XII Congresso Brasileiro de Ecotoxicologia
25 a 28 de setembro de 2012
Porto de Galinhas – PE
COMBINED EFFECTS OF COPPER AND SALINITY ON THE DEVELOPMENT OF
ZEBRAFISH EMBRYOS
Thayres S. Andrade1; Barbara Santos1; Rui Ribeiro2; Isabel Lopes1; Amadeu M. V. M Soares1;
Inês Domingues1
1
[email protected] (Departament of Biology & CESAM, University of Aveiro, Aveiro, Portugal)
[email protected] (Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal)
2
[email protected] (IMAR – Instituto do Mar, Department of Life Sciences, University of Coimbra,
Coimbra, Portugal
1
[email protected] (Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal)
1
[email protected] (Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal)
1
[email protected] (Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal)
1
Climate changes are expected to modify environmental parameters in aquatic ecosystems. Within these
scenarios, an increase in salinity, due to the sea level rise, is predicted to occur in coastal freshwater
ecosystems. According, a set of works has already addressed the sensitivity of several freshwater species to
increased salinity in order to evaluate the potential risks associated with the salinization of such coastal
ecosystems. However, as many of these coastal freshwater lagoons are already impacted with metal
contamination, it is pertinent and important to assess and understand the combined effects of metals and
increased salinity to freshwater species. Accordingly, the present work intended to evaluate the possible
interactions of copper and NaCl (as a measure of increasing salinity) on the development of zebrafish
embryos. To achieve this goal, embryos (2 hpf) were exposed to several concentrations of copper (0.33 –
2.49 µg/L) and NaCl (2.2 – 10.62 g/L), both individually and combined (using a full factorial design), during
96h. During exposure, several endpoints (mortality, hatching rate, edemas, malformations) were monitored.
Preliminary results showed that in the highest NaCl concentrations (without copper), mortality was higher,
but when combined with copper, mortality decreased. Furthermore, the highest copper concentrations
(without NaCl) caused higher mortality rates. These data suggest a possible antagonism between copper and
NaCl toxicity effects on mortality rate. Sublethal endpoints showed different responses patterns. Both NaCl
and copper alone did not cause increase of malformations or edemas but when the same concentrations of
both chemicals were combined there was an increase of incidence of these two parameters. This same
scenario was observed for hatching rate, which was inhibited in the combined treatments. It is then expected
that a synergistic effect could result from the combination of copper and NaCl and increase toxicity at
sublethal level. These initial results suggest that attention must be paid to the effects of salinization on
aquatic ecosystems impacted with metals as interactions are likely to occur, and already chemical-impacted
populations may be at a higher risk comparatively with non-exposed ones.
Keywords: copper, salinization, combined effects
Sociedade Brasileira de Ecotoxicologia (SBE)
Universidade Federal de Pernambuco (UFPE)
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