Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Meteor	M153	15.02.2019 - 31.03.2019	TRAFFIC	SE Atlantic (Limit 20?W) South Atlantic Ocean

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Ekau Werner	Zentrum fur Marine Tropenokologie, Bremen	Walvis Bay	Mindelo

Ziel der Reise / Objectives of Cruise:

This cruise was a joint effort of several German and Southern African institutes and contributes to the project TRAFFIC. Overall objective is to enhance our knowledge about processes that drive the trophic systems of the northern and southern Benguela upwelling sub-systems (nBUS, sBUS), respectively, and govern the associated feedbacks to fisheries and climate. Despite similar primary production rates (PP) rates, significant differences are found in composition and biomass of fish stocks and top predators, and while nBUS is a significant source of CO2 to the atmosphere, sBUS acts as CO2 sink. Our aim is to study the food web structure and its functional links, to analyse the trophic transfer efficiency (TTE), and the associated effects of the biologically mediated CO2 uptake. We hypothesise that a more efficient TTE supports higher fishery yields and a net CO2 uptake in the sBUS, whereas in the nBUS, the pelagic food web structure generates in lower fishery yields and elevated CO2 emission in the nBUS. Different gear was deployed to measure CO2-flux via sinking material, and to assess primary producers, zooplankton, fish and matter fluxes as well as their metabolic rates. Results will be used to develop conceptual models of the two BUS subsystems, explaining how changes in ecosystem structure affect fisheries and the biologically mediated CO2 fluxes. The cruise started in Walvis Bay, Namibia, and worked first in South African waters. After changing part of the South African scientific crew the vessel worked in Namibian waters. After desembarking part of the scientific crew in Walvis Bay, the vessel headed towards Mindelo performing underway investigations in oceanic waters beyond EEZ by means of acoustic (biomass estimation) and biogeochemical equipment (carbon isotope measurements).

Messungen / Measurements

Verankerungen / Moorings