Effects of aqueous extracts of wildfire ashes on tadpoles of Pelophylax perezi: Influence of plant coverage

Diogo Santos; Nelson Abrantes; Isabel Campos; Inês Domingues; Isabel Lopes

doi:10.1016/j.scitotenv.2022.158746

Effects of aqueous extracts of wildfire ashes on tadpoles of Pelophylax perezi: Influence of plant coverage

Sci Total Environ. 2023 Jan 1:854:158746. doi: 10.1016/j.scitotenv.2022.158746. Epub 2022 Sep 15.

Authors

Diogo Santos¹, Nelson Abrantes², Isabel Campos², Inês Domingues³, Isabel Lopes⁴

Affiliations

¹ Department of Biology, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
² Department of Environment and Planning, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal; CESAM, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
³ Department of Biology, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal; CESAM, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
⁴ Department of Biology, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal; CESAM, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal. Electronic address: ilopes@ua.pt.

PMID: 36116652
DOI: 10.1016/j.scitotenv.2022.158746

Abstract

Wildfires have been pointed out as an important source of diffuse contamination to aquatic ecosystems, namely through the input of toxic compounds such as polycyclic aromatic hydrocarbons and metals. However, amphibians' responses to this disturbance have been largely ignored. Hence, this study intended to assess how ashes from Pinus sp. and Eucalyptus sp. plantation forests affect tadpoles of Pelophylax perezi. Tadpoles were exposed 14 days to serial concentrations (26.9 %-100 %) of aqueous extracts of ashes (AEA, with 10 g L^-1 of ashes) containing Eucalypt (ELS) and Pine (PLS) ashes. The following endpoints were measured: mortality, malformations, developmental stage, body length and weight. Effects at sub-individual level were also monitored for oxidative stress, neurotoxicity, and energetic metabolism. Chemical characterization of the AEA of ELS showed higher concentrations of As, Cd, Co, Cr, Pb and V, while PLS showed higher concentrations of Cu, Mn, Ni and Zn. Concerning the lethal effects of AEAs on tadpoles, both extracts were able to induce mortality at high concentrations (76.9 and/or 100 % of AEA), although a high variability in the response was found. A significant mortality in tadpoles exposed to ELS was observed at the concentration of 76.9 %. For organisms exposed to PLS, though a mortality above 20 % was registered at the two highest tested concentrations, it was not significantly different from the control. No significant sub-lethal effects were observed in the ELS treatments. Contrasting, exposure to PLS induced a decrease in body length, weight, glutathione-S-transferase activity and an increase in oxygen consumption. Overall, the distinct effects of ELS and PLS suggest an influence of vegetation cover in ash toxicity. In conclusion, exposure to both ash extracts negatively affected sublethal responses of tadpoles of P. perezi. Future research is needed to assess how these effects at individual level may translate into effects at population level.

Keywords: Amphibians; Ecotoxicity; Iberian green frog; Metals; Post-fire contamination.

MeSH terms

Animals
Ecosystem
Forests
Larva
Ranidae
Water / metabolism
Wildfires*

Substances

Water