Using fluffy layer material to study the fate of particle-bound organic pollutants in the southern Baltic Sea.

This paper examines the utility of fluffy layer material for studying and monitoring the environmental levels, transport, and fate of particle-bound contaminants in coastal ecosystems. Fluffy layer material is the very young and mobile layer of particulate matter that accumulates on the sediment surface under quiescent conditions. We used this material to study the behavior of polycyclic aromatic hydrocarbons (PAHs) that are discharged by the Oder River into the Baltic Sea. With the fluffy layer material, it was possible to (i) do fingerprint analysis to trace the sources of PAHs in the river discharge, (ii) follow the modification of the PAHs from the mouth of the river to the depositional basin and identify the responsible processes, (iii) monitor the seasonal variation in the PAH input, (iv) study the influence of a major flood event on the PAH loading to the coastal ecosystem, and (v) conduct a PAH mass balance to estimate the contribution of the Oder River source to PAH accumulation in the depositional basin. The fluffy layer material integrated the particle-bound contaminant signal over a period ranging from several days to several months, depending on the sampling location. As such, fluffy layer material is a valuable addition to the matrixes commonly used for studying particle-associated chemicals: SPM and sediment, which reflect time scales of hours and years, respectively.