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Vossgaetter L, Dudeck T, Crouch J, Cope M, Ivanova T, Siyan I, Niyaz A, Riyaz M, Araujo G. Non-invasive methods characterise the world's largest tiger shark aggregation in Fuvahmulah, Maldives. Sci Rep 2024; 14:21998. [PMID: 39313535 PMCID: PMC11420367 DOI: 10.1038/s41598-024-73079-3] [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: 04/08/2024] [Accepted: 09/13/2024] [Indexed: 09/25/2024] Open
Abstract
Tiger sharks are apex predators with a circumglobal tropical and warm-temperate distribution, with a general lack of population data for the central Indian Ocean. In Fuvahmulah, Maldives, tiger sharks display frequent use of the harbour area, attracted by discarded fish waste. Here, we document the population structure, residency, and reproductive characteristics of the world's largest known tiger shark aggregation in a geographically-restricted area. Using non-invasive methods, photo identification and laser photogrammetry, we identified 239 individual tiger sharks over a 7-year study period. The aggregation was female-dominated (84.5%), with both large juveniles and adults present. Adult females were resighted over the entire study period displaying strong inter- and intra-annual site fidelity. Modelled residency using maximum likelihood methods suggests they spent 60.7 ± S.E. 7.5 days in Fuvahmulah, with a larger aggregation size, shorter residence periods and longer absence periods compared to juvenile females. Prolonged abdominal distensions of adult females indicate they likely stay near Fuvahmulah during gestation and reproduce biennially. Fuvahmulah seems to provide suitable conditions for gestation given the year-round provision of food and warm waters, exhibited by strong site fidelity and temporal residency. Our results show indications of a thriving population within the confines of protected waters.
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Affiliation(s)
- Lennart Vossgaetter
- Leibniz Centre for Tropical Marine Research, 28334, Bremen, Germany.
- University of Bremen, 28334, Bremen, Germany.
| | - Tim Dudeck
- Leibniz Centre for Tropical Marine Research, 28334, Bremen, Germany
- University of Bremen, 28334, Bremen, Germany
| | - Jamie Crouch
- Fuvahmulah Dive School, Fuvahmulah, 18011, Maldives
| | - Maiah Cope
- Fuvahmulah Dive School, Fuvahmulah, 18011, Maldives
| | | | | | | | | | - Gonzalo Araujo
- Marine Research and Conservation Foundation, Lydeard St Lawrence, Somerset, UK
- Environmental Science Program, Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
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2
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Espinoza M, Quesada-Perez F, Madrigal-Mora S, Naranjo-Elizondo B, Clarke TM, Cortés J. A decade of submersible observations revealed temporal trends in elasmobranchs in a remote island of the Eastern Tropical Pacific Ocean. Sci Rep 2024; 14:13786. [PMID: 38877056 PMCID: PMC11178919 DOI: 10.1038/s41598-024-64157-7] [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: 10/30/2023] [Accepted: 06/05/2024] [Indexed: 06/16/2024] Open
Abstract
No-take marine protected areas (MPAs) can mitigate the effects of overfishing, climate change and habitat degradation, which are leading causes of an unprecedented global biodiversity crisis. However, assessing the effectiveness of MPAs, especially in remote oceanic islands, can be logistically challenging and often restricted to relatively shallow and accessible environments. Here, we used a long-term dataset (2010-2019) collected by the DeepSee submersible of the Undersea Hunter Group that operates in Isla del Coco National Park, Costa Rica, to (1) determine the frequency of occurrence of elasmobranch species at two depth intervals (50-100 m; 300-400 m), and (2) investigate temporal trends in the occurrence of common elasmobranch species between 2010 and 2019, as well as potential drivers of the observed changes. Overall, we observed 17 elasmobranch species, 15 of which were recorded on shallow dives (50-100 m) and 11 on deep dives (300-400 m). We found a decreasing trend in the probability of occurrence of Carcharhinus falciformis over time (2010-2019), while other species (e.g. Taeniurops meyeni, Sphyrna lewini, Carcharhinus galapagensis, Triaenodon obesus, and Galeocerdo cuvier) showed an increasing trend. Our study suggests that some species like S. lewini may be shifting their distributions towards deeper waters in response to ocean warming but may also be sensitive to low oxygen levels at greater depths. These findings highlight the need for regional 3D environmental information and long-term deepwater surveys to understand the extent of shark and ray population declines in the ETP and other regions, as most fishery-independent surveys from data-poor countries have been limited to relatively shallow waters.
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Affiliation(s)
- Mario Espinoza
- Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San Pedro, San José, 11501-2060, Costa Rica.
- Escuela de Biología, Universidad de Costa Rica, San Pedro, San José, 11501-2060, Costa Rica.
- MigraMar, Bodega Bay, CA, 94923, USA.
| | - Fabio Quesada-Perez
- Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San Pedro, San José, 11501-2060, Costa Rica
| | | | - Beatriz Naranjo-Elizondo
- Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San Pedro, San José, 11501-2060, Costa Rica
- MigraMar, Bodega Bay, CA, 94923, USA
- Centro de Investigación en Estructuras Microscópicas (CIEMic), Universidad de Costa Rica, San Pedro, San José, 11501-2060, Costa Rica
- Pelagos Okeanos, Moravia, San José, 11401, Costa Rica
| | - Tayler M Clarke
- Changing Ocean Research Unit, Institute for the Oceans and Fisheries, University of British Columbia, AERL, 2202 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Jorge Cortés
- Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San Pedro, San José, 11501-2060, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San Pedro, San José, 11501-2060, Costa Rica
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Coghlan AR, Morales N. New shark in the park: Tiger shark Galeocerdo cuvier observations in the remote South Pacific. JOURNAL OF FISH BIOLOGY 2024; 104:2098-2101. [PMID: 38556875 DOI: 10.1111/jfb.15737] [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: 01/29/2024] [Revised: 03/05/2024] [Accepted: 03/11/2024] [Indexed: 04/02/2024]
Abstract
We present the first photographic records of the tiger shark (Galeocerdo cuvier) at the remote Rapa Nui (Easter Island) in the south-east Pacific. Previous anecdotal sightings exist for tiger sharks in this region; however these records have not been reported within the scientific domain. The present sighting occurred in a period of unusually warm sea surface temperature, which has been shown to influence tiger shark range extensions elsewhere. Novel and historic species occurrence records are valuable for determining and predicting species' environmental tolerances, migratory routes, and distributional limits.
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Affiliation(s)
- Amy Rose Coghlan
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Naiti Morales
- Millennium Nucleus for Ecology and Sustainable Management of Oceanic Islands (ESMOI). Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
- Instituto de Fomento Pesquero (IFOP), Valparaíso, Chile
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4
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Kohler J, Gore M, Ormond R, Johnson B, Austin T. Individual residency behaviours and seasonal long-distance movements in acoustically tagged Caribbean reef sharks in the Cayman Islands. PLoS One 2023; 18:e0293884. [PMID: 38011196 PMCID: PMC10681323 DOI: 10.1371/journal.pone.0293884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/23/2023] [Indexed: 11/29/2023] Open
Abstract
Understanding how reef-associated sharks use coastal waters through their ontogeny is important for their effective conservation and management. This study used the horizontal movements of acoustically tagged Caribbean reef sharks (Carcharhinus perezi) to examine their use of coastal space around the Cayman Islands between 2009 and 2019. A total of 39 (59.1%) tagged sharks (male = 22, female = 17, immature = 18, mature = 21) were detected on the islands wide network of acoustic receivers. The detection data were used to calculate values of Residency Index (RI), Site-Fidelity Index (SFI) and minimum linear displacement (MLD), as well as for network analysis of individual shark movements to test for differences between demographics, seasons, and diel periods. Sharks were detected for up to 1,598 days post-tagging and some individuals showed resident behaviour but the majority of tagged individuals appear to have been one-off or only occasional transient visitors to the area. Generally, individuals showed strong site-fidelity to different areas displaying linear home ranges of < 20 km. The evidence indicates that there was no pattern of diel behaviour. Tagged sharks generally showed increased movements within and between islands during the summer (April-September), which may be related to breeding activity. Some individuals even made occasional excursions across 110 km of open water > 2,000 m deep between Grand Cayman and Little Cayman. One mature female shark showed a displacement of 148.21 km, the greatest distance reported for this species. The data shows that the distances over which some sharks moved, greatly exceeded the extent of any one of the islands' marine protected areas indicating that this species may be more mobile and dispersive than previously thought. This study provides support for the blanket protection to all sharks throughout Cayman waters, which was incorporated within the National Conservation Act in 2015.
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Affiliation(s)
- Johanna Kohler
- Department of the Environment, Cayman Islands Government, George Town, Cayman Islands
- Centre for Marine Biodiversity and Biotechnology, Heriot-Watt University, Edinburgh, Scotland, United Kingdom
| | - Mauvis Gore
- Centre for Marine Biodiversity and Biotechnology, Heriot-Watt University, Edinburgh, Scotland, United Kingdom
- Marine Conservation International, Edinburgh, Scotland, United Kingdom
| | - Rupert Ormond
- Centre for Marine Biodiversity and Biotechnology, Heriot-Watt University, Edinburgh, Scotland, United Kingdom
- Marine Conservation International, Edinburgh, Scotland, United Kingdom
| | - Bradley Johnson
- Department of the Environment, Cayman Islands Government, George Town, Cayman Islands
| | - Timothy Austin
- Department of the Environment, Cayman Islands Government, George Town, Cayman Islands
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Séguigne C, Bègue M, Meyer C, Mourier J, Clua É. Provisioning ecotourism does not increase tiger shark site fidelity. Sci Rep 2023; 13:7785. [PMID: 37179390 PMCID: PMC10183044 DOI: 10.1038/s41598-023-34446-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 04/30/2023] [Indexed: 05/15/2023] Open
Abstract
A perennial criticism of provisioning ecotourism is that it alters the natural behavior and ecology of the target species by providing an artificial food source. Here we evaluate its impact on the long-term site fidelity patterns of tiger sharks in French Polynesia. We hypothesized that a significant impact of provisioning would lead to (1) increases in individual site fidelity over time, and (2) an increase in the number of resident individuals over time. Of 53 individuals photo-identified and monitored during > 500 dives over five years, 10 individuals accounted for > 75% of all sightings, whereas 35 sharks were sighted very infrequently. Even the most frequently observed tiger sharks exhibited overall low fidelity at the site and showed no increase in site fidelity over time. Furthermore, the number of tiger sharks sighted during each dive did not increase. The observed patterns of tiger shark sightings were best explained by natural movements, including general roaming within home ranges along the coastline and seasonal migrations. Despite the apparent lack of impact of provisioning ecotourism on tiger shark ecology in Tahitian waters, it would be prudent to implement a strict code of conduct during any future provisioning activities to maximize the safety of participants and animals involved.
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Affiliation(s)
- Clémentine Séguigne
- PSL Université Paris: EPHE-UPVD-CNRS, USR 3278 CRIOBE, BP 1013, 98729, Papetoai, Moorea, French Polynesia.
- Laboratoire d'Excellence "CORAIL", 98729, Papetoai, Moorea, French Polynesia.
| | - Michel Bègue
- PSL Université Paris: EPHE-UPVD-CNRS, USR 3278 CRIOBE, BP 1013, 98729, Papetoai, Moorea, French Polynesia
| | - Carl Meyer
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, P. O. Box 1346, Kaneohe, HI, USA
| | - Johann Mourier
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Sète, France
| | - Éric Clua
- PSL Université Paris: EPHE-UPVD-CNRS, USR 3278 CRIOBE, BP 1013, 98729, Papetoai, Moorea, French Polynesia
- Laboratoire d'Excellence "CORAIL", 98729, Papetoai, Moorea, French Polynesia
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Merlo PJ, Venerus LA, Irigoyen AJ. Fine-scale variation in the proximity of baited remote underwater video stations (BRUVS) to rocky reefs reveals changes in the structure of temperate fish assemblages. MARINE ENVIRONMENTAL RESEARCH 2023; 185:105902. [PMID: 36736235 DOI: 10.1016/j.marenvres.2023.105902] [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: 09/01/2022] [Revised: 01/05/2023] [Accepted: 01/29/2023] [Indexed: 06/18/2023]
Abstract
We investigated changes in the structure of coastal fish assemblages in Northern Patagonia, Southwestern Atlantic, by using baited remote underwater video stations (BRUVS) deployed at increasing distances from rocky reefs: 0-5 m, 15-20 m and 50-60 m. We estimated species richness and abundance (total and by preferred habitat type) and searched for diagnostic species in each distance range. We recorded 14 taxa across 11 families in 19 areas surveyed. Species richness and abundance were higher on reef ledges and decreased with distance from them, at a finer spatial scale than previously reported. Acanthistius patachonicus and Sebastes oculatus were indicative of reef ledges; they were less abundant at 15-20 m and disappeared at 50-60 m. Callorinchus callorynchus and Odontesthes spp. occurred only at distances >15-20 m from the reefs, while Galeorhinus galeus was distributed homogeneously throughout the surveyed area. Our findings have practical implications for monitoring ecotone demersal habitats with BRUVS.
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Affiliation(s)
- Pablo J Merlo
- Centro para el Estudio de Sistemas Marinos (CESIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CCT CENPAT-CONICET), Blvd. Brown 2915, U9120ACD, Puerto Madryn, Chubut, Argentina.
| | - Leonardo A Venerus
- Centro para el Estudio de Sistemas Marinos (CESIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CCT CENPAT-CONICET), Blvd. Brown 2915, U9120ACD, Puerto Madryn, Chubut, Argentina
| | - Alejo J Irigoyen
- Centro para el Estudio de Sistemas Marinos (CESIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CCT CENPAT-CONICET), Blvd. Brown 2915, U9120ACD, Puerto Madryn, Chubut, Argentina
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7
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Lesturgie P, Lainé H, Suwalski A, Chifflet-Belle P, Maisano Delser P, Clua E, Jaquemet S, Magalon H, Mona S. Ecological and biogeographic features shaped the complex evolutionary history of an iconic apex predator (Galeocerdo cuvier). BMC Ecol Evol 2022; 22:147. [PMID: 36526977 PMCID: PMC9758794 DOI: 10.1186/s12862-022-02100-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The tiger shark (Galeocerdo cuvier) is a large iconic marine predator inhabiting worldwide tropical and subtropical waters. So far, only mitochondrial markers and microsatellites studies have investigated its worldwide historical demography with inconclusive outcomes. Here, we assessed for the first time the genomic variability of tiger shark based on RAD-seq data for 50 individuals from five sampling sites in the Indo-Pacific (IP) and one in the Atlantic Ocean (AO) to decipher the extent of the species' global connectivity and its demographic history. RESULTS Clustering algorithms (PCA and NMF), FST and an approximate Bayesian computation framework revealed the presence of two clusters corresponding to the two oceanic basins. By modelling the two-dimensional site frequency spectrum, we tested alternative isolation/migration scenarios between these two identified populations. We found the highest support for a divergence time between the two ocean basins of ~ 193,000 years before present (B.P) and an ongoing but limited asymmetric migration ~ 176 times larger from the IP to the AO (Nm ~ 3.9) than vice versa (Nm ~ 0.02). CONCLUSIONS The two oceanic regions are isolated by a strong barrier to dispersal more permeable from the IP to the AO through the Agulhas leakage. We finally emphasized contrasting recent demographic histories for the two regions, with the IP characterized by a recent bottleneck around 2000 years B.P. and the AO by an expansion starting 6000 years B.P. The large differentiation between the two oceanic regions and the absence of population structure within each ocean basin highlight the need for two large management units and call for future conservation programs at the oceanic rather than local scale, particularly in the Indo-Pacific where the population is declining.
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Affiliation(s)
- Pierre Lesturgie
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France
| | - Hugo Lainé
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France
| | - Arnaud Suwalski
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France ,grid.424469.90000 0001 2195 5365EPHE, PSL Research University, Paris, France
| | - Pascaline Chifflet-Belle
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France ,grid.424469.90000 0001 2195 5365EPHE, PSL Research University, Paris, France
| | | | - Eric Clua
- grid.424469.90000 0001 2195 5365EPHE, PSL Research University, Paris, France ,Laboratoire d’Excellence CORAIL, Papetoai, French Polynesia
| | - Sébastien Jaquemet
- grid.11642.300000 0001 2111 2608UMR ENTROPIE (Université de La Réunion/IRD/CNRS), Université de La Réunion, Saint Denis, France
| | - Hélène Magalon
- Laboratoire d’Excellence CORAIL, Papetoai, French Polynesia ,grid.11642.300000 0001 2111 2608UMR ENTROPIE (Université de La Réunion/IRD/CNRS), Université de La Réunion, Saint Denis, France
| | - Stefano Mona
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France ,grid.424469.90000 0001 2195 5365EPHE, PSL Research University, Paris, France ,Laboratoire d’Excellence CORAIL, Papetoai, French Polynesia
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8
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Cortelezzi P, Paulet TG, Olbers JM, Harris JM, Bernard ATF. Conservation benefits of a marine protected area on South African chondrichthyans. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115691. [PMID: 35839646 DOI: 10.1016/j.jenvman.2022.115691] [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: 04/12/2022] [Revised: 06/21/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Chondrichthyans are threatened worldwide due to their life-history traits combined with a plethora of anthropogenic impacts that are causing populations to collapse. Marine Protected Areas (MPAs) are a conservation option, but their efficacy for chondrichthyans is still unclear. Conservation efforts might be challenging especially in developing countries, due to a lack of resources and monitoring and limited data and stakeholder support. Here Baited Remote Underwater Stereo-Video systems (stereo-BRUVs) were deployed inside and outside a small partially protected MPA (Robberg MPA, Western Cape, South Africa) to assess the status of cartilaginous fishes' assemblages and to investigate the potential benefits derived from the presence of a marine reserve. Overall, 19 chondrichthyan species in 11 different families were observed. Chondrichthyans were observed in 78.5% of the sites and, of these, 89.7% of the MPA sites showed at least one chondrichthyan, while only in the 67.5% of surrounding exploited sites a cartilaginous fish was sighted. The presence of the MPA had a significant effect on the relative abundance of batoids, threatened species and local endemics, with more observations inside the MPA than outside, indicating the potential benefit of marine reserves on species that are more vulnerable to fishing pressure. Relative abundance was generally higher inside the bay than in the exposed area, and both relative abundance and species richness decreased significantly with depth. The analysis of the body length showed that the 35.5% of species had an average body length below maturity length, indicating that the area might be used as nursery ground for different species. This study provides evidence that MPAs, even though small and partially protected, can provide benefits for chondrichthyans, specifically to threatened species, endemic species and lesser-known species. Importantly, different environmental parameters must be considered to maximize the benefits an MPA can provide.
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Affiliation(s)
- Paolo Cortelezzi
- Earth and Environmental Science Department, University of Milano Bicocca, Piazza Della Scienza 1, 20126, Milano, Italy; South African Shark Conservancy (SASC), Hermanus, 7200, Western Cape, South Africa.
| | - Timothy G Paulet
- South African Shark Conservancy (SASC), Hermanus, 7200, Western Cape, South Africa
| | - Jennifer M Olbers
- Wildlands Conservation Trust, 460 Townbush Road, Pietermaritzburg, 3201, South Africa
| | - Jean M Harris
- Wildlands Conservation Trust, 460 Townbush Road, Pietermaritzburg, 3201, South Africa; Institute for Coastal and Marine Research (CMR), Nelson Mandela University, Gomeroy Avenue, Summerstrand, Port Elizabeth 6031, South Africa
| | - Anthony T F Bernard
- South African Institute for Aquatic Biodiversity, Somerset Street, Makhanda, 6139, South Africa; Rhodes University, Department of Zoology and Entomology, Makhanda, 6139, South Africa
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Lubitz N, Bradley M, Sheaves M, Hammerschlag N, Daly R, Barnett A. The role of context in elucidating drivers of animal movement. Ecol Evol 2022; 12:e9128. [PMID: 35898421 PMCID: PMC9309038 DOI: 10.1002/ece3.9128] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 05/10/2022] [Accepted: 07/01/2022] [Indexed: 11/26/2022] Open
Abstract
Despite its consequences for ecological processes and population dynamics, intra-specific variability is frequently overlooked in animal movement studies. Consequently, the necessary resolution to reveal drivers of individual movement decisions is often lost as animal movement data are aggregated to infer average or population patterns. Thus, an empirical understanding of why a given movement pattern occurs remains patchy for many taxa, especially in marine systems. Nonetheless, movement is often rationalized as being driven by basic life history requirements, such as acquiring energy (feeding), reproduction, predator-avoidance, and remaining in suitable environmental conditions. However, these life history requirements are central to every individual within a species and thus do not sufficiently account for the high intra-specific variability in movement behavior and hence fail to fully explain the occurrence of multiple movement strategies within a species. Animal movement appears highly context dependent as, for example, within the same location, the behavior of both resident and migratory individuals is driven by life history requirements, such as feeding or reproduction, however different movement strategies are utilized to fulfill them. A systematic taxa-wide approach that, instead of averaging population patterns, incorporates and utilizes intra-specific variability to enable predictions as to which movement patterns can be expected under a certain context, is needed. Here, we use intra-specific variability in elasmobranchs as a case study to introduce a stepwise approach for studying animal movement drivers that is based on a context-dependence framework. We examine relevant literature to illustrate how this context-focused approach can aid in reliably identifying drivers of a specific movement pattern. Ultimately, incorporating behavioral variability in the study of movement drivers can assist in making predictions about behavioral responses to environmental change, overcoming tagging biases, and establishing more efficient conservation measures.
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Affiliation(s)
- Nicolas Lubitz
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Michael Bradley
- Marine Data Technology HubCollege of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Marcus Sheaves
- Marine Data Technology HubCollege of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Neil Hammerschlag
- Rosenstiel School of Marine and Atmospheric ScienceUniversity of MiamiMiamiFloridaUSA
| | - Ryan Daly
- Oceanographic Research InstituteDurbanSouth Africa
- South African Institute for Aquatic Biodiversity (SAIAB)MakhandaSouth Africa
| | - Adam Barnett
- Marine Data Technology HubCollege of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
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10
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Manuzzi A, Jiménez-Mena B, Henriques R, Holmes BJ, Pepperell J, Edson J, Bennett MB, Huveneers C, Ovenden JR, Nielsen EE. Retrospective genomics highlights changes in genetic composition of tiger sharks (Galeocerdo cuvier) and potential loss of a south-eastern Australia population. Sci Rep 2022; 12:6582. [PMID: 35449439 PMCID: PMC9023511 DOI: 10.1038/s41598-022-10529-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/06/2022] [Indexed: 11/08/2022] Open
Abstract
Over the last century, many shark populations have declined, primarily due to overexploitation in commercial, artisanal and recreational fisheries. In addition, in some locations the use of shark control programs also has had an impact on shark numbers. Still, there is a general perception that populations of large ocean predators cover wide areas and therefore their diversity is less susceptible to local anthropogenic disturbance. Here we report on temporal genomic analyses of tiger shark (Galeocerdo cuvier) DNA samples that were collected from eastern Australia over the past century. Using Single Nucleotide Polymorphism (SNP) loci, we documented a significant change in genetic composition of tiger sharks born between ~1939 and 2015. The change was most likely due to a shift over time in the relative contribution of two well-differentiated, but hitherto cryptic populations. Our data strongly indicate a dramatic shift in the relative contribution of these two populations to the overall tiger shark abundance on the east coast of Australia, possibly associated with differences in direct or indirect exploitation rates.
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Affiliation(s)
- Alice Manuzzi
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark.
| | - Belen Jiménez-Mena
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Romina Henriques
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Bonnie J Holmes
- School of Science, Technology & Engineering, University of the Sunshine Coast, Sippy Downs, QLD, 4556, Australia
| | - Julian Pepperell
- Pepperell Research and Consulting, PO Box 1475, Noosaville DC, QLD, 4566, Australia
| | - Janette Edson
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Mike B Bennett
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Charlie Huveneers
- College of Science and Engineering, Flinders University, Adelaide, SA, 5001, Australia
| | - Jennifer R Ovenden
- Molecular Fisheries Laboratory, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Einar E Nielsen
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
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11
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Forecasting intraspecific changes in distribution of a wide-ranging marine predator under climate change. Oecologia 2021; 198:111-124. [PMID: 34787703 PMCID: PMC8803685 DOI: 10.1007/s00442-021-05075-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 10/31/2021] [Indexed: 11/03/2022]
Abstract
Globally, marine animal distributions are shifting in response to a changing climate. These shifts are usually considered at the species level, but individuals are likely to differ in how they respond to the changing conditions. Here, we investigate how movement behaviour and, therefore, redistribution, would differ by sex and maturation class in a wide-ranging marine predator. We tracked 115 tiger sharks (Galeocerdo cuvier) from 2002 to 2020 and forecast class-specific distributions through to 2030, including environmental factors and predicted occurrence of potential prey. Generalised Linear and Additive Models revealed that water temperature change, particularly at higher latitudes, was the factor most associated with shark movements. Females dispersed southwards during periods of warming temperatures, and while juvenile females preferred a narrow thermal range between 22 and 23 °C, adult female and juvenile male presence was correlated with either lower (< 22 °C) or higher (> 23 °C) temperatures. During La Niña, sharks moved towards higher latitudes and used shallower isobaths. Inclusion of predicted distribution of their putative prey significantly improved projections of suitable habitats for all shark classes, compared to simpler models using temperature alone. Tiger shark range off the east coast of Australia is predicted to extend ~ 3.5° south towards the east coast of Tasmania, particularly for juvenile males. Our framework highlights the importance of combining long-term movement data with multi-factor habitat projections to identify heterogeneity within species when predicting consequences of climate change. Recognising intraspecific variability will improve conservation and management strategies and help anticipate broader ecosystem consequences of species redistribution due to ocean warming.
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12
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Love MS, Bizzarro JJ, Cornthwaite AM, Frable BW, Maslenikov KP. Checklist of marine and estuarine fishes from the AlaskaYukon Border, Beaufort Sea, to Cabo San Lucas, Mexico. Zootaxa 2021; 5053:1-285. [PMID: 34810850 DOI: 10.11646/zootaxa.5053.1.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Indexed: 11/04/2022]
Abstract
This paper is a checklist of the fishes that have been documented, through both published and unpublished sources, in marine and estuarine waters, and out 200 miles, from the United States-Canadian border on the Beaufort Sea to Cabo San Lucas, Mexico. A minimum of 241 families and 1,644 species are known within this range, including both native and nonnative species. For each of these species, we include maximum size, geographic and depth ranges, whether it is native or nonnative, as well as a brief mention of any taxonomic issues.
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Affiliation(s)
- Milton S Love
- Marine Science Institute, University of California, Santa Barbara, CA 93106.
| | - Joseph J Bizzarro
- Cooperative Institute for Marine Ecosystems and Climate, University of California, Santa Cruz, 110 McAllister Way, Santa Cruz, CA 95060. .
| | - A Maria Cornthwaite
- Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, BC, V9T 6N7, Canada .
| | - Benjamin W Frable
- Marine Vertebrate Collection, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0244, USA. .
| | - Katherine P Maslenikov
- University of Washington Fish Collection, School of Aquatic and Fishery Sciences and Burke Museum of Natural History and Culture, 1122 NE Boat St., Seattle, WA 98105.
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13
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Bernard AM, Finnegan KA, Pavinski Bitar P, Stanhope MJ, Shivji MS. Genomic assessment of global population structure in a highly migratory and habitat versatile apex predator, the tiger shark (Galeocerdo cuvier). J Hered 2021; 112:497-507. [PMID: 34374783 DOI: 10.1093/jhered/esab046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 08/09/2021] [Indexed: 11/12/2022] Open
Abstract
Understanding the population dynamics of highly mobile, widely distributed, oceanic sharks, many of which are overexploited, is necessary to aid their conservation management. We investigated the global population genomics of tiger sharks (Galeocerdo cuvier), a circumglobally distributed, apex predator displaying remarkable behavioral versatility in its diet, habitat use (near coastal, coral reef, pelagic), and individual movement patterns (spatially resident to long-distance migrations). We genotyped 242 tiger sharks from 10 globally distributed locations at more than 2000 single nucleotide polymorphisms. Although this species often conducts massive distance migrations, the data show strong genetic differentiation at both neutral (FST=0.125-0.144) and candidate outlier loci (FST=0.570-0.761) between western Atlantic and Indo-Pacific sharks, suggesting the potential for adaptation to the environments specific to these oceanic regions. Within these regions, there was mixed support for population differentiation between northern and southern hemispheres in the western Atlantic, and none for structure within the Indian Ocean. Notably, the results demonstrate a low level of population differentiation of tiger sharks from the remote Hawaiian archipelago compared to sharks from the Indian Ocean (FST=0.003-0.005, P<0.01). Given concerns about biodiversity loss and marine ecosystem impacts caused by overfishing of oceanic sharks in the midst of rapid environmental change, our results suggest it imperative that international fishery management prioritize conservation of the evolutionary potential of the highly genetically differentiated Atlantic and Indo-Pacific populations of this unique apex predator. Furthermore, we suggest targeted management attention to tiger sharks in the Hawaiian archipelago based on a precautionary biodiversity conservation perspective.
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Affiliation(s)
- Andrea M Bernard
- Save Our Seas Foundation Shark Research Center, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA
| | - Kimberly A Finnegan
- Save Our Seas Foundation Shark Research Center, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA.,Guy Harvey Research Institute, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA
| | - Paulina Pavinski Bitar
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Michael J Stanhope
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Mahmood S Shivji
- Save Our Seas Foundation Shark Research Center, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA.,Guy Harvey Research Institute, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA
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14
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Nosal AP, Cartamil DP, Ammann AJ, Bellquist LF, Ben‐Aderet NJ, Blincow KM, Burns ES, Chapman ED, Freedman RM, Klimley AP, Logan RK, Lowe CG, Semmens BX, White CF, Hastings PA. Triennial migration and philopatry in the critically endangered soupfin shark
Galeorhinus galeus. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13848] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andrew P. Nosal
- Department of Environmental and Ocean Sciences University of San Diego San Diego CA USA
- Marine Biology Research Division Scripps Institution of Oceanography University of California – San Diego La Jolla CA USA
| | - Daniel P. Cartamil
- Marine Biology Research Division Scripps Institution of Oceanography University of California – San Diego La Jolla CA USA
| | - Arnold J. Ammann
- Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries ServiceNOAA Santa Cruz CA USA
| | - Lyall F. Bellquist
- Marine Biology Research Division Scripps Institution of Oceanography University of California – San Diego La Jolla CA USA
- The Nature Conservancy San Francisco CA USA
| | - Noah J. Ben‐Aderet
- Fisheries Resources Division Southwest Fisheries Science Center NOAA Fisheries La Jolla CA USA
| | - Kayla M. Blincow
- Marine Biology Research Division Scripps Institution of Oceanography University of California – San Diego La Jolla CA USA
| | - Echelle S. Burns
- Bren School of Environmental Science and Management University of California – Santa Barbara Santa Barbara CA USA
| | - Eric D. Chapman
- Department of Wildlife, Fish and Conservation Biology University of California – Davis Davis CA USA
- ICF Sacramento CA USA
| | - Ryan M. Freedman
- NOAA Channel Islands National Marine Sanctuary University of California – Santa Barbara Santa Barbara CA USA
| | - A. Peter Klimley
- Department of Wildlife, Fish and Conservation Biology University of California – Davis Davis CA USA
- Biotelemetry Consultants Petaluma CA USA
| | - Ryan K. Logan
- Guy Harvey Research Institute Nova Southeastern University Dania Beach FL USA
| | | | - Brice X. Semmens
- Marine Biology Research Division Scripps Institution of Oceanography University of California – San Diego La Jolla CA USA
| | - Connor F. White
- Department of Organismic and Evolutionary Biology Harvard University Cambridge MA USA
| | - Philip A. Hastings
- Marine Biology Research Division Scripps Institution of Oceanography University of California – San Diego La Jolla CA USA
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15
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da Silva TEF, Lessa R, Santana FM. Current knowledge on biology, fishing and conservation of the blue shark (Prionace glauca). NEOTROPICAL BIOLOGY AND CONSERVATION 2021. [DOI: 10.3897/neotropical.16.e58691] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The blue shark (Prionace glauca) is a large predator in marine ecosystems, figuring as the most common and abundant species in oceanic fisheries. For this reason, many studies on this species were conducted throughout its entire distribution range. However, no comparison has been made regarding the variability of the aspects addressed herein. Thus, the present study aims at analyzing the available information on P. glauca. This species constitutes between 85 and 90% of the total elasmobranchs caught by oceanic fisheries with pelagic longlines. Growth parameters reveal that individuals in the Atlantic Ocean show the highest asymptotic lengths when compared to those found in other oceans. Females present an average uterine fecundity of 30 embryos. Although it shows a diverse diet, it is mainly composed of teleost fish and cephalopods. Currently, the main threat to the species is commercial fishing, being listed in Brazil and worldwide, according to IUCN as Near Threatened. Regardless, information on crucial aspects, such as its population dynamics, are still scarce or unreliable for many areas. Despite the number of studies regarding its distribution, abundance, and biology, data for new stock assessments of P. glauca are still needed to improve the species’ management.
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16
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Le Croizier G, Lorrain A, Sonke JE, Jaquemet S, Schaal G, Renedo M, Besnard L, Cherel Y, Point D. Mercury isotopes as tracers of ecology and metabolism in two sympatric shark species. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114931. [PMID: 32590319 DOI: 10.1016/j.envpol.2020.114931] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/27/2020] [Accepted: 06/01/2020] [Indexed: 06/11/2023]
Abstract
In coastal ecosystems, top predators are exposed to a wide variety of nutrient and contaminant sources due to the diversity of trophic webs within inshore marine habitats. Mercury contamination could represent an additional threat to shark populations that are declining worldwide. Here we measured total mercury, carbon and nitrogen isotopes, as well as mercury isotopes, in two co-occurring shark species (the bull shark Carcharhinus leucas and the tiger shark Galeocerdo cuvier) and their potential prey from a coastal ecosystem of the western Indian Ocean (La Réunion Island). Our primary goals were to (i) determine the main trophic Hg sources for sharks and (ii) better characterize their diet composition and foraging habitat. Hg isotope signatures (Δ199Hg and δ202Hg) of shark prey suggested that bull sharks were exposed to methylmercury (MeHg) produced in offshore epipelagic waters, while tiger sharks were exposed to offshore mesopelagic MeHg with additional microbial transformation in slope sediments. Δ199Hg values efficiently traced the ecology of the two predators, demonstrating that bull sharks targeted coastal prey in shallow waters while tiger sharks were mainly foraging on mesopelagic species in the deeper waters of the island slope. Unexpectedly, we found a positive shift in δ202Hg (>1‰) between sharks and their prey, leading to high δ202Hg values in the two shark species (e.g. 1.91 ± 0.52‰ in bull sharks). This large shift in δ202Hg indicates that sharks may display strong MeHg demethylation abilities, possibly reflecting evolutionary pathways for mitigating their MeHg contamination.
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Affiliation(s)
- Gaël Le Croizier
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées (OMP), UMR 5563 CNRS/IRD/Université Paul Sabatier, 14 avenue Edouard Belin, 31400, Toulouse, France.
| | - Anne Lorrain
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France
| | - Jeroen E Sonke
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées (OMP), UMR 5563 CNRS/IRD/Université Paul Sabatier, 14 avenue Edouard Belin, 31400, Toulouse, France
| | - Sébastien Jaquemet
- Laboratoire ENTROPIE, UMR 9220 CNRS/IRD/Université de La Réunion, 15 Avenue René Cassin, BP 92003, 97744, Saint-Denis, La Réunion, France
| | - Gauthier Schaal
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France
| | - Marina Renedo
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées (OMP), UMR 5563 CNRS/IRD/Université Paul Sabatier, 14 avenue Edouard Belin, 31400, Toulouse, France
| | - Lucien Besnard
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France
| | - Yves Cherel
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, 79360, Villiers-en-Bois, France
| | - David Point
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées (OMP), UMR 5563 CNRS/IRD/Université Paul Sabatier, 14 avenue Edouard Belin, 31400, Toulouse, France
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17
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Martín G, Espinoza M, Heupel M, Simpfendorfer CA. Estimating marine protected area network benefits for reef sharks. J Appl Ecol 2020. [DOI: 10.1111/1365-2664.13706] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gerardo Martín
- MRC Centre for Global Infectious Disease Analysis Department of Infectious Disease Epidemiology Faculty of Medicine Imperial College London at St. Mary's London UK
| | - Mario Espinoza
- Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) Universidad de Costa Rica San José Costa Rica
| | - Michelle Heupel
- Australian Institute of Marine Science Townsville Qld Australia
| | - Colin A. Simpfendorfer
- Centre for Sustainable Tropical Fisheries and Aquaculture & College of Science and Engineering James Cook University Townsville Qld Australia
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18
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Spaet JLY, Patterson TA, Bradford RW, Butcher PA. Spatiotemporal distribution patterns of immature Australasian white sharks (Carcharodon carcharias). Sci Rep 2020; 10:10169. [PMID: 32576876 PMCID: PMC7311443 DOI: 10.1038/s41598-020-66876-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 05/26/2020] [Indexed: 11/09/2022] Open
Abstract
In Australian and New Zealand waters, current knowledge on white shark (Carcharodon carcharias) movement ecology is based on individual tracking studies using relatively small numbers of tags. These studies describe a species that occupies highly variable and complex habitats. However, uncertainty remains as to whether the proposed movement patterns are representative of the wider population. Here, we tagged 103 immature Australasian white sharks (147-350 cm fork length) with both acoustic and satellite transmitters to expand our current knowledge of population linkages, spatiotemporal dynamics and coastal habitats. Eighty-three sharks provided useable data. Based on individual tracking periods of up to 5 years and a total of 2,865 days of tracking data, we were able to characterise complex movement patterns over ~45° of latitude and ~72° of longitude and distinguish regular/recurrent patterns from occasional/exceptional migration events. Shark movements ranged from Papua New Guinea to sub-Antarctic waters and to Western Australia, highlighting connectivity across their entire Australasian range. Results over the 12-year study period yielded a comprehensive characterisation of the movement ecology of immature Australasian white sharks across multiple spatial scales and substantially expanded the body of knowledge available for population assessment and management.
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Affiliation(s)
- Julia L Y Spaet
- Evolutionary Ecology Group, Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK. .,Southern Cross University, Coffs Harbour, New South Wales, 2450, Australia.
| | | | | | - Paul A Butcher
- Southern Cross University, Coffs Harbour, New South Wales, 2450, Australia.,NSW Fisheries, NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, New South Wales, 2450, Australia
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19
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Parton KJ, Galloway TS, Godley BJ. Global review of shark and ray entanglement in anthropogenic marine debris. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr00964] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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20
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Pirog A, Jaquemet S, Ravigné V, Cliff G, Clua E, Holmes BJ, Hussey NE, Nevill JEG, Temple AJ, Berggren P, Vigliola L, Magalon H. Genetic population structure and demography of an apex predator, the tiger shark Galeocerdo cuvier. Ecol Evol 2019; 9:5551-5571. [PMID: 31160982 PMCID: PMC6540675 DOI: 10.1002/ece3.5111] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 01/20/2019] [Accepted: 02/26/2019] [Indexed: 12/16/2022] Open
Abstract
Population genetics has been increasingly applied to study large sharks over the last decade. Whilst large shark species are often difficult to study with direct methods, improved knowledge is needed for both population management and conservation, especially for species vulnerable to anthropogenic and climatic impacts. The tiger shark, Galeocerdo cuvier, is an apex predator known to play important direct and indirect roles in tropical and subtropical marine ecosystems. While the global and Indo-West Pacific population genetic structure of this species has recently been investigated, questions remain over population structure and demographic history within the western Indian (WIO) and within the western Pacific Oceans (WPO). To address the knowledge gap in tiger shark regional population structures, the genetic diversity of 286 individuals sampled in seven localities was investigated using 27 microsatellite loci and three mitochondrial genes (CR,COI, and cytb). A weak genetic differentiation was observed between the WIO and the WPO, suggesting high genetic connectivity. This result agrees with previous studies and highlights the importance of the pelagic behavior of this species to ensure gene flow. Using approximate Bayesian computation to couple information from both nuclear and mitochondrial markers, evidence of a recent bottleneck in the Holocene (2,000-3,000 years ago) was found, which is the most probable cause for the low genetic diversity observed. A contemporary effective population size as low as 111 [43,369] was estimated during the bottleneck. Together, these results indicate low genetic diversity that may reflect a vulnerable population sensitive to regional pressures. Conservation measures are thus needed to protect a species that is classified as Near Threatened.
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Affiliation(s)
- Agathe Pirog
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS)Université de La RéunionSaint Denis, La RéunionFrance
| | - Sébastien Jaquemet
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS)Université de La RéunionSaint Denis, La RéunionFrance
| | | | - Geremy Cliff
- KwaZulu‐Natal Sharks BoardUmhlanga RocksSouth Africa
- School of Life SciencesUniversity of KwaZulu‐NatalDurbanSouth Africa
| | - Eric Clua
- EPHE‐CNRS‐UPVDCNRS UPVDUSR 3278 CRIOBEPSL Research UniversityPerpignanFrance
- Laboratoire d'Excellence CORAILPerpignanFrance
| | - Bonnie J. Holmes
- School of Biological SciencesUniversity of Queensland, St LuciaBrisbaneQueenslandAustralia
| | - Nigel E. Hussey
- Biological SciencesUniversity of WindsorWindsorOntarioCanada
| | | | - Andrew J. Temple
- School of Natural and Environmental SciencesNewcastle UniversityNewcastle‐upon‐TyneUK
| | - Per Berggren
- School of Natural and Environmental SciencesNewcastle UniversityNewcastle‐upon‐TyneUK
| | - Laurent Vigliola
- Laboratoire d'Excellence CORAILPerpignanFrance
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS)Institut de Recherche pour le DéveloppementNouméaNouvelle CalédonieFrance
| | - Hélène Magalon
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS)Université de La RéunionSaint Denis, La RéunionFrance
- Laboratoire d'Excellence CORAILPerpignanFrance
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21
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Paxton AB, Blair E, Blawas C, Fatzinger MH, Marens M, Holmberg J, Kingen C, Houppermans T, Keusenkothen M, McCord J, Silliman BR, Penfold LM. Citizen science reveals female sand tiger sharks (Carcharias taurus) exhibit signs of site fidelity on shipwrecks. Ecology 2019; 100:e02687. [PMID: 31009086 DOI: 10.1002/ecy.2687] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/07/2019] [Accepted: 02/20/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Avery B Paxton
- South-East Zoo Alliance for Reproduction & Conservation, 581705 White Oak Road, Yulee, Florida, 32097, USA.,Nicholas School of the Environment, Duke University Marine Lab, 135 Duke Marine Lab Road, Beaufort, North Carolina, 28516, USA
| | - Erica Blair
- Nicholas School of the Environment, Duke University Marine Lab, 135 Duke Marine Lab Road, Beaufort, North Carolina, 28516, USA.,Department of Biology, Duke University, 130 Science Drive, Durham, North Carolina, 27708, USA
| | - Camryn Blawas
- Department of Biology, University of North Carolina at Chapel Hill, 120 South Road, Chapel Hill, North Carolina, 27599, USA
| | - Michael H Fatzinger
- North Carolina Aquarium at Pine Knoll Shores, 1 Roosevelt Boulevard, Pine Knoll Shores, North Carolina, 28512, USA
| | - Madeline Marens
- North Carolina Aquarium at Fort Fisher, 900 Loggerhead Road, Kure Beach, North Carolina, 28449, USA.,Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, Wilmington, North Carolina, 28403, USA
| | - Jason Holmberg
- Wild Me, 1726 North Terry Street, Portland, Oregon, 92717, USA
| | - Colin Kingen
- Wild Me, 1726 North Terry Street, Portland, Oregon, 92717, USA
| | - Tanya Houppermans
- Blue Elements Imaging LLC, 711 Edwards Drive, Fredericksburg, Virginia, 22405, USA
| | - Mark Keusenkothen
- Diving and Water Safety Office, East Carolina University, Building 43, Greenville, North Carolina, 27858, USA
| | - John McCord
- Coastal Studies Institute, East Carolina University, 850 NC-345, Wanchese, North Carolina, 27981, USA
| | - Brian R Silliman
- Nicholas School of the Environment, Duke University Marine Lab, 135 Duke Marine Lab Road, Beaufort, North Carolina, 28516, USA
| | - Linda M Penfold
- South-East Zoo Alliance for Reproduction & Conservation, 581705 White Oak Road, Yulee, Florida, 32097, USA
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22
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Barkley AN, Gollock M, Samoilys M, Llewellyn F, Shivji M, Wetherbee B, Hussey NE. Complex transboundary movements of marine megafauna in the Western Indian Ocean. Anim Conserv 2019. [DOI: 10.1111/acv.12493] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- A. N. Barkley
- Biological Sciences University of Windsor Windsor ON Canada
| | - M. Gollock
- Zoological Society of London Regent's Park London England
| | - M. Samoilys
- Coastal Oceans Research and Development – Indian Ocean Mombasa Kenya
| | - F. Llewellyn
- Zoological Society of London Regent's Park London England
| | - M. Shivji
- Guy Harvey Research Institute Department of Biological Sciences Nova Southeastern University Fort Lauderdale FL USA
| | - B. Wetherbee
- Guy Harvey Research Institute Department of Biological Sciences Nova Southeastern University Fort Lauderdale FL USA
- Biological Sciences College of Environment and Life Sciences University of Rhode Island Kingston RI USA
| | - N. E. Hussey
- Biological Sciences University of Windsor Windsor ON Canada
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23
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Werry JM, Sumpton W, Otway NM, Lee SY, Haig JA, Mayer DG. Rainfall and sea surface temperature: key drivers for occurrence of bull shark, Carcharhinus leucas, in beach areas. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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24
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Meyer CG, Anderson JM, Coffey DM, Hutchinson MR, Royer MA, Holland KN. Habitat geography around Hawaii's oceanic islands influences tiger shark (Galeocerdo cuvier) spatial behaviour and shark bite risk at ocean recreation sites. Sci Rep 2018; 8:4945. [PMID: 29563552 PMCID: PMC5862960 DOI: 10.1038/s41598-018-23006-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 03/05/2018] [Indexed: 11/28/2022] Open
Abstract
We compared tiger shark (Galeocerdo cuvier) spatial behaviour among 4 Hawaiian Islands to evaluate whether local patterns of movement could explain higher numbers of shark bites seen around Maui than other islands. Our sample consisted of 96 electronically-tagged (satellite and acoustic transmitters) tiger sharks, individually tracked for up to 6 years. Most individuals showed fidelity to a specific ‘home’ island, but also swam between islands and sometimes ranged far (up to 1,400 km) offshore. Movements were primarily oriented to insular shelf habitat (0–200 m depth) in coastal waters, and individual sharks utilized core-structured home ranges within this habitat. Core utilization areas of large tiger sharks were closer to high-use ocean recreation sites around Maui, than around Oahu. Tiger sharks routinely visited shallow ocean recreation sites around Maui and were detected on more days overall at ocean recreation sites around Maui (62–80%) than Oahu (<6%). Overall, our results suggest the extensive insular shelf surrounding Maui supports a fairly resident population of tiger sharks and also attracts visiting tiger sharks from elsewhere in Hawaii. Collectively these natural, habitat-driven spatial patterns may in-part explain why Maui has historically had more shark bites than other Hawaiian Islands.
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Affiliation(s)
- Carl G Meyer
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, P. O. Box, 1346, Kaneohe, Hawaii, USA.
| | - James M Anderson
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, P. O. Box, 1346, Kaneohe, Hawaii, USA
| | - Daniel M Coffey
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, P. O. Box, 1346, Kaneohe, Hawaii, USA
| | - Melanie R Hutchinson
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, P. O. Box, 1346, Kaneohe, Hawaii, USA.,Joint Institute for Marine and Atmospheric Research, Pacific Islands Fisheries Science Center, 1845 Wasp Blvd. Bldg. 176, Honolulu, Hawaii, 96818, USA
| | - Mark A Royer
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, P. O. Box, 1346, Kaneohe, Hawaii, USA
| | - Kim N Holland
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, P. O. Box, 1346, Kaneohe, Hawaii, USA
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25
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Braun CD, Galuardi B, Thorrold SR. HMMoce: An R package for improved geolocation of archival‐tagged fishes using a hidden Markov method. Methods Ecol Evol 2018. [DOI: 10.1111/2041-210x.12959] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Camrin D. Braun
- Massachusetts Institute of Technology‐Woods Hole Oceanographic Institution Joint Program in Oceanography/Applied Ocean Science and Engineering Cambridge MA USA
- Biology DepartmentWoods Hole Oceanographic Institution Woods Hole MA USA
| | - Benjamin Galuardi
- School of Marine Science and TechnologyUniversity of Massachusetts Dartmouth Fairhaven MA USA
- Greater Atlantic Regional Fisheries OfficeNational Marine Fisheries ServiceNational Oceanic and Atmospheric Administration Gloucester MA USA
| | - Simon R. Thorrold
- Biology DepartmentWoods Hole Oceanographic Institution Woods Hole MA USA
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26
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Bakker J, Wangensteen OS, Chapman DD, Boussarie G, Buddo D, Guttridge TL, Hertler H, Mouillot D, Vigliola L, Mariani S. Environmental DNA reveals tropical shark diversity in contrasting levels of anthropogenic impact. Sci Rep 2017; 7:16886. [PMID: 29203793 PMCID: PMC5715122 DOI: 10.1038/s41598-017-17150-2] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 11/19/2017] [Indexed: 01/27/2023] Open
Abstract
Sharks are charismatic predators that play a key role in most marine food webs. Their demonstrated vulnerability to exploitation has recently turned them into flagship species in ocean conservation. Yet, the assessment and monitoring of the distribution and abundance of such mobile species in marine environments remain challenging, often invasive and resource-intensive. Here we pilot a novel, rapid and non-invasive environmental DNA (eDNA) metabarcoding approach specifically targeted to infer shark presence, diversity and eDNA read abundance in tropical habitats. We identified at least 21 shark species, from both Caribbean and Pacific Coral Sea water samples, whose geographical patterns of diversity and read abundance coincide with geographical differences in levels of anthropogenic pressure and conservation effort. We demonstrate that eDNA metabarcoding can be effectively employed to study shark diversity. Further developments in this field have the potential to drastically enhance our ability to assess and monitor elusive oceanic predators, and lead to improved conservation strategies.
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Affiliation(s)
- Judith Bakker
- Ecosystems & Environment Research Centre, School of Environment & Life Sciences, University of Salford, Salford, M5 4WT, UK
| | - Owen S Wangensteen
- Ecosystems & Environment Research Centre, School of Environment & Life Sciences, University of Salford, Salford, M5 4WT, UK
| | - Demian D Chapman
- Department of Biological Sciences, Florida International University, 11200 S.W., 8th Street, Miami, Florida, 33199, USA
| | - Germain Boussarie
- MARBEC, UMR IRD-CNRS-UM-IFREMER 9190, Université Montpellier, Languedoc-Roussillon, 34095, Montpellier Cedex, France
- IRD (Institut de Recherche pour le Développement), Laboratoire d'Excellence Labex Corail, UMR IRD-UR-CNRS ENTROPIE, Centre IRD de Noumea, BP A5, 98800, Noumea Cedex, New Caledonia, France
| | - Dayne Buddo
- University of the West Indies, Discovery Bay Marine Laboratory and Field Station, P.O. Box 35, Discovery Bay, St. Ann, Jamaica
| | | | - Heidi Hertler
- The SFS Centre for Marine Resource Studies, Turks and Caicos Islands, UK
| | - David Mouillot
- MARBEC, UMR IRD-CNRS-UM-IFREMER 9190, Université Montpellier, Languedoc-Roussillon, 34095, Montpellier Cedex, France
| | - Laurent Vigliola
- IRD (Institut de Recherche pour le Développement), Laboratoire d'Excellence Labex Corail, UMR IRD-UR-CNRS ENTROPIE, Centre IRD de Noumea, BP A5, 98800, Noumea Cedex, New Caledonia, France
| | - Stefano Mariani
- Ecosystems & Environment Research Centre, School of Environment & Life Sciences, University of Salford, Salford, M5 4WT, UK.
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Tiger sharks can connect equatorial habitats and fisheries across the Atlantic Ocean basin. PLoS One 2017; 12:e0184763. [PMID: 28926627 PMCID: PMC5604974 DOI: 10.1371/journal.pone.0184763] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 08/30/2017] [Indexed: 12/02/2022] Open
Abstract
Increasing our knowledge about the spatial ecology of apex predators and their interactions with diverse habitats and fisheries is necessary for understanding the trophic mechanisms that underlie several aspects of marine ecosystem dynamics and for guiding informed management policies. A preliminary assessment of tiger shark (Galeocerdo cuvier) population structure off the oceanic insular system of Fernando de Noronha (FEN) and the large-scale movements performed by this species in the equatorial Atlantic Ocean was conducted using longline and handline fishing gear and satellite telemetry. A total of 25 sharks measuring 175–372 cm in total length (TL) were sampled. Most sharks were likely immature females ranging between 200 and 260 cm TL, with few individuals < 200 cm TL being caught. This contrasts greatly with the tiger shark size-distribution previously reported for coastal waters off the Brazilian mainland, where most individuals measured < 200 cm TL. Also, the movements of 8 individuals measuring 202–310 cm TL were assessed with satellite transmitters for a combined total of 757 days (mean = 94.6 days∙shark-1; SD = 65.6). These sharks exhibited a considerable variability in their horizontal movements, with three sharks showing a mostly resident behavior around FEN during the extent of the respective tracks, two sharks traveling west to the South American continent, and two sharks moving mostly along the middle of the oceanic basin, one of which ending up in the northern hemisphere. Moreover, one shark traveled east to the African continent, where it was eventually caught by fishers from Ivory Coast in less than 474 days at liberty. The present results suggest that young tiger sharks measuring < 200 cm TL make little use of insular oceanic habitats from the western South Atlantic Ocean, which agrees with a previously-hypothesized ontogenetic habitat shift from coastal to oceanic habitats experienced by juveniles of this species in this region. In addition, this study adds evidence that tiger sharks are able to connect marine trophic webs from the neritic provinces of the eastern and western margins of the Atlantic Ocean across the equatorial basin and that they may experience mortality induced by remote fisheries. All this information is extremely relevant for understanding the energetic balance of marine ecosystems as much as the exposure of this species to fishing pressure in this yet poorly-known region.
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28
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Acuña-Marrero D, Smith ANH, Hammerschlag N, Hearn A, Anderson MJ, Calich H, Pawley MDM, Fischer C, Salinas-de-León P. Residency and movement patterns of an apex predatory shark (Galeocerdo cuvier) at the Galapagos Marine Reserve. PLoS One 2017; 12:e0183669. [PMID: 28829820 PMCID: PMC5567640 DOI: 10.1371/journal.pone.0183669] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 08/08/2017] [Indexed: 11/19/2022] Open
Abstract
The potential effectiveness of marine protected areas (MPAs) as a conservation tool for large sharks has been questioned due to the limited spatial extent of most MPAs in contrast to the complex life history and high mobility of many sharks. Here we evaluated the movement dynamics of a highly migratory apex predatory shark (tiger shark Galeocerdo cuvier) at the Galapagos Marine Reserve (GMR). Using data from satellite tracking passive acoustic telemetry, and stereo baited remote underwater video, we estimated residency, activity spaces, site fidelity, distributional abundances and migration patterns from the GMR and in relation to nesting beaches of green sea turtles (Chelonia mydas), a seasonally abundant and predictable prey source for large tiger sharks. Tiger sharks exhibited a high degree of philopatry, with 93% of the total satellite-tracked time across all individuals occurring within the GMR. Large sharks (> 200 cm TL) concentrated their movements in front of the two most important green sea turtle-nesting beaches in the GMR, visiting them on a daily basis during nocturnal hours. In contrast, small sharks (< 200 cm TL) rarely visited turtle-nesting areas and displayed diurnal presence at a third location where only immature sharks were found. Small and some large individuals remained in the three study areas even outside of the turtle-nesting season. Only two sharks were satellite-tracked outside of the GMR, and following long-distance migrations, both individuals returned to turtle-nesting beaches at the subsequent turtle-nesting season. The spatial patterns of residency and site fidelity of tiger sharks suggest that the presence of a predictable source of prey and suitable habitats might reduce the spatial extent of this large shark that is highly migratory in other parts of its range. This highly philopatric behaviour enhances the potential effectiveness of the GMR for their protection.
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Affiliation(s)
- David Acuña-Marrero
- Charles Darwin Research Station, Puerto Ayora, Islas Galápagos, Ecuador
- Institute of Natural and Mathematical Sciences (INMS), Massey University, Albany Campus, Auckland, New Zealand
- * E-mail:
| | - Adam N. H. Smith
- Institute of Natural and Mathematical Sciences (INMS), Massey University, Albany Campus, Auckland, New Zealand
| | - Neil Hammerschlag
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, United States of America
- Abess Center for Ecosystem Science & Policy, University of Miami, Miami, United States of America
| | - Alex Hearn
- Universidad San Francisco de Quito, Quito, Ecuador
| | - Marti J. Anderson
- New Zealand Institute for Advanced Study (NZIAS), Massey University, Auckland, New Zealand
| | - Hannah Calich
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, United States of America
| | - Matthew D. M. Pawley
- Institute of Natural and Mathematical Sciences (INMS), Massey University, Albany Campus, Auckland, New Zealand
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29
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Ferreira LC, Thums M, Heithaus MR, Barnett A, Abrantes KG, Holmes BJ, Zamora LM, Frisch AJ, Pepperell JG, Burkholder D, Vaudo J, Nowicki R, Meeuwig J, Meekan MG. The trophic role of a large marine predator, the tiger shark Galeocerdo cuvier. Sci Rep 2017; 7:7641. [PMID: 28794497 PMCID: PMC5550416 DOI: 10.1038/s41598-017-07751-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 07/03/2017] [Indexed: 11/09/2022] Open
Abstract
Tiger sharks were sampled off the western (Ningaloo Reef, Shark Bay) and eastern (the Great Barrier Reef; GBR, Queensland and New South Wales; NSW) coastlines of Australia. Multiple tissues were collected from each shark to investigate the effects of location, size and sex of sharks on δ13C and δ15N stable isotopes among these locations. Isotopic composition of sharks sampled in reef and seagrass habitats (Shark Bay, GBR) reflected seagrass-based food-webs, whereas at Ningaloo Reef analysis revealed a dietary transition between pelagic and seagrass food-webs. In temperate habitats off southern Queensland and NSW coasts, shark diets relied on pelagic food-webs. Tiger sharks occupied roles at the top of food-webs at Shark Bay and on the GBR, but not at Ningaloo Reef or off the coast of NSW. Composition of δ13C in tissues was influenced by body size and sex of sharks, in addition to residency and diet stability. This variability in stable isotopic composition of tissues is likely to be a result of adaptive foraging strategies that allow these sharks to exploit multiple shelf and offshore habitats. The trophic role of tiger sharks is therefore both context- and habitat-dependent, consistent with a generalist, opportunistic diet at the population level.
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Affiliation(s)
- Luciana C Ferreira
- School of Biological Sciences and Oceans Institute, University of Western Australia, Crawley, WA, 6009, Australia. .,Australian Institute of Marine Science (M096), University of Western Australia, Crawley, WA, 6009, Australia.
| | - Michele Thums
- Australian Institute of Marine Science (M096), University of Western Australia, Crawley, WA, 6009, Australia
| | - Michael R Heithaus
- School of Environment, Arts, and Society, Florida International University, North Miami, FL, 33181, USA
| | - Adam Barnett
- College of Marine and Environmental Sciences, James Cook University, Cairns, QLD 4878, Australia
| | - Kátya G Abrantes
- College of Marine and Environmental Sciences, James Cook University, Cairns, QLD 4878, Australia
| | - Bonnie J Holmes
- School of Biological Sciences, University of Queensland, St Lucia, Queensland, QLD 4072, Australia
| | - Lara M Zamora
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7001, Australia
| | - Ashley J Frisch
- Reef HQ, Great Barrier Reef Marine Park Authority, Townsville, QLD 4810, Australia.,Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Julian G Pepperell
- Pepperell Research and Consulting Pty Ltd., Noosaville DC, Qld, Australia
| | - Derek Burkholder
- School of Environment, Arts, and Society, Florida International University, North Miami, FL, 33181, USA
| | - Jeremy Vaudo
- The Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, FL, 33004, USA
| | - Robert Nowicki
- School of Environment, Arts, and Society, Florida International University, North Miami, FL, 33181, USA.,Elizabeth Moore International Center for Coral Reef Research and Restoration, Mote Marine Laboratory, 24244 Overseas Highway, Summerland Key, FL, 33042, USA
| | - Jessica Meeuwig
- Centre for Marine Futures, University of Western Australia, Crawley, WA, 6009, Australia
| | - Mark G Meekan
- Australian Institute of Marine Science (M096), University of Western Australia, Crawley, WA, 6009, Australia
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30
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Holmes BJ, Williams SM, Otway NM, Nielsen EE, Maher SL, Bennett MB, Ovenden JR. Population structure and connectivity of tiger sharks ( Galeocerdo cuvier) across the Indo-Pacific Ocean basin. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170309. [PMID: 28791159 PMCID: PMC5541554 DOI: 10.1098/rsos.170309] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/25/2017] [Indexed: 05/15/2023]
Abstract
Population genetic structure using nine polymorphic nuclear microsatellite loci was assessed for the tiger shark (Galeocerdo cuvier) at seven locations across the Indo-Pacific, and one location in the southern Atlantic. Genetic analyses revealed considerable genetic structuring (FST > 0.14, p < 0.001) between all Indo-Pacific locations and Brazil. By contrast, no significant genetic differences were observed between locations from within the Pacific or Indian Oceans, identifying an apparent large, single Indo-Pacific population. A lack of differentiation between tiger sharks sampled in Hawaii and other Indo-Pacific locations identified herein is in contrast to an earlier global tiger shark nDNA study. The results of our power analysis provide evidence to suggest that the larger sample sizes used here negated any weak population subdivision observed previously. These results further highlight the need for cross-jurisdictional efforts to manage the sustainable exploitation of large migratory sharks like G. cuvier.
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Affiliation(s)
- Bonnie J. Holmes
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- Molecular Fisheries Laboratory, The University of Queensland, St Lucia, Queensland 4072Australia
| | - Samuel M. Williams
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- Molecular Fisheries Laboratory, The University of Queensland, St Lucia, Queensland 4072Australia
| | - Nicholas M. Otway
- New South Wales Department of Primary Industries, Port Stephens Fisheries Institute, Taylors Beach, New South Wales 2316, Australia
| | - Einar E. Nielsen
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600 Silkeborg, Denmark
| | - Safia L. Maher
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- Molecular Fisheries Laboratory, The University of Queensland, St Lucia, Queensland 4072Australia
| | - Mike B. Bennett
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
| | - Jennifer R. Ovenden
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072Australia
- Molecular Fisheries Laboratory, The University of Queensland, St Lucia, Queensland 4072Australia
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31
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An Assessment of Mobile Predator Populations along Shallow and Mesophotic Depth Gradients in the Hawaiian Archipelago. Sci Rep 2017. [PMID: 28634373 PMCID: PMC5478628 DOI: 10.1038/s41598-017-03568-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Large-bodied coral reef roving predators (sharks, jacks, snappers) are largely considered to be depleted around human population centers. In the Hawaiian Archipelago, supporting evidence is primarily derived from underwater visual censuses in shallow waters (≤30 m). However, while many roving predators are present or potentially more abundant in deeper strata (30–100 m+), distributional information remains sparse. To partially fill that knowledge gap, we conducted surveys in the remote Northwestern Hawaiian Islands (NWHI) and populated Main Hawaiian Islands (MHI) from 2012–2014 using baited remote underwater stereo-video. Surveys between 0–100 m found considerable roving predator community dissimilarities between regions, marked conspicuous changes in species abundances with increasing depth, and largely corroborated patterns documented during shallow water underwater visual censuses, with up to an order of magnitude more jacks and five times more sharks sampled in the NWHI compared to the MHI. Additionally, several species were significantly more abundant and larger in mesophotic versus shallow depths, which remains particularly suggestive of deep-water refugia effects in the MHI. Stereo-video extends the depth range of current roving predator surveys in a more robust manner than was previously available, and appears to be well-suited for large-scale roving predator work in the Hawaiian Archipelago.
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32
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Dicken ML, Hussey NE, Christiansen HM, Smale MJ, Nkabi N, Cliff G, Wintner SP. Diet and trophic ecology of the tiger shark (Galeocerdo cuvier) from South African waters. PLoS One 2017; 12:e0177897. [PMID: 28594833 PMCID: PMC5464543 DOI: 10.1371/journal.pone.0177897] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 05/04/2017] [Indexed: 11/18/2022] Open
Abstract
Knowledge of the diet and trophic ecology of apex predators is key for the implementation of effective ecosystem as well as species-based management initiatives. Using a combination of stomach content data and stable isotope analysis (δ15N and δ13C) the current study provides information on size-based and sex-specific variations in diet, trophic position (TP) and foraging habitat of tiger sharks (Galeocerdo cuvier) caught in the KwaZulu-Natal Sharks Board bather protection program. This study presents the longest time-series and most detailed analysis of stomach content data for G. cuvier worldwide. Prey identified from 628 non-empty stomachs revealed a size-based shift in diet. Reptiles, birds, mysticetes, and large shark species increased in dietary importance with G. cuvier size, concomitant with a decrease in smaller prey such as batoids and teleosts. Seasonal and decadal shifts in diet driven primarily by changes in the importance of elasmobranchs and mammal (cetacean) prey were recorded for medium sized (150-220 cm) G. cuvier. Both stomach content and stable isotope analysis indicated that G. cuvier is a generalist feeder at the population level. Size-based δ13C profiles indicated a movement to offshore foraging habitats by larger G. cuvier. Calculated TP varied by method ranging from 4.0 to 5.0 (TPSCA for stomach contents) and from 3.6 to 4.5 (TPscaled and TPadditive for δ15N). Large (> 220 cm) G. cuvier did not feed at discrete trophic levels, but rather throughout the food web. These data provide key information on the ecological role of G. cuvier to improve the accuracy of regional food web modelling. This will enable a better understanding of the ecological impacts related to changes in the abundance of this predator.
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Affiliation(s)
- Matthew L. Dicken
- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa
- Department of Zoology and Entomology, University of Fort Hare, Alice. South Africa
- * E-mail:
| | - Nigel E. Hussey
- University of Windsor–Biological Sciences, Windsor, Ontario, Canada
| | | | - Malcolm J. Smale
- Department of Zoology, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa
- Port Elizabeth Museum, Humewood, Port Elizabeth, South Africa
| | - Nomfundo Nkabi
- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa
| | - Geremy Cliff
- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban South Africa
| | - Sabine P. Wintner
- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban South Africa
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33
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Doherty PD, Baxter JM, Gell FR, Godley BJ, Graham RT, Hall G, Hall J, Hawkes LA, Henderson SM, Johnson L, Speedie C, Witt MJ. Long-term satellite tracking reveals variable seasonal migration strategies of basking sharks in the north-east Atlantic. Sci Rep 2017; 7:42837. [PMID: 28216646 PMCID: PMC5316944 DOI: 10.1038/srep42837] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 01/16/2017] [Indexed: 11/09/2022] Open
Abstract
Animal migration is ubiquitous in nature with individuals within a population often exhibiting varying movement strategies. The basking shark (Cetorhinus maximus) is the world's second largest fish species, however, a comprehensive understanding of their long-term wider-ranging movements in the north-east Atlantic is currently lacking. Seventy satellite tags were deployed on basking sharks over four years (2012-2015) off the west coast of Scotland and the Isle of Man. Data from 28 satellite tags with attachment durations of over 165 days reveal post-summer ranging behaviours. Tagged sharks moved a median minimum straight-line distance of 3,633 km; achieving median displacement of 1,057 km from tagging locations. Tagged individuals exhibited one of three migration behaviours: remaining in waters of UK, Ireland and the Faroe Islands; migrating south to the Bay of Biscay or moving further south to waters off the Iberian Peninsula, and North Africa. Sharks used both continental shelf areas and oceanic habitats, primarily in the upper 50-200 m of the water column, spanning nine geo-political zones and the High Seas, demonstrating the need for multi-national cooperation in the management of this species across its range.
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Affiliation(s)
- P. D. Doherty
- Environment & Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - J. M. Baxter
- Scottish Natural Heritage, Silvan House, 231 Corstorphine Road, Edinburgh, EH12 7AT, UK
| | - F. R. Gell
- Department of Environment, Food and Agriculture, Thie Sileau Whallian, Foxdale Road, St John’s, Isle of Man, IM4 3AS
| | - B. J. Godley
- Environment & Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - R. T. Graham
- MarAlliance, PO Box 283, San Pedro, Ambergris Caye, Belize
| | - G. Hall
- Manx Basking Shark Watch, Glen Chass Farmhouse, Port St Mary, Isle of Man, IM9 5PJ
| | - J. Hall
- Manx Basking Shark Watch, Glen Chass Farmhouse, Port St Mary, Isle of Man, IM9 5PJ
| | - L. A. Hawkes
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - S. M. Henderson
- Scottish Natural Heritage, Great Glen House, Inverness, Scotland, IV3 8NW, UK
| | - L. Johnson
- Wave Action, 3 Beacon Cottages, Falmouth, TR11 2LZ, UK
| | - C. Speedie
- Wave Action, 3 Beacon Cottages, Falmouth, TR11 2LZ, UK
| | - M. J. Witt
- Environment & Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
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34
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Bernard AM, Feldheim KA, Heithaus MR, Wintner SP, Wetherbee BM, Shivji MS. Global population genetic dynamics of a highly migratory, apex predator shark. Mol Ecol 2016; 25:5312-5329. [DOI: 10.1111/mec.13845] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 08/09/2016] [Accepted: 08/25/2016] [Indexed: 01/19/2023]
Affiliation(s)
- Andrea M. Bernard
- Save Our Seas Shark Research Center Halmos College of Natural Sciences & Oceanography Nova Southeastern University 8000 N. Ocean Drive Dania Beach FL 33004 USA
| | - Kevin A. Feldheim
- The Field Museum of Natural History Pritzker Laboratory for Molecular Systematics and Evolution 1400 South Lake Shore Drive Chicago IL 60605 USA
| | - Michael R. Heithaus
- School of Environment and Society Florida International University Miami FL USA
| | - Sabine P. Wintner
- KwaZulu‐Natal Sharks Board Private Bag 2 Umhlanga Rocks 4320 South Africa
- Biomedical Resource Unit University of KwaZulu‐Natal Durban 4000 South Africa
| | - Bradley M. Wetherbee
- Department of Biological Sciences University of Rhode Island Kingston RI USA
- Guy Harvey Research Institute Dania Beach, FL 33004 USA
| | - Mahmood S. Shivji
- Save Our Seas Shark Research Center and Guy Harvey Research Institute Halmos College of Natural Sciences & Oceanography Nova Southeastern University 8000 N. Ocean Drive Dania Beach FL 33004 USA
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35
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Hammerschlag N, Bell I, Fitzpatrick R, Gallagher AJ, Hawkes LA, Meekan MG, Stevens JD, Thums M, Witt MJ, Barnett A. Behavioral evidence suggests facultative scavenging by a marine apex predator during a food pulse. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2183-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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36
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Lopes MS, Bertucci TCP, Rapagnã L, Tubino RDA, Monteiro-Neto C, Tomas ARG, Tenório MC, Lima T, Souza R, Carrillo-Briceño JD, Haimovici M, Macario K, Carvalho C, Aguilera Socorro O. The Path towards Endangered Species: Prehistoric Fisheries in Southeastern Brazil. PLoS One 2016; 11:e0154476. [PMID: 27355355 PMCID: PMC4939631 DOI: 10.1371/journal.pone.0154476] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/14/2016] [Indexed: 12/03/2022] Open
Abstract
Brazilian shellmounds are archaeological sites with a high concentration of
marine faunal remains. There are more than 2000 sites along the coast of Brazil
that range in age from 8,720 to 985 cal BP. Here, we studied the
ichthyoarchaeological remains (i.e., cranial/postcranial bones, otoliths, and
teeth, among others) at 13 shellmounds on the southern coast of the state of Rio
de Janeiro, which are located in coastal landscapes, including a sandy plain
with coastal lagoons, rocky islands, islets and rocky bays. We identified
patterns of similarity between shellmounds based on fish diversity, the ages of
the assemblages, littoral geomorphology and prehistoric fisheries. Our new
radiocarbon dating, based on otolith samples, was used for fishery
characterization over time. A taxonomical study of the ichthyoarchaeological
remains includes a diversity of 97 marine species, representing 37% of all
modern species (i.e., 265 spp.) that have been documented along the coast of Rio
de Janeiro state. This high fish diversity recovered from the shellmounds is
clear evidence of well-developed prehistoric fishery activity that targeted
sharks, rays and finfishes in a productive area influenced by coastal marine
upwelling. The presence of adult and neonate shark, especially oceanic species,
is here interpreted as evidence of prehistoric fisheries capacity for
exploitation and possibly overexploitation in nursery areas. Various tools and
strategies were used to capture finfish in seasonal fisheries, over rocky reef
bottoms and in sandy littoral environments. Massive catches of whitemouth
croaker, main target dermersal species of South Atlantic coast, show evidence of
a reduction in body size of approximately 28% compared with modern fisheries.
Fishery activity involving vulnerable species, especially in nursery areas,
could mark the beginning of fish depletion along the southeastern Brazilian
coast and the collapse of natural fish populations.
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Affiliation(s)
- Mariana Samôr Lopes
- Universidade Federal Fluminense, Instituto de Biologia, Campus do
Valonguinho, Outeiro São João Batista, s/n°.CEP: 24020–141, Niterói, Rio de
Janeiro, Brasil
| | - Thayse Cristina Pereira Bertucci
- Universidade Federal Fluminense, Instituto de Biologia, Campus do
Valonguinho, Outeiro São João Batista, s/n°.CEP: 24020–141, Niterói, Rio de
Janeiro, Brasil
- * E-mail:
| | - Luciano Rapagnã
- Universidade Federal Fluminense, Instituto de Biologia, Campus do
Valonguinho, Outeiro São João Batista, s/n°.CEP: 24020–141, Niterói, Rio de
Janeiro, Brasil
| | - Rafael de Almeida Tubino
- Universidade Federal Fluminense, Instituto de Biologia, Campus do
Valonguinho, Outeiro São João Batista, s/n°.CEP: 24020–141, Niterói, Rio de
Janeiro, Brasil
| | - Cassiano Monteiro-Neto
- Universidade Federal Fluminense, Instituto de Biologia, Campus do
Valonguinho, Outeiro São João Batista, s/n°.CEP: 24020–141, Niterói, Rio de
Janeiro, Brasil
| | - Acácio Ribeiro Gomes Tomas
- Instituto de Pesca, Centro APTA Pescado Marinho, Av. Bartolomeu de Gusmão
192, Santos, São Paulo, CEP: 11030–906, Brasil
| | - Maria Cristina Tenório
- Universidade Federal do Rio de Janeiro, Museu Nacional, Departamento de
Antropologia. Quinta da Boa Vista, Rio de Janeiro, CEP: 20940–040,
Brasil
| | - Tânia Lima
- Universidade Federal do Rio de Janeiro, Museu Nacional, Departamento de
Antropologia. Quinta da Boa Vista, Rio de Janeiro, CEP: 20940–040,
Brasil
| | - Rosa Souza
- Universidade Federal Fluminense, Instituto de Biologia, Campus do
Valonguinho, Outeiro São João Batista, s/n°.CEP: 24020–141, Niterói, Rio de
Janeiro, Brasil
| | | | - Manuel Haimovici
- Universidade Federal do Rio Grande, Instituto de Oceanografia, Campus
Carreiros, Av. Itália, Rio Grande, Rio Grande do Sul, CEP: 96201–900,
Brasil
| | - Kita Macario
- Universidade Federal Fluminense, Instituto de Física, Campus da Praia
Vermelha, Boa Viagem, CEP: 24210–310, Niterói, Rio de Janeiro,
Brasil
| | - Carla Carvalho
- Universidade Federal Fluminense, Instituto de Física, Campus da Praia
Vermelha, Boa Viagem, CEP: 24210–310, Niterói, Rio de Janeiro,
Brasil
| | - Orangel Aguilera Socorro
- Universidade Federal Fluminense, Instituto de Biologia, Campus do
Valonguinho, Outeiro São João Batista, s/n°.CEP: 24020–141, Niterói, Rio de
Janeiro, Brasil
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Pickard AE, Vaudo JJ, Wetherbee BM, Nemeth RS, Blondeau JB, Kadison EA, Shivji MS. Comparative Use of a Caribbean Mesophotic Coral Ecosystem and Association with Fish Spawning Aggregations by Three Species of Shark. PLoS One 2016; 11:e0151221. [PMID: 27144275 PMCID: PMC4856273 DOI: 10.1371/journal.pone.0151221] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/23/2016] [Indexed: 11/19/2022] Open
Abstract
Understanding of species interactions within mesophotic coral ecosystems (MCEs; ~ 30-150 m) lags well behind that for shallow coral reefs. MCEs are often sites of fish spawning aggregations (FSAs) for a variety of species, including many groupers. Such reproductive fish aggregations represent temporal concentrations of potential prey that may be drivers of habitat use by predatory species, including sharks. We investigated movements of three species of sharks within a MCE and in relation to FSAs located on the shelf edge south of St. Thomas, United States Virgin Islands. Movements of 17 tiger (Galeocerdo cuvier), seven lemon (Negaprion brevirostris), and six Caribbean reef (Carcharhinus perezi) sharks tagged with acoustic transmitters were monitored within the MCE using an array of acoustic receivers spanning an area of 1,060 km2 over a five year period. Receivers were concentrated around prominent grouper FSAs to monitor movements of sharks in relation to these temporally transient aggregations. Over 130,000 detections of telemetered sharks were recorded, with four sharks tracked in excess of 3 years. All three shark species were present within the MCE over long periods of time and detected frequently at FSAs, but patterns of MCE use and orientation towards FSAs varied both spatially and temporally among species. Lemon sharks moved over a large expanse of the MCE, but concentrated their activities around FSAs during grouper spawning and were present within the MCE significantly more during grouper spawning season. Caribbean reef sharks were present within a restricted portion of the MCE for prolonged periods of time, but were also absent for long periods. Tiger sharks were detected throughout the extent of the acoustic array, with the MCE representing only portion of their habitat use, although a high degree of individual variation was observed. Our findings indicate that although patterns of use varied, all three species of sharks repeatedly utilized the MCE and as upper trophic level predators they are likely involved in a range of interactions with other members of MCEs.
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Affiliation(s)
- Alexandria E. Pickard
- Guy Harvey Research Institute, Guy Harvey Oceanographic Center, Nova Southeastern University, 8000 N Ocean Drive, Dania Beach, FL, 33004, United States of America
| | - Jeremy J. Vaudo
- Guy Harvey Research Institute, Guy Harvey Oceanographic Center, Nova Southeastern University, 8000 N Ocean Drive, Dania Beach, FL, 33004, United States of America
| | - Bradley M. Wetherbee
- Guy Harvey Research Institute, Guy Harvey Oceanographic Center, Nova Southeastern University, 8000 N Ocean Drive, Dania Beach, FL, 33004, United States of America
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, 02881, United States of America
- * E-mail:
| | - Richard S. Nemeth
- Center for Marine and Environmental Studies, University of the Virgin Islands, #2 John Brewers Bay, St. Thomas, USVI, 00802, United States of America
| | - Jeremiah B. Blondeau
- Center for Marine and Environmental Studies, University of the Virgin Islands, #2 John Brewers Bay, St. Thomas, USVI, 00802, United States of America
| | - Elizabeth A. Kadison
- Center for Marine and Environmental Studies, University of the Virgin Islands, #2 John Brewers Bay, St. Thomas, USVI, 00802, United States of America
| | - Mahmood S. Shivji
- Guy Harvey Research Institute, Guy Harvey Oceanographic Center, Nova Southeastern University, 8000 N Ocean Drive, Dania Beach, FL, 33004, United States of America
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Pinto C, Thorburn JA, Neat F, Wright PJ, Wright S, Scott BE, Cornulier T, Travis JMJ. Using individual tracking data to validate the predictions of species distribution models. DIVERS DISTRIB 2016. [DOI: 10.1111/ddi.12437] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Cecilia Pinto
- Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen AB24 2TZ UK
- Marine Scotland Science; Marine Laboratory; 375 Victoria Road Aberdeen AB11 9DB UK
| | - James A. Thorburn
- Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen AB24 2TZ UK
| | - Francis Neat
- Marine Scotland Science; Marine Laboratory; 375 Victoria Road Aberdeen AB11 9DB UK
| | - Peter J. Wright
- Marine Scotland Science; Marine Laboratory; 375 Victoria Road Aberdeen AB11 9DB UK
| | - Serena Wright
- Centre for Environment Fisheries & Aquaculture Science; Pakefield Road Lowestoft Suffolk NR33 0HT UK
| | - Beth E. Scott
- Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen AB24 2TZ UK
| | - Thomas Cornulier
- Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen AB24 2TZ UK
| | - Justin M. J. Travis
- Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen AB24 2TZ UK
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Wilmé L, Waeber PO, Ganzhorn JU. Marine turtles used to assist Austronesian sailors reaching new islands. C R Biol 2016; 339:78-82. [PMID: 26857090 DOI: 10.1016/j.crvi.2015.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 11/30/2015] [Accepted: 12/03/2015] [Indexed: 11/24/2022]
Abstract
Austronesians colonized the islands of Rapa Nui, Hawaii, the Marquesas and Madagascar. All of these islands have been found to harbor Austronesian artifacts and also, all of them are known nesting sites for marine turtles. Turtles are well known for their transoceanic migrations, sometimes totalling thousands of miles, between feeding and nesting grounds. All marine turtles require land for nesting. Ancient Austronesians are known to have had outstanding navigation skills, which they used to adjust course directions. But these skills will have been insufficient to locate tiny, remote islands in the vast Indo-Pacific oceans. We postulate that the Austronesians must have had an understanding of the marine turtles' migration patterns and used this knowledge to locate remote and unknown islands. The depth and speed at which marine turtles migrate makes following them by outrigger canoes feasible. Humans have long capitalized on knowledge of animal behavior.
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Affiliation(s)
- Lucienne Wilmé
- University of Antananarivo, School of Agronomy, Water and Forest Department, BP 175, Antananarivo 101, Madagascar; Missouri Botanical Garden, Madagascar Research & Conservation Program, BP 3391, Antananarivo 101, Madagascar.
| | - Patrick O Waeber
- Forest Management and Development, Department of Environmental Sciences, Swiss Federal Institute of Technology Zurich, 8092 Zurich, Switzerland.
| | - Joerg U Ganzhorn
- Animal Ecology and Conservation, Hamburg University, 20146 Hamburg, Germany.
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Espinoza M, Heupel MR, Tobin AJ, Simpfendorfer CA. Evidence of Partial Migration in a Large Coastal Predator: Opportunistic Foraging and Reproduction as Key Drivers? PLoS One 2016; 11:e0147608. [PMID: 26841110 PMCID: PMC4740466 DOI: 10.1371/journal.pone.0147608] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 01/06/2016] [Indexed: 11/18/2022] Open
Abstract
Understanding animal movement decisions that involve migration is critical for evaluating population connectivity, and thus persistence. Recent work on sharks has shown that often only a portion of the adult population will undertake migrations, while the rest may be resident in an area for long periods. Defining the extent to which adult sharks use specific habitats and their migratory behaviour is essential for assessing their risk of exposure to threats such as fishing and habitat degradation. The present study used acoustic telemetry to examine residency patterns and migratory behaviour of adult bull sharks (Carcharhinus leucas) along the East coast of Australia. Fifty-six VR2W acoustic receivers were used to monitor the movements of 33 bull sharks in the central Great Barrier Reef (GBR). Both males and females were detected year-round, but their abundance and residency peaked between September and December across years (2012–2014). High individual variability in reef use patterns was apparent, with some individuals leaving the array for long periods, whereas others (36%) exhibited medium (0.20–0.40) or high residency (> 0.50). A large portion of the population (51%) undertook migrations of up to 1,400 km to other coral reefs and/or inshore coastal habitats in Queensland and New South Wales. Most of these individuals (76%) were mature females, and the timing of migrations coincided with the austral summer (Dec-Feb). All migrating individuals (except one) returned to the central GBR, highlighting its importance as a potential foraging ground. Our findings suggest that adult bull sharks appear to be highly dependent on coral reef resources and provide evidence of partial migration, where only a portion of the female population undertook seasonal migrations potentially to give birth. Given that estuarine habitats face constant anthropogenic pressures, understanding partial migration and habitat connectivity of large coastal predators should be a priority for their management.
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Affiliation(s)
- Mario Espinoza
- Centre for Sustainable Tropical Fisheries and Aquaculture & College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, 4811, Australia
- AIMS@JCU, Australian Institute of Marine Science, College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, 4811, Australia
- * E-mail:
| | - Michelle R. Heupel
- Centre for Sustainable Tropical Fisheries and Aquaculture & College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, 4811, Australia
- Australian Institute of Marine Science, PMB No 3, Townsville, Queensland, 4810, Australia
| | - Andrew J. Tobin
- Centre for Sustainable Tropical Fisheries and Aquaculture & College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, 4811, Australia
| | - Colin A. Simpfendorfer
- Centre for Sustainable Tropical Fisheries and Aquaculture & College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, 4811, Australia
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Espinoza M, Lédée EJI, Simpfendorfer CA, Tobin AJ, Heupel MR. Contrasting movements and connectivity of reef-associated sharks using acoustic telemetry: implications for management. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2015; 25:2101-2118. [PMID: 26910942 DOI: 10.1890/14-2293.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Understanding the efficacy of marine protected areas (MPAs) for wide-ranging predators is essential to designing effective management and conservation approaches. The use of acoustic monitoring and network analysis can improve our understanding of the spatial ecology and functional connectivity of reef-associated species, providing a useful approach for reef-based conservation planning. This study compared and contrasted the movement and connectivity of sharks with different degrees of reef association. We examined the residency, dispersal, degree of reef connectivity, and MPA use of grey reef (Carcharhinus amblyrhynchos), silvertip (C. albimarginatus), and bull (C. leucas) sharks monitored in the central Great Barrier Reef (GBR). An array of 56 acoustic receivers was used to monitor shark movements on 17 semi-isolated reefs. Carcharhinus amblyrhynchos and C. albimarginatus were detected most days at or near their tagging reef. However, while C. amblyrhynchos spent 80% of monitoring days in the array, C. albimarginatus was only detected 50% of the time. Despite both species moving similar distances (< 50 km), a large portion of the population of C. albimarginatus (71%) was detected on multiple reefs and moved more frequently between reefs and management zones than C. amblyrhynchos. Carcharhinus leucas was detected less than 20% of the time within the tagging array, and 42% of the population undertook long-range migrations to other arrays in the GBR. Networks derived for C. leucas were larger and more complex than those for C. amblyrhynchos and C. albimarginatus. Our findings suggest that protecting specific reefs based on prior knowledge (e.g., healthier reefs with high fish biomass) and increasing the level of protection to include nearby, closely spaced reef habitats (< 20 km) may perform better for species like C. albimarginatus than having either a single or a network of isolated MPAs. This design would also provide protection for larger male C. amblyrhynchos, which tend to disperse more and use larger areas than females. For wide-ranging sharks like C. leucas, a combination of spatial planning and other alternative measures is critical. Our findings demonstrate that acoustic monitoring can serve as a useful platform for designing more effective MPA networks for reef predators displaying a range of movement patterns.
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White ER, Myers MC, Flemming JM, Baum JK. Shifting elasmobranch community assemblage at Cocos Island--an isolated marine protected area. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2015; 29:1186-1197. [PMID: 25807991 DOI: 10.1111/cobi.12478] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 12/14/2014] [Indexed: 06/04/2023]
Abstract
Fishing pressure has increased the extinction risk of many elasmobranch (shark and ray) species. Although many countries have established no-take marine reserves, a paucity of monitoring data means it is still unclear if reserves are effectively protecting these species. We examined data collected by a small group of divers over the past 21 years at one of the world's oldest marine protected areas (MPAs), Cocos Island National Park, Costa Rica. We used mixed effects models to determine trends in relative abundance, or probability of occurrence, of 12 monitored elasmobranch species while accounting for variation among observers and from abiotic factors. Eight of 12 species declined significantly over the past 2 decades. We documented decreases in relative abundance for 6 species, including the iconic scalloped hammerhead shark (Sphyrna lewini) (-45%), whitetip reef shark (Triaenodon obesus) (-77%), mobula ray (Mobula spp.) (-78%), and manta ray (Manta birostris) (-89%), and decreases in the probability of occurrence for 2 other species. Several of these species have small home ranges and should be better protected by an MPA, which underscores the notion that declines of marine megafauna will continue unabated in MPAs unless there is adequate enforcement effort to control fishing. In addition, probability of occurrence at Cocos Island of tiger (Galeocerdo cuvier), Galapagos (Carcharhinus galapagensis), blacktip (Carcharhinus limbatus), and whale (Rhincodon typus) sharks increased significantly. The effectiveness of MPAs cannot be evaluated by examining single species because population responses can vary depending on life history traits and vulnerability to fishing pressure.
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Affiliation(s)
- Easton R White
- Department of Biology, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada
| | - Mark C Myers
- Department of Biology, University of Northern Iowa, 144 McCollum Science Hall, Cedar Falls, IA, 50614-0421, U.S.A
| | - Joanna Mills Flemming
- Department of Mathematics and Statistics, Dalhousie University, 6316 Coburg Road, P.O. Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Julia K Baum
- Department of Biology, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada
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Holmes BJ, Peddemors VM, Gutteridge AN, Geraghty PT, Chan RWK, Tibbetts IR, Bennett MB. Age and growth of the tiger shark Galeocerdo cuvier off the east coast of Australia. JOURNAL OF FISH BIOLOGY 2015; 87:422-48. [PMID: 26248806 DOI: 10.1111/jfb.12732] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 05/22/2015] [Indexed: 05/15/2023]
Abstract
Total lengths (L(T)) at age and growth rates for south-west Pacific Galeocerdo cuvier were estimated from vertebral growth-band counts of 202 sagitally sectioned centra from 112 females (71-430 cm L(T)), 79 males (72-351 cm L(T)) and 11 of unknown sex. Captive growth data were also examined to complement vertebral age estimations. The sexes combined modelled growth coefficient (k = 0.08) was smaller than previously reported for G. cuvier populations elsewhere. Split-band and narrow banding patterns were identified as potential sources of age underestimation in this species.
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Affiliation(s)
- B J Holmes
- School of Biological Science, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - V M Peddemors
- Department of Primary Industries, Fisheries New South Wales, Sydney Institute of Marine Science, Mosman, NSW, 2088, Australia
| | - A N Gutteridge
- School of Biological Science, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - P T Geraghty
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - R W K Chan
- Office of Planning and Strategic Management, Australian Catholic University, North Sydney, NSW, 2060, Australia
| | - I R Tibbetts
- School of Biological Science, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - M B Bennett
- School of Biological Science, The University of Queensland, St Lucia, Qld, 4072, Australia
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Lea JSE, Wetherbee BM, Queiroz N, Burnie N, Aming C, Sousa LL, Mucientes GR, Humphries NE, Harvey GM, Sims DW, Shivji MS. Repeated, long-distance migrations by a philopatric predator targeting highly contrasting ecosystems. Sci Rep 2015; 5:11202. [PMID: 26057337 PMCID: PMC4460898 DOI: 10.1038/srep11202] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/23/2015] [Indexed: 11/09/2022] Open
Abstract
Long-distance movements of animals are an important driver of population spatial dynamics and determine the extent of overlap with area-focused human activities, such as fishing. Despite global concerns of declining shark populations, a major limitation in assessments of population trends or spatial management options is the lack of information on their long-term migratory behaviour. For a large marine predator, the tiger shark Galeocerdo cuvier, we show from individuals satellite-tracked for multiple years (up to 1101 days) that adult males undertake annually repeated, round-trip migrations of over 7,500 km in the northwest Atlantic. Notably, these migrations occurred between the highly disparate ecosystems of Caribbean coral reef regions in winter and high latitude oceanic areas in summer, with strong, repeated philopatry to specific overwintering insular habitat. Partial migration also occurred, with smaller, immature individuals displaying reduced migration propensity. Foraging may be a putative motivation for these oceanic migrations, with summer behaviour showing higher path tortuosity at the oceanic range extremes. The predictable migratory patterns and use of highly divergent ecosystems shown by male tiger sharks appear broadly similar to migrations seen in birds, reptiles and mammals, and highlight opportunities for dynamic spatial management and conservation measures of highly mobile sharks.
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Affiliation(s)
- James S E Lea
- 1] The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, Florida 33004, United States of America [2] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [3] Danah Divers, Marine Research Facility, PO Box 10646, Jeddah, 21443, Saudi Arabia [4] University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA, UK
| | - Bradley M Wetherbee
- 1] The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, Florida 33004, United States of America [2] Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Nuno Queiroz
- 1] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [2] CIBIO - Universidade do Porto, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4485-668 Vairão, Portugal
| | | | | | - Lara L Sousa
- 1] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [2] CIBIO - Universidade do Porto, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Rua Padre Armando Quintas, 4485-668 Vairão, Portugal [3] Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Gonzalo R Mucientes
- 1] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [2] Instituto de Investigaciones Marinas, CSIC, Eduardo Cabello 6, 36208, Vigo, Spain [3] CETMAR, Eduardo Cabello 6, 36208, Vigo, Spain
| | - Nicolas E Humphries
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
| | - Guy M Harvey
- The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, Florida 33004, United States of America
| | - David W Sims
- 1] Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK [2] Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK [3] Centre for Biological Sciences, Building 85, University of Southampton, Highfield Campus, Southampton SO17 1BJ, UK
| | - Mahmood S Shivji
- The Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, Florida 33004, United States of America
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Zsebők S, Czabán D, Farkas J, Siemers BM, von Merten S. Acoustic species identification of shrews: Twittering calls for monitoring. ECOL INFORM 2015. [DOI: 10.1016/j.ecoinf.2015.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ferreira LC, Thums M, Meeuwig JJ, Vianna GMS, Stevens J, McAuley R, Meekan MG. Crossing latitudes--long-distance tracking of an apex predator. PLoS One 2015; 10:e0116916. [PMID: 25671609 PMCID: PMC4324986 DOI: 10.1371/journal.pone.0116916] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 12/16/2014] [Indexed: 11/18/2022] Open
Abstract
Tiger sharks (Galeocerdo cuvier) are apex predators occurring in most tropical and warm temperate marine ecosystems, but we know relatively little of their patterns of residency and movement over large spatial and temporal scales. We deployed satellite tags on eleven tiger sharks off the north-western coast of Western Australia and used the Brownian Bridge kernel method to calculate home ranges and analyse movement behaviour. One individual recorded one of the largest geographical ranges of movement ever reported for the species, travelling over 4000 km during 517 days of monitoring. Tags on the remainder of the sharks reported for shorter periods (7-191 days). Most of these sharks had restricted movements and long-term (30-188 days) residency in coastal waters in the vicinity of the area where they were tagged. Core home range areas of sharks varied greatly from 1166.9 to 634,944 km2. Tiger sharks spent most of their time in water temperatures between 23°-26°C but experienced temperatures ranging from 6°C to 33°C. One shark displayed seasonal movements among three distinct home range cores spread along most of the coast of Western Australia and generalized linear models showed that this individual had different patterns of temperature and depth occupancy in each region of the coast, with the highest probability of residency occurring in the shallowest areas of the coast with water temperatures above 23°C. These results suggest that tiger sharks can migrate over very large distances and across latitudes ranging from tropical to the cool temperate waters. Such extensive long-term movements may be a key element influencing the connectivity of populations within and among ocean basins.
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Affiliation(s)
- Luciana C Ferreira
- The UWA Oceans Institute, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia; Australian Institute of Marine Science, Perth, Western Australia, Australia
| | - Michele Thums
- Australian Institute of Marine Science, Perth, Western Australia, Australia
| | - Jessica J Meeuwig
- Centre for Marine Futures, The University of Western Australia, Crawley, Western Australia, Australia
| | - Gabriel M S Vianna
- The UWA Oceans Institute, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia; Australian Institute of Marine Science, Perth, Western Australia, Australia
| | - John Stevens
- CSIRO Marine and Atmospheric Research, Hobart, Tasmania, Australia
| | - Rory McAuley
- Department of Fisheries, Government of Western Australia, WA Fisheries and Marine Research Laboratories, Perth, Western Australia, Australia
| | - Mark G Meekan
- Australian Institute of Marine Science, Perth, Western Australia, Australia
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Smith KR, Scarpaci C, Louden BM, Otway NM. Behaviour of aggregated grey nurse sharks Carcharias taurus off eastern Australia: similarities and differences among life-history stages and sites. ENDANGER SPECIES RES 2015. [DOI: 10.3354/esr00652] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Afonso AS, Hazin FHV. Vertical movement patterns and ontogenetic niche expansion in the tiger shark, Galeocerdo cuvier. PLoS One 2015; 10:e0116720. [PMID: 25629732 PMCID: PMC4309595 DOI: 10.1371/journal.pone.0116720] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 12/12/2014] [Indexed: 11/24/2022] Open
Abstract
Sharks are top predators in many marine ecosystems and can impact community dynamics, yet many shark populations are undergoing severe declines primarily due to overfishing. Obtaining species-specific knowledge on shark spatial ecology is important to implement adequate management strategies for the effective conservation of these taxa. This is particularly relevant concerning highly-mobile species that use wide home ranges comprising coastal and oceanic habitats, such as tiger sharks, Galeocerdo cuvier. We deployed satellite tags in 20 juvenile tiger sharks off northeastern Brazil to assess the effect of intrinsic and extrinsic factors on depth and temperature usage. Sharks were tracked for a total of 1184 d and used waters up to 1112 m in depth. The minimum temperature recorded equaled 4°C. All sharks had a clear preference for surface (< 5 m) waters but variability in depth usage was observed as some sharks used mostly shallow (< 60 m) waters whereas others made frequent incursions into greater depths. A diel behavioral shift was detected, with sharks spending considerably more time in surface (< 10 m) waters during the night. Moreover, a clear ontogenetic expansion in the vertical range of tiger shark habitat was observed, with generalized linear models estimating a ~4-fold increase in maximum diving depth from 150- to 300-cm size-classes. The time spent in the upper 5 m of the water column did not vary ontogenetically but shark size was the most important factor explaining the utilization of deeper water layers. Young-of-the-year tiger sharks seem to associate with shallow, neritic habitats but they progressively move into deeper oceanic habitats as they grow larger. Such an early plasticity in habitat use could endow tiger sharks with access to previously unavailable prey, thus contributing to a wider ecological niche.
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Affiliation(s)
- André S. Afonso
- Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil
- Faculdade de Ciências e Tecnologia, Universidade do Algarve, Faro, Portugal
| | - Fábio H. V. Hazin
- Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil
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Read TC, FitzSimmons NN, Wantiez L, Jensen MP, Keller F, Chateau O, Farman R, Werry J, MacKay KT, Petro G, Limpus CJ. Mixed stock analysis of a resident green turtle, Chelonia mydas, population in New Caledonia links rookeries in the South Pacific. WILDLIFE RESEARCH 2015. [DOI: 10.1071/wr15064] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
Migratory species are known to pose a challenge for conservation because it is essential to understand their complex life history in order to implement efficient conservation actions.
Aims
In New Caledonia, large seagrass habitats in the Grand Lagon Sud (GLS) are home to resident green turtles (Chelonia mydas) of unknown origins. To assess the stock composition in the GLS, 164 foraging turtles were sampled for genetic analysis of ~770 base pairs of the mitochondrial DNA (mtDNA) control region.
Methods
Foraging turtles ranging in size from 48.0 to 108.4 cm curved carapace length were captured at five different sites within the GLS between September 2012 and December 2013. To provide baseline data for mixed stock analysis, published data from rookeries were used in addition to 105 samples collected at rookeries in the d’Entrecasteaux Islands and Chesterfield Islands in New Caledonia and at Malekula Island in Vanuatu. Exact tests of population differentiation and pairwise FST estimates were used to test for differences in mtDNA haplotype frequencies.
Key results
These analyses indicated that rookeries in the d’Entrecasteaux Islands and Vanuatu form unique management units and that the Chesterfield Islands rookeries are linked to the Coral Sea management unit. Mixed stock analysis indicated the highest proportion (mean = 0.63) of foraging turtles originate from the d’Entrecasteaux stock.
Conclusions
The larger contribution is estimated to be from a large rookery from New Caledonia, but smaller contributions are suggested from other rookeries in the South Pacific.
Implications
Marine conservation policies in New Caledonia need to consider the links between the foraging and nesting populations of C. mydas in New Caledonia and other rookeries and foraging grounds in the Coral Sea.
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Vignaud TM, Mourier J, Maynard JA, Leblois R, Spaet J, Clua E, Neglia V, Planes S. Blacktip reef sharks, Carcharhinus melanopterus, have high genetic structure and varying demographic histories in their Indo-Pacific range. Mol Ecol 2014; 23:5193-207. [PMID: 25251515 DOI: 10.1111/mec.12936] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 09/19/2014] [Indexed: 12/20/2022]
Abstract
For free-swimming marine species like sharks, only population genetics and demographic history analyses can be used to assess population health/status as baseline population numbers are usually unknown. We investigated the population genetics of blacktip reef sharks, Carcharhinus melanopterus; one of the most abundant reef-associated sharks and the apex predator of many shallow water reefs of the Indian and Pacific Oceans. Our sampling includes 4 widely separated locations in the Indo-Pacific and 11 islands in French Polynesia with different levels of coastal development. Four-teen microsatellite loci were analysed for samples from all locations and two mitochondrial DNA fragments, the control region and cytochrome b, were examined for 10 locations. For microsatellites, genetic diversity is higher for the locations in the large open systems of the Red Sea and Australia than for the fragmented habitat of the smaller islands of French Polynesia. Strong significant structure was found for distant locations with FST values as high as ~0.3, and a smaller but still significant structure is found within French Polynesia. Both mitochondrial genes show only a few mutations across the sequences with a dominant shared haplotype in French Polynesia and New Caledonia suggesting a common lineage different to that of East Australia. Demographic history analyses indicate population expansions in the Red Sea and Australia that may coincide with sea level changes after climatic events. Expansions and flat signals are indicated for French Polynesia as well as a significant recent bottleneck for Moorea, the most human-impacted lagoon of the locations in French Polynesia.
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Affiliation(s)
- Thomas M Vignaud
- Laboratoire d'Excellence "CORAIL", USR 3278 CNRS - EPHE, CRIOBE, BP 1013 - 98 729 Papetoai, Moorea, Polynésie, Française
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