abstract
Climate change is leading to a gradual increase in the ocean temperature, which can cause physiological and biochemical impairments in aquatic organisms. Along with the environmental changes, the presence of emerging pollutants such as titanium dioxide (TiO2) in marine coastal systems has also been a topic of concern, especially considering the interactive effects that both factors may present to inhabiting organisms. In the present study, it has been assessed the effects of the presence in water of particles of rutile, the most common polymorph of TiO2, in Mytilus galloprovincialis, under actual and predicted warming conditions. Organisms were exposed to different concentrations of rutile (0, 5, 50,100 mu g/L) at control (18 +/- 1.0 degrees C) and increased (22 +/- 1.0 degrees C) temperatures. Histopathological and biochemical changes were evaluated in mussels after 28 days of exposure. Histopathological examination revealed similar alterations on mussels' gills and digestive glands with increasing rutile concentrations at both temperatures. Biochemical markers showed that contaminated mussels have an unchanged metabolic capacity at 18 degrees C, which increased at 22 degrees C. Although antioxidant defences were activated in contaminated organisms at 22 degrees C, cellular damage was still observed. Overall, our findings showed that histopathological impacts occurred after rutile exposure regardless of the temperature, while biochemical alterations were only significantly noticeable when temperature was enhanced to 22 degrees C. Thus, this study demonstrated that temperature rise may significantly enhance the sensitivity of bivalves towards emerging pollutants. (C) 2020 Elsevier Ltd. All rights reserved.
keywords
OXIDATIVE STRESS; TIO2 NANOPARTICLES; DIGESTIVE GLAND; HISTOPATHOLOGICAL INDEXES; RUDITAPES-DECUSSATUS; MEDITERRANEAN MUSSEL; BIOCHEMICAL MARKERS; THERMAL-STRESS; WASTE-WATER; ACCUMULATION
subject category
Environmental Sciences & Ecology
authors
Leite, C; Coppola, F; Monteiro, R; Russo, T; Polese, G; Silva, MRF; Lourenco, MAO; Ferreira, P; Soares, AMVM; Pereira, E; Freitas, R
our authors
Mariana Rodrigues Ferreira da Silva
Research Fellowship
Mirtha A. O. Lourenço
Researcher
Paula Celeste da Silva Ferreira
Coordinating Researcheracknowledgements
Carla Leite benefited from BSc grant under the project ASAR-ISAFE (NSFC/0001/2016) funded by the Portuguese Science Foundation (FCT). Francesca Coppola, and Rui Monteiro benefited from PhD grants (SFRH/BD/118582/2016 and SFRH/BD/108535/2015, respectively), given by the National Funds through the FCT, supported by FSE and Programa Operacional Capital Humano (POCH) e da Uniao Europeia. Paula Ferreira acknowledge the grant IF/00300/2015. Rosa Freitas was funded by national funds (OE), through FCT, 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. This work was also financially supported by the project BISPECIAl: BIvalveS under Polluted Environment and ClImate chAnge PTDC/CTA-AMB/28425/2017 (POCI-01-0145-FEDER-028425) funded by FEDER, through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI), and by national funds (OE), through FCT/MCTES. Thanks are due for the financial support to CESAM (UIDB/50017/2020thornUIDP/50017/2020), CICECO (UIDB/50011/2020 & UIDP/50011/2020) and Smart Green Homes Project (POCI-01-0247-FEDER-007678), financed by national funds through the FCT/MEC and co-financed by FEDER under the PT2020 Partnership Agreement and Compete 2020.