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Liu N, Meng F, Zhang L, Qin Y, Xue H, Liang Z. Toxicity threshold and ecological risk of nitrate in rivers based on endocrine-disrupting effects: A case study in the Luan River basin, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172859. [PMID: 38692316 DOI: 10.1016/j.scitotenv.2024.172859] [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: 01/23/2024] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/03/2024]
Abstract
Nitrate, as a crucial nutrient, is consistently targeted for controlling water eutrophication globally. However, there is considerable evidence suggesting that nitrate has endocrine-disrupting potential on aquatic organisms. In this study, the sensitivity of various adverse effects to nitrate nitrogen (nitrate-N) was compared, and a toxicity threshold based on endocrine-disrupting effects was derived. The spatiotemporal variations of nitrate-N concentrations in the Luan River basin were investigated, and the associated aquatic ecological risks were evaluated using a comprehensive approach. The results showed that reproduction and development were the most sensitive endpoints to nitrate, and their distribution exhibited significant differences compared to behavior. The derived threshold based on endocrine-disrupting effects was 0.65 mgL-1, providing adequate protection for the aquatic ecosystem. In the Luan River basin, the mean nitrate-N concentrations during winter (4.4 mgL-1) were significantly higher than those observed in spring (0.7 mgL-1) and summer (1.2 mgL-1). Tributary inputs had an important influence on the spatial characteristics of nitrate-N in the mainstream, primarily due to agricultural and population-related contamination. The risk quotients (RQ) during winter, summer, and spring were evaluated as 6.7, 1.8, and 1.1, respectively, and the frequency of exposure concentrations exceeding the threshold was 100 %, 64.3 %, and 42.5 %, respectively. At the ecosystem level, nitrate posed intermediate risks to aquatic organisms during winter and summer in the Luan River basin and at the national scale in China. We suggest that nitrate pollution control should not solely focus on water eutrophication but also consider the endocrine disruptive effect on aquatic animals.
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Affiliation(s)
- Na Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Fansheng Meng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Lingsong Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Yaqiang Qin
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Hao Xue
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zhuming Liang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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Zambrano-Fernández S, Zamora-Camacho FJ, Aragón P. Direct and indirect effects of chronic exposure to ammonium on anuran larvae survivorship, morphology, and swimming speed. CHEMOSPHERE 2022; 287:132349. [PMID: 34826957 DOI: 10.1016/j.chemosphere.2021.132349] [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: 05/23/2021] [Revised: 09/06/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Several constituents of the current global change are usually deemed accountable for the worldwide declines of amphibian populations. Among these, water contamination poses a major threat, especially to larval stages, which are unable to escape a polluted water body. This problem is remarkable in agrosystems, one of the main sources of water pollution and whose area is forecasted to increase in the forthcoming decades. However, pollutants represent a selective pressure that may result in tolerance in affected areas. In this work, we tested whether chronic exposure to a sublethal concentration of ammonium (10 mg/L), one of the most frequent agrochemicals, affects differently hatching success, survivorship, morphology and swimming performance of Pelophylax perezi tadpoles from agrosystem and pine grove habitats. Ammonium diminished survivorship at the earliest stages after hatching. Thus, lower density was a by-product of exposure to ammonium. Higher density slowed down development, reduced snout-vent length, and had a sharper negative effect on body mass and tail length and depth of ammonium treated individuals with respect to the control. In turn, ammonium accelerated development and increased body mass, SVL, and tail length and depth. These effects did not depend on provenance habitat. However, only pine grove tadpoles' swimming speed was negatively affected by ammonium, which supports the hypothesis that agrosystem tadpoles are more tolerant to ammonium. Finally, corroborating previous findings, tadpoles with larger bodies and tails were faster swimmers, whereas proportionally more massive individuals were slower, and tail depth was unrelated to swimming speed.
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Affiliation(s)
| | - Francisco Javier Zamora-Camacho
- Museo Nacional de Ciencias Naturales, (MNCN-CSIC), C/ José Gutiérrez Abascal 2, 28006, Madrid, Spain; Universidad Complutense de Madrid, C/José Antonio Novais 2, 2804, Madrid, Spain.
| | - Pedro Aragón
- Museo Nacional de Ciencias Naturales, (MNCN-CSIC), C/ José Gutiérrez Abascal 2, 28006, Madrid, Spain; Universidad Complutense de Madrid, C/José Antonio Novais 2, 2804, Madrid, Spain
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3
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Gomez Isaza DF, Cramp RL, Franklin CE. Living in polluted waters: A meta-analysis of the effects of nitrate and interactions with other environmental stressors on freshwater taxa. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114091. [PMID: 32062099 DOI: 10.1016/j.envpol.2020.114091] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/21/2020] [Accepted: 01/27/2020] [Indexed: 05/27/2023]
Abstract
Nutrient effluents from urban and agricultural inputs have resulted in high concentrations of nitrate in freshwater ecosystems. Exposure to nitrate can be particularly threatening to aquatic organisms, but a quantitative synthesis of the overall effects on amphibians, amphipods and fish is currently unavailable. Moreover, in disturbed ecosystems, organisms are unlikely to face a single stressor in isolation, and interactions among environmental stressors can enhance the negative effects of nitrate on organisms. Here, the effects of elevated nitrate on activity level, deformity rates, hatching success, growth and survival of three taxonomic groups of aquatically respiring organisms are documented. Effect sizes were extracted from 68 studies and analysed using meta-analytical techniques. The influence of nitrate on life-stages was also assessed. A factorial meta-analysis was conducted to examine the effect of nitrate and its interaction with other ecological stressors on organismal survival. Overall, the impacts of nitrate are biased towards amphibians (46 studies) and fish (13 studies), and less is known about amphipods (five studies). We found that exposure to nitrate translates to a 79% decrease in activity, a 29% decrease in growth, and reduces survival by 62%. Nitrate exposure also increases developmental deformities but does not affect hatching success. Nitrate exposure was found to influence all life-stages except embryos. Differences in the sensitivity of nitrate among taxonomic groups tended to be negligible. The factorial meta-analysis (14 amphibians and two amphipod studies) showed that nitrate in combination with other stressors affects survival in a non-additive manner. Our results indicate that nitrate can have strong effects on aquatic organisms and can interact with other environmental stressors which compound the negative effects on survival. Overall, the impacts of nitrate and additional stressors are complex requiring a holistic approach to better conserve freshwater biodiversity in the face of ongoing global change.
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Affiliation(s)
- Daniel F Gomez Isaza
- School of Biological Science, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Rebecca L Cramp
- School of Biological Science, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Craig E Franklin
- School of Biological Science, The University of Queensland, Brisbane, QLD 4072, Australia
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4
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Gomez Isaza DF, Cramp RL, Franklin CE. Simultaneous exposure to nitrate and low pH reduces the blood oxygen-carrying capacity and functional performance of a freshwater fish. CONSERVATION PHYSIOLOGY 2020; 8:coz092. [PMID: 31988749 PMCID: PMC6977012 DOI: 10.1093/conphys/coz092] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/12/2019] [Accepted: 11/05/2019] [Indexed: 05/31/2023]
Abstract
Human activities present aquatic species with numerous of environmental challenges, including excessive nutrient pollution (nitrate) and altered pH regimes (freshwater acidification). In isolation, elevated nitrate and acidic pH can lower the blood oxygen-carrying capacity of aquatic species and cause corresponding declines in key functional performance traits such as growth and locomotor capacity. These factors may pose considerable physiological challenges to organisms but little is known about their combined effects. To characterise the energetic and physiological consequences of simultaneous exposure to nitrate and low pH, we exposed spangled perch (Leiopotherapon unicolor) to a combination of nitrate (0, 50 or 100 mg L-1) and pH (pH 7.0 or 4.0) treatments in a factorial experimental design. Blood oxygen-carrying capacity (haemoglobin concentration, methaemoglobin concentrations and oxygen equilibrium curves), aerobic scope and functional performance traits (growth, swimming performance and post-exercise recovery) were assessed after 28 days of exposure. The oxygen-carrying capacity of fish exposed to elevated nitrate (50 and 100 mg L-1) was compromised due to reductions in haematocrit, functional haemoglobin levels and a 3-fold increase in methaemoglobin concentrations. Oxygen uptake was also impeded due to a right shift in oxygen-haemoglobin binding curves of fish exposed to nitrate and pH 4.0 simultaneously. A reduced blood oxygen-carrying capacity translated to a lowered aerobic scope, and the functional performance of fish (growth and swimming performance and increased post-exercise recovery times) was compromised by the combined effects of nitrate and low pH. These results highlight the impacts on aquatic organisms living in environments threatened by excessive nitrate and acidic pH conditions.
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Affiliation(s)
- Daniel F Gomez Isaza
- School of Biological Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rebecca L Cramp
- School of Biological Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Craig E Franklin
- School of Biological Science, The University of Queensland, Brisbane, Queensland 4072, Australia
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5
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Egea-Serrano A, Van Buskirk J. Responses to nitrate pollution, warming and density in common frog tadpoles (Rana temporaria). AMPHIBIA-REPTILIA 2016. [DOI: 10.1163/15685381-00003029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Amphibians face a variety of anthropogenic environmental perturbations that could act alone or in combination to influence population size. We investigated interactive effects of warming conditions, a moderate pulse of nitrogen pollution, and conspecific density on larvae of the common frog, Rana temporaria. The 16-day experiment had a 2 × 2 × 2 factorial design implemented in 80-l outdoor mesocosms. High density and warm temperature both resulted in reduced activity and visibility; tadpoles grew and developed more quickly at low density and high temperature. The high-nitrogen treatment did not influence behavior, growth, or development rate. We attribute this to several realistic features of our study, including a pulsed treatment application and natural denitrification within the mesocosms. There was only a single interaction among the three factors: higher temperature exacerbated density-dependence in growth rate. These results illustrate that climate warming may benefit temperate amphibians, although the benefits may be counteracted by enhanced larval crowding.
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Affiliation(s)
- Andrés Egea-Serrano
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, CH-8057 Zurich, Switzerland
- Universidade Estadual de Santa Gruz, Laboratorio Zoología de Vertebrados, Pavilhão Max de Menezes, Campus Soane Nazaré de Andrade, Rodovia Jorge Amado km 16, Bairro Salobrinho, 45662-900 Ilhéus-Bahia, Brazil
| | - Josh Van Buskirk
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, CH-8057 Zurich, Switzerland
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6
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Hopkins GR, Brodie ED. Occurrence of Amphibians in Saline Habitats: A Review and Evolutionary Perspective. HERPETOLOGICAL MONOGRAPHS 2015. [DOI: 10.1655/herpmonographs-d-14-00006] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Fasola E, Ribeiro R, Lopes I. Microevolution due to pollution in amphibians: A review on the genetic erosion hypothesis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 204:181-190. [PMID: 25969378 DOI: 10.1016/j.envpol.2015.04.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 04/18/2015] [Accepted: 04/27/2015] [Indexed: 06/04/2023]
Abstract
The loss of genetic diversity, due to exposure to chemical contamination (genetic erosion), is a major threat to population viability. Genetic erosion is the loss of genetic variation: the loss of alleles determining the value of a specific trait or set of traits. Almost a third of the known amphibian species is considered to be endangered and a decrease of genetic variability can push them to the verge of extinction. This review indicates that loss of genetic variation due to chemical contamination has effects on: 1) fitness, 2) environmental plasticity, 3) co-tolerance mechanisms, 4) trade-off mechanisms, and 5) tolerance to pathogens in amphibian populations.
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Affiliation(s)
- E Fasola
- Department of Biology & CESAM (Centro de Estudos do Ambiente e do Mar), University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
| | - R Ribeiro
- CFE - Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| | - I Lopes
- Department of Biology & CESAM (Centro de Estudos do Ambiente e do Mar), University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal
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8
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Ortiz-Santaliestra ME, Marco A. Influence of dissolved oxygen conditions on toxicity of ammonium nitrate to larval natterjack toads. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2015; 69:95-103. [PMID: 25586169 DOI: 10.1007/s00244-014-0126-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 12/29/2014] [Indexed: 06/04/2023]
Abstract
Temporary ponds, where many amphibians from temperate regions breed, show an annual cycle with a maximum water volume in spring followed by a progressive desiccation throughout late spring and summer. This desiccation leads to a decrease in dissolved oxygen and an increase in nitrogen levels, which can additionally increase because of anthropogenic sources such as chemical fertilizers. We analyzed the toxicity posed by environmentally relevant levels of a common nitrogenous fertilizer, ammonium nitrate, at different conditions of oxygen availability to Bufo calamita tadpoles, which typically develop in ephemeral ponds. Ammonium nitrate (90.3 mg N-NO3NH4/l) and hypoxic conditions (initial dissolved oxygen 4.53 ± 0.40 mg/l) caused significant lethal effects after 7 and 12 days of exposure, respectively. At the end of experiment (16 days), mortality rates were 32.5 % in individuals exposed to the fertilizer and 15 % in those growing under hypoxic conditions. When both stressors were combined, they showed an additive effect on tadpole survival. Malformations, such as oedemas and spinal curvatures, and locomotory abnormalities, were detected after 12 days of experiment in >90 % of individuals exposed to 45.2 mg N-NO3NH4/l under hypoxic conditions, whereas none of these stressors by separate related to abnormality rates >35 %. Delayed development was also observed in tadpoles exposed to ammonium nitrate with hypoxia affecting developmental rate only after 12 days of exposure. The results are discussed in terms of potential mechanisms linking negative effects of both factors as well as in terms of potential alterations of the ecological plasticity that often allows amphibians to survive in unpredictable environments.
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9
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Egea-Serrano A, Tejedo M. Contrasting effects of nitrogenous pollution on fitness and swimming performance of Iberian waterfrog, Pelophylax perezi (Seoane, 1885), larvae in mesocosms and field enclosures. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 146:144-153. [PMID: 24296112 DOI: 10.1016/j.aquatox.2013.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/27/2013] [Accepted: 11/02/2013] [Indexed: 06/02/2023]
Abstract
Amphibians are declining worldwide and pollutants have been implicated as a major contributor to these declines. To understand these declines, many studies have assessed the impact of pollutants on amphibian behaviour. However, information regarding their effect on locomotor abilities, as well as the intra-specific variation of the tolerance to pollutants, is extremely rare. Further, the majority of studies examining the impact of pollutants on amphibians have been conducted in simplified laboratory settings. Given the complexity of natural systems, determining whether amphibian responses in laboratory studies can be generalized to more realistic natural scenarios is critical. Towards this goal, this study assessed the impact of nitrogenous pollution on survival and fitness-related larval traits (growth, mass and swimming performance) for three populations of the frog Pelophylax perezi, exposed to different degrees of eutrophication in two different and complementary experiments: (1) pond mesocosms, with NH4Cl isolated or combined with NaNO2 and NaNO3, and (2) field enclosures placed in natural streams differing in their degree of pollution. For both mesocosm and field enclosure experiments, larval mortality was unaffected by nitrogenous pollution. However, in the mesocosm experiment, exposure to nitrogenous compounds reduced final larvae mass and growth. In contrast, in the enclosure experiment, polluted locations facilitated final mass and growth of surviving tadpoles. Population-level variation in the effect of pollution was observed for final larval mass in the mesocosm but not in the field enclosure experiment. In addition, although nitrogenous compounds in both mesocosm and natural conditions had no direct effect on absolute larval swimming performance, they may impact the viability of larvae by affecting the relationships between growth and the swimming abilities. The differential pattern found in the impacts of nitrogenous compounds on larvae of P. perezi when raised in different experimental venues (mesocosms and field conditions) points to the convenience of considering more realistic natural scenarios in assessing the impact of pollutants on amphibians.
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Affiliation(s)
- A Egea-Serrano
- Department of Zoology and Physical Anthropology, University of Murcia, 30100 Murcia, Spain.
| | - M Tejedo
- Department of Evolutionary Ecology, Estación Biológica de Doñana, CSIC, Avda, Américo Vespucio s/n., 41092 Sevilla, Spain.
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Santos B, Ribeiro R, Domingues I, Pereira R, Soares AMVM, Lopes I. Salinity and copper interactive effects on Perez's frog Pelophylax perezi. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:1864-1872. [PMID: 23625701 DOI: 10.1002/etc.2257] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 12/21/2012] [Accepted: 04/22/2013] [Indexed: 06/02/2023]
Abstract
The present study was intended to assess the influence of salinity on the effects of copper on 2 life stages of Pelophylax perezi. Single and combined effects of salinity (NaCl) and Cu on survival, malformations, body length, and biochemical markers (catalase [CAT], cholinesterases, lactate dehidrogenase [LDH], and glutathione S-transferase) of individuals were evaluated in a multifactorial design. Two experiments were performed, 1 with embryos and the other with tadpoles. Each of these life stages was exposed to individual and combinations of Cu (0.0-7.4 mg/L and 0.0-2.4 mg/L, respectively) and NaCl (0.0-10.2 g/L and 0.0-7.4 g/L, respectively) concentrations. Copper alone had a higher lethal toxicity to tadpoles (90%; 2.4 mg/L) than to embryos (65%; 7.4 mg/L). Conversely, NaCl alone had a higher lethal toxicity to embryos (100%; 6.9 g/L) than to tadpoles (50%; 7.4 g/L). The 4 lowest tested NaCl concentrations decreased the lethal effects of Cu to embryos and the incidence of malformations, but the same outcome was not observed for tadpoles. Regarding enzymatic activities, although significant interactions between Cu and NaCl were observed for the activity of CAT and LDH in embryo and tadpole, a consistent pattern of NaCl and Cu interactive effects was not observed. The authors' results suggest a life-stage dependence on the effects of exposure to the individual substances or their combination. Also, it was observed that moderate salinity might have a shield effect against Cu lethal toxicity for embryos of P. perezi. These results highlight the need within ecological risk evaluations to characterize the sensitivity of different amphibian life stages to individual chemicals but also their combination with other environmental conditions resulting from climate changes.
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Affiliation(s)
- Bárbara Santos
- Centre for Environmental and Marine Studies, University of Aveiro, Santiago University Campus, Aveiro, Portugal
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11
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Shinn C, Marco A, Serrano L. Influence of low levels of water salinity on toxicity of nitrite to anuran larvae. CHEMOSPHERE 2013; 92:1154-1160. [PMID: 23466091 DOI: 10.1016/j.chemosphere.2013.01.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 01/10/2013] [Accepted: 01/22/2013] [Indexed: 06/01/2023]
Abstract
Reactive nitrogen compounds such as nitrite (NO2(-)) are highly toxic to aquatic animals and are partly responsible for the global decline of amphibians. On some fish and Caudata amphibian species low levels of sodium chloride significantly reduce the toxicity of nitrite. However, the nitrite-salinity interaction has not been properly studied in anuran amphibians. To verify if chloride (Cl(-)) attenuates NO2(-) toxicity, eggs and larvae of three anuran species were subjected to a series of NO2(-) solutions combined with three salt concentrations (0, 0.4 and 2 or 0, 0.052 and 0.2gL(-1)NaCl). One of the species tested originated from two different populations inhabiting highly contrasted nutrient richness environments: lowland Doñana Natural Park and Sierra de Gredos Mountain. In general, the presence of Cl(-) increased survival and growth of lowland Pelophylax perezi and activity of mountain P. perezi larvae exposed to NO2(-), thus attenuating the toxicity of NO2(-) to developing amphibians. Mountain amphibian populations appeared to be much more sensitive to the concentrations of NO2(-) and Cl(-) used in this experiment than coastal conspecifics, suggesting possible adaptation of populations to local conditions. Nitrogen pollution in coastal wetlands poses a serious threat to aquatic organisms, causing direct toxicity or indirect effects via ecosystem eutrophication. The presence of low to medium levels of salinity that would be common in coastal wetlands may attenuate the direct effects of increasing concentrations of nitrogenous compounds in water bodies. Furthermore, treating cultures of endangered anurans with small amounts of NaCl may provide an additional protective measure.
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Affiliation(s)
- C Shinn
- Estación Biológica de Doñana, CSIC, C/Americo Vespucio, s/n, 41092 Isla de la Cartuja, Sevilla, Spain.
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Bernabò I, Bonacci A, Coscarelli F, Tripepi M, Brunelli E. Effects of salinity stress on Bufo balearicus and Bufo bufo tadpoles: Tolerance, morphological gill alterations and Na(+)/K(+)-ATPase localization. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 132-133:119-33. [PMID: 23474321 DOI: 10.1016/j.aquatox.2013.01.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 01/11/2013] [Accepted: 01/20/2013] [Indexed: 05/26/2023]
Abstract
Freshwater habitats are globally threatened by human-induced secondary salinization. Amphibians are generally poorly adapted to survive in saline environments. We experimentally investigated the effects of chronic exposure to various salinities (5%, 10%, 15%, 20%, 25%, 30% and 35% seawater, SW) on survival, larval growth and metamorphosis of tadpoles from two amphibian populations belonging to two species: the green toad Bufo balearicus and the common toad Bufo bufo. In addition, gill morphology of tadpoles of both species after acute exposure to hypertonic conditions (20%, 25%, and 30% SW) was examined by light and electron microscopy. Tadpoles experienced 100% mortality above 20% SW in B. balearicus while above 15% SW in B. bufo. We detected also sublethal effects of salinity stress on growth and metamorphosis. B. bufo cannot withstand chronic exposure to salinity above 5% SW, tadpoles grew slower and were significantly smaller than those in control at metamorphosis. B. balearicus tolerated salinity up to 20% SW without apparent effects during larval development, but starting from 15% SW tadpoles metamorphosed later and at a smaller size compared with control. We also revealed a negative relation between increasing salt concentration and gill integrity. The main modifications were increased mucous secretion, detachment of external layer, alteration of epithelial surface, degeneration phenomena, appearance of residual bodies, and macrophage immigration. These morphological alterations of gill epithelium can interfere with respiratory function and both osmotic and acid-base regulation. Significant variations in branchial Na(+)/K(+)-ATPase activity were also observed between two species; moreover an increase in enzyme activity was evident in response to SW exposure. Epithelial responses to increasing salt concentration were different in the populations belonging to two species: the intensity of histological and ultrastructural pathology in B. bufo was greater and we noticed the appearance in exposed samples of the tubular vesicle cells (TVCs). Taken together, our results demonstrated that increased salinity of freshwater may give cause for concern and must be considered a stressor for amphibians as well as other pollutants.
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Affiliation(s)
- Ilaria Bernabò
- Department of Ecology, University of Calabria, Via P. Bucci, 87036 Rende (Cosenza), Italy
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13
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Ruiz de Arcaute C, Salgado Costa C, Demetrio PM, Natale GS, Ronco AE. Influence of existing site contamination on sensitivity of Rhinella fernandezae (Anura, Bufonidae) tadpoles to Lorsban®48E formulation of chlorpyrifos. ECOTOXICOLOGY (LONDON, ENGLAND) 2012; 21:2338-2348. [PMID: 22918748 DOI: 10.1007/s10646-012-0990-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/11/2012] [Indexed: 06/01/2023]
Abstract
Effects of the widely employed insecticide Lorsban(®)48E formulation of chlorpyrifos (CPF) was studied on Rhinella fernandezae tadpoles, a native species of Argentina, Brazil, Paraguay and Uruguay, under the hypothesis of a differential response of organisms from ponds of two sites with different degree of anthropogenic disturbance: S1 an unpolluted area, and S2 area with high degree of antropogenic disturbance. To collect a representative sample of the genotypic variability of each population, small portions from six clutches were taken randomly from each site when the period of clutching was finished. Embryos and tadpoles were maintained under controlled laboratory conditions. Toxicity tests were conducted under standardized conditions to study acute and chronic lethal (mortality) and sublethal effects (behavior, growth, and abnormalities), within the range of concentrations of 0.010 to 5 mg/L. Chronic effects were assessed with organisms from one of the demes (S1). CPF showed high toxicity on the tadpoles, inducing lethal and sublethal effects at 96 h exposure within a narrow range of concentrations from 0.066 to 0.887 mg/L. Results indicate that R. fernandezae tadpoles are below the 30th percentile in the species sensitivity distribution of existing data. The acute LC50, NOEC, and LOEC values were 0.151, 0.066, and 0.133 mg/L for S1, and 0.293, 0.177, and 0.266 mg/L for S2, respectively. Considering all acute end-points evaluated, the effects of CPF showed no significant differences (p = 0.3484) between the studied populations. CPF has more severe effects at higher concentrations than at higher times of exposure. Contaminants in S2 do not seem to induce local adaptation. Sublethal effects data and measured environmental concentrations indicate potential risk for populations inhabiting agroecosystems.
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Affiliation(s)
- Celeste Ruiz de Arcaute
- Centro de Investigaciones del Medio Ambiente, Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata-CONICET, 47 y 115, 1900, La Plata, Argentina
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FICKEN KRISTINALG, BYRNE PHILLIPG. Heavy metal pollution negatively correlates with anuran species richness and distribution in south-eastern Australia. AUSTRAL ECOL 2012. [DOI: 10.1111/j.1442-9993.2012.02443.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - PHILLIP G. BYRNE
- The Institute for Conservation Biology & Environmental Management, School of Biological Sciences; University of Wollongong; Wollongong; NSW; 2522; Australia
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Egea-Serrano A, Relyea RA, Tejedo M, Torralva M. Understanding of the impact of chemicals on amphibians: a meta-analytic review. Ecol Evol 2012; 2:1382-97. [PMID: 22957147 PMCID: PMC3434931 DOI: 10.1002/ece3.249] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 02/29/2012] [Indexed: 11/29/2022] Open
Abstract
Many studies have assessed the impact of different pollutants on amphibians across a variety of experimental venues (laboratory, mesocosm, and enclosure conditions). Past reviews, using vote-counting methods, have described pollution as one of the major threats faced by amphibians. However, vote-counting methods lack strong statistical power, do not permit one to determine the magnitudes of effects, and do not compare responses among predefined groups. To address these challenges, we conducted a meta-analysis of experimental studies that measured the effects of different chemical pollutants (nitrogenous and phosphorous compounds, pesticides, road deicers, heavy metals, and other wastewater contaminants) at environmentally relevant concentrations on amphibian survival, mass, time to hatching, time to metamorphosis, and frequency of abnormalities. The overall effect size of pollutant exposure was a medium decrease in amphibian survival and mass and a large increase in abnormality frequency. This translates to a 14.3% decrease in survival, a 7.5% decrease in mass, and a 535% increase in abnormality frequency across all studies. In contrast, we found no overall effect of pollutants on time to hatching and time to metamorphosis. We also found that effect sizes differed among experimental venues and among types of pollutants, but we only detected weak differences among amphibian families. These results suggest that variation in sensitivity to contaminants is generally independent of phylogeny. Some publication bias (i.e., selective reporting) was detected, but only for mass and the interaction effect size among stressors. We conclude that the overall impact of pollution on amphibians is moderately to largely negative. This implies that pollutants at environmentally relevant concentrations pose an important threat to amphibians and may play a role in their present global decline.
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Affiliation(s)
- Andrés Egea-Serrano
- Facultad de Biología, Departamento de Zoología y Antropología Física, Universidad de Murcia30100 Murcia, Spain
| | - Rick A Relyea
- Department of Biological Sciences, University of Pittsburgh101 Clapp Hall, Pittsburgh, Pennsylvania 15260
| | - Miguel Tejedo
- Department of Evolutionary Ecology, Estación Biológica de DoñanaCSIC, Avda. Américo Vespucio s/n, 41092 Sevilla, Spain
| | - Mar Torralva
- Facultad de Biología, Departamento de Zoología y Antropología Física, Universidad de Murcia30100 Murcia, Spain
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Ortiz-Santaliestra ME, Fernández-Benéitez MJ, Marco A. Density effects on ammonium nitrate toxicity on amphibians. Survival, growth and cannibalism. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 110-111:170-176. [PMID: 22326654 DOI: 10.1016/j.aquatox.2012.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 01/10/2012] [Accepted: 01/15/2012] [Indexed: 05/31/2023]
Abstract
Temporary ponds where many amphibians breed experience a gradual desiccation that leads to growing larval densities, which can reduce tadpole survival rates and increase cannibalistic interactions among carnivorous salamander larvae. Concentrations of many agrochemicals, including nitrogenous fertilizers, can also increase as the water volume decreases. We analyzed the effects of ammonium nitrate fertilizer at two larval densities on growth and survival of Rana dalmatina tadpoles, and on cannibalistic behaviors of Salamandra salamandra larvae. We observed synergistic lethal effects until day 17 of exposure, when ammonium nitrate-related mortality of tadpoles was five times greater at high than at low density. The fertilizer impaired tadpole growth. This effect was stronger at low density than at high density. In the absence of ammonium nitrate, the incidence of cannibalism was higher at high than at low larval density. However, fertilizer exposure removed this density-dependent effect, which, under field conditions, would negate some potentially advantageous effects of cannibalism such as reduced intraspecific competition and the stimulation of defensive behaviors.
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Affiliation(s)
- Manuel E Ortiz-Santaliestra
- Instituto de Investigación en Recursos Cinegéticos (IREC) CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13071 Ciudad Real, Spain.
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Alexander LG, Lailvaux SP, Pechmann JHK, DeVries PJ. Effects of Salinity on Early Life Stages of the Gulf Coast Toad, Incilius nebulifer (Anura: Bufonidae). COPEIA 2012. [DOI: 10.1643/cp-09-206] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Miaud C, Oromí N, Guerrero S, Sanuy D. Intra-specific variation in nitrate tolerance in tadpoles of the Natterjack toad. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:1176-1183. [PMID: 21448620 DOI: 10.1007/s10646-011-0662-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/19/2011] [Indexed: 05/30/2023]
Abstract
Anthropogenic sources of nitrogen that pollute bodies of water can have toxic and sub-lethal effects on amphibians. It has been hypothesized that such exposure may promote local adaptation, that is, selection for higher tolerance in individuals in populations exposed to pollutants. We tested this hypothesis with respect to the Natterjack toad (Bufo calamita Laurenti, 1768), by comparing the nitrate dose response of tadpoles from eight populations (doses: 0, 50, 100, 500 and 1000 mg/l nitrate) from relatively unpolluted and intensively farmed environments. We evaluated the effect of nitrate exposure by observing the behavior (movements) of tadpoles exposed to different concentrations of nitrates. Exposure to high nitrate levels did not cause tadpole mortality in the populations used in our experiments; however, we did observe changes in activity for all populations, with these changes being either dose-related responses (decreased activity after exposure to 500 or 1000 mg/l), or more complex responses (increased activity when exposed to 50 or 100 mg/l nitrate, followed by decreased activity at higher concentrations). Natterjack toad tadpoles exhibited variable behavioural responses among the tested populations. Although these populations were selected on the basis of their potential agrochemical contamination, the observed variation in population tolerance was not related to the parameters used to estimate this contamination in these breeding sites. Possible explanations for this apparent lack of local adaptation in B. calamita tadpoles include inadequate estimates of the toads' actual nitrate exposure in the field, and the biological characteristics of B. calamita, which may limit the effects of exposure or favor phenotypic plasticity.
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Affiliation(s)
- Claude Miaud
- Laboratory of Alpine Ecology, University of Savoie, UMR CNRS 5553, Le Bourget du Lac, France.
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Ortiz-Santaliestra ME, Marco A, Lizana M. Realistic Levels of a Fertilizer Impair Iberian Newt Embryonic Development. HERPETOLOGICA 2011. [DOI: 10.1655/herpetologica-d-10-0001.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ortiz-Santaliestra ME, Fernández-Benéitez MJ, Marco A, Lizana M. Influence of ammonium nitrate on larval anti-predatory responses of two amphibian species. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2010; 99:198-204. [PMID: 20493565 DOI: 10.1016/j.aquatox.2010.04.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 04/15/2010] [Accepted: 04/24/2010] [Indexed: 05/29/2023]
Abstract
Sublethal effects of toxicants can upset normal behavioural responses to predators, leading to increased predation. For example, sensory capabilities can be impaired by toxicants, leading to difficulty in detecting predators or other threats. Alteration of locomotor abilities by pollutants can also explain the difficulty of tadpoles to escape from predators. Here we assess the effects of a nitrogenous fertilizer on the response to predators shown by anuran tadpoles. In a first experiment, we chronically exposed Iberian painted frog (Discoglossus galganoi) and spadefoot toad (Pelobates cultripes) tadpoles to environmentally relevant concentrations of ammonium nitrate. After the exposure, we tested tadpoles' ability to avoid predation by the red crayfish (Procambarus clarkii). In a second experiment, we analysed the escape behaviour of P. cultripes tadpoles as a function of ammonium nitrate exposure and presence of predatory crayfishes. Tadpoles of both species that were exposed to ammonium nitrate were consumed by crayfishes faster than controls (mean time of predation: Dg controls=18.03 h, 90.3 mg N-NO(3)NH(4)/L=7.48 h; Pc controls=16.12h, 90.3 mg N-NO(3)NH(4)/L=9.46 h). Control larval P. cultripes showed specific anti-predator escape responses, whereas those exposed to the fertilizer did not. We demonstrate, for the first time in amphibians, how nitrogenous fertilizers can affect larval defensive behaviours, and thereby increase the risk of predation. Our results emphasize the importance of considering environmental stresses on the ecotoxicological studies with amphibians.
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