196 
3 2 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 
Figure 43: Concentrations of endosulfan I in fish liver; upper fig. in pg/kg wet weight, lower fig. in 
pg/kg lipid weight 
6.4.3.4 Discussion 
This is the first time that endosulfan was detected in the North Sea and Baltic Sea, and 
concentrations above the LOQ were found. While endosulfan II levels were generally 
lower than endosulfan I levels and often were not detectable in marine samples from the 
North Sea and Baltic Sea, the isomer endosulfan I was identified in many water samples 
and some sediment and biota samples. However, concentrations were very low, with a 
median of 25 pg/L in water samples and 20.5 ng/kg dw in sediments. Median 
concentrations of 0.44 pg/kg ww and 1.9 pg/kg lipid were found in fish liver. 
Comparisons with literature data are difficult because the LODs in most studies were far 
higher (>ng/L) than in this survey and endosulfan is mostly reported to be below LOD.