Accumulation of heavy metals by flounder, Platichthys flesus (Linnaeus 1758), in a heterogeneously contaminated nursery area

摘要

Estuaries and associated coastal waters across the world are among the most modified and threatened aquatic environments (e.g. Suchanek, 1994; Vernberg, 1997; Goksoyr et al., 1997). The Douro estuary, in Northern Portugal, is a heavily modified urban estuary, receiving untreated sewage from over one million people, as well as industrial discharges. Despite public health concerns, this estuarine system has never been subject to an ecotoxicological study. Industrial discharges into estuaries have been the main source of heavy metals contamination with several sub-lethal and lethal effects being reported for estuarine species, mainly in North European and North American estuaries (e.g. Amiard et al., 1982; Haedrich and Haed-rich, 1974; Amiard-Triquet et al., 1986; Long et al., 1995). Some of the most common effects of this type of pollution are physiological disturbances such as enzymatic and hormonal alterations (Amiard et al., 1982; Amiard-Triquet et al., 1986).