Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Heincke	HE541	06.09.2019 - 19.09.2019		North Sea

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
van Beusekom Justus E.E.	Helmholtz-Zentrum Geesthacht Zentrum fur Materialforschung und Kustenforschung	Bremerhaven	Bremerhaven

Ziel der Reise / Objectives of Cruise:

From Sep. 14th 2019 (departure Bremerhaven) until Sep. 27th 2019 (arrival Bremerhaven) 12 scientists from AWI, from HZG, from the MPI-Bremen and from the University Kiel investigated biogeochemical exchange processes between water and sediment at the eight stations between 20m and 30m depth along the German North Sea coast (German Bight). We hypothesized that accumulation processes (driven by coastward directed bottom currents) of suspended matter and associated organic matter would lead to higher turnover rates at the coastal stations. With two Lander (AWI, MPI-Bremen) oxygen fluxes were quantified in relation to microtopography and permeability. Sediment samples were taken with grabs and a mulitcorer and further investigated in the lab including respiration rates and nutrient fluxes. Special attention was given to the relation between alkalinity and denitrification. For that matter, DIC, alkalinity, nutrients were measured both in the porewater and in the water column. 15N sediment incubations were carried out for quantifying nitrogen turnover. To quantify the exchange between water and sediment, Radium was enriched on board from large water volumes and measured on board. A newly developed video sled system was deployed successfully to characterize the benthic communities at the sampling stations. The cruise was scheduled for the second half of September enabling us to describe the transition between the summer situation with high turnover rates and the autumn with low turnover rates. Despite stormy weather conditions (storm during Sep. 17th and 18th), all but one lander deployment could be carried out successfully. Despite the weather conditions, the cruise was successful (8 out of 9 stations).

Messungen / Measurements