Lead and cadmium in the Weser Estuary and the German Bight: Correlations between bacteria populations, heavy metals and organic carbon

Organic carbon, lead and cadmium contents of 20 sediments were determined and compared with the colony counts of anaerobic heterotrophic, anaerobic nitrogen fixing, chitinoclastic and cellulolytic bacteria. Organic carbon content, which is dependent on the sediment type, was positively correlated with lead and cadmium as well as with colony counts of all 4 physiological groups of bacteria. Even the sediments with the highest concentrations of 251.7 ppm Pb and 3.1 ppm Cd showed no reduction in their colony counts. From 2 different sediment sampIes with lead contents of 140 ppm and 21 ppm lead tolerance of the aerobic heterotrophic bacteria was investigated. However, no significant difference in lead tolerance of the 2 heterotrophic populations was found. Water from 6 stations was analysed for dissolved and particulate organic carbon, lead and cadmium. Dissolved lead concentrations were in the range of 0.2-0.5 µg/l and the particulate lead contents were between 0.05 and 4.3 µg/l. The concentrations of total lead for the stations off-shore were only one order of magnitude from the concentrations of the near-shore stations. The same phenomenon was observed for dissolved cadmium (0.02 - 0.25 µg/l) and particulate cadmium (0.003 - 0.15 µg/I) concentrations. Correlations between dissolved (1.6 - 10.8 mg/I) and particulate organic carbon (0.25 - 1.53 mg/I) with dissolved and particulate lead or cadmium were not found.

Abundance and biomass of in- and epibenthic invertebrate macrofauna in the German Bight from 1969 to 2000

In order to examine the long-term development of offshore macrozoobenthic soft-bottom communities of the German Bight, four representative permanent stations (MZB-SSd, -FSd, -Slt, -WB) have been sampled continuously since 1969. Inter-annual variability and possible long-term trends were analysed based on spring-time samples from 1969 until 2000. This is part of the ecological long-term series of the AWI and is supplemented by periodic large-scale mapping of the benthos. The main factors influencing the development of the benthic communities are biological interactions, climate, food supply (eutrophication) and the disturbance regime. The most frequent disturbances are sediment relocations during strong storms or by bottom trawling, while occasional oxygen deficiencies and extremely cold winters are important disturbance events working on a much larger scale. Benthic communities at the sampling stations show a large inter-annual variability combined with a variation on a roughly decadal scale. In accordance with large-scale system shifts reported for the North Sea, benthic community transitions occurred between roughly the 1970ies, 80ies and 90ies. The transitions between periods are not distinctly marked by strong changes but rather reflected in gradual changes of the species composition and dominance structure.

Documentation of Graf-Wilczek-Knoll

During Leg ANT-XXIII/9 on the 31st March 2007 the German research vessel Polarstern mapped a significant bathymetric feature with its swath sonar system at the north-west margin of the Kerguelen Plateau. Due to the fact, that the feature was discovered just a month after the third IPY 2007/2008 has started, it was named after Graf Wilczek who, together with Carl Weyprecht, had promoted the first IPY. The undersea feature name proposal was officialy accepted by the GEBCO Sub-Committee on Undersea Feature Names (SCUFN) at its 20th meeting in late July and was added to the GEBCO Gazetteer of UFN (http://www.iho.shom.fr/COMMITTEES/GEBCO/SCUFN/scufn_intro.htm). ______________ Graf Hans Wilczek (Notation of the name from the book of Wilczek's daughter Elisabeth Kinsky- Wilczek). The Austrian naval hero Tegetthoff in 1871 planned an expedition to the southern hemisphere. The geophysicist G. Neumayer (1826-1909) already was selected as its chief scientist. Also the naval officer Carl Weyprecht (1838-1881) and the mountaineer Julius Payer (1841-1915) were to participate. Because of the sudden death of Tegettoff the project came to a halt and eventually was cancelled. By support of the well known geographer August Petermann (1822-1878) Weyprecht and Payer made a voyage into the Barents Sea which made them believe having seen the "open polar sea". An additional undertaking to confirm and to extend the find was obvious. At this stage of the affair count Hans Wilczek (1837-1922) got involved. He not only fostered a new expedition with a considerable sum of money, but he participated in commanding a support vessel to Novaya Zemlya. Wilczek managed to get home but the expedition vessel under Weyprecht's command became imprisoned in the pack for two years and at least had to be abandoned. After an adventurous trip back to civilisation Weyprecht changed his mind in what he considered the best way of polar research. Together with Wilczek in 1875 he started the promotion of international station-based polar exploration - the IPY was born. Wilczek guaranteed the constitution of an Austrian station on Novaya Zemlya and was ready to winter over there personally. Because of several political and other obstructions the beginning of the IPY was delayed till 1882. Wilczek's friend Weyprecht had passed away already. The command of the Austrian station, eventually erected on Jan Mayen, was given to Emil v. Wohlgemuth (1843-1896). Wilczek financed the main part of the Austrian IPY participation. Wilczek is described as honest and popular. On the one hand acquainted with the most prominent persons of his days, he respected everybody and had many relationships with scientists and artists. There is a kind of autobiography under the title: Hans Wilczek erzählt seinen Enkeln Erinnerungen aus seinem Leben (Hans Wilczek tells his grandchildren reminiscences from his life); edited by his daughter Elisabeth Kinsky-Wilczek, Graz 1933, 502 p. The book is available in an English version: Happy Retrospect - the Reminiscences of Count Wilczek 1837-1922, Bell and Sons, London 1934, 295 p.