Summary 
26 
Nordseezustand 2004 
annual cycle linked to application periods of agricultural pesticides. The herbicide stra 
zine continues to be present in the German Bight at relatively high levels (median: 
3 ng/L), although its use is no longer legal in Germany. The levels of herbicides iso- 
proturone and diurone were relatively high in 2004 as well; median concentrations in 
coastal waters were at 1.2 and 5.0 ng/L, respectively. 
Metals 
As with many non-polar organic substances, spatial distributions of dissolved mercury, 
cadmium, lead, copper, and zinc display strong concentration gradients from the coast 
towards the open sea. Highest concentrations were found in the inner German Bight 
and Elbe River estuary, but elevated levels also occurred in the Weser and Ems estu 
aries. 
Cadmium, lead, and zinc levels in filtered water, as well as mercury in unfiltered water, 
had declined until about 1990, yet have varied without clear trend since then. In 2004, 
the dissolved fractions of cadmium, copper, lead and zinc in the outer German Bight 
were on the order of background levels or slightly higher, while, near the coast, back 
ground levels of zinc and cadmium were clearly exceeded. According to current knowl 
edge, the metal levels found in sea water do not pose an immediate threat to the ma 
rine ecosystem. 
Metals originating from riverine inputs mainly accumulate in near-shore sediments. 
Most notably, mercury, silver, zinc, cadmium, lead, and copper were found here at con 
siderably higher concentrations than further seaward. Along the coast of Schleswig- 
Holstein, enrichments of silver and mercury were found, which clearly are indicative of 
Elbe River inputs. Unlike the other elements, lead occurred at high levels of similar 
magnitude in both, sediments in the outer German Bight and near-shore samples. 
While mercury, zinc and lead levels exceeded background values in the entire domain, 
excessive cadmium and copper levels mainly occurred near the coast. 
Since the beginning of routine monitoring in the 1970s, concentrations of mercury, 
copper, cadmium, and nickel have clearly decreased in the silt/clay fraction, especially 
in near-shore surface sediments. Decreasing zinc levels were found only here - spe 
cifically off the coast of Lower Saxony, while no uniform trend was detectable in the re 
mainder of the German Bight. As to lead concentrations, no long-term temporal trend 
has been identified either. In the former acid waste disposal area northwest of Helgo 
land, levels of iron in particular, and to a lesser extent zinc, lead, and arsenic, contin 
ued to be above ambient levels. Even though acid waste discharge discontinued in 
1989, contamination levels have not decreased here as yet. In sediments influenced 
by the Elbe River plume, levels of mercury, as well as lead, and zinc were found to have 
increased again lately. 
Radioactive Substances 
Monitoring in 2004 focused on dose-relevant radionuclides 137 Cs, 90 Sr, and transuran- 
ics 238 Pu, 239 - 240 Pu, and 241 Am in the German Bight. Generally, distributions of vol 
ume activity displayed but minor spatial differences here. Concentrations hardly ex 
ceeded those in North Atlantic surface water due to global radioactive fallout from at 
mospheric nuclear weapons testing conducted in the 1950s and 1960s. Activity levels 
of 137 Cs in northwestern parts were slightly elevated as compared to those in coastal