Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Alkor	AL528	18.09.2019 - 30.09.2019		Baltic Sea

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Suhling Jorg	Helmholtz Centre for Ocean Research Kiel (GEOMAR)	Kiel	Kiel

Ziel der Reise / Objectives of Cruise:

The overall objective of this practical for students is to investigate the ecological role of gelatinous plankton in the Baltic Sea food webs and alongside the salinity gradient. To demonstrate the temporal as well as spatial variation of pelagic communities such as bacteria-, phyto and zooplankton as well as in the benthic food webs, different food web tracers will be used. Main focus here is therefore to obtain qualitative and quantitative sample sets of gelatinous zooplankton to investigate their distinct role on bentho-pelagic processes.Over the last several decades, a significant increase of both frequency and severity of jellyfish (JF) blooms were reported worldwide. Blooms of these organisms can extend for thousands of square kilometers, with drastic consequences and economic losses. When JF outbreak, they will not only affect the pelagic community by direct feeding on fish larvae, fish eggs or competing for the prey with bigger fishes, but only serve as organic matter source for benthic systems via sinking to the sea floor. Due to the scarcity of data on the potential role of gelatinous zooplankton from only few locations in the Baltic Sea, there is only a limited understanding on the role of JF in the bentho-pelagic food web of the Baltic Sea. A quantitative and qualitative assessment of gelatinous zooplankton in the BS systems and their functioning with regard to salinity gradient of the Baltic Sea , are now urgently needed to better account for the role of gelatinous zooplankton in the future of the system. Applicant and working group have performed this student research/educational cruise with the specific focus on jellyfish ecology every year and on a regular basis since 2013. During this two-week cruise students will perform the compulsory ?Practical at Sea". The general goal is to survey and characterize the temporal and special distribution of bacterial, phyto-, zooplankton and macroplankton specially jellyfish in Skagerrak and Baltic Sea.

Messungen / Measurements