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Agricultural contaminants in freshwater ecosystems and disposition of fungicides in amphibians

Tess Goessens (UGent)
(2021)
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(UGent) , (UGent) , (UGent) and (UGent)
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Abstract
Amphibian breeding waters are becoming more and more subject to chemical pollution resulting from agricultural practices. As agrochemicals are known to influence amphibian health (i.e. disease susceptibility including chytrid disease dynamics) and foodweb structure, it is recommended to perform spatiotemporal screening of these compounds in ponds during the reproductive season of newts, when exposure to aquatic contaminants is most likely. Chytrid disease is caused by the fungi Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) and is responsible for worldwide amphibian population declines. In this doctoral dissertation, a multi-residue SPE-UHPLC-HRMS method for the targeted and untargeted analysis of antimicrobial drug residues, and suitable multi-residue SPE-UHPLC-MS/MS methods for the targeted analysis of anthelmintics, coccidiostats and mycotoxins in pond water samples, were developed. All methods were thoroughly validated and applied to water samples collected from 18 freshwater ponds situated in the Zwalm river basin of Flanders (Belgium) as part of a pilot study demonstrating each methods’ applicability. The newly developed and validated methods were then applied, along with other established and validated multi-residue methods (i.e. SPE-UHPLC-MS/MS and SPE-GC-ECD for pesticides and ICP-OES for heavy metals), to analyse 178 agricultural contaminants in a large spatio-temporal field study. This field study was performed on 26 amphibian breeding ponds situated in the Zwalm river basin of Flanders, that were sampled at four monthly occasions, from March until June 2019. This period coincides with the aquatic phase of amphibians. Parallel to the water sampling, information was gathered on amphibian abundance (i.e. Ichthyosaura alpestris and Lissotriton helveticus) and chytrid prevalence (i.e. Bd) by use of fish funnel traps and qPCR, respectively. Results showed the presence of in total 80 contaminants from 5 different agrochemical groups, i.e. antimicrobial drug residues, coccidiostats and anthelmintics, heavy metals, mycotoxins and pesticides. Within each group, the highest detected concentration was obtained for 4-epioxytetracycline (0.422 μg L-1), levamisole (0.550 μg L-1), zinc (333.1 μg L-1), 3-acetyldeoxynivalenol (0.013 μg L-1) and terbuthylazine (38.7 μg L-1), respectively, with detection frequencies ranging from one (i.e. 3-acetyldeoxynivalenol) to 26 (i.e. zinc) out of 26 ponds. Furthermore, high detection frequencies and concentrations were found for some azole fungicides, i.e. detections in all ponds for tebuconazole in June and concentrations up to 3.37 and 3.33 μg L-1 for epoxiconazole and propiconazole, respectively. When comparing the concentrations of all contaminants to reported acute and chronic toxicity data for amphibians and aquatic invertebrates, a substantial environmental risk was found for cadmium, copper, mercury, cypermethrin, terbuthylazine and zinc to the aquatic invertebrate Daphnia magna. Furthermore, no significant correlation (p-value < 0.05) was demonstrated between the number of detected compounds per pond, as well as the concentrations of the most frequently detected contaminants within each group 4-epioxytetracycline, levamisole, zinc, enniatin B and terbuthylazine, and the percentage of surrounding arable land, suggesting the influence of various other natural and/or Summary 251 anthropogenic sources of agrochemical pollution in the amphibian breeding ponds. Additionally, alpine and palmate newts were detected in all ponds during at least two of the four sampling events and Bd was detected in 11 out of 26 amphibian breeding ponds, in 3 - 69% of the sampled alpine newts. Based on the high detection frequencies and concentrations of azole fungicides found within the 26 sampled ponds, and due to their intrinsic toxic and chemical properties, the aquatic uptake kinetics, bioaccumulation and elimination kinetics of epoxiconazole, propiconazole and tebuconazole were assessed in the whole body, liver and skin of the Japanese red-bellied newt (Cynops pyrrhogaster). Overall, compounds were rapidly absorbed and accumulated during waterborne exposure at 50 μg L-1 in newt liver and skin, and were rapidly eliminated after withdrawal, with similar kinetic profiles in both organs. Elimination half-lives ranged between 1.03 and 1.37 days for newt skin and between 1.10 and 1.64 days for newt liver. Furthermore, whole body bioconcentration factor values indicated an accumulation factor of 12.3 (epoxiconazole), 11.1 (propiconazole) and 9.2 (tebuconazole) in relation to water. The organ-specific and whole-body bioaccumulation potential of these three azole fungicides raises concerns about potential adverse effects and impact on immunity and amphibian disease dynamics. In conclusion, this doctoral dissertation demonstrates for the first time the spatiotemporal pollution, amphibian abundance and chytrid prevalence of amphibian breeding ponds situated in an agricultural landscape in the Zwalm river basin, and the organ-specific uptake, bioaccumulation and elimination potential of epoxiconazole, propiconazole and tebuconazole, after waterborne exposure, in the Japanese red-bellied newt as model organism for semi-aquatic amphibians habituating agricultural landscapes.
Keywords
pond water, analytical chemistry, veterinary drugs, mycotoxins, pesticides, heavy metals, newts, amphibians, chytridiomycosis

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MLA
Goessens, Tess. Agricultural Contaminants in Freshwater Ecosystems and Disposition of Fungicides in Amphibians. Ghent University. Faculty of Veterinary Medicine, 2021.
APA
Goessens, T. (2021). Agricultural contaminants in freshwater ecosystems and disposition of fungicides in amphibians. Ghent University. Faculty of Veterinary Medicine, Ghent, Belgium.
Chicago author-date
Goessens, Tess. 2021. “Agricultural Contaminants in Freshwater Ecosystems and Disposition of Fungicides in Amphibians.” Ghent, Belgium: Ghent University. Faculty of Veterinary Medicine.
Chicago author-date (all authors)
Goessens, Tess. 2021. “Agricultural Contaminants in Freshwater Ecosystems and Disposition of Fungicides in Amphibians.” Ghent, Belgium: Ghent University. Faculty of Veterinary Medicine.
Vancouver
1.
Goessens T. Agricultural contaminants in freshwater ecosystems and disposition of fungicides in amphibians. [Ghent, Belgium]: Ghent University. Faculty of Veterinary Medicine; 2021.
IEEE
[1]
T. Goessens, “Agricultural contaminants in freshwater ecosystems and disposition of fungicides in amphibians,” Ghent University. Faculty of Veterinary Medicine, Ghent, Belgium, 2021.
@phdthesis{8713869,
  abstract     = {{Amphibian breeding waters are becoming more and more subject to chemical pollution resulting from agricultural practices. As agrochemicals are known to influence amphibian health (i.e. disease susceptibility including chytrid disease dynamics) and foodweb structure, it is recommended to perform spatiotemporal screening of these compounds in ponds during the reproductive season of newts, when exposure to aquatic contaminants is most likely. Chytrid disease is caused by the fungi Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) and is responsible for worldwide amphibian population declines. In this doctoral dissertation, a multi-residue SPE-UHPLC-HRMS method for the targeted and untargeted analysis of antimicrobial drug residues, and suitable multi-residue SPE-UHPLC-MS/MS methods for the targeted analysis of anthelmintics, coccidiostats and mycotoxins in pond water samples, were developed. All methods were thoroughly validated and applied to water samples collected from 18 freshwater ponds situated in the Zwalm river basin of Flanders (Belgium) as part of a pilot study demonstrating each methods’ applicability. The newly developed and validated methods were then applied, along with other established and validated multi-residue methods (i.e. SPE-UHPLC-MS/MS and SPE-GC-ECD for pesticides and ICP-OES for heavy metals), to analyse 178 agricultural contaminants in a large spatio-temporal field study. This field study was performed on 26 amphibian breeding ponds situated in the Zwalm river basin of Flanders, that were sampled at four monthly occasions, from March until June 2019. This period coincides with the aquatic phase of amphibians. Parallel to the water sampling, information was gathered on amphibian abundance (i.e. Ichthyosaura alpestris and Lissotriton helveticus) and chytrid prevalence (i.e. Bd) by use of fish funnel traps and qPCR, respectively. Results showed the presence of in total 80 contaminants from 5 different agrochemical groups, i.e. antimicrobial drug residues, coccidiostats and anthelmintics, heavy metals, mycotoxins and pesticides. Within each group, the highest detected concentration was obtained for 4-epioxytetracycline (0.422 μg L-1), levamisole (0.550 μg L-1), zinc (333.1 μg L-1), 3-acetyldeoxynivalenol (0.013 μg L-1) and terbuthylazine (38.7 μg L-1), respectively, with detection frequencies ranging from one (i.e. 3-acetyldeoxynivalenol) to 26 (i.e. zinc) out of 26 ponds. Furthermore, high detection frequencies and concentrations were found for some azole fungicides, i.e. detections in all ponds for tebuconazole in June and concentrations up to 3.37 and 3.33 μg L-1 for epoxiconazole and propiconazole, respectively. When comparing the concentrations of all contaminants to reported acute and chronic toxicity data for amphibians and aquatic invertebrates, a substantial environmental risk was found for cadmium, copper, mercury, cypermethrin, terbuthylazine and zinc to the aquatic invertebrate Daphnia magna. Furthermore, no significant correlation (p-value < 0.05) was demonstrated between the number of detected compounds per pond, as well as the concentrations of the most frequently detected contaminants within each group 4-epioxytetracycline, levamisole, zinc, enniatin B and terbuthylazine, and the percentage of surrounding arable land, suggesting the influence of various other natural and/or
Summary
251
anthropogenic sources of agrochemical pollution in the amphibian breeding ponds. Additionally, alpine and palmate newts were detected in all ponds during at least two of the four sampling events and Bd was detected in 11 out of 26 amphibian breeding ponds, in 3 - 69% of the sampled alpine newts. Based on the high detection frequencies and concentrations of azole fungicides found within the 26 sampled ponds, and due to their intrinsic toxic and chemical properties, the aquatic uptake kinetics, bioaccumulation and elimination kinetics of epoxiconazole, propiconazole and tebuconazole were assessed in the whole body, liver and skin of the Japanese red-bellied newt (Cynops pyrrhogaster). Overall, compounds were rapidly absorbed and accumulated during waterborne exposure at 50 μg L-1 in newt liver and skin, and were rapidly eliminated after withdrawal, with similar kinetic profiles in both organs. Elimination half-lives ranged between 1.03 and 1.37 days for newt skin and between 1.10 and 1.64 days for newt liver. Furthermore, whole body bioconcentration factor values indicated an accumulation factor of 12.3 (epoxiconazole), 11.1 (propiconazole) and 9.2 (tebuconazole) in relation to water. The organ-specific and whole-body bioaccumulation potential of these three azole fungicides raises concerns about potential adverse effects and impact on immunity and amphibian disease dynamics.
In conclusion, this doctoral dissertation demonstrates for the first time the spatiotemporal pollution, amphibian abundance and chytrid prevalence of amphibian breeding ponds situated in an agricultural landscape in the Zwalm river basin, and the organ-specific uptake, bioaccumulation and elimination potential of epoxiconazole, propiconazole and tebuconazole, after waterborne exposure, in the Japanese red-bellied newt as model organism for semi-aquatic amphibians habituating agricultural landscapes.}},
  author       = {{Goessens, Tess}},
  keywords     = {{pond water,analytical chemistry,veterinary drugs,mycotoxins,pesticides,heavy metals,newts,amphibians,chytridiomycosis}},
  language     = {{eng}},
  pages        = {{VI, 330}},
  publisher    = {{Ghent University. Faculty of Veterinary Medicine}},
  school       = {{Ghent University}},
  title        = {{Agricultural contaminants in freshwater ecosystems and disposition of fungicides in amphibians}},
  year         = {{2021}},
}