In winter 2023/24 a high precipitation rate in northern and eastern Germany increased the run-off volume of the Elbe and Weser rivers tremendously. The MOSES Sternfahrt-11 was conducted during and directly after the flood event, between 28th of December 2023 and 29th of January 2024 to identify its influence on the solution of different indication parameters. On January 10th and 11th in total seven samples within the port of Hamburg and the Elbe Estuary were taken from HPS ships and the Glückstadt ferry. The last two ships Mya II and Littorina covered the outflow of the Elbe into the German Bight. Both Ships had a transportable container laboratory (MOSES container) with a sensor system (see additional metadata) on board, measuring continuously different environmental data. Mya II started sampling on the 17th of January in Cuxhaven, cruising along the northern part of the German Bight towards Büsum. The second day the crew headed west towards Helgoland. The following crew on Littorina took over for the last two days, the 28th and 29th of January, covering the western part of the German Bight between Helgoland and Cuxhaven.
As the previous cruises were mainly conducted in August / September, this cruise was set up to cover a late spring situation in the German Bight. The cruise track and positions of the stations were similar to Sternfahrt_5 in September 2020, thus covering a wide range from 7.6°E to 8.9°E and from 53.5°N to 54.8°N. Continuous sampling for Chlorophyll-a and dissolved organic matter from the Elbe, Tide-Elbe and North Sea and subsequent detailed analysis at the UFZ will give new insights on the chemical transformations of these compounds. The southern North Sea (German Bight) is influenced by the water flowing into the Tide-Elbe area and how it is further modified. For a better understanding of the different branches of relevant events it is necessary to investigate the main impacting factors for the terrestrial and coastal water quality. Therefore, during different cruises between 2019 and 2022 a group of parameters was continuously traced from the Elbe River basin (Czech/German border) to Tide-Elbe and Elbe estuary (Hamburg, Germany) until the German Bight. The vessel Littorina started already on the 29th of May in Kiel heading to the assembly point Cuxhaven and setting up the sensor systems. On May 30th all ships began the cruise traveling to Heligoland, nevertheless only the Ludwig Prandtl and Littorina could realize the first inter-calibration station (see file description) in front of Cuxhaven. An inter-calibration with all ships was conducted the next morning (31st of May) in front of Heligoland, before they went separate ways. While the Littorina crew covered the eastern part of the sampling area going towards Büsum, the scientists from Ludwig Prandtl headed further North to the island Amrum and the Uthörn covered the western part (see map in additional metadata). Littorina followed on the way to Büsum a more direct track, while on its way back to Heligoland on June 1st, the crew took a different route to extend the area further north. On the 2nd of June they travelled straight back to Cuxhaven to the last joined station with all three vessels. Instead, Ludwig Prandtl stayed the third and fourth day around Amrum, where they had to start sampling early in the morning (03:44h, 03:30h), due to the tide dependent entrance to the port. From there they headed directly back to Cuxhaven. The vessel Uthörn made a circuit north of Heligoland on the second day. On the third day the crew navigated from Heligoland to Cuxhaven and back to Heligoland in a triangle form. The last day the vessel headed back to Bremerhaven with a detour in Cuxhaven. Thus, all vessels closed the survey on the 2nd of June with a last inter-calibration station off Cuxhaven at about 10h. Additional information about the whole campaign and different cruises can be found in the article(s) cited, see also 'related to'.
Aerial surveys were conducted in the Elbe Estuary, Germany, to count harbour seals on their haul-out sites. Haul-out sites were located within the intertidal zone, usually close to the waterway or tidal creeks. The north-western border of the study area was located at river-km 728 (city of Cuxhaven) and the south-eastern border was located at river-km 632 (Mühlenberger Loch). Flights were performed monthly from August 2018 until July 2019 (12 flights in total) at low tide. Within each month, a flight date in the middle of the month was chosen, depending on the tide and weather conditions. Flights were performed with a twin-engined aircraft at a height of approximately 600 feet and at an average speed of 100 knots. The flight routes were tracked via GPS. Sighted harbour seals were photographed on their haul-out sites and the corresponding geographic position was recorded. In the office, the photos were used to count the animals. In the beginning of the pupping season in June, adult and juvenile individuals were counted separately. The sizes of individual seals were used to distinguish between both age classes. Later in the year, juvenile seals could no longer visually be distinguished from adult individuals due to the pups' rapid growth. Consequently, count data of juvenile harbour seals are only available for June 2019.