Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Heincke	HE425	23.05.2014 - 07.06.2014	TRR 51 ROSEOBACTER	North Sea

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Billerbeck Sara	Institut fur Chemie und Biologie des Meeres	Bremerhaven	Bremerhaven

Ziel der Reise / Objectives of Cruise:

The cruise HE425 with RV Heincke took place within the framework of CRC51 "Roseobacter" funded by the DFG. Scientists and students from the Universities of Oldenburg (ICBM) and Gottingen as well as the DMSZ in Braunschweig participated in the cruise. The main interest of the cruise was to investigate the population dynamics of different subgroups of the Roseobacter clade of Alphaproteobacteria during a phytoplankton bloom in the North Sea west of Norway. The aim was to take water samples in- and outside the bloom and to process and analyze these on board or later in the lab. The influence of the time of day on the bacterial community and its expression of specific genes was investigated in three 24 hours time series. On two transects from Bremerhaven to the sampling area and back more water samples were collected to access the populations of important members of the Roseobacter clade in the water column. Overall the goals of the cruise were achieved despite of some problems with a rough sea. Instead of an expected bloom of coccolithophores we sampled two decaying dinoflagelate blooms west of the coast of Norway. An additional phytoplankton bloom was sampled during the return transect west of the coast of Denmark. Overall 47 CTD profiles were conducted and at 34 stations seawater samples were taken at different depths. Samples were processed and analyzed, respectively, for following parameters: Secchi depth, diversity of zoo- and phytoplankton (hand net tows), phytoplankton abundance, concentrations of chlorophyll a and its phaeopigments, nutrients, particulate and dissolved und dissolved organic carbon, dissolved amino acids and carbohydrates, DNA, RNA, cell numbers and autofluorescence of bacteria and small phytoplankton, bacterial activity/abundance, isolation of microorganisms and filters samples for metagenome, metatranscriptome as well as metaproteome analyses. First analysis on board of bacterial cell numbers revealed highest numbers at stations with the decaying bloom event southwestern of the coast of Norway and during a phytoplankton bloom west of Amrum.

Messungen / Measurements