Productivity and Life Cycles of Plankton and Nekton in the Coastal Upwelling Area of the Benguela Shelf – Trophic and Physical-Chemical Control Mechanisms – Cruise No. MSM07 – February 19 – April 17, 2008 – Las Palmas (Spain) – Mindelo (Cape Verde).

Freier Zugriff
in MARIA S. MERIAN-Berichte; MSM07; 1-92; MARIA S. MERIAN-Berichte

Dokumentinformationen

  • Format / Umfang:
    92 pages
  • ISSN:
  • DOI:
  • Medientyp:
    Aufsatz (Zeitschrift)
  • Format:
    Elektronische Ressource
  • Sprache:
    Englisch
  • Klassifikation:
    DDC:    550 Earth sciences and geology

Abstract

The RV MARIA S. MERIAN -cruise MSM07 was part of the German IMBER-Initiative (GIMBER: German IMBER1) and concentrated on analysing the interrelationships between pelagic (PELA-GIMBER) ecosystem components, biogeochemical and physical processes as well as human impact. The investigations performed during the three cruise legs were focusing on the analysis of physical-chemical drivers on the primary production level up to interrelationships between and within higher trophic levels in the ecosystem. - On transit between Las Palmas de Canaria and Walvis Bay the effect of different biogeochemical environments on the production/decomposition-processes at the lower ecosystem levels was studied. On a multi-station transect across the equator the physical processes in the equatorial current system and the resulting chemical and biological structures were observed. On the SE-African shelf off the Kunene river mouth benthic colonization patterns were compared with the distribution of functional properties such as the exchange dynamics between sediment and water. - During leg MSM07/2b the pelagic communities in the northern Benguela upwelling were sampled along three transects perpendicular to the coast with 5 stations each at 17.5°S, 20°S and 23°S. Information on distribution, abundance and biomass of different pelagic species was collected to detect different nutritional preferences. The hydrographical conditions in the study area were recorded by means of a CTDO-probe equipped with a lowered ADCP (LADCP). Nutrient analyses, study of the N:P ratio and permanent recordings of VMADCP and thermosalinograph were performed in parallel. - Leg MSM7/3 was dedicated especially to the implementation of physiological experiments on board of the ship. Based on the more large scale hydrographical and planktological station work especially of cruise leg 2b as well as on real-time satellite images of sea surface temperature and chlorophyll-a distribution, live organisms in good condition were caught for the experiments on board. In selected areas between Kunene River (17°15'S) and Palgrave Point (20°S), short transects perpendicular to the coast have been performed, and a number of different nets with different mesh sizes were used to sample the complete size spectrum of the plankton community. Different taxonomical groups of plankton were in the focus of these works: copepods, euphausiids, fish larvae and young fish.