Author(s):
Costa, Pedro M. 
; Caeiro, Sandra ; Diniz, Mário S. ; Lobo, Jorge ; Martins, Marta ; Ferreira, Ana M. ; Caetano, Miguel ; Vale, Carlos ; DelValls, Ángel ; Costa, Maria Helena
Date: 2009
Persistent ID: http://hdl.handle.net/10400.2/1399
Origin: Repositório Aberto da Universidade Aberta
Subject(s): Senegalese sole; Contaminated sediments; Bioaccumulation; Metallothionein; CYP1A; Sado estuary
Description
Juvenile Solea senegalensis were exposed to
fresh sediments from three stations of the Sado estuary
(Portugal) in 28-day laboratory assays. Sediments revealed
distinct levels of total organic matter, fine fraction, redox
potential, trace elements (arsenic, cadmium, chromium,
copper, nickel, lead and zinc) and organic contaminants
(polycyclic aromatic hydrocarbons, polychlorinated
biphenyls and a pesticide: dichloro diphenyl trichloroethane).
Organisms were surveyed for contaminant bioaccumulation
and induction of two hepatic biochemical
biomarkers: metallothionein (MT) and cytochrome P450
(CYP1A), as potential indicators of exposure to metallic
and organic contaminants, respectively. Using an integrative
approach it was established that, although bioaccumulation
is in general accordance with sediment
contamination, lethality and biomarker responses are not
linearly dependent of the cumulative concentrations of
sediment contaminants but rather of their bioavailability
and synergistic effects in organisms. It is concluded that
metals and organic contaminants modulate both MT and
CYP1A induction and it is suggested that reactive oxygen
species may be the link between responses and effects of
toxicity.
