Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Maria S. Merian	MSM33	02.11.2013 - 06.12.2013		Strait of Gibraltar Black Sea Mediterranean Sea

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Arz Helge	Leibniz-Institut fur Ostseeforschung, Warnemunde	Cadiz	Varna

Ziel der Reise / Objectives of Cruise:

Objectives. The overarching goal of the proposed cruise is to investigate the biology and biogeochemistry of the central Black Sea with special consideration of the processes at the pelagic redoxcline. By identifying microbiological agents and assessing rates of the coupled cycles of carbon, nitrogen, phosphorus, sulfur, manganese and iron at the redox boundary the functional response of this specific environment upon the change of external conditions will be visible. As element speciation and the elemental input/output relation in marginal seas with anoxic water bodies are different from oxic environments, this study fosters the understanding of land/ocean interaction in terms of element transfer. As a major and immediate forcing factor for redoxcline turnover the particle export from the mixed layer will be studied as a function of abundance and activity of pelagic populations. Furthermore it is important to understand the changes in the quantity and quality of particle flux from aerated water through redoxcline and anoxic conditions to the sediment with the emphasis on the carbon cycle and to establish a time series station in the central part of the western gyre in the Black Sea. Particle fluxes will be additionally determined by using 234Th as a naturally occurring radiotracer for the euphotic zone and analysis of sediment trap material below the particle remineralisation zone and the redoxcline. This part of the programme will be completed by geological studies that aim to reconstruct historic changes in redoxcline functioning by means of multiple proxy approaches on the background of general and long term climatic developments in the area. Narrative. In the morning of the 2nd November RV M.S.Merian departed from Cadiz, Spain for a 8 days long transit across the Mediterranean Sea to arrive the main working area in the Black Sea. Main task during the transit was to continuously sample water from the ships clean seawater supply for volatile organic compounds, organic pollutants, nutrien, and stable isotope (O,C,H) analyses. After exchange/completion of the scientific crew in Sevastopol westarted our work west of Crimea. Here we recovered a first sound velocity profile for the acoustic systems and identified a first sediment sampling station in the center of the main submarine Dnjepr canyon. In the northernmost part of this working area we deployed a ADCP mooring station at water depths of about 170 m close to the shelf edge in order to record for the next 8 days temporal changes of the redoxcline structure fringing the upper slope. On several stations from the shelf down to the central western Black Sea Basin we performed an extensive water column sampling program. More than four days were spent on our first "main station" in the central western Black Sea, with more than 30 deployments and the installation of a sediment-trap mooring. After recovering the ADCP mooring we left the western working area on the 19 Nov and spent several days with stations along a upslope transect towards the Kerch Strait east of the Crimean peninsula. After water column work on the second "main station" in the eastern central Black Sea, on the 25 Nov we headed towards the southeastern working area in the Turkish part of the Black Sea. Target was the Archangelsky Ridge, were we did sediment acoustic mapping during night time and geological sampling stations during day time. On the 29 Nov we returned to the eastern main station to continue water column work there. On the way back to Sevastopol, despite impaired weather conditions, we deployed for the last time on a station close to the initial ADCP mooring position in the shallow water area west of Sevastopol the Pump-CTD system to continuously record vertical profiles across the redoxcline for more than 12 hours. After debarking our Ukrainian colleagues on the 4 Dec we headed towards Varna, Bulgaria, which was the final harbor and the end of the altogether very successful cruise MSM33.

Messungen / Measurements

Verankerungen / Moorings