22 
Compilation of Summaries 
discharge of the Elbe was sliqhtly below the lonqterm averaqe at approxi 
mately 20 km 3 /a. 
The winter salt distribution in 2010 largely corresponded to that of the previous 
year, but with lower salinity off the southern Norwegian coast. This minimum 
was also observed during summer. The summer salt distribution also changed 
slightly compared with the previous year. No AW was observed in the area of 
the eastern outflow of the Channel in summer 2010. The total salt content of 
the North Sea corresponded more or less to that one of 2009. The overall water 
discharge of the Elbe increased considerably in comparison to the seven pre 
ceding years. This was caused primarily by increased run-off volumes in the 
second half of the year. 
There are no data available for winter 2011/2012 for the Norwegian Trench area, 
but the distribution in the northern North Sea largely matches the two preceding 
years. In contrast, the salinity in the southern North Sea decreased considerably 
compared to previous years. In the summer, the 35 isohaline was much further 
north than in winter and previous summers. The area of AW (S > 35) was much 
smaller in the surface layer, while the ribbon of less saline coastal waters parallel 
to the Norwegian coast was considerably wider. The total salt content of 
1.114 x 10 12 1 was the lowest since 2001. In January and February 2011, the total 
monthly volumes of water discharge exceeded the long-term average signifi 
cantly, although the total water discharge in 2011 was lower than in the previous 
year, it was still significantly higher than the long-term average. 
4 Marine Chemistry 
Nutrients (Page 159 et seq.) 
While nitrogen compounds and phosphate loads transported by the Elbe into 
the German Bight showed a significant downward trend despite interannual 
variability, silicate loads are subject to significant different concentrations be 
tween years. No temporal trend can be identified here. 
Nutrient levels in the German Bight changed only slightly within the range of 
natural fluctuations compared with those of previous years. The “orientation 
value” of dissolved phosphate was recorded in the coastal zone, but not for 
total phosphorous. The concentrations of nitrogen compounds continued con 
siderably above the “orientation value”. The last environmental assessment 
(OSPAR Commission, 2008) classified both coastal waters and the central Ger 
man Bight as “problem areas” (PA). Although nutrient concentrations in the 
outer German Bight, classified as a “potential problem area” (PPA), are within 
the range of the “orientation value”, oxygen deficiency in deeper water hori 
zons due to increasing chlorophyll levels are still to be expected here. 
Despite seasonal variability and interannual differences, a statistically signifi 
cant downward trend for the pH-value in the German Bight can be ascertained. 
Increasing atmospheric carbon dioxide concentration, due to fossil carbon 
burning is responsible for the ocean acidification effect by decreasing pH-value 
in seawater with its negative impacts to the marine environment. The distribu 
tion of oxygen saturation values in bottom water was comparable to those of 
previous years (80 %-100 %). The strongest oxygen deficits occurred during