Heavy metal concentrations were measured in the surface sediment, the
settled particulate matter (SPM), the macroalgal biomass and some zoob
enthic taxa of three areas (Alberoni, Sacca Sessola and S. Giuliano) s
panning the main bio-geo-physico-chemical differences of the central l
agoon of Venice. In terms of average metal content the observed contam
ination indicates the following sequence: SPM>sediment>macroalgae>zoob
enthos. The dominant macroalgal species in the central lagoon of Venic
e, that is Ulva rigida C.Ag., showed a preferential enrichment of Zn a
nd Mn compared to other metals. Both seasonality and frond age were re
sponsible for the heavy metals found in the macroalgae. Finally, consi
dering the amount of metals involved in the total gross primary produc
tion (GPP) and the total heavy metal quantity flowing into the central
lagoon by streams and rivers, in situ turnover is thought to take pla
ce.