Environ Monit Assess (2008) 136:267–275
DOI 10.1007/s10661-007-9682-6
Heavy metals in water, sediment and tissues of Liza
saliens from Esmoriz–Paramos lagoon, Portugal
C. Fernandes & A. Fontaínhas-Fernandes &
D. Cabral & M. A. Salgado
Received: 7 December 2006 / Accepted: 28 February 2007 / Published online: 20 April 2007
# Springer Science + Business Media B.V. 2007
Abstract Esmoriz–Paramos lagoon is an ecosystem
of great ecological importance that is located on the
northwest coast of Portugal and has been degraded as
a result of industrial and anthropogenic activities.
Concentrations of heavy metals (Cr, Cu, Pb and Zn)
were measured in water, sediment and in tissues (liver
C. Fernandes
ESA – Escola Superior Agrária, Instituto Politécnico
de Bragança, CIMO – Centro de Investigação de Montanha,
Campus de Santa Apolónia,
Apartado 1038,
5301-854 Bragança, Portugal
A. Fontaínhas-Fernandes (*)
UTAD – Universidade de Trás-os-Montes e Alto Douro,
CETAV – Centro de Estudos Tecnológicos,
do Ambiente e da Vida,
Apartado 1013,
5000-911 Vila Real, Portugal
e-mail: [email protected]
D. Cabral
ESA – Escola Superior Agrária, Instituto Politécnico
de Bragança, CIMO – Centro de Investigação de Montanha,
Campus de Santa Apolónia,
Apartado 1172,
5301-855 Bragança, Portugal
M. A. Salgado
ICBAS – Instituto de Ciências Biomédicas de Abel Salazar,
Universidade do Porto, CIIMAR – Centro Interdisciplinar
de Investigação Marinha e Ambiental,
Rua dos Bragas, 289,
4050-123 Porto, Portugal
and muscle) of Liza saliens, which is the dominant
fish from the lagoon. Comparisons between metal
concentrations in water and sediments were made with
those in tissues of fish caught at the lagoon. Metals in
water were quantified predominantly bound to particulate and equalled or exceeded the limit of chronic
reference values. Metal concentrations in sediments
varied among sampled sites. The relative order of
concentrations was “Zn>Cu∼Pb>Cr” the same pattern observed for metals in water. Metals in fish
tissues showed higher concentrations in liver (262 mg
Cu·Kg−1 and 89 mg Zn·Kg−1) than in muscle (<3 mg
Cu·Kg−1 and 26 mg Zn·Kg−1), while Pb and Cr were
not detected. These results suggest that Cu and Zn are
the metals of major concern in the lagoon. Mullet
detritivorous feeding habits, bioaccumulation pattern
and the high sediment metals concentrations relative
to the water suggest that sediments can be the most
important source of contamination in this ecosystem.
The positive relationship found between Cu in liver
and fish length demonstrates that time of exposure is a
crucial factor in bioaccumulation. Condition indices
(K and HSI) in mullets from the lagoon were higher
compared to mullets from sea, suggesting abnormal
condition in the lagoon population. We conclude that
metals chronic exposure in the lagoon can impose
considerable fish stress. The results also show that the
lagoon is an area of environmental concern.
Keywords Esmoriz–Paramos . Heavy metals .
Sediment . Water . Fish