Author(s):
Costa, Pedro M. 
; Diniz, Mário S. ; Caeiro, Sandra ; Lobo, Jorge ; Martins, Marta ; Ferreira, Ana M. ; Caetano, Miguel ; Vale, Carlos ; DelValls, Ángel ; Costa, Maria Helena
Date: 2009
Persistent ID: http://hdl.handle.net/10400.2/1397
Origin: Repositório Aberto da Universidade Aberta
Subject(s): Solea senegalensis; Histopathological indices; Bioassays; Sado estuary; Sediment; Metallic and organic contaminants
Description
Young juvenile Solea senegalensis were exposed to three sediments with distinct contamination profiles
collected from a Portuguese estuary subjected to anthropogenic sources of contamination (the Sado estuary,
western Portugal). Sedimentswere surveyed formetals (cadmium, chromium, copper, nickel, lead and
zinc), ametalloid (arsenic) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated
biphenyls and a pesticide, dichloro-diphenyl-trichloroethane plus itsmetabolites), aswell as total organic
matter, redox potential and particle fine fraction. The fish were exposed to freshly collected sediments
in a 28-day laboratorial assay and collected for histological analyses at days 0 (T0), 14 (T14) and 28 (T28).
Individual weighted histopathological indices were obtained, based on presence/absence data of eight
and nine liver and gill pathologies, respectively, and on their biological significance. Although livers sustained
more severe lesions, the sediments essentially contaminated by organic substances caused more
damage to both organs than the sediments contaminated by both metallic and organic contaminants,
suggesting a possible synergistic effect. Correlation analyses showed that some alterations are linked,
forming distinctive histopathological patterns that are in accordance with the severity of lesions and
sediment characteristics. The presence of large eosinophilic bodies in liver and degeneration of mucous
cells in gills (a first-time described alteration)were some of the most noticeable alterations observed and
were related to sediment organic contaminants. Body size has been found to be negatively correlated
with histopathological damage in livers following longer term exposures. It is concluded that histopathological
indices provide reliable and discriminatory data even when biomonitoring as complex media as
natural sediments. It is also concluded that the effects of contamination may result not only from toxicant
concentrations but also from their interactions, relative potency and sediment characteristics that
ultimately determine bioavailability.
