Organic matter characterization in the sea surface microlayers in the subarctic Norwegian fjords region

Abstract

The uppermost layer of the ocean, the sea surface microlayer (ML), covers more than 70 % of the world's surface. It is a sink for natural and anthropogenic material that determines its chemical composition. This article is aimed at providing novel data on the characterization of organic matter in ML and underlying waters (ULW) in the rarely investigated subarctic, north that organic substances in the films were mainly produced in the subsurface water. There was negligible fractionation of hydrophobic substances to the microlayer and even depletion of fatty acids was found in some ML samples. Fjords' surface waters were found to be very rich in fatty acids in July, up to 188 g/l, with high contributions of polyunsaturated compounds.The enrichment of DOC and SAS concentrations in the ML as compared to the ULW was in the range of 1.2 -2.8, while higher enrichment factors (1.3 -5.1) were determined for copper complexing ligands, indicating increased contribution of hydrophilic, lower molecular weight molecules. The detected characteristics and concentrations of organic substances in the surface microlayer and adjacent subsurface water differ for each month of sampling.Gašparović, Blaženka; Plavšić, Marta; Ćosović, Božena; Saliot, Alain. Organic matter characterization in the sea surface microlayers in the subarctic Norwegian fjords region. // Marine Chemistry.

Comparison of sea surface microlayer and subsurface water bacterial communities in the Baltic Sea

“…Our results did not show any significant differences between the quantity of DOC in SML and SSW samples. Similar observations or low enrichment factors in the SML have been made in several previous studies on oceanic, coastal and lake waters (Gasparovic et al 2007, Wurl & Holmes 2008, Baastrup-Spohr & Staehr 2009). More significant enrichments of SML were observed previously for a series of organic compounds such as dissolved and particulate fulvic acid (Calace et al 2007); transparent exopolymer particles (polysaccharides, proteins and lipids) (Wurl & Holmes 2008); and a range of organic pollutants (Wurl & Obbard 2004).…”

Organic matter characterization and copper complexing capacity in the sea surface microlayer of coastal areas of the Eastern Mediterranean

“…To the best of our knowledge measurements of the complexing capacity of Cu ions in the SML have been carried out only by Gašparović et al (2007) and Plavšić et al (2007) (280 to 940 nM in the NW Mediterranean, coastal waters in France and Spain). However, in the Norwegian fjords a higher enrichment factor of L T in SML was calculated (mean value equal to 2.5) in comparison to the present work (1.2) and in the NW Mediterranean a similar value of 1.2 was obtained.…”

Speciation of trace metals in natural waters: The influence of an adsorbed layer of natural organic matter (NOM) on voltammetric behaviour of copper

“…Very important parameter in the protocol of MCC determination is the sensitivity, which is used for transformation of peak heights into the concentration of metal found in the sample (this step is a prerequisite for all calculations in metal speciation studies using voltammetric methods) [5]. Usually, authors use the sensitivity obtained either in the range where, according to the titration curve, all sites are almost saturated (linear part of the plot) [39,41] or from the separately determined sensitivity in a UV digested sample (where all organic matter is destroyed) [31]. According to the theoretical calculations for metal complexes with known stability constants, the slope which corresponds to the titration curve without the ligands is never reached in real samples (only asymptotically approaching) [5].…”