Compilation of Summaries 
23 
the summer periods 2009 and 2011 in the north-eastern Elbe “Urstromtal” and 
“Entenschnabel” at 66 % saturation. 
The chlorophyll concentrations were low with nitrate being the limiting factor 
during summer months. The highest concentrations were measured in coastal 
waters nearby Sylt at 6.8 |xg/L. 
Organic Pollutants (Page 187 et seq.) 
Water: Water: Organic pollutants are mainly discharged by the river Elbe into 
coastal waters of the German Bight, and subsequently distributed and diluted 
in the North Sea. Generally, contaminants are detected in a gradient from the 
coastline towards the open sea. However, with regard to absolute concentra 
tions and the decrease by the gradient of the concentration, varying spatial 
patterns of various organic pollutants were found. 
Beyond the Elbe plume, the concentrations of lipophilic contaminants are usu 
ally very low. Therefore, the spatial distribution of strongly lipophilic substances 
like chlorinated hydrocarbons (e. g. HCBs, PCBs and DDT) and highly con 
densed polycyclic aromatic hydrocarbons (PAH) was characterized by a rapid 
decline of concentrations from the coast towards the open sea. Furthermore, 
the concentrations of these lipophilic pollutants are greatly dependent on the 
amount of suspended particulate matter (SPM). Consequently, in the open sea, 
where water contains less suspended particles, the concentrations of these 
substances were observed to be 100 to 1 000 times lower than in the river Elbe. 
Nonetheless, due to the low analytical limits of quantitation achieved by the 
laboratory of the Federal Maritime and Hydrographic Agency, it was possible to 
detect most of the substances in the outer German Bight, in very low concen 
trations (0.7 to 10 pg/L). Polar or hydrophilic substances showed predomi 
nantly smaller concentration gradients. Beside “modern” pesticides (e.g. Diu- 
ron, Simazin, Terbutylazin), these polar compounds include new substance 
categories such as perfluorinated surfactants (PFOA, PFOS) or other persistent 
substances which are used in large quantities in both industry and households 
(sequestrants, flame retardants). Due to the fact that discharges of these sub 
stances from rivers are often higher than the loads of “classical” lipophilic com 
pounds, these compounds were consequently detected at higher concentra 
tions in sea water (concentrations of up to 10 ng/L in coastal areas and in the 
open sea within the range of 10 pg/L to 500 pg/L). Based on their polar and 
persistent properties, relatively good inverse correlations between substance 
concentration and salinity are found, which identifies the large rivers, draining 
into the southern North Sea, as the major sources for the input of these com 
pounds into the marine environment. 
The amounts of the lipophilic chlorinated hydrocarbons and PAHs in sea water 
were comparable to those to previous years. No temporal trend could be iden 
tified between 2000 and 2011, what is explainable by relatively large variations 
in the detected concentration in sea water combined with only minor changes 
in absolute amounts. However, since these substances are either already re 
stricted in their use (or even banished) for a long time (like DDT and PCB) and/ 
or occur ubiquitously in the environment (like PAHs), profound changes regard 
ing their amounts are currently not to be expected.