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Parrish K, Kirkland P, Horwood P, Chessman B, Ruming S, McGilvray G, Rose K, Hall J, Skerratt L. Delving into the Aftermath of a Disease-Associated Near-Extinction Event: A Five-Year Study of a Serpentovirus (Nidovirus) in a Critically Endangered Turtle Population. Viruses 2024; 16:653. [PMID: 38675993 PMCID: PMC11055124 DOI: 10.3390/v16040653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 04/17/2024] [Accepted: 04/20/2024] [Indexed: 04/28/2024] Open
Abstract
Bellinger River virus (BRV) is a serpentovirus (nidovirus) that was likely responsible for the catastrophic mortality of the Australian freshwater turtle Myuchelys georgesi in February 2015. From November 2015 to November 2020, swabs were collected from turtles during repeated river surveys to estimate the prevalence of BRV RNA, identify risk factors associated with BRV infection, and refine sample collection. BRV RNA prevalence at first capture was significantly higher in M. georgesi (10.8%) than in a coexisting turtle, Emydura macquarii (1.0%). For M. georgesi, various risk factors were identified depending on the analysis method, but a positive BRV result was consistently associated with a larger body size. All turtles were asymptomatic when sampled and conjunctival swabs were inferred to be optimal for ongoing monitoring. Although the absence of disease and recent BRV detections suggests a reduced ongoing threat, the potential for the virus to persist in an endemic focus or resurge in cyclical epidemics cannot be excluded. Therefore, BRV is an ongoing potential threat to the conservation of M. georgesi, and strict adherence to biosecurity principles is essential to minimise the risk of reintroduction or spread of BRV or other pathogens.
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Affiliation(s)
- Kate Parrish
- Virology Laboratory, Elizabeth Macarthur Agriculture Institute, Department of Primary Industries, Menangle, NSW 2568, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4810, Australia
| | - Peter Kirkland
- Virology Laboratory, Elizabeth Macarthur Agriculture Institute, Department of Primary Industries, Menangle, NSW 2568, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4810, Australia
| | - Paul Horwood
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4810, Australia
| | | | - Shane Ruming
- Biodiversity Conservation and Science, New South Wales Department of Climate Change, Energy, the Environment and Water, Coffs Harbour, NSW 2450, Australia
| | - Gerry McGilvray
- Biodiversity Conservation and Science, New South Wales Department of Climate Change, Energy, the Environment and Water, Coffs Harbour, NSW 2450, Australia
| | - Karrie Rose
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Mosman, NSW 2088, Australia
| | - Jane Hall
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Mosman, NSW 2088, Australia
| | - Lee Skerratt
- Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, VIC 3030, Australia
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Hamilton AT, Schäfer RB, Pyne MI, Chessman B, Kakouie K, Boersma KS, Verdonschot PF, Verdonschot RC, Mims M, Khamis K, Bierwagen B, Stamp J. Limitations of trait-based approaches for stressor assessment: The case of freshwater invertebrates and climate drivers. Glob Chang Biol 2020; 26:364-379. [PMID: 31553112 PMCID: PMC10839858 DOI: 10.1111/gcb.14846] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 08/29/2019] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
The appeal of trait-based approaches for assessing environmental vulnerabilities arises from the potential insight they provide into the mechanisms underlying the changes in populations and community structure. Traits can provide ecologically based explanations for observed responses to environmental changes, along with predictive power gained by developing relationships between traits and environmental variables. Despite these potential benefits, questions remain regarding the utility and limitations of these approaches, which we explore focusing on the following questions: (a) How reliable are predictions of biotic responses to changing conditions based on single trait-environment relationships? (b) What factors constrain detection of single trait-environment relationships, and how can they be addressed? (c) Can we use information on meta-community processes to reveal conditions when assumptions underlying trait-based studies are not met? We address these questions by reviewing published literature on aquatic invertebrate communities from stream ecosystems. Our findings help to define factors that influence the successful application of trait-based approaches in addressing the complex, multifaceted effects of changing climate conditions on hydrologic and thermal regimes in stream ecosystems. Key conclusions are that observed relationships between traits and environmental stressors are often inconsistent with predefined hypotheses derived from current trait-based thinking, particularly related to single trait-environment relationships. Factors that can influence findings of trait-based assessments include intercorrelations of among traits and among environmental variables, spatial scale, strength of biotic interactions, intensity of habitat disturbance, degree of abiotic stress, and methods of trait characterization. Several recommendations are made for practice and further study to address these concerns, including using phylogenetic relatedness to address intercorrelation. With proper consideration of these issues, trait-based assessment of organismal vulnerability to environmental changes can become a useful tool to conserve threatened populations into the future.
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Affiliation(s)
| | - Ralf B. Schäfer
- iES Landau, Institute for Environmental Sciences, University Koblenz-Landau Fortstrasse 7 76829 Landau, Germany
| | | | - Bruce Chessman
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW Sydney, NSW, Australia
| | - Karan Kakouie
- Department of Ecosystem Research, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Kate S. Boersma
- Department of Biology, University of San Diego, San Diego, CA, USA
| | - Piet F.M. Verdonschot
- Wageningen Environmental Research, Wageningen University and Research, Wageningen, The Netherlands
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Ralf C.M. Verdonschot
- Wageningen Environmental Research, Wageningen University and Research, Wageningen, The Netherlands
| | - Meryl Mims
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Kieran Khamis
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Britta Bierwagen
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Washington, DC, USA
| | - Jen Stamp
- Tetra Tech Center for Ecological Sciences, Montpelier, VT, USA
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Van Dyke JU, Spencer RJ, Thompson MB, Chessman B, Howard K, Georges A. Conservation implications of turtle declines in Australia's Murray River system. Sci Rep 2019; 9:1998. [PMID: 30760813 PMCID: PMC6374471 DOI: 10.1038/s41598-019-39096-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 11/30/2018] [Indexed: 11/30/2022] Open
Abstract
Conservation requires rapid action to be effective, which is often difficult because of funding limitations, political constraints, and limited data. Turtles are among the world’s most endangered vertebrate taxa, with almost half of 356 species threatened with extinction. In Australia’s Murray River, nest predation by invasive foxes (Vulpes vulpes) was predicted to drive turtle declines in the 1980s. We assessed populations of the broad-shelled turtle (Chelodina expansa), eastern long-necked turtle (C. longicollis), and Murray River turtle (Emydura macquarii) in the Murray River and some of its associated waterways. Our results suggest that the predicted decline is occurring. All three species are rare in the lower Murray River region, and were undetected in many locations in South Australia. Moreover, E. macquarii had considerable population aging almost everywhere, possibly due to comprehensive nest destruction by foxes. Chelodina longicollis also had population aging at some sites. Sustained low recruitment has potential to lead to collapses as turtles age, which is particularly worrying because it was predicted over 30 years ago and may have already occurred in South Australia. Our results show that turtle declines were not mitigated since that prediction. If the crash continues, a vertebrate guild responsible for considerable nutrient cycling in the aquatic ecosystem will disappear. Our results highlight a worst-case outcome when species declines are predicted, but insufficiently mitigated.
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Affiliation(s)
- J U Van Dyke
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.,School of Environmental Sciences, Institute for Land, Water, and Society, Charles Sturt University, Albury-Wodonga Campus, Albury, NSW, 2640, Australia
| | - R-J Spencer
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
| | - M B Thompson
- School of Life and Environmental Sciences, Heydon-Laurence Building (A08), University of Sydney, Sydney, NSW, 2006, Australia
| | - B Chessman
- Centre for Ecosystem Science, University of New South Wales, Sydney, NSW, 2052, Australia
| | - K Howard
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - A Georges
- Institute for Applied Ecology, University of Canberra, Canberra, ACT, 2601, Australia
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Chessman B, Williams S, Besley C. Bioassessment of streams with macroinvertebrates: effect of sampled habitat and taxonomic resolution. ACTA ACUST UNITED AC 2007. [DOI: 10.1899/06-074.1] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Bruce Chessman
- Department of Natural Resources, PO Box 3720, Parramatta, New South Wales 2124, Australia
| | - Simon Williams
- Department of Natural Resources, PO Box 867 Wollongong, New South Wales 2520, Australia
| | - Colin Besley
- Sydney Water Corporation, PO Box 73 West Ryde, New South Wales 2114, Australia
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