Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Elisabeth Mann Borgese	EMB277	02.10.2021 - 08.10.2021		Baltic Sea Bornholm Basin Skagerrak Kattegat Arkona Basin

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Dutz Joerg	Leibniz-Institut fur Ostseeforschung, Warnemunde	Rostock	Rostock

Ziel der Reise / Objectives of Cruise:

The cruise was part of the educational Master programme of Marine Biology at the University of Rostock conducted by the Leibniz Institute for Baltic Sea Research (IOW). Oceanography increasingly combines analyses of diverse data with experimental studies in the field and the laboratory to further the understanding of biogeochemical and ecological processes in the marine environment. In this context, the cruise aimed at practical experience in biological oceanography onboard RV Elisabeth Mann Borgese (EMB). In a combination of field work, own projects and lectures, students were introduced into current research topics and received hands-on training in observational methods and techniques of hydrographical, chemical and biological sampling and analysis. Fieldwork was carried out on a Skagerrak-Bornholm Basin transect in order to explore the changing environmental conditions from marine to brackish water. The hydrographical situation reflected largely the expected changes with a reduction in salinity, a relatively constant surface temperature and increasing nutrient availability. Chla concentrations increased from the Skagerrak into the Kattegat/Oresund. The phyto- and zooplankton also showed a strong change in composition. The phytoplankton community shifted from a dominance of dinoflagellates and diatoms in the Skagerrak/Kattegat to a community dominated by cyanobacteria and flagellates in the Baltic Proper. Zooplankton diversity decreased and only few species dominated in brackish water. Egg production of a selected species, Acartia bifilosa, increased from the Kattegat to the Arkona Sea in relation to Chla. Additional experiments confirmed the limitation by food availability in marine waters. In comparison to the experimental approach, empirical models based on T and body weight alone overestimated production, while the model including food concentration compared quite well

Messungen / Measurements