Dissolved organic carbon and surface active substances in the northern Adriatic Sea: Long-term trends, variability and drivers.

The paper presents a unique time series of organic matter content (dissolved organic carbon, DOC, and its surface active substances fraction, SAS) collected in the northern Adriatic along the Po-Rovinj transect between 1998 and 2017. The data were collected on a monthly or bimonthly basis. Seasonal variance of organic matter content does not exceed 30% of its total variance, while the DOC and the SAS trends are significantly negative and positive, respectively, over the whole transect.

Dissolved organic carbon as potential indicator of global change: A long-term investigation in the northern Adriatic.

Dissolved organic carbon (DOC) is an essential component of the biogeochemical marine system, effecting biological and chemical reactions that take place in the sea. DOC represents a dynamic component of the global carbon cycle. This paper reports 25years of measurements of DOC content and distribution at seven stations along the transect Po River delta - Rovinj in the northern Adriatic (NA).

Physicochemical signatures of natural sea films from Middle Adriatic stations.

Monolayer studies and a force-area quantification approach, in combination with electrochemical methods, are applied for physicochemical characterization of surface active substances (SAS) of the sea surface microlayers (MLs) from Middle Adriatic stations. Higher primary production during late spring-early autumn was reflected in the presence of MLs of higher surfactant activity containing on average molecules of lower molecular masses (M(w) = 0.65 ± 0.

Temporal dynamics of dissolved and particulate organic carbon in the northern Adriatic Sea in relation to the mucilage events.

The accumulation of dissolved and particulate organic matter may play an important role in mucilage formation in the northern Adriatic. Distributions of dissolved and particulate organic carbon were therefore investigated during the period June 1999-July 2002, when massive mucilage events occurred: in the summer of 2000 and, to a greater extent, of 2002. The seasonal variations in dissolved organic carbon (DOC) concentrations were significant, doubling in summer (up to 150 micromol L(-1)) with respect to winter.

Copper complexing properties of melanoidins and marine humic material.

Melanoidins, condensation products of sugars and amino acids, represent a key link in the transformation of polysaccharides to humic material in the marine environment. We investigated the complexing capacity of melanoidins that were prepared in deionized water and seawater and separated into different molecular mass fractions. The copper complexing properties of humic material isolated from marine lagoon sediments were determined for comparison.