CESAM-Centre for Environmental and Marine Studies, Department of Environment and Planning, University of Aveiro, 3810-193 Aveiro, Portugal.
CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal.
Int J Environ Res Public Health. 2023 Jan 11;20(2):1326. doi: 10.3390/ijerph20021326.
Wildfires constitute a source of contamination to both freshwater and marine ecosystems. This study aimed to compare the antioxidant defense response of the freshwater clam and the marine cockle () to wildfire ash exposure and the concomitant metal body burden. Organisms were exposed to different concentrations (0%, 12.5%, 25%, 50%, and 100%) of aqueous extracts of Eucalypt ash (AEAs) from a moderate-to-high severity wildfire. The activity of various enzymes, as well as lipid peroxidation, protein content, and metal body burden, were determined after 96 h of exposure. A significant increase in the protein content of soft tissues was observed for at AEA concentrations ≥ 25%, unlike for . Similarly, significant effects on lipid peroxidation were observed for cockles, but not for clams. For both species, a significant effect in the total glutathione peroxidase activity was observed at AEA concentrations ≥ 25%. Relative to the control, AEAs-exposed clams showed higher Cd content, whereas AEAs-exposed cockles showed higher Cu content, thus exhibiting different responses to the exposure to wildfire ash. The susceptibility of bivalves to ashes, at environmentally relevant concentrations, raises concern about the effects of post-fire runoff to bivalve species.
野火是淡水和海洋生态系统污染的一个来源。本研究旨在比较淡水蛤和海洋贻贝在暴露于野火灰和随之而来的金属体负荷时的抗氧化防御反应。将生物体暴露于中等到高强度野火的桉树灰（AEAs）的不同浓度（0%、12.5%、25%、50%和 100%）的水溶液中。暴露 96 小时后，测定了各种酶的活性、脂质过氧化、蛋白质含量和金属体负荷。与贻贝不同，在 AEAs 浓度≥25%时，软体组织的蛋白质含量显著增加。同样，对贻贝的脂质过氧化也有显著影响，但对蛤没有影响。对于这两个物种，在 AEAs 浓度≥25%时，总谷胱甘肽过氧化物酶活性均有显著影响。与对照组相比，暴露于 AEAs 的蛤中 Cd 含量较高，而暴露于 AEAs 的贻贝中 Cu 含量较高，因此对暴露于野火灰的反应不同。在环境相关浓度下，双壳类动物对灰烬的敏感性引起了对火灾后径流对双壳类物种影响的关注。
