29 
and 1.9 pg/kg lw were observed. The measured sea water concentrations of endosulfan 
were about ten times lower than the proposed WFD EQS of 0.5 ng/L. 
The observed concentrations and distribution patterns are best explained by a low 
general background load by e.g. atmospheric deposition or only minor local sources. 
Concentrations in the river Elbe - the most important source of pollutant input to the 
German Bight - are often around or below the LOQ. Therefore, no distinct 
concentration gradients have been observed in the German Bight. Considering the low 
concentrations of local sources, it is astonishing that endosulfan has been detected in the 
North and Baltic Seas at all. 
Concentrations of endosulfan in water were higher than for classical lipophilic 
pollutants such as HCB, DDT, PCBs or PAHs but below those for HCH. Compared to 
classical chlorinated pollutants, the endosulfan concentration in sediment is about 10 to 
100 times lower. The bioaccumulation potential of endosulfan becomes apparent when 
comparing concentrations in the three compartments investigated. The estimated 
“enrichment” of endosulfan in biota compared to the water phase is about 17,600 based 
on wet weight, and 76000 based on lipid weight. 
The observed endosulfan levels in biota are comparable to classical pollutants like HCH 
and HCB but below the more lipophilic DDT and PCB group. In 2000, typical HCH 
concentrations in the German Bight ranged from 0.2 to 0.6 pg/kg ww; HCB had a 
median of 0.84 pg/kg ww, and the sum of DDTs one of 3.7 pg/kg ww. The low 
concentrations of endosulfan in the North Sea and Baltic Sea is well explainable by its 
pattern of use in Europe. According to the OSPAR commission’s background paper on 
endosulfan, endosulfan is used mainly in the south of Europe, while only 38.1 t/a were 
used in the countries bordering the North Sea and Baltic Sea in 1999. In most north 
European countries, endosulfan has not been used any more since the mid-1990s. 
2.2.10 Dicofol in the marine environment of the North and Baltic Seas 
Dicofol was not detectable in North Sea and Baltic Sea water (LOD: 1 ng/L). 
Degradation experiments in sea water showed a half-life of less than one day.