Sedimentary biogeochemical data fromthe Gulf of Palermo,which borders one of themajor urban and industrialareas of the centralMediterranean, provide a decennial–centennial-scale record of the effects of human activityon this coastal environment. In this studywe report trace elements (TE), Corg/Ntot ratios, δ13Corg, and δ15Ntot fromdated (210Pb) sediments collected in two coastal stations variably influenced by urban/fluvial loadings and illegaldumping and we compare them with published data for offshore sediments, in order to investigate at a largespatial scale the influence of on-land activities on sedimentary marine system. TE were generally low exceptfor Hg and Pb, which exhibited moderate enrichments. Low TE enrichment factors with respect to Corg indicatethat trace elements were mainly trapped by sedimentary organic matter. Corg/Ntot, δ13Corg, and δ15Ntot depthprofiles showed that sediments received organicmatter derived frommarine sourcesmixed with organicmatterfrom the erosion of terrestrial material as well as unregulated sewage discharges. Superimposed on thesepatterns, repeated shifts in δ13Corg towards values higher than those typical of offshore Palermo sedimentswere concomitant with higher Corg/Ntot. These shifts observed in the core portions covering the last 40 yearsreflect enhanced eutrophication as result of elevated nutrient input into marine waters. The results of thisstudy have traced the origin and extent of the organic enrichment and emphasized the importance of utilizinga complete range of chemical and isotopic analyses from sedimentary records to reconstruct the environmentalhistory of coastal ecosystems impacted by urbanization processes.
|Numero di pagine||12|
|Rivista||Journal of Marine Systems|
|Stato di pubblicazione||Published - 2012|
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