Metal deposition in deep sediments from the Central and South Adriatic Sea

Abstract

Geochemical analysis and trace element distribution were performed on the marine sediments from short cores (30 to 50 cm) from the Middle (Jabuka and Palagruža pits, depth 230 m and 170 m, respectively) and South Adriatic Sea (depth 1030 m) and the Albanian offshore (50 m depth). The distribution of trace elements (As, Co, Cd, Cu Cr, Ni, Zn, Hg, and Pb) and major elements (Al, Ca and Mn) and mineralogy in the sediments is presented. Sediments are highly heterogeneous and consist of carbonate and detrital aluminosilicate minerals. The main mineral phase is calcite, followed by quartz, feldspars, micas and clay minerals (smectite, chlorite, illite and kaolinite). The cores were dated using 137 Cs. The cores from the South Adriatic Pit and Palagruža Sill gave estimated sedimentation rates of 1.8 mm y -1 and 3.1 mm y -1 in Jabuka Pit. Distributions of Ni and Cr showed that they can be used as tracers of sediment provenance along the southern part of the Eastern Adriatic Current. Calculated enrichment factors for Pb, Cd and Hg are highest in the top 2 cm of the cores. Mercury shows the highest degree of enrichment in 0-2 cm sediment intervals (the highest in the Albania core). Generally the estimated surface enrichment follows the order: Hg>Pb>Cd. No enrichment was found for Zn, Ni and Cr.

Size-related mineralogical and surface physicochemical properties of the mineral particles from the recent sediments of the Eastern Adriatic Sea

“…Although these results are generally in agreement with the earlier investigations (Ilijanić et al, 2014;Tomadin, 2000a), the new data were acquired based on the analysis of different micron-and submicron-sized sediment fractions of the Adriatic sediments, and provides a more detailed identification of clay minerals.…”

Mercury Content in Central and Southern Adriatic Sea Sediments in Relation to Seafloor Geochemistry and Sedimentology

“…Comparison of the present data with earlier results from sediments with similar grain size and sampling thickness (maximum 4 cm) highlighted comparable and slightly lower mercury concentrations in our samples in the same areas [17,18] [39][40][41] (Table 1). In contrast, our values are much lower than those measured in highly impacted areas such as the Gulf of Trieste and Marano Lagoon [18,19] and Rijeka harbour [50].…”

A baseline study of the metallothioneins content in digestive gland of the Norway lobster Nephrops norvegicus from Northern Adriatic Sea: Body size, season, gender and metal specific variability

“…However, considering the fairly weak correlation, it is difficult to speculate to what extent the level of Cd in N. norvegicus digestive gland might be related to MTs content fluctuations in this particular case. According to recent data on sediment metal concentrations (Cukrov et al, 2011(Cukrov et al, , 2014Ilijanić et al, 2014), there are no indications of particular sediment Cd enrichment at sampling sites in comparison to other offshore areas of unpolluted Adriatic and Mediterranean regions. Besides, concentrations of Cd for digestive gland were in line with data previously reported for N.…”

“…Sediment metal enrichment of various offshore areas of the Kvarner Bay corresponds to that of unpolluted sites within central and southern Adriatic far from any known anthropogenic sources (Ilijanić et al, 2014). Nevertheless, the possibility of accidental discharge cannot be ruled out since both sampling sites are intersected with important transport routes for cargo and touristic ships.…”