Natural and anthropogenic sources of Hg, Cd, Pb, Cu and Zn in seawater and sediment of Mljet National Park, Croatia

Influence of submarine groundwater discharge on seawater properties in Rovanjska-Modrič karst region (Croatia)

“…The most probable cause of locally increased SST is a bottom compensation current which brings warmer seawater directly into the freshwater discharge area at about 1 m above sea bottom, as observed by Kuhta and Novosel (2000) in a similar study area in the northern Velebit Channel. Table 1 comprises data on physical and chemical properties of the seawater samples from the 2013 winter leg, compared with data from Report of the Programme for Monitoring Environment Coastal Conditions and Marine Pollution in Zadar County 2006-2013, and with the Standard Seawater for the major chemical elements (considering constancy of composition of major dissolved constituents' ratio) (Millero et al 2008), while for minor elements, which tend to be site-specific, reference values were taken from the Adriatic sites off the Zlarin Island (Martinčić et al 1992) and off the Mljet Island (Cuculić et al 2009). Practically all parameters indicate mixture of sea and fresh water, as follows: (1) significantly lowered concentrations of major seawater elements (Cl, Na, Ca, Mg, K, F) and therefore decreased salinity/conductivity as primary indicators of fresh water input; (2) lower pH values were the footprint of the karst groundwater, having increased CO 2 concentration; (3) turbidity was significantly increased since after the heavy rains and snowmelt the discharging fresh water carries suspended material from the karst underground, and additionally lifts marine sediment from the sea floor; (4) increased nitrates are also the sign of the terrestrial origin of the water, whether through SGD or periodical surface runoff; (5) generally elevated concentrations of trace elements (Zn, Cd, Pb, Cu) might indicate anthropogenic influence from a nearby shore.…”

Evaluation of Discrete and Passive Sampling (Diffusive Gradients in Thin-films – DGT) Approach for the Assessment of Trace Metal Dynamics in Marine Waters – a Case Study in a Small Harbor

“…While only slightly higher concentrations were evidenced for Zn and Pb, concentrations of other metals were at the level of unpolluted coastal regions in the Adriatic, out of direct impact from harbor/marina activities. [2,9,42] In addition to trace metals, concentrations of dissolved organic carbon (DOC) were also low and at the level of unpolluted regions [2] (≈ 1 mg C L −1 ; see Figure S2 in supporting materials).…”

“…[5][6][7][8] The most common approach providing sufficient information to understand general behavior of trace metals distribution is based on discrete sampling and the measurement of dissolved and total metal concentrations. [2,4,9] However, for a greater understanding of the behavior and the interactions of trace metals with other constituents (including biota), specific techniques were developed and widely applied, providing valuable information on the trace metal speciation. [6,[10][11][12][13][14][15][16][17] Bioavailability of trace metals is of primary concern when considering if trace metals serve as nutrients or as toxicants.…”

An Assessment of the Distribution of Heavy Metals in the Riverine Sediments of Kortalaiyar River in Tamilnadu, India

“…Cr, Ni, Cu, Mn, Zn, Ti, Co, Pb, Cd etc) in aquatic environment are often considered indicators of anthropogenic influence and are themselves of high potential risk to the natural environment. Therefore, it is important to assess and monitor the abundance of these heavy metals in aquatic ecosystems [5].…”

“…Numerous studies have revealed that the riverine sediments are highly polluted by heavy metals; therefore the evaluation of metal distribution in surface sediment is useful to assess pollution in the aquatic environment [3,4]. Enriched Heavy metal concentrations (e.g.…”