Do Freshwater and Marine Bivalves Differ in Their Response to Wildfire Ash? Effects on the Antioxidant Defense System and Metal Body Burden

Int J Environ Res Public Health. 2023 Jan 11;20(2):1326. doi: 10.3390/ijerph20021326.

Abstract

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 Corbicula fluminea and the marine cockle (Cerastoderma edule) 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 C. edule at AEA concentrations ≥ 25%, unlike for C. fluminea. 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.

Keywords: enzymes activity; filter-feeders; metal body burden; oxidative stress; wildfire ash.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / metabolism
  • Body Burden
  • Corbicula* / metabolism
  • Ecosystem
  • Fresh Water
  • Metals / metabolism
  • Metals / toxicity
  • Proteins
  • Water Pollutants, Chemical* / analysis
  • Wildfires*

Substances

  • Antioxidants
  • Metals
  • Proteins
  • Water Pollutants, Chemical

Grants and funding

This work was performed within the scope and with the support of the FIREMIX project (PTDC/BIA-ECO/29601/2017), funded by FEDER, through COMPETE2020—Programa Operacional Competitividade e Internacionalização, and by national funds, through FCT/MCTES. The work was also supported by the AQUAFIRE (PTDC/CTA-AMB/28936/2017) project, funded by FEDER, through COMPETE2020 and by national funds, through FCT/MCTES. The authors would further like to acknowledge the financial support to CESAM by FCT/MCTES (UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020), LA/P/0069/2020 granted to the Associate Laboratory ARNET and UIDB/04292/2020 granted to Marine and Environmental Sciences Centre (MARE), by national funds through FCT, I.P. Dalila Serpa was funded by national funds (OE) through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. A. M. M. Gonçalves acknowledges University of Coimbra for the contract IT057-18-7253.