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Esmaeilbeigi M, P Duncan R, J Kefford B, Ezaz T, Clulow S. Evidence for a metal disease refuge: The amphibian-killing fungus (Batrachochytrium dendrobatidis) is inhibited by environmentally-relevant concentrations of metals tolerated by amphibians. ENVIRONMENTAL RESEARCH 2024; 261:119752. [PMID: 39117053 DOI: 10.1016/j.envres.2024.119752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 07/27/2024] [Accepted: 08/05/2024] [Indexed: 08/10/2024]
Abstract
The amphibian-killing fungus Batrachochytrium dendrobatidis (Bd) has caused substantial declines in Bd-susceptible amphibian species worldwide. However, some populations of Bd-susceptible frogs have managed to survive at existing metal-polluted sites, giving rise to the hypothesis that frogs might persist in the presence of Bd if Bd is inhibited by metals at concentrations that frogs can tolerate. We tested this hypothesis by measuring the survival of Bd zoospores, the life stage that infects amphibians, and calculated the LC50 after exposure to environmentally-relevant elevated concentrations of copper (Cu), zinc (Zn), and their combination (Cu + Zn) in two repeated 4-day acute exposure runs. We also measured the chronic sensitivity of Bd to these metals over three generations by measuring the number of colonies and live zoospores and calculating EC50 concentrations after 42 days of exposure. We then compared acute and chronic sensitivity of Bd with amphibian sensitivities by constructing species sensitivity distributions (SSDs) using LC50 and EC50 data obtained from the literature. Acute sensitivity data showed that Bd zoospore survival decreased with increasing metal concentrations and exposure durations relative to the control, with the highest LC50 values for Cu and Zn being 2.5 μg/L and 250 μg/L, respectively. Chronic exposures to metals resulted in decreased numbers of Bd colonies and live zoospores after 42 days, with EC50 values of 0.75 μg/L and 1.19 μg/L for Cu and Zn, respectively. Bd zoospore survival was 10 and 8 times more sensitive to Cu and Zn, respectively in acute, and 2 and 5 times more sensitive to Cu and Zn in chronic exposure experiments than the most sensitive amphibian species recorded. Our findings are consistent with the hypothesis that metals in existing metal-polluted sites may have a greater impact on Bd relative to amphibians' performance, potentially enabling Bd-susceptible amphibians to persist with Bd at these sites.
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Affiliation(s)
- Milad Esmaeilbeigi
- Centre for Applied Water Science, Institute for Applied Ecology, Faculty of Science and Technology, University of Canberra, Canberra, Bruce ACT, 2617, Australia.
| | - Richard P Duncan
- Center for Conservation Ecology and Genomics, Institute for Applied Ecology, Faculty of Science and Technology, University of Canberra, Canberra, Bruce ACT, 2617, Australia.
| | - Ben J Kefford
- Centre for Applied Water Science, Institute for Applied Ecology, Faculty of Science and Technology, University of Canberra, Canberra, Bruce ACT, 2617, Australia.
| | - Tariq Ezaz
- Center for Conservation Ecology and Genomics, Institute for Applied Ecology, Faculty of Science and Technology, University of Canberra, Canberra, Bruce ACT, 2617, Australia.
| | - Simon Clulow
- Center for Conservation Ecology and Genomics, Institute for Applied Ecology, Faculty of Science and Technology, University of Canberra, Canberra, Bruce ACT, 2617, Australia.
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da Costa RL, Souza IC, Morozesk M, de Carvalho LB, Carvalho CDS, Monferrán MV, Wunderlin DA, Fernandes MN, Monteiro DA. Toxic, genotoxic, mutagenic, and bioaccumulative effects of metal mixture from settleable particulate matter on American bullfrog tadpoles (Lithobates catesbeianus). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 340:122846. [PMID: 37926415 DOI: 10.1016/j.envpol.2023.122846] [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: 07/09/2023] [Revised: 10/29/2023] [Accepted: 10/30/2023] [Indexed: 11/07/2023]
Abstract
Amphibians are more susceptible to environmental stressors than other vertebrates due to their semipermeable skin and physiological adaptations to living in very specific microhabitats. Therefore, the aim of the present study was to investigate the effects of a metal mixture from settleable particulate matter (SePM) released from metallurgical industries on Lithobates catesbeianus tadpoles. Endpoints analyzed included metal bioconcentration, morphological (biometrical indices), hematological parameters (hemoglobin and blood cell count), and erythrocyte DNA damage (genotoxicity and mutagenicity). American bullfrog tadpoles (Gosner's stage 25) were kept under control condition (no contaminant addition) or exposed to a sub-lethal and environmentally relevant concentration (1 g.L-1) of SePM for 96 h. Tadpoles exposed to SePM exhibited elevated whole blood levels of Fe56, AL, Sn, Pb, Zn, Cr, Cu, Ti, Rb, V, Ce, La, Ag, As. SePM-exposed tadpoles showed a significant decrease in condition factor (12%) and increases in hepatosomatic index (25%), hemoglobin concentration (17%), and total leukocytes (82%), thrombocytes (90%), and monocytes (78%) abundance. In addition, exposed tadpoles showed higher MN and ENAs (340 and 140%, respectively) frequencies, and erythrocyte DNA damage with approximately 1.2- to 1.8-fold increases in comet parameters. Taken together, these results suggest that the multimetal mixture found in SePM is potentially genotoxic and mutagenic to L. catesbeianus tadpoles, induces stress associated with hematological changes, and negatively affects growth. Although such contamination occurs at sublethal levels, regulatory standards are needed to control the emission of SePM and protect amphibian populations.
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Affiliation(s)
- Regiane Luiza da Costa
- Departamento de Ciências Fisiológicas (DCF), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), 13565-905, São Carlos, São Paulo, Brazil; Programa de Pós-Graduação Em Ciências Ambientais (PPGCAm), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), Brazil
| | - Iara Costa Souza
- Departamento de Ciências Fisiológicas (DCF), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), 13565-905, São Carlos, São Paulo, Brazil
| | - Mariana Morozesk
- Departamento de Ciências Fisiológicas (DCF), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), 13565-905, São Carlos, São Paulo, Brazil
| | - Luana Beserra de Carvalho
- Departamento de Ciências Fisiológicas (DCF), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), 13565-905, São Carlos, São Paulo, Brazil; Programa de Pós-Graduação Em Ciências Ambientais (PPGCAm), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), 13565-905, São Carlos, São Paulo, Brazil
| | - Cleoni Dos Santos Carvalho
- Departamento de Biologia (DBio), Centro de Ciências Humanas e Biológicas (CCHB), Universidade Federal de São Carlos (UFSCar), 18052-780, São Carlos, São Paulo, Brazil
| | - Magdalena Victoria Monferrán
- ICYTAC, Instituto de Ciencia y Tecnología de Alimentos Córdoba, CONICET and Dpto. Qca. Orgánica, Fac. Cs. Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000, Córdoba, Argentina
| | - Daniel Alberto Wunderlin
- ICYTAC, Instituto de Ciencia y Tecnología de Alimentos Córdoba, CONICET and Dpto. Qca. Orgánica, Fac. Cs. Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000, Córdoba, Argentina
| | - Marisa Narciso Fernandes
- Departamento de Ciências Fisiológicas (DCF), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), 13565-905, São Carlos, São Paulo, Brazil
| | - Diana Amaral Monteiro
- Departamento de Ciências Fisiológicas (DCF), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), 13565-905, São Carlos, São Paulo, Brazil.
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Nolan N, Hayward MW, Klop-Toker K, Mahony M, Lemckert F, Callen A. Complex Organisms Must Deal with Complex Threats: How Does Amphibian Conservation Deal with Biphasic Life Cycles? Animals (Basel) 2023; 13:1634. [PMID: 37238064 PMCID: PMC10215276 DOI: 10.3390/ani13101634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/08/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
The unprecedented rate of global amphibian decline is attributed to The Anthropocene, with human actions triggering the Sixth Mass Extinction Event. Amphibians have suffered some of the most extreme declines, and their lack of response to conservation actions may reflect challenges faced by taxa that exhibit biphasic life histories. There is an urgent need to ensure that conservation measures are cost-effective and yield positive outcomes. Many conservation actions have failed to meet their intended goals of bolstering populations to ensure the persistence of species into the future. We suggest that past conservation efforts have not considered how different threats influence multiple life stages of amphibians, potentially leading to suboptimal outcomes for their conservation. Our review highlights the multitude of threats amphibians face at each life stage and the conservation actions used to mitigate these threats. We also draw attention to the paucity of studies that have employed multiple actions across more than one life stage. Conservation programs for biphasic amphibians, and the research that guides them, lack a multi-pronged approach to deal with multiple threats across the lifecycle. Conservation management programs must recognise the changing threat landscape for biphasic amphibians to reduce their notoriety as the most threatened vertebrate taxa globally.
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Affiliation(s)
- Nadine Nolan
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; (M.W.H.); (K.K.-T.); (M.M.); (A.C.)
| | - Matthew W. Hayward
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; (M.W.H.); (K.K.-T.); (M.M.); (A.C.)
| | - Kaya Klop-Toker
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; (M.W.H.); (K.K.-T.); (M.M.); (A.C.)
| | - Michael Mahony
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; (M.W.H.); (K.K.-T.); (M.M.); (A.C.)
| | - Frank Lemckert
- Eco Logical Australia Pty Ltd., Perth, WA 6000, Australia;
| | - Alex Callen
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; (M.W.H.); (K.K.-T.); (M.M.); (A.C.)
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Liu Y, Sun J, Zhao M, Ni Y, Wang X, Fan Z. Seasonal Variation and Contamination Risk Assessment of Heavy Metals in Surface Sediment of an Estuary Alluvial Island in Eastern China. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 108:337-343. [PMID: 35083496 DOI: 10.1007/s00128-021-03413-2] [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: 03/17/2020] [Accepted: 10/13/2021] [Indexed: 06/14/2023]
Abstract
The heavy metal pollution of estuary wetlands caused by industrial and agricultural production activities has aroused widespread concern. The Hakanson Pollution index, Geo-accumulation index (Igeo) and Redundancy analysis were used to explore the seasonal variation and contamination risk of heavy metals in surface sediments. Results showed that the heavy metal concentrations were ranked in descending order: Cd > Cu > Zn > Pb > Cr. The analysis result of HPI and Igeo showed that there was a low level of heavy metal contamination both in summer and winter. Redundancy analysis showed that the correlation between heavy metals and physicochemical properties of sediment was significantly different in winter and summer. Our findings provide scientific support for the prevention of heavy metal pollution in estuary wetlands.
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Affiliation(s)
- Yafeng Liu
- Anhui Academy of Environmental Science, Hefei, 230022, China
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Jiaxun Sun
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Menglu Zhao
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Yiyao Ni
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Xiangrong Wang
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Zhengqiu Fan
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
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Azizishirazi A, Klemish JL, Pyle GG. Sensitivity of Amphibians to Copper. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:1810-1821. [PMID: 33749926 DOI: 10.1002/etc.5049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/08/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Amphibian populations are declining globally. Major drivers of these global declines are known. However, the contribution of these major drivers to population declines varies by the presence or absence and the interactive effect of drivers, thus creating local challenges for conservation of populations. Studies have determined that environmental contaminants contribute to amphibian population declines. However, there is a disagreement over the use of amphibians as sentinel species in ecotoxicological testing rather than the traditional taxa used, fish and invertebrates. Reviews of ecotoxicological studies have demonstrated that amphibians are generally less sensitive than fish and invertebrates to different groups of contaminants. Nonetheless, because of the distinct nature and mechanism of toxicity of various contaminants, it is necessary to study contaminants individually to be able to come to any conclusion on the relative sensitivity of amphibians. Copper is one of the most studied environmental contaminants. We conducted a literature review of Cu toxicity to amphibians and the relative sensitivity of amphibians to other aquatic animals. The available data suggest that although amphibians may be tolerant of acute Cu exposure, they are relatively sensitive to chronic exposure (i.e., 100-fold greater sensitivity to chronic compared to acute exposure). In addition, ecologically relevant endpoints specific to amphibians (e.g., duration of metamorphosis and behavior) are shown to provide a better understanding of their sensitivity compared to traditional endpoints (e.g., survival and growth). Our current knowledge on amphibian sensitivity is far from complete. Considering the current status of this globally threatened class of animals, it is necessary to fill the knowledge gaps regarding their sensitivity to individual contaminants, beginning with Cu. Environ Toxicol Chem 2021;40:1810-1821. © 2021 SETAC.
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Affiliation(s)
- Ali Azizishirazi
- British Columbia Ministry of Environment and Climate Change Strategy, Victoria, British Columbia, Canada
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Jaimie L Klemish
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Gregory G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
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