title: Integrated biomarker responses of the invasive species Corbicula fluminea in relation to environmental abiotic conditions: a potential indicator of the likelihood of clam's summer mortality syndrome.
abstract: The aim of this study was to investigate the variation of several biomarkers in wild populations of Corbicula fluminea in relation to abiotic condition changes to identify environmental factors associated with increased stress in this species potentially leading to massive mortality events. The study was carried out from July to October in the freshwater tidal areas of the estuaries of Minho and Lima Rivers (NW Iberian Peninsula). Monthly, 7 biomarkers (biotransformation, energy production, anti-oxidant defenses and lipid peroxidation damages) were determined in C. fluminea and 17 abiotic parameters were determined in water or sediments in 4 sampling sites: M1, M2 and M3 in Minho (up=> downstream); and L in Lima estuaries. The results of biomarkers were integrated using the Integrated Biomarker Response (IBR), Index and also analysed in relation to environmental parameters by Redundancy Analysis (RDA). Overall, the findings of the present study indicate that July and August are particularly stressful months for the studied C. fluminea populations, especially at downstream sites; the increase of nutrients and ammonium water concentrations, water temperature and conductivity are major contributors for this increased stress; the biomarkers indicated that in July/August C. fluminea is exposed to oxidative stress inducers, environmental chemical contaminants biotransformed by esterases and glutathione S-transferase enzymes, and that organisms need additional energy to cope with the chemical and/or thermally-induced stress. The findings of the present study stress the importance of biomonitoring the health condition of C. fluminea because it may allow determining the likelihood of summer/post summer mortality syndrome in this species.
authors.affiliation: ICBAS-Institute of Biomedical Sciences of Abel Salazar, University of Porto, Department of Populations Studies, Laboratory of Ecotoxicology, Rua de Jorge Viterbo Ferreira 228, P 4050-313 Porto, Portugal; CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, Laboratory of Ecotoxicology and Ecology, University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal. Electronic address: colivei@ciimar.up.pt.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Oliveira
authors.affiliation: ICBAS-Institute of Biomedical Sciences of Abel Salazar, University of Porto, Department of Populations Studies, Laboratory of Ecotoxicology, Rua de Jorge Viterbo Ferreira 228, P 4050-313 Porto, Portugal; CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, Laboratory of Ecotoxicology and Ecology, University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Vilares
authors.affiliation: ICBAS-Institute of Biomedical Sciences of Abel Salazar, University of Porto, Department of Populations Studies, Laboratory of Ecotoxicology, Rua de Jorge Viterbo Ferreira 228, P 4050-313 Porto, Portugal; CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, Laboratory of Ecotoxicology and Ecology, University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal.
authors.forename: Lúcia
authors.initials: L
authors.lastname: Guilhermino
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D049874:Corbicula / Q000502:physiology*; D004784:Environmental Monitoring; D063366:Estuaries; D019015:Geologic Sediments; D005982:Glutathione Transferase / Q000378:metabolism; D058865:Introduced Species; D015227:Lipid Peroxidation; D009026:Mortality; D012621:Seasons; D013030:Spain; D013312:Stress, Physiological; D013696:Temperature
chemical_list: D015415:Biomarkers; D002374:Catalase; D005982:Glutathione Transferase
keywords: Abiotic variation; Biomarkers; Bivalve massive mortality; Invasive species; Summer