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Dunn RE, Benkwitt CE, Maury O, Barrier N, Carr P, Graham NAJ. Island restoration to rebuild seabird populations and amplify coral reef functioning. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2024:e14313. [PMID: 38887868 DOI: 10.1111/cobi.14313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/19/2024] [Accepted: 04/15/2024] [Indexed: 06/20/2024]
Abstract
Mobile organisms like seabirds can provide important nutrient flows between ecosystems, but this connectivity has been interrupted by the degradation of island ecosystems. Island restoration (via invasive species eradications and the restoration of native vegetation) can reestablish seabird populations and their nutrient transfers between their foraging areas, breeding colonies, and adjacent nearshore habitats. Its diverse benefits are making island restoration increasingly common and scalable to larger islands and whole archipelagos. We identified the factors that influence breeding seabird abundances throughout the Chagos Archipelago in the Indian Ocean and conducted predictive modeling to estimate the abundances of seabirds that the archipelago could support under invasive predator eradication and native vegetation restoration scenarios. We explored whether the prey base exists to support restored seabird populations across the archipelago, calculated the nitrogen that restored populations of seabirds might produce via their guano, and modeled the cascading conservation gains that island restoration could provide. Restoration was predicted to increase breeding pairs of seabirds to over 280,000, and prey was predicted to be ample to support the revived seabird populations. Restored nutrient fluxes were predicted to result in increases in coral growth rates, reef fish biomasses, and parrotfish grazing and bioerosion rates. Given these potential cross-ecosystem benefits, our results support island restoration as a conservation priority that could enhance resilience to climatic change effects, such as sea-level rise and coral bleaching. We encourage the incorporation of our estimates of cross-ecosystem benefits in prioritization exercises for island restoration.
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Affiliation(s)
- Ruth E Dunn
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
- The Lyell Centre, Heriot-Watt University, Edinburgh, UK
| | | | - Olivier Maury
- Institut de Recherche pour le Développement, Université de Montpellier, Sète, France
| | - Nicolas Barrier
- Institut de Recherche pour le Développement, Université de Montpellier, Sète, France
| | - Peter Carr
- Institute of Zoology, Zoological Society of London, London, UK
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2
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Hays GC, Laloë JO, Mortimer JA, Rattray A, Tromp JJ, Esteban N. Remote submerged banks and mesophotic ecosystems can provide key habitat for endangered marine megafauna. SCIENCE ADVANCES 2024; 10:eadl2838. [PMID: 38381823 PMCID: PMC10881038 DOI: 10.1126/sciadv.adl2838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/18/2024] [Indexed: 02/23/2024]
Abstract
The importance of some ecosystems remains poorly understood. We showed that mesophotic ecosystems (30 to 150 m) are a key habitat for a critically endangered species, with strong evidence that a globally important population of adult hawksbill turtles (Eretmochelys imbricata) almost exclusively foraged at these depths on remote submerged banks. This discovery highlights the need for such areas to be included in conservation planning, for example, as part of the United Nations High Seas Treaty. We equipped nesting turtles with Fastloc-GPS (Global Positioning System) satellite tags at an Indian Ocean breeding area and they all traveled to deep foraging sites (6765 days of tracking data across 22 individuals including 183,921 dive-depth measurements) rather than shallow coral reef sites. Both chart depths and depth data relayed from the tags indicated that turtles foraged at mesophotic depths, the modal dive depths being between 35 and 40 m. We calculate that 55,554 km2 of the western Indian Ocean alone consists of submerged banks between 30 and 60 m.
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Affiliation(s)
- Graeme C. Hays
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Jacques-Olivier Laloë
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Jeanne A. Mortimer
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
- PO Box 1443, Victoria, Mahé, Seychelles
| | - Alex Rattray
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Jared J. Tromp
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Nicole Esteban
- Department of Biosciences, Swansea University, Swansea SA2 8PP, Wales, UK
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Monteforte KIP, Butcher PA, Morris SG, Kelaher BP. The Relative Abundance and Occurrence of Sharks off Ocean Beaches of New South Wales, Australia. BIOLOGY 2022; 11:biology11101456. [PMID: 36290360 PMCID: PMC9599013 DOI: 10.3390/biology11101456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/15/2022] [Accepted: 09/29/2022] [Indexed: 11/05/2022]
Abstract
There is still limited information about the diversity, distribution, and abundance of sharks in and around the surf zones of ocean beaches. We used long-term and large-scale drone surveying techniques to test hypotheses about the relative abundance and occurrence of sharks off ocean beaches of New South Wales, Australia. We quantified sharks in 36,384 drone flights across 42 ocean beaches from 2017 to 2021. Overall, there were 347 chondrichthyans recorded, comprising 281 (81.0%) sharks, with observations occurring in <1% of flights. Whaler sharks (Carcharhinus spp.) had the highest number of observations (n = 158) recorded. There were 34 individuals observed for both white sharks (Carcharodon carcharias) and critically endangered greynurse sharks (Carcharias taurus). Bull sharks (Carcharhinus leucas), leopard sharks (Stegostoma tigrinum) and hammerhead species (Sphyrna spp.) recorded 29, eight and three individuals, respectively. Generalised additive models were used to identify environmental drivers for detection probability of white, bull, greynurse, and whaler sharks. Distances to the nearest estuary, headland, and island, as well as water temperature and wave height, were significant predictors of shark occurrence; however, this varied among species. Overall, we provide valuable information for evidence-based species-specific conservation and management strategies for coastal sharks.
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Affiliation(s)
- Kim I. P. Monteforte
- National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW 2450, Australia
- Correspondence:
| | - Paul A. Butcher
- National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW 2450, Australia
- NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, NSW 2450, Australia
| | - Stephen G. Morris
- NSW Department of Primary Industries, Wollongbar, NSW 2477, Australia
| | - Brendan P. Kelaher
- National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW 2450, Australia
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Robinson D, Newman SP, Whittingham MJ, Francksen RM, Adam MS, Stead SM. Fisher–shark interactions: A loss of support for the Maldives shark sanctuary from reef fishers whose livelihoods are affected by shark depredation. Conserv Lett 2022. [DOI: 10.1111/conl.12912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Danielle Robinson
- School of Natural and Environmental Sciences Newcastle University Newcastle upon Tyne UK
| | | | - Mark J. Whittingham
- School of Natural and Environmental Sciences Newcastle University Newcastle upon Tyne UK
| | - Richard M. Francksen
- School of Natural and Environmental Sciences Newcastle University Newcastle upon Tyne UK
| | - M. Shiham Adam
- International Pole and Line Foundation London, United Kingdom, Marine Research Centre Malé Republic of Maldives
| | - Selina M. Stead
- Faculty of Environment University of Leeds Leeds UK
- Institute of Aquaculture University of Stirling Stirling UK
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Dunn RE, Bradley D, Heithaus MR, Caselle JE, Papastamatiou YP. Conservation implications of forage base requirements of a marine predator population at carrying capacity. iScience 2022; 25:103646. [PMID: 35024583 PMCID: PMC8728395 DOI: 10.1016/j.isci.2021.103646] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/29/2021] [Accepted: 12/14/2021] [Indexed: 11/16/2022] Open
Abstract
Prey depletion may contribute to marine predator declines, yet the forage base required to sustain an unfished population of predatory fish at carrying capacity is unknown. We integrated demographic and physiological data within a Bayesian bioenergetic model to estimate annual consumption of a gray reef shark (Carcharhinus amblyrhynchos) population at a remote Pacific atoll (Palmyra Atoll) that are at carrying capacity. Furthermore, we estimated the proportion of the atoll's reef fish biomass production consumed by the gray reef sharks, assuming sharks either partially foraged pelagically (mean 7%), or solely within the reef environment (mean 52%). We then predicted the gray reef shark population potential of other, less remote Pacific Ocean coral reef islands, illustrating that current populations are substantially smaller than could be supported by their forage base. Our research highlights the utility of modeling how far predator population sizes are from their expected carrying capacity in informing marine conservation. Diet impacts the consumptive influence of gray reef sharks on reef fish resources Some gray reef shark populations could be larger, considering their forage base Modeling potential predator population sizes can inform their conservation
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Affiliation(s)
- Ruth E Dunn
- Institute of Environment, Department of Biological Sciences, Florida International University, Miami, FL, USA.,Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Darcy Bradley
- Marine Science Institute, University of California, Santa Barbara, CA, USA
| | - Michael R Heithaus
- Institute of Environment, Department of Biological Sciences, Florida International University, Miami, FL, USA
| | - Jennifer E Caselle
- Marine Science Institute, University of California, Santa Barbara, CA, USA
| | - Yannis P Papastamatiou
- Institute of Environment, Department of Biological Sciences, Florida International University, Miami, FL, USA
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Hays GC, Mortimer JA, Rattray A, Shimada T, Esteban N. High accuracy tracking reveals how small conservation areas can protect marine megafauna. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02418. [PMID: 34278636 DOI: 10.1002/eap.2418] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/01/2021] [Accepted: 03/03/2021] [Indexed: 06/13/2023]
Abstract
Space use estimates can inform conservation management but relaying high-accuracy locations is often not straightforward. We used Fastloc-GPS Argos satellite tags with the innovation of additional data relay via a ground station (termed a "Mote") to record high volumes (typically >20 locations per individual per day) of high accuracy tracking data. Tags were attached in the Chagos Archipelago (Indian Ocean) in 2018-2019 to 23 immature turtles of two species for which there have been long-standing conservation concerns: 21 hawksbill turtles (Eretmochelys imbricata) and two green turtles (Chelonia mydas). Over long tracking durations (mean 227.6 d per individual), most turtles moved very little. For example, 17 of 21 hawksbill turtles remained continuously in the lagoon where they were equipped, with 95% and 50% utilization distributions (UDs) averaging only 1.03 and 0.18 km2 , respectively. Many individuals, and both species, could use the same small spaces, i.e., individuals did not maintain unique home ranges. However, three hawksbill turtles travelled hundreds of kilometers from the tagging site. Our results show that, for some large marine vertebrates, even small protected areas of only a few square kilometers can encompass the movements of a large proportion of individuals over long periods. High accuracy tracking may likewise reveal the details of space use for many other animals that move little and/or use important focal areas and where previous low-accuracy tracking techniques have tended to overestimate space use.
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Affiliation(s)
| | - Jeanne A Mortimer
- Department of Biology, University of Florida, Gainesville, Florida, 32611, USA
- P.O. Box 1443, Victoria, Mahé, Seychelles
| | | | - Takahiro Shimada
- Department of Environment and Science, Queensland Government, GPO Box 2454, Dutton Park, Brisbane, Queensland, 4001, Australia
| | - Nicole Esteban
- Department of Biosciences, Swansea University, Swansea, Wales, SA2 8PP, United Kingdom
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Collins C, Nuno A, Benaragama A, Broderick A, Wijesundara I, Wijetunge D, Letessier TB. Ocean‐scale footprint of a highly mobile fishing fleet: Social‐ecological drivers of fleet behaviour and evidence of illegal fishing. PEOPLE AND NATURE 2021. [DOI: 10.1002/pan3.10213] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Claire Collins
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
- Institute of Zoology Zoological Society of London London UK
| | - Ana Nuno
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
- Interdisciplinary Centre of Social Sciences (CICS.NOVA) School of Social Sciences and Humanities (NOVA FCSH) NOVA University Lisbon Lisboa Portugal
| | | | - Annette Broderick
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
| | | | | | - Tom B. Letessier
- Institute of Zoology Zoological Society of London London UK
- The UWA Oceans Institute University of Western Australia (M092) Crawley WA Australia
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Sherman CS, Heupel MR, Johnson M, Kaimuddin M, Qamar LMS, Chin A, Simpfendorfer CA. Repeatability of baited remote underwater video station (BRUVS) results within and between seasons. PLoS One 2020; 15:e0244154. [PMID: 33332427 PMCID: PMC7745976 DOI: 10.1371/journal.pone.0244154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 12/04/2020] [Indexed: 11/19/2022] Open
Abstract
Baited remote underwater video stations (BRUVS) are increasingly being used to evaluate and monitor reef communities. Many BRUVS studies compare multiple sites sampled at single time points that may differ from the sampling time of another site. As BRUVS use grows in its application to provide data relevant to sustainable management, marine protected area success, and overall reef health, understanding repeatability of sampling results is vital. We examined the repeatability of BRUVS results for the elasmobranch community both within and between seasons and years, and explored environmental factors affecting abundances at two sites in Indonesia. On 956 BRUVS, 1139 elasmobranchs (69% rays, 31% sharks) were observed. We found consistent results in species composition and abundances within a season and across years. However, elasmobranch abundances were significantly higher in the wet season. The elasmobranch community was significantly different between the two sites sampled, one site being more coastal and easily accessed by fishermen. Our results demonstrate that while BRUVS are a reliable and repeatable method for surveying elasmobranchs, care must be taken in the timing of sampling between different regions to ensure that any differences observed are due to inherent differences amongst sampling areas as opposed to seasonal dissimilarities.
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Affiliation(s)
- C. Samantha Sherman
- Centre for Sustainable Tropical Fisheries and Aquaculture; College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- AIMS@JCU, DB17-063, James Cook University, Townsville, Queensland, Australia
- Department of Biological Sciences, Earth to Oceans Research Group, Simon Fraser University, Burnaby, British Columbia, Canada
- * E-mail:
| | - Michelle R. Heupel
- Australian Institute of Marine Science, Cape Cleveland, Queensland, Australia
| | - Mohini Johnson
- Operation Wallacea, Spilsby, Lincolnshire, United Kingdom
| | | | - L. M. Sjamsul Qamar
- Fisheries Department, Universitas Dayanu Ikhsanuddin, Bau Bau, Southeast Sulawesi, Indonesia
| | - Andrew Chin
- Centre for Sustainable Tropical Fisheries and Aquaculture; College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Cape Cleveland, Queensland, Australia
| | - Colin A. Simpfendorfer
- Centre for Sustainable Tropical Fisheries and Aquaculture; College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
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Schlaff AM, Heupel MR, Udyawer V, Simpfendorfer CA. Sex-based differences in movement and space use of the blacktip reef shark, Carcharhinus melanopterus. PLoS One 2020; 15:e0231142. [PMID: 32271802 PMCID: PMC7145100 DOI: 10.1371/journal.pone.0231142] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 03/17/2020] [Indexed: 11/18/2022] Open
Abstract
Information on the spatial ecology of reef sharks is critical to understanding life-history patterns, yet gaps remain in our knowledge of how these species move and occupy space. Previous studies have focused on offshore reefs and atolls with little information available on the movement and space use of sharks utilising reef habitats closer to shore. Cross-shelf differences in physical and biological properties of reefs can alter regional ecosystem processes resulting in different movement patterns for resident sharks. Passive acoustic telemetry was used to examine residency, space use and depth use of 40 blacktip reef sharks, Carcharhinus melanopterus, on an inshore reef in Queensland, Australia, and assess temporal or biological influences. All sharks showed strong site-attachment to inshore reefs with residency highest among adult females. Sharks exhibited a sex-based, seasonal pattern in space use where males moved more, occupied more space and explored new areas during the reproductive season, while females utilised the same amount of space throughout the year, but shifted the location of the space used. A positive relationship was also observed between space use and size. There was evidence of seasonal site fidelity and long-distance movement with the coordinated, annual migration of two adult males to the study site during the mating season. Depth use was segregated with some small sharks occupying shallower depths than adults throughout the day and year, most likely as refuge from predation. Results highlight the importance of inshore reef habitats to blacktip reef sharks and provide evidence of connectivity with offshore reefs, at least for adult males.
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Affiliation(s)
- Audrey M. Schlaff
- Centre for Sustainable Tropical Fisheries and Aquaculture & College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- * E-mail:
| | - Michelle R. Heupel
- Centre for Sustainable Tropical Fisheries and Aquaculture & College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Integrated Marine Observing System, University of Tasmania, Hobart, Tasmania, Australia
| | - Vinay Udyawer
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Colin A. Simpfendorfer
- Centre for Sustainable Tropical Fisheries and Aquaculture & College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
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Speed CW, Rees MJ, Cure K, Vaughan B, Meekan MG. Protection from illegal fishing and shark recovery restructures mesopredatory fish communities on a coral reef. Ecol Evol 2019; 9:10553-10566. [PMID: 31624567 PMCID: PMC6787830 DOI: 10.1002/ece3.5575] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 07/13/2019] [Accepted: 07/30/2019] [Indexed: 12/17/2022] Open
Abstract
The recovery of communities of predatory fishes within a no-take marine reserve after the eradication of illegal fishing provides an opportunity to examine the role of sharks and other large-bodied mesopredatory fishes in structuring reef fish communities. We used baited remote underwater video stations to investigate whether an increase in sharks was associated with a change in structure of the mesopredatory fish community at Ashmore Reef, Western Australia. We found an almost fourfold increase in shark abundance in reef habitat from 0.64 hr-1 ± 0.15 SE in 2004, when Ashmore Reef was being fished illegally, to 2.45 hr-1 ± 0.37 in 2016, after eight years of full-time enforcement of the reserve. Shark recovery in reef habitat was accompanied by a two and a half-fold decline in the abundance of small mesopredatory fishes (≤50 cm TL) (14.00 hr-1 ± 3.79 to 5.6 hr-1 ± 1.20) and a concomitant increase in large mesopredatory fishes (≥100 cm TL) from 1.82 hr-1 ± 0.48 to 4.27 hr-1 ± 0.93. In contrast, near-reef habitats showed an increase in abundance of large mesopredatory fishes between years (2.00 hr-1 ± 0.65 to 4.56 hr-1 ± 1.11), although only smaller increases in sharks (0.67 hr-1 ± 0.25 to 1.22 hr-1 ± 0.34) and smaller mesopredatory fishes. Although the abundance of most mesopredatory groups increased with recovery from fishing, we suggest that the large decline of small mesopredatory fish in reef habitat was mostly due to higher predation pressure following the increase in sharks and large mesopredatory fishes. At the regional scale, the structure of fished communities at Ashmore Reef in 2004 resembled those of present day Scott Reefs, where fishing still continues today. In 2016, Ashmore fish communities resembled those of the Rowley Shoals, which have been protected from fishing for decades.
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Affiliation(s)
- Conrad W. Speed
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
- Global FinPrint ProjectIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
| | - Matthew J. Rees
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
- Global FinPrint ProjectIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
| | - Katherine Cure
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
| | - Brigit Vaughan
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
| | - Mark G. Meekan
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
- Global FinPrint ProjectIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
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Tickler DM, Letessier TB, Koldewey HJ, Meeuwig JJ. Correction: Drivers of abundance and spatial distribution of reef-associated sharks in an isolated atoll reef system. PLoS One 2017; 12:e0186560. [PMID: 29023531 PMCID: PMC5638561 DOI: 10.1371/journal.pone.0186560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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