Costa Rica. We tested whether this method could reliably measure this relatively small and globular morphology, and whether it could detect differences among individuals. We tested reliability in three ways: within-photo (coefficient of variation [CV] = 4.7%), between-photo (CV = 5.5%), and interobserver (intraclass correlation = 0.92). We found an average volume of 36.2 cm3 and a range of 16.4-54.4 cm3, indicating variation in testes size between individuals. Furthermore, these sizes are consistent with a previous study that collected measurements by hand, suggesting that PLP is a useful method for making noninvasive measurements of testes.
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Affiliation(s)
- Austen J Ehrie
- Department of Biology, Texas A&M University, College Station, Texas, USA
- Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, Indiana, USA
| | - Alec A Iruri-Tucker
- Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, Indiana, USA
| | - Yasmin B Lord
- Department of Anthropology, Indiana University, Bloomington, Indiana, USA
| | - Heidi G Williamson
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, Texas, USA
| | - Kevin D Hunt
- Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, Indiana, USA
- Department of Anthropology, Indiana University, Bloomington, Indiana, USA
| | - P David Polly
- Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, Indiana, USA
- Department of Geology, Indiana University, Bloomington, Indiana, USA
| | | | - Michael D Wasserman
- Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, Indiana, USA
- Department of Anthropology, Indiana University, Bloomington, Indiana, USA
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2
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Richardson JL, Levy EJ, Ranjithkumar R, Yang H, Monson E, Cronin A, Galbany J, Robbins MM, Alberts SC, Reeves ME, McFarlin SC. Automated, high-throughput image calibration for parallel-laser photogrammetry. Mamm Biol 2022. [DOI: 10.1007/s42991-021-00174-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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3
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Parallel lasers and digital photography to estimate limb size of chimpanzees (Pan troglodytes) at Ngogo, Kibale National Park, Uganda. Primates 2022; 63:217-224. [DOI: 10.1007/s10329-022-00982-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/08/2022] [Indexed: 10/19/2022]
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4
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Pancaldi F, Páez-Osuna F, Marmolejo-Rodríguez AJ, Whitehead DA, González-Armas R, Soto-Jiménez MF, O'Hara T, Vazquéz-Haikin A, Galván-Magaña F. Variation of essential and non-essential trace elements in whale shark epidermis associated to two different feeding areas of the Gulf of California. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:36803-36816. [PMID: 33710489 DOI: 10.1007/s11356-021-13364-0] [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: 09/22/2020] [Accepted: 03/04/2021] [Indexed: 06/12/2023]
Abstract
The Gulf of California represents an important hotspot for whale shark (Rhincodon typus) aggregation. Anthropogenic activities and natural sources could expose sharks to high levels of trace elements (TEs). To determinate these levels in this endangered species, concentrations of As, Cd, Cu, Pb and Zn (in ng/g ww) were measured in 130 whale shark skin biopsies and 44 zooplankton samples collected from two areas of the Gulf of California, Bahía de Los Angeles (BLA) and Bahía de La Paz (LAP) during 2016-2018. For biopsies, Zn exhibited highest concentrations in BLA (2016-2017, 298 ± 406; 2017-2018, 1959 ± 2545) and at LAP (in 2016-2017, 595 ± 554; in 2017-2018, 2642 ± 1261). On the other hand, Cd (BLA 2016-2017, 3 ± 3; LAP 2016-2017, 4 ± 3; BLA 2017-2018, 17 ± 14; LAP 2017-2018, 13 ± 10) and Pb (BLA 2016-2017, 7 ± 7; LAP 2016-2017, 15 ± 32; BLA 2017-2018, 69 ± 76; LAP 2017-2018, 7 ± 5) showed lowest concentrations. Significant differences in TE concentrations between sites and periods occurred. Arsenic found in shark biopsies from La Paz suggested enrichment and/or increased bioavailability in this area. Sex alone was not a significant factor in TE concentration; nevertheless, a sex-dependent difference in correlation of TE concentration and size was noted (negative in males, positive in females). This indicates feeding strategies of whale shark may be sex and size segregated. During 2017-2018, zooplankton and sharks showed enrichment in all TEs. Essential elements were not biomagnified by sharks. Lead was biomagnified through zooplankton. Strong positive correlation between selected elements indicates that Zn, Cd and Pb follow the same metabolic route in the sharks' body.
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Affiliation(s)
- Francesca Pancaldi
- Instituto Politécnico Nacional. Centro Interdisciplinario de Ciencias Marinas, Av. IPN s/n, 23096, La Paz, BCS, Mexico
| | - Federico Páez-Osuna
- Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, 82040, Mazatlán, Sinaloa, Mexico
- Miembro de El Colegio de Sinaloa, Antonio Rosales 435 Poniente, Culiacán, Sinaloa, Mexico
| | | | | | - Rogelio González-Armas
- Instituto Politécnico Nacional. Centro Interdisciplinario de Ciencias Marinas, Av. IPN s/n, 23096, La Paz, BCS, Mexico
| | - Martin Federico Soto-Jiménez
- Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, 82040, Mazatlán, Sinaloa, Mexico
| | - Todd O'Hara
- Veterinary Integrative Biosciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Abraham Vazquéz-Haikin
- Asociación de pesca deportiva y ecoturismo de Bahía de Los Ángeles, Domicilio conocido, 22980, Bahía de Los Ángeles, Baja California, Mexico
| | - Felipe Galván-Magaña
- Instituto Politécnico Nacional. Centro Interdisciplinario de Ciencias Marinas, Av. IPN s/n, 23096, La Paz, BCS, Mexico.
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Zhao P, Liu S, Zhou Y, Lynch T, Lu W, Zhang T, Yang H. Estimating animal population size with very high-resolution satellite imagery. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2021; 35:316-324. [PMID: 32839996 DOI: 10.1111/cobi.13613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
Very high-resolution (VHR) satellite sensors can be used to estimate the size of animal populations, a critical factor in wildlife management, and acquire animal spatial distributions in an economical, easy, and precise way. We developed a method for satellite population size estimation that includes a noninvasive photogrammetry, from which the animal's average orthographic area is calculated, and an imagery interpretation method that estimates population size based on the ratio of an observed animal population area to the average individual area. As a proof of concept, we used this method to estimate the population size of Whooper Swans (Cygnus cygnus) in a national nature reserve in China. To reduce errors, the reserve was subdivided into regions of interest based on locations of Whooper Swan and background brightness. Estimates from the satellite pixels were compared with manual counts made over 2 years, at 3 locations, and in 3 land-cover types. Our results showed 1124 Whooper Swans occupied a national nature reserve on 15 February 2013, and the average percent error was 3.16% (SE = 1.37). These results demonstrate that our method produced robust data for population size estimation that were indistinguishable from manual count data. Our method may be used generally to estimate population sizes of visible and gregarious animals that exhibit high contrast relative to their environments and may inform estimations of populations in complex backgrounds.
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Affiliation(s)
- Peng Zhao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- National Marine Data & Information Service, Tianjin, 300171, China
| | - Shuming Liu
- National Marine Data & Information Service, Tianjin, 300171, China
| | - Yi Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Tim Lynch
- CSIRO Oceans and Atmosphere Flagship, Hobart, 7001, Australia
| | - Wenhu Lu
- National Marine Data & Information Service, Tianjin, 300171, China
| | - Tao Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Hongsheng Yang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
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6
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Cui S, Chen D, Sun J, Chu H, Li C, Jiang Z. A simple use of camera traps for photogrammetric estimation of wild animal traits. J Zool (1987) 2020. [DOI: 10.1111/jzo.12788] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Cui
- College of Forestry Shanxi Agricultural University Taigu Shanxi China
- Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Beijing China
- University of Chinese Academy of Sciences Beijing China
| | - D. Chen
- Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Beijing China
- University of Chinese Academy of Sciences Beijing China
| | - J. Sun
- Kanas National Nature Reserve Buerjin Xinjiang China
| | - H. Chu
- College of Resources and Environment Sciences Xinjiang University Urumqi Xinjiang China
- Mt. Kalamaili Ungulate Nature Reserve Altay Xinjiang China
| | - C. Li
- Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Beijing China
| | - Z. Jiang
- Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Beijing China
- University of Chinese Academy of Sciences Beijing China
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7
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Araujo G, Legaspi CGM, Ferber S, Murray R, Burdett K, Grundy S, Labaja J, Snow S, Yaptinchay A, Ponzo A. In-water methods reveal population dynamics of a green turtle Chelonia mydas foraging aggregation in the Philippines. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr00989] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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8
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Rohner CA, Richardson AJ, Jaine FRA, Bennett MB, Weeks SJ, Cliff G, Robinson DP, Reeve-Arnold KE, Pierce SJ. Satellite tagging highlights the importance of productive Mozambican coastal waters to the ecology and conservation of whale sharks. PeerJ 2018; 6:e4161. [PMID: 29312815 PMCID: PMC5755488 DOI: 10.7717/peerj.4161] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 11/23/2017] [Indexed: 11/25/2022] Open
Abstract
The whale shark Rhincodon typus is an endangered, highly migratory species with a wide, albeit patchy, distribution through tropical oceans. Ten aerial survey flights along the southern Mozambican coast, conducted between 2004–2008, documented a relatively high density of whale sharks along a 200 km stretch of the Inhambane Province, with a pronounced hotspot adjacent to Praia do Tofo. To examine the residency and movement of whale sharks in coastal areas around Praia do Tofo, where they may be more susceptible to gill net entanglement, we tagged 15 juveniles with SPOT5 satellite tags and tracked them for 2–88 days (mean = 27 days) as they dispersed from this area. Sharks travelled between 10 and 2,737 km (mean = 738 km) at a mean horizontal speed of 28 ± 17.1 SD km day−1. While several individuals left shelf waters and travelled across international boundaries, most sharks stayed in Mozambican coastal waters over the tracking period. We tested for whale shark habitat preferences, using sea surface temperature, chlorophyll-a concentration and water depth as variables, by computing 100 random model tracks for each real shark based on their empirical movement characteristics. Whale sharks spent significantly more time in cooler, shallower water with higher chlorophyll-a concentrations than model sharks, suggesting that feeding in productive coastal waters is an important driver of their movements. To investigate what this coastal habitat choice means for their conservation in Mozambique, we mapped gill nets during two dedicated aerial surveys along the Inhambane coast and counted gill nets in 1,323 boat-based surveys near Praia do Tofo. Our results show that, while whale sharks are capable of long-distance oceanic movements, they can spend a disproportionate amount of time in specific areas, such as along the southern Mozambique coast. The increasing use of drifting gill nets in this coastal hotspot for whale sharks is likely to be a threat to regional populations of this iconic species.
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Affiliation(s)
- Christoph A Rohner
- Manta Ray & Whale Shark Research Centre, Marine Megafauna Foundation, Praia do Tofo, Mozambique
| | - Anthony J Richardson
- CSIRO Oceans and Atmosphere, Dutton Park, QLD, Australia.,Centre for Applications in Natural Resource Mathematics (CARM), School of Mathematics and Physics, The University of Queensland, St Lucia, QLD, Australia
| | - Fabrice R A Jaine
- Manta Ray & Whale Shark Research Centre, Marine Megafauna Foundation, Praia do Tofo, Mozambique.,Sydney Institute of Marine Science, Mosman, NSW, Australia.,Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Michael B Bennett
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Scarla J Weeks
- Biophysical Oceanography Group, School of Geography, Planning and Environmental Management, The University of Queensland, St Lucia, QLD, Australia
| | - Geremy Cliff
- Kwa-Zulu Natal Sharks Board, Umhlanga, KZN, South Africa.,Biomedical Resource Unit, University of KwaZulu-Natal, Durban, KZN, South Africa
| | | | | | - Simon J Pierce
- Manta Ray & Whale Shark Research Centre, Marine Megafauna Foundation, Praia do Tofo, Mozambique
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9
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Cheney B, Wells RS, Barton TR, Thompson PM. Laser photogrammetry reveals variation in growth and early survival in free-ranging bottlenose dolphins. Anim Conserv 2017. [DOI: 10.1111/acv.12384] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- B. Cheney
- Institute of Biological and Environmental Science; University of Aberdeen; Lighthouse Field Station Cromarty UK
| | - R. S. Wells
- Sarasota Dolphin Research Program; Chicago Zoological Society, c/o Mote Marine Laboratory; Sarasota FL USA
| | - T. R. Barton
- Institute of Biological and Environmental Science; University of Aberdeen; Lighthouse Field Station Cromarty UK
| | - P. M. Thompson
- Institute of Biological and Environmental Science; University of Aberdeen; Lighthouse Field Station Cromarty UK
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10
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Norman BM, Holmberg JA, Arzoumanian Z, Reynolds SD, Wilson RP, Rob D, Pierce SJ, Gleiss AC, de la Parra R, Galvan B, Ramirez-Macias D, Robinson D, Fox S, Graham R, Rowat D, Potenski M, Levine M, Mckinney JA, Hoffmayer E, Dove ADM, Hueter R, Ponzo A, Araujo G, Aca E, David D, Rees R, Duncan A, Rohner CA, Prebble CEM, Hearn A, Acuna D, Berumen ML, Vázquez A, Green J, Bach SS, Schmidt JV, Beatty SJ, Morgan DL. Undersea Constellations: The Global Biology of an Endangered Marine Megavertebrate Further Informed through Citizen Science. Bioscience 2017. [DOI: 10.1093/biosci/bix127] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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11
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Rogers TD, Cambiè G, Kaiser MJ. Determination of size, sex and maturity stage of free swimming catsharks using laser photogrammetry. MARINE BIOLOGY 2017; 164:213. [PMID: 29104316 PMCID: PMC5651705 DOI: 10.1007/s00227-017-3241-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 10/04/2017] [Indexed: 06/07/2023]
Abstract
The lack of detailed life history (LH) information (e.g. age, growth, size at maturity, sex composition etc.) for many species of conservation importance limits the implementation of appropriate conservation measures. Typically, LH information is acquired using lethal sampling techniques, which undermines the goal of conservation. This is particularly problematic for many shark species that have low fecundity and slow growth rates. Here we tested the use of non-invasive laser photogrammetry to measure body morphometry in vivo. We used random forest classification models to identify allometric relationships (ratios between body measurements) that discriminated between the sex and stage of sexual maturity of Scyliorhinus canicula. We coupled the use of allometric ratios (determined from cadavers) with parallel laser photogrammetry, in order to collect total length (TL) and finer scale morphometrics from 37 free-swimming individuals. TL measurements proved to be accurate (SE = 5.2%) and precise (CV = 1.8%), and did not differ significantly from the known TL of the respective animal (t36 = 0.7, P = 0.5). Conditional Inference tree model predictions of free-swimming sharks correctly predicted 100% of mature males and 79% of immature males. Our results suggest that when used together, allometric ratios and parallel laser photogrammetry have the potential to be a promising alternative to collect essential life history information from free swimming animals and avoids the need for destructive sampling.
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Affiliation(s)
- Toby D. Rogers
- School of Ocean Sciences, Bangor University, Anglesey, LL59 5AB UK
| | - Giulia Cambiè
- School of Ocean Sciences, Bangor University, Anglesey, LL59 5AB UK
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Lowestoft, Suffolk NR33 0HT UK
| | - Michel J. Kaiser
- School of Ocean Sciences, Bangor University, Anglesey, LL59 5AB UK
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12
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Ryan JP, Green JR, Espinoza E, Hearn AR. Association of whale sharks (Rhincodon typus) with thermo-biological frontal systems of the eastern tropical Pacific. PLoS One 2017; 12:e0182599. [PMID: 28854201 PMCID: PMC5576648 DOI: 10.1371/journal.pone.0182599] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/23/2017] [Indexed: 11/30/2022] Open
Abstract
Satellite tracking of 27 whale sharks in the eastern tropical Pacific, examined in relation to environmental data, indicates preferential occupancy of thermo-biological frontal systems. In these systems, thermal gradients are caused by wind-forced circulation and mixing, and biological gradients are caused by associated nutrient enrichment and enhanced primary productivity. Two of the frontal systems result from upwelling, driven by divergence in the current systems along the equator and the west coast of South America; the third results from wind jet dynamics off Central America. All whale sharks were tagged near Darwin Island, Galápagos, within the equatorial Pacific upwelling system. Occupancy of frontal habitat is pronounced in synoptic patterns of shark locations in relation to serpentine, temporally varying thermal fronts across a zonal expanse > 4000 km. 80% of shark positions in northern equatorial upwelling habitat and 100% of positions in eastern boundary upwelling habitat were located within the upwelling front. Analysis of equatorial shark locations relative to thermal gradients reveals occupancy of a transition point in environmental stability. Equatorial subsurface tag data show residence in shallow, warm (>22°C) water 94% of the time. Surface zonal current speeds for all equatorial tracking explain only 16% of the variance in shark zonal movement speeds, indicating that passive drifting is not a primary determinant of movement patterns. Movement from equatorial to eastern boundary frontal zones occurred during boreal winter, when equatorial upwelling weakens seasonally. Off Peru sharks tracked upwelling frontal positions within ~100–350 km from the coast. Off Central America, the largest tagged shark (12.8 m TL) occupied an oceanic front along the periphery of the Panama wind jet. Seasonal movement from waning equatorial upwelling to productive eastern boundary habitat is consistent with underlying trophic dynamics. Persistent shallow residence in thermo-biological frontal zones suggests the role of physical-biological interactions that concentrate food resources.
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Affiliation(s)
- John P. Ryan
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
- * E-mail:
| | | | - Eduardo Espinoza
- Galápagos National Park Directorate, Puerto Ayora, Galápagos Islands, Ecuador
| | - Alex R. Hearn
- Universidad San Francisco de Quito / Galápagos Science Center, Quito, Ecuador
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13
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Farcomeni A. Fully general Chao and Zelterman estimators with application to a whale shark population. J R Stat Soc Ser C Appl Stat 2017. [DOI: 10.1111/rssc.12219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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van der Hoop JM, Corkeron P, Henry AG, Knowlton AR, Moore MJ. Predicting lethal entanglements as a consequence of drag from fishing gear. MARINE POLLUTION BULLETIN 2017; 115:91-104. [PMID: 27923466 DOI: 10.1016/j.marpolbul.2016.11.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 11/23/2016] [Accepted: 11/24/2016] [Indexed: 06/06/2023]
Abstract
Large whales are frequently entangled in fishing gear and sometimes swim while carrying gear for days to years. Entangled whales are subject to additional drag forces requiring increased thrust power and energy expenditure over time. To classify entanglement cases and aid potential disentanglement efforts, it is useful to know how long an entangled whale might survive, given the unique configurations of the gear they are towing. This study establishes an approach to predict drag forces on fishing gear that entangles whales, and applies this method to ten North Atlantic right whale cases to estimate the resulting increase in energy expenditure and the critical entanglement duration that could lead to death. Estimated gear drag ranged 11-275N. Most entanglements were resolved before critical entanglement durations (mean±SD 216±260days) were reached. These estimates can assist real-time development of disentanglement action plans and U.S. Federal Serious Injury assessments required for protected species.
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Affiliation(s)
- Julie M van der Hoop
- Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program in Oceanography and Applied Ocean Science and Engineering, Cambridge, MA 02139, USA; Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
| | - Peter Corkeron
- NOAA Fisheries, Northeast Fisheries Science Center, Woods Hole, MA 02543, USA
| | - Allison G Henry
- NOAA Fisheries, Northeast Fisheries Science Center, Woods Hole, MA 02543, USA
| | - Amy R Knowlton
- New England Aquarium, Central Wharf, Boston, MA 02110, USA
| | - Michael J Moore
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
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15
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Whale Shark (Rhincodon typus) Seasonal Occurrence, Abundance and Demographic Structure in the Mid-Equatorial Atlantic Ocean. PLoS One 2016; 11:e0164440. [PMID: 27783634 PMCID: PMC5082610 DOI: 10.1371/journal.pone.0164440] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 09/26/2016] [Indexed: 11/28/2022] Open
Abstract
Whale sharks are generally associated with environmental factors that drive their movements to specific locations where food availability is high. Consequently, foraging is believed to be the main reason for the formation of whale shark aggregations. Feeding aggregations occur mainly in nearshore areas and are composed primarily of immature individuals. Conversely, aggregations of mature adults are rarely observed, and their occurrence is correlated with oceanic environments. Despite an increase in the number of whale shark studies, information on mating and parturition grounds is still lacking. In the present work, we assessed the ecological and behavioural aspects of the whale sharks that visit the archipelago of São Pedro and São Paulo (ASPSP), located ~1,000 km off the coast of Brazil in the equatorial Atlantic Ocean. Forty-nine whale sharks were recorded from February 2005 to May 2014. The estimated mean ± SD size was 8.27 ± 2.52 m (range: 2.5–14.0 m) with no significant differences in size across the year. The maturational stages were classified by size as immature (<8.0 m; 32.56%) and mature (>9.0 m; 46.51%); with almost half of the observed animals being mature specimens. The majority of sightings occurred between February and June. During this period, the ocean current weakens and the waters are enriched by eggs and larvae of fishes and invertebrates that attract marine life to forage. At the same time, evidence of reproductive activity in adult females (i.e. swollen abdomen and bite marks on the pectoral fins), and the potential mating behaviour exhibited by one male, suggest that the ASPSP area might also have a role in whale shark reproduction. Irrespective of its use for feeding or reproduction, this insular habitat serves as a meeting point for both juvenile and adult whale sharks, and may play an important ecological role for the species.
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16
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Robinson DP, Jaidah MY, Bach S, Lee K, Jabado RW, Rohner CA, March A, Caprodossi S, Henderson AC, Mair JM, Ormond R, Pierce SJ. Population Structure, Abundance and Movement of Whale Sharks in the Arabian Gulf and the Gulf of Oman. PLoS One 2016; 11:e0158593. [PMID: 27362839 PMCID: PMC4928964 DOI: 10.1371/journal.pone.0158593] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 06/17/2016] [Indexed: 11/19/2022] Open
Abstract
Data on the occurrence of whale sharks, Rhincodon typus, in the Arabian Gulf and Gulf of Oman were collected by dedicated boat surveys and via a public-sightings scheme during the period from 2011 to 2014. A total of 422 individual whale sharks were photo-identified from the Arabian Gulf and the northern Gulf of Oman during that period. The majority of sharks (81%, n = 341) were encountered at the Al Shaheen area of Qatar, 90 km off the coast, with the Musandam region of Oman a secondary area of interest. At Al Shaheen, there were significantly more male sharks (n = 171) than females (n = 78; X2 = 17.52, P < 0.05). Mean estimated total length (TL) for sharks was 6.90 m ± 1.24 (median = 7 m; n = 296). Males (7.25 m ± 1.34; median = 8 m, n = 171) were larger than females (6.44 m ±1.09; median = 7 m, n = 78; Mann-Whitney U test, p < 0.01). Of the male sharks assessed for maturity 63% were mature (n = 81), with 50% attaining maturity by 7.29 m and 100% by 9.00 m. Two female sharks of >9 m individuals were visually assessed as pregnant. Connectivity among sharks sighted in Qatari, Omani and UAE waters was confirmed by individual spot pattern matches. A total of 13 identified sharks were re-sighted at locations other than that at which they were first sighted, including movements into and out of the Arabian Gulf through the Strait of Hormuz. Maximum likelihood techniques were used to model an estimated combined population for the Arabian Gulf and Gulf of Oman of 2837 sharks ± 1243.91 S.E. (95% C.I. 1720-6295). The Al Shaheen aggregation is thus the first site described as being dominated by mature males while the free-swimming pregnant females are the first reported from the Indian Ocean.
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Affiliation(s)
- David P. Robinson
- Heriot-Watt University, Edinburgh, United Kingdom
- Sharkwatch Arabia, Dubai, UAE
- * E-mail:
| | | | - Steffen Bach
- Maersk Oil Research and Technology Centre, Doha, Qatar
| | - Katie Lee
- Environment Department, University of York, York, United Kingdom
| | | | | | - Abi March
- Environment Department, University of York, York, United Kingdom
| | | | | | | | - Rupert Ormond
- Heriot-Watt University, Edinburgh, United Kingdom
- Marine Conservation International, Edinburgh, United Kingdom
| | - Simon J. Pierce
- Marine Megafauna Foundation, Truckee, CA, United States of America
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17
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Raoult V, David PA, Dupont SF, Mathewson CP, O'Neill SJ, Powell NN, Williamson JE. GoPros™ as an underwater photogrammetry tool for citizen science. PeerJ 2016; 4:e1960. [PMID: 27168973 PMCID: PMC4860335 DOI: 10.7717/peerj.1960] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/01/2016] [Indexed: 12/02/2022] Open
Abstract
Citizen science can increase the scope of research in the marine environment; however, it suffers from necessitating specialized training and simplified methodologies that reduce research output. This paper presents a simplified, novel survey methodology for citizen scientists, which combines GoPro imagery and structure from motion to construct an ortho-corrected 3D model of habitats for analysis. Results using a coral reef habitat were compared to surveys conducted with traditional snorkelling methods for benthic cover, holothurian counts, and coral health. Results were comparable between the two methods, and structure from motion allows the results to be analysed off-site for any chosen visual analysis. The GoPro method outlined in this study is thus an effective tool for citizen science in the marine environment, especially for comparing changes in coral cover or volume over time.
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Affiliation(s)
- Vincent Raoult
- Biological Sciences, Macquarie University , Sydney NSW , Australia
| | - Peter A David
- Biological Sciences, Macquarie University , Sydney NSW , Australia
| | - Sally F Dupont
- Biological Sciences, Macquarie University , Sydney NSW , Australia
| | | | - Samuel J O'Neill
- Biological Sciences, Macquarie University , Sydney NSW , Australia
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18
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Sequeira AMM, Thums M, Brooks K, Meekan MG. Error and bias in size estimates of whale sharks: implications for understanding demography. ROYAL SOCIETY OPEN SCIENCE 2016; 3:150668. [PMID: 27069656 PMCID: PMC4821267 DOI: 10.1098/rsos.150668] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 02/18/2016] [Indexed: 05/30/2023]
Abstract
Body size and age at maturity are indicative of the vulnerability of a species to extinction. However, they are both difficult to estimate for large animals that cannot be restrained for measurement. For very large species such as whale sharks, body size is commonly estimated visually, potentially resulting in the addition of errors and bias. Here, we investigate the errors and bias associated with total lengths of whale sharks estimated visually by comparing them with measurements collected using a stereo-video camera system at Ningaloo Reef, Western Australia. Using linear mixed-effects models, we found that visual lengths were biased towards underestimation with increasing size of the shark. When using the stereo-video camera, the number of larger individuals that were possibly mature (or close to maturity) that were detected increased by approximately 10%. Mean lengths calculated by each method were, however, comparable (5.002 ± 1.194 and 6.128 ± 1.609 m, s.d.), confirming that the population at Ningaloo is mostly composed of immature sharks based on published lengths at maturity. We then collated data sets of total lengths sampled from aggregations of whale sharks worldwide between 1995 and 2013. Except for locations in the East Pacific where large females have been reported, these aggregations also largely consisted of juveniles (mean lengths less than 7 m). Sightings of the largest individuals were limited and occurred mostly prior to 2006. This result highlights the urgent need to locate and quantify the numbers of mature male and female whale sharks in order to ascertain the conservation status and ensure persistence of the species.
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Affiliation(s)
- Ana M. M. Sequeira
- IOMRC and The UWA Oceans Institute, School of Animal Biology and Centre for Marine Futures, University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Michele Thums
- School of Civil, Environmental and Mining Engineering and UWA Oceans Institute, University of Western Australia (M470), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
- Australian Institute of Marine Science, c/o UWA Oceans Institute (MO96), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Kim Brooks
- Australian Institute of Marine Science, c/o UWA Oceans Institute (MO96), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Mark G. Meekan
- Australian Institute of Marine Science, c/o UWA Oceans Institute (MO96), 35 Stirling Highway, Crawley, Western Australia 6009, Australia
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19
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O'Connell CP, Leurs G. A minimally invasive technique to assess several life-history characteristics of the endangered great hammerhead shark Sphyrna mokarran. JOURNAL OF FISH BIOLOGY 2016; 88:1257-1264. [PMID: 26832609 DOI: 10.1111/jfb.12900] [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: 06/28/2015] [Accepted: 12/17/2015] [Indexed: 06/05/2023]
Abstract
A dorsal-fin photo-identification technique paired with a non-invasive parallel laser photogrammetry technique was used to non-invasively identify individual Sphyrna mokarran over time. Based on the data collected over a duration of 59 days, 16 different S. mokarran (mean ± S.D. pre-caudal length: 220·82 ± 13·66 cm; mean ± S.D. cephalofoil width: 71·38 ± 7·94 cm) were identified using dorsal-fin photo-identification, with a mean ± S.D. shark re-sighting frequency of 4·05 ± 3·06 at-sea days. The results illustrate a high S. mokarran sighting rate and therefore, the utilization of parallel laser photogrammetry and dorsal-fin photo-identification may be a plausible multi-year approach to aid in non-invasively determining the growth rate and inter-annual site fidelity of these animals.
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Affiliation(s)
- C P O'Connell
- O'Seas Conservation Foundation, Inc., Yonkers, NY, 10701, U.S.A
| | - G Leurs
- Wageningen University and Research Centre, Wageningen, Netherlands
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20
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Leurs G, O'Connell CP, Andreotti S, Rutzen M, Vonk Noordegraaf H. Risks and advantages of using surface laser photogrammetry on free-ranging marine organisms: a case study on white sharks Carcharodon carcharias. JOURNAL OF FISH BIOLOGY 2015; 86:1713-1728. [PMID: 25903107 DOI: 10.1111/jfb.12678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 03/01/2015] [Indexed: 06/04/2023]
Abstract
This study employed a non-lethal measurement tool, which combined an existing photo-identification technique with a surface, parallel laser photogrammetry technique, to accurately estimate the size of free-ranging white sharks Carcharodon carcharias. Findings confirmed the hypothesis that surface laser photogrammetry is more accurate than crew-based estimations that utilized a shark cage of known size as a reference tool. Furthermore, field implementation also revealed that the photographer's angle of reference and the shark's body curvature could greatly influence technique accuracy, exposing two limitations. The findings showed minor inconsistencies with previous studies that examined pre-caudal to total length ratios of dead specimens. This study suggests that surface laser photogrammetry can successfully increase length estimation accuracy and illustrates the potential utility of this technique for growth and stock assessments on free-ranging marine organisms, which will lead to an improvement of the adaptive management of the species.
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Affiliation(s)
- G Leurs
- Applied Biology, HAS University of Applied Sciences, 's-Hertogenbosch, 5200 MA, The Netherlands
| | - C P O'Connell
- School of Marine Science and Technology, University of Massachusetts Dartmouth, New Bedford, MA 02740, U.S.A
- O'Seas Conservation Foundation, Bronx, NY 10463, U.S.A
| | - S Andreotti
- Evolutionary Genomics Group, Department of Botany and Zoology, Private Bag X1, Stellenbosch University, Stellenbosch 7600, South Africa
| | - M Rutzen
- Shark Diving Unlimited, Kleinbaai, Gansbaai 7220, South Africa
| | - H Vonk Noordegraaf
- Applied Biology, HAS University of Applied Sciences, 's-Hertogenbosch, 5200 MA, The Netherlands
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21
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Barrickman NL, Schreier AL, Glander KE. Testing parallel laser image scaling for remotely measuring body dimensions on mantled howling monkeys (Alouatta palliata). Am J Primatol 2015; 77:823-32. [DOI: 10.1002/ajp.22416] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 02/02/2015] [Accepted: 03/13/2015] [Indexed: 11/08/2022]
Affiliation(s)
| | | | - Kenneth E. Glander
- Department of Evolutionary Anthropology; Duke University; Durham North Carolina
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22
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Rohner CA, Richardson AJ, Prebble CEM, Marshall AD, Bennett MB, Weeks SJ, Cliff G, Wintner SP, Pierce SJ. Laser photogrammetry improves size and demographic estimates for whale sharks. PeerJ 2015; 3:e886. [PMID: 25870776 PMCID: PMC4393817 DOI: 10.7717/peerj.886] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 03/19/2015] [Indexed: 11/20/2022] Open
Abstract
Whale sharks Rhincodon typus are globally threatened, but a lack of biological and demographic information hampers an accurate assessment of their vulnerability to further decline or capacity to recover. We used laser photogrammetry at two aggregation sites to obtain more accurate size estimates of free-swimming whale sharks compared to visual estimates, allowing improved estimates of biological parameters. Individual whale sharks ranged from 432-917 cm total length (TL) (mean ± SD = 673 ± 118.8 cm, N = 122) in southern Mozambique and from 420-990 cm TL (mean ± SD = 641 ± 133 cm, N = 46) in Tanzania. By combining measurements of stranded individuals with photogrammetry measurements of free-swimming sharks, we calculated length at 50% maturity for males in Mozambique at 916 cm TL. Repeat measurements of individual whale sharks measured over periods from 347-1,068 days yielded implausible growth rates, suggesting that the growth increment over this period was not large enough to be detected using laser photogrammetry, and that the method is best applied to estimating growth rates over longer (decadal) time periods. The sex ratio of both populations was biased towards males (74% in Mozambique, 89% in Tanzania), the majority of which were immature (98% in Mozambique, 94% in Tanzania). The population structure for these two aggregations was similar to most other documented whale shark aggregations around the world. Information on small (<400 cm) whale sharks, mature individuals, and females in this region is lacking, but necessary to inform conservation initiatives for this globally threatened species.
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Affiliation(s)
- Christoph A Rohner
- Marine Megafauna Foundation , Praia do Tofo Inhambane , Mozambique ; CSIRO Oceans and Atmosphere Flagship , Brisbane Queensland , Australia
| | - Anthony J Richardson
- CSIRO Oceans and Atmosphere Flagship , Brisbane Queensland , Australia ; Centre for Applications in Natural Resource Mathematics (CARM), School of Mathematics and Physics, The University of Queensland , St Lucia Queensland , Australia
| | | | - Andrea D Marshall
- Marine Megafauna Foundation , Praia do Tofo Inhambane , Mozambique ; Wild Me , Praia do Tofo Inhambane , Mozambique
| | - Michael B Bennett
- School of Biomedical Sciences, The University of Queensland , St Lucia Queensland , Australia
| | - Scarla J Weeks
- Biophysical Oceanography Group, School of Geography, Planning and Environmental Management, The University of Queensland , St Lucia Queensland , Australia
| | - Geremy Cliff
- KwaZulu-Natal Sharks Board , Umhlanga , South Africa ; Biomedical Resource Unit, University of KwaZulu-Natal , Durban , South Africa
| | - Sabine P Wintner
- KwaZulu-Natal Sharks Board , Umhlanga , South Africa ; Biomedical Resource Unit, University of KwaZulu-Natal , Durban , South Africa
| | - Simon J Pierce
- Marine Megafauna Foundation , Praia do Tofo Inhambane , Mozambique ; Wild Me , Praia do Tofo Inhambane , Mozambique
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23
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Williams JL, Pierce SJ, Fuentes MMPB, Hamann M. Effectiveness of recreational divers for monitoring sea turtle populations. ENDANGER SPECIES RES 2015. [DOI: 10.3354/esr00647] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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24
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McClain CR, Balk MA, Benfield MC, Branch TA, Chen C, Cosgrove J, Dove ADM, Gaskins L, Helm RR, Hochberg FG, Lee FB, Marshall A, McMurray SE, Schanche C, Stone SN, Thaler AD. Sizing ocean giants: patterns of intraspecific size variation in marine megafauna. PeerJ 2015; 3:e715. [PMID: 25649000 PMCID: PMC4304853 DOI: 10.7717/peerj.715] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 12/10/2014] [Indexed: 11/20/2022] Open
Abstract
What are the greatest sizes that the largest marine megafauna obtain? This is a simple question with a difficult and complex answer. Many of the largest-sized species occur in the world’s oceans. For many of these, rarity, remoteness, and quite simply the logistics of measuring these giants has made obtaining accurate size measurements difficult. Inaccurate reports of maximum sizes run rampant through the scientific literature and popular media. Moreover, how intraspecific variation in the body sizes of these animals relates to sex, population structure, the environment, and interactions with humans remains underappreciated. Here, we review and analyze body size for 25 ocean giants ranging across the animal kingdom. For each taxon we document body size for the largest known marine species of several clades. We also analyze intraspecific variation and identify the largest known individuals for each species. Where data allows, we analyze spatial and temporal intraspecific size variation. We also provide allometric scaling equations between different size measurements as resources to other researchers. In some cases, the lack of data prevents us from fully examining these topics and instead we specifically highlight these deficiencies and the barriers that exist for data collection. Overall, we found considerable variability in intraspecific size distributions from strongly left- to strongly right-skewed. We provide several allometric equations that allow for estimation of total lengths and weights from more easily obtained measurements. In several cases, we also quantify considerable geographic variation and decreases in size likely attributed to humans.
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Affiliation(s)
- Craig R McClain
- National Evolutionary Synthesis Center , Durham, NC , USA ; Department of Biology, Duke University , Durham, NC , USA
| | - Meghan A Balk
- Department of Biology, University of New Mexico , Albuquerque, NM , USA
| | - Mark C Benfield
- Department of Oceanography and Coastal Sciences, Louisiana State University , Baton Rouge, LA , USA
| | - Trevor A Branch
- School of Aquatic & Fishery Sciences, University of Washington , Seattle, WA , USA
| | - Catherine Chen
- Department of Biology, Duke University , Durham, NC , USA
| | - James Cosgrove
- Natural History Section, Royal British Columbia Museum , Victoria, BC , Canada
| | | | - Leo Gaskins
- Department of Biology, Duke University , Durham, NC , USA
| | - Rebecca R Helm
- Department of Ecology and Evolutionary Biology, Brown University , Providence, RI , USA
| | - Frederick G Hochberg
- Department of Invertebrate Zoology, Santa Barbara Museum of Natural History , Santa Barbara, CA , USA
| | - Frank B Lee
- Department of Biology, Duke University , Durham, NC , USA
| | | | - Steven E McMurray
- Department of Biology and Marine Biology, University of North Carolina Wilmington , Wilmington, NC , USA
| | | | - Shane N Stone
- Department of Biology, Duke University , Durham, NC , USA
| | - Andrew D Thaler
- Blackbeard Biologic: Science and Environmental Advisors , Vallejo, CA , USA
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25
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Acuña-Marrero D, Jiménez J, Smith F, Doherty PF, Hearn A, Green JR, Paredes-Jarrín J, Salinas-de-León P. Whale shark (Rhincodon typus) seasonal presence, residence time and habitat use at darwin island, galapagos marine reserve. PLoS One 2014; 9:e115946. [PMID: 25551553 PMCID: PMC4281130 DOI: 10.1371/journal.pone.0115946] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 11/27/2014] [Indexed: 11/18/2022] Open
Abstract
The life history of the whale shark (Rhincodon typus), including its reproductive ecology, still remains largely unknown. Here, we present results from the first whale shark population study around Darwin Island, Galapagos Marine Reserve. Following a diversified approach we characterized seasonal occurrence, population structure and size, and described habitat use of whale sharks based on fine scale movements around the island. Whale shark presence at Darwin Island was negatively correlated with Sea Surface Temperature (SST), with highest abundance corresponding to a cool season between July and December over six years of monitoring. From 2011 to 2013 we photo-identified 82 whale sharks ranging from 4 to 13.1 m Total Length (TL). Size distribution was bimodal, with a great majority (91.5%) of adult female individuals averaging 11.35 m±0.12 m (TL±SE), all but one showing signs of a potential pregnancy. Population dynamics models for apparently pregnant sharks estimated the presence of 3.76±0.90 (mean ± SE) sharks in the study area per day with an individual residence time of 2.09±0.51 (mean ± SE) days. Movement patterns analysis of four apparently pregnant individuals tracked with acoustic tags at Darwin Island revealed an intense use of Darwin's Arch, where no feeding or specific behavior has been recorded, together with periodic excursions around the island's vicinity. Sharks showed a preference for intermediate depths (20-30 m) with occasional dives mostly to mid-water, remaining the majority of their time at water temperatures between 24-25°C. All of our results point to Darwin Island as an important stopover in a migration, possibly with reproductive purposes, rather than an aggregation site. Current studies carried out in this area to investigate regional scale movement patterns may provide essential information about possible pupping grounds for this enigmatic species.
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Affiliation(s)
| | - Jesús Jiménez
- Charles Darwin Research Station, Puerto Ayora, Galapagos Islands, Ecuador
| | - Franz Smith
- Charles Darwin Research Station, Puerto Ayora, Galapagos Islands, Ecuador
| | - Paul F. Doherty
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Alex Hearn
- Turtle Island Restoration Network, Olema, California, United States of America
| | - Jonathan R. Green
- Charles Darwin Research Station, Puerto Ayora, Galapagos Islands, Ecuador
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26
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Jadejaroen J, Hamada Y, Kawamoto Y, Malaivijitnond S. Use of photogrammetry as a means to assess hybrids of rhesus (Macaca mulatta) and long-tailed (M. fascicularis) macaques. Primates 2014; 56:77-88. [DOI: 10.1007/s10329-014-0450-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 09/30/2014] [Indexed: 01/30/2023]
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27
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Abstract
AbstractThe whale shark Rhincodon typus is a popular focal species in the marine tourism industry. We analysed 689 encounters with at least 142 individual sharks during 2008–2010 to assess their behaviour in the presence of swimmers at Tofo Beach, Mozambique. Sharks varied in size (estimated 3.0–9.5 m total length) and the majority (74%) were males. The sharks displayed avoidance behaviours during 64.7% of encounters. Encounter duration decreased significantly, from 12 minutes 37 s with undisturbed sharks to 8 minutes 25 s when sharks expressed avoidance behaviours, indicating that interactions with tourists affected the sharks’ short-term behaviour. However, during the 2.5-year study period we found no trend in the mean encounter duration, the overall expression of avoidance behaviour or the likelihood of an individual shark exhibiting avoidance behaviours. Potential effects of tourism may be mitigated by the non-breeding status and transient behaviour of sharks at this aggregation site.
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28
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Araujo G, Lucey A, Labaja J, So CL, Snow S, Ponzo A. Population structure and residency patterns of whale sharks, Rhincodon typus, at a provisioning site in Cebu, Philippines. PeerJ 2014; 2:e543. [PMID: 25279256 PMCID: PMC4179391 DOI: 10.7717/peerj.543] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/06/2014] [Indexed: 12/01/2022] Open
Abstract
This study represents the first description of whale sharks, Rhincodon typus, occurring at a provisioning site in Oslob, Cebu, Philippines. Frequent observations of sharks are often difficult, even at tourism sites, giving rise to provisioning activities to attract them. The present study provides repeated longitudinal data at a site where daily provisioning activities took place, and whale sharks were present every day. A total of 158 individual whale sharks were photographically identified between Mar 2012 and Dec 2013, with 129 males (82%), 19 females (12%) and 10 (6%) of undetermined sex. Mean estimated total length was 5.5 m (±1.3 m S.D.). Twenty individuals were measured with laser photogrammetry to validate researchers’ estimated sizes, yielding a good correlation (r2 = 0.83). Fifty-four (34%) individuals were observed being hand-fed by local fishermen (provisioned), through in-water behavioural observations. Maximum likelihood methods were used to model mean residency time of 44.9 days (±20.6 days S.E.) for provisioned R. typus contrasting with 22.4 days (±8.9 days S.E.) for non-provisioned individuals. Propeller scars were observed in 47% of the animals. A mean of 12.7 (±4.3 S.D.) R. typus were present in the survey area daily, with a maximum of 26 individuals (Aug 10 2013) and a minimum of 2 (Dec 6 2012). Twelve (8%) individuals were seen on at least 50% of survey days (n = 621), with a maximum residency of 572 days for one individual (P-396). Twenty four individuals were photographically identified across regional hotsposts, highlighting the species’ migratory nature and distribution. Extended residency and differences in lagged identification rates suggest behavioural modification on provisioned individuals, underlying the necessity for proper management of this tourism activity.
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Affiliation(s)
- Gonzalo Araujo
- Large Marine Vertebrates Research Institute Philippines , Jagna, Bohol , Philippines ; Physalus NGO, Large Marine Vertebrates Project Philippines , Largo Callifonte, Rome , Italy
| | - Anna Lucey
- Large Marine Vertebrates Research Institute Philippines , Jagna, Bohol , Philippines
| | - Jessica Labaja
- Large Marine Vertebrates Research Institute Philippines , Jagna, Bohol , Philippines
| | - Catherine Lee So
- Large Marine Vertebrates Research Institute Philippines , Jagna, Bohol , Philippines
| | - Sally Snow
- Large Marine Vertebrates Research Institute Philippines , Jagna, Bohol , Philippines
| | - Alessandro Ponzo
- Large Marine Vertebrates Research Institute Philippines , Jagna, Bohol , Philippines ; Physalus NGO, Large Marine Vertebrates Project Philippines , Largo Callifonte, Rome , Italy
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29
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Fox S, Foisy I, De La Parra Venegas R, Galván Pastoriza BE, Graham RT, Hoffmayer ER, Holmberg J, Pierce SJ. Population structure and residency of whale sharks Rhincodon typus at Utila, Bay Islands, Honduras. JOURNAL OF FISH BIOLOGY 2013; 83:574-87. [PMID: 23991875 DOI: 10.1111/jfb.12195] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 06/13/2013] [Indexed: 05/26/2023]
Abstract
There were 479 reported whale shark Rhincodon typus encounters between 1999 and 2011 at the island of Utila, which forms part of the Meso-American Barrier Reef System (MBRS) in the western Caribbean Sea. The majority of R. typus were found to feed on small bait fish associated with various tuna species. Ninety-five individual R. typus, ranging from 2 to 11 m total length (LT ), were identified through their unique spot patterns. A significant male bias (65%) was present. There was no significant difference between the mean ± s.d. LT of female (6·66 ± 1·65 m) and male (6·25 ± 1·60 m) R. typus. Most R. typus were transient to Utila, with 78% sighted only within a single calendar year, although some individuals were sighted in up to 5 years. Mean residency time was modelled to be 11·76 days using maximum likelihood methods.
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Affiliation(s)
- S Fox
- Utila Whale Shark Research, Utila, Honduras
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30
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Couturier LIE, Marshall AD, Jaine FRA, Kashiwagi T, Pierce SJ, Townsend KA, Weeks SJ, Bennett MB, Richardson AJ. Biology, ecology and conservation of the Mobulidae. JOURNAL OF FISH BIOLOGY 2012; 80:1075-1119. [PMID: 22497374 DOI: 10.1111/j.1095-8649.2012.03264.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The Mobulidae are zooplanktivorous elasmobranchs comprising two recognized species of manta rays (Manta spp.) and nine recognized species of devil rays (Mobula spp.). They are found circumglobally in tropical, subtropical and temperate coastal waters. Although mobulids have been recorded for over 400 years, critical knowledge gaps still compromise the ability to assess the status of these species. On the basis of a review of 263 publications, a comparative synthesis of the biology and ecology of mobulids was conducted to examine their evolution, taxonomy, distribution, population trends, movements and aggregation, reproduction, growth and longevity, feeding, natural mortality and direct and indirect anthropogenic threats. There has been a marked increase in the number of published studies on mobulids since c. 1990, particularly for the genus Manta, although the genus Mobula remains poorly understood. Mobulid species have many common biological characteristics although their ecologies appear to be species-specific, and sometimes region-specific. Movement studies suggest that mobulids are highly mobile and have the potential to rapidly travel large distances. Fishing pressure is the major threat to many mobulid populations, with current levels of exploitation in target fisheries unlikely to be sustainable. Advances in the fields of population genetics, acoustic and satellite tracking, and stable-isotope and fatty-acid analyses will provide new insights into the biology and ecology of these species. Future research should focus on the uncertain taxonomy of mobulid species, the degree of overlap between their large-scale movement and human activities such as fisheries and pollution, and the need for management of inter-jurisdictional fisheries in developing nations to ensure their long-term sustainability. Closer collaboration among researchers worldwide is necessary to ensure standardized sampling and modelling methodologies to underpin global population estimates and status.
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Affiliation(s)
- L I E Couturier
- School of Biomedical Sciences, The University of Queensland, St Lucia, Qld 4072, Australia.
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Marshall AD, Pierce SJ. The use and abuse of photographic identification in sharks and rays. JOURNAL OF FISH BIOLOGY 2012; 80:1361-79. [PMID: 22497388 DOI: 10.1111/j.1095-8649.2012.03244.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The use of photography to discriminate between individuals in a population using natural markings or aberrations is increasingly being utilized to support field research on elasmobranchs. This non-intrusive method has facilitated investigation of a wide variety of subjects including population composition, abundance estimates, residency and movement, demography and social behaviours. Here the first detailed review of photo-identification as a research technique for sharks and rays is provided, and its assumptions, current applications and potential highlighted. The limitations and practical considerations of photographic studies are also investigated with recommendations on initial survey design and ongoing data collection using current technology. Future directions are also explored with an emphasis on a move towards standardized approaches and automated recognition programmes to facilitate global collaborative work.
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Affiliation(s)
- A D Marshall
- Manta Ray & Whale Shark Research Centre, Marine Megafauna Association, Tofo Beach, Inhambane, Mozambique.
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Rowat D, Brooks KS. A review of the biology, fisheries and conservation of the whale shark Rhincodon typus. JOURNAL OF FISH BIOLOGY 2012; 80:1019-56. [PMID: 22497372 DOI: 10.1111/j.1095-8649.2012.03252.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Although the whale shark Rhincodon typus is the largest extant fish, it was not described until 1828 and by 1986 there were only 320 records of this species. Since then, growth in tourism and marine recreation globally has lead to a significant increase in the number of sightings and several areas with annual occurrences have been identified, spurring a surge of research on the species. Simultaneously, there was a great expansion in targeted R. typus fisheries to supply the Asian restaurant trade, as well as a largely un-quantified by-catch of the species in purse-seine tuna fisheries. Currently R. typus is listed by the IUCN as vulnerable, due mainly to the effects of targeted fishing in two areas. Photo-identification has shown that R. typus form seasonal size and sex segregated feeding aggregations and that a large proportion of fish in these aggregations are philopatric in the broadest sense, tending to return to, or remain near, a particular site. Somewhat conversely, satellite tracking studies have shown that fish from these aggregations can migrate at ocean-basin scales and genetic studies have, to date, found little graphic differentiation globally. Conservation approaches are now informed by observational and environmental studies that have provided insight into the feeding habits of the species and its preferred habitats. Notwithstanding these advances, there remain notable gaps in the knowledge of this species particularly with respect to the life history of neonates and adults who are not found in the feeding aggregations.
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Affiliation(s)
- D Rowat
- Marine Conservation Society Seychelles, P. O. Box 1299, Victoria, Mahe, Seychelles.
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