Beschreibung: The Universität Hamburg is part of the environmental studies in the INDEX (Indian Ocean Exploration) program, which was established by the BGR (Federal Institute for Geosciences and Natural Resources), Hanover. The INDEX license area is located in the oligotrophic subtropical gyre of the South Indian Ocean. Sinking particulate matter samples were collected by sediment trap mooring 05-01 to measure vertical particle flux quantitatively and qualitatively. Mooring 05-01 was deployed during cruise PE394 (RV Pelagia) and recovered during cruise PE405.

Beschreibung: The Universität Hamburg is part of the environmental studies in the INDEX (Indian Ocean Exploration) program, which was established by the BGR (Federal Institute for Geosciences and Natural Resources), Hanover. The INDEX license area is located in the oligotrophic subtropical gyre of the South Indian Ocean. Sinking particulate matter samples were collected by sediment trap mooring 01-02 to measure vertical particle flux quantitatively and qualitatively. Mooring 01-02 was deployed during cruise SO259 (RV Sonne) and recovered during cruise PE446 (RV Pelagia).

Beschreibung: The Universität Hamburg is part of the environmental studies in the INDEX (Indian Ocean Exploration) program, which was established by the BGR (Federal Institute for Geosciences and Natural Resources), Hanover. The INDEX license area is located in the oligotrophic subtropical gyre of the South Indian Ocean. Sinking particulate matter samples were collected by sediment trap mooring 07-01 to measure vertical particle flux quantitatively and qualitatively. Mooring 07-01 was deployed during cruise SO259 (RV Sonne) and recovered during cruise PE446 (RV Pelagia).

Beschreibung: The Universität Hamburg is part of the environmental studies in the INDEX (Indian Ocean Exploration) program, which was established by the BGR (Federal Institute for Geosciences and Natural Resources), Hanover. The INDEX license area is located in the oligotrophic subtropical gyre of the South Indian Ocean. Sinking particulate matter samples were collected by sediment trap mooring 04-03 to measure vertical particle flux quantitatively and qualitatively. Mooring 04-03 was deployed with three sediment traps at different depths during cruise SO259 (RV Sonne) and recovered during cruise PE446 (RV Pelagia).

Beschreibung: The Universität Hamburg is part of the environmental studies in the INDEX (Indian Ocean Exploration) program, which was established by the BGR (Federal Institute for Geosciences and Natural Resources), Hanover. The INDEX license area is located in the oligotrophic subtropical gyre of the South Indian Ocean. Sinking particulate matter samples were collected by sediment trap mooring 10-01 to measure vertical particle flux quantitatively and qualitatively. Mooring 10-01 was deployed during cruise SO259 (RV Sonne) and recovered during cruise PE446 (RV Pelagia).

Beschreibung: The Universität Hamburg is part of the environmental studies in the INDEX (Indian Ocean Exploration) program, which was established by the BGR (Federal Institute for Geosciences and Natural Resources), Hanover. The INDEX license area is located in the oligotrophic subtropical gyre of the South Indian Ocean. Sinking particulate matter samples were collected by sediment trap mooring 12-01 to measure vertical particle flux quantitatively and qualitatively. Mooring 12-01 was deployed during cruise SO259 (RV Sonne) and recovered during cruise PE446 (RV Pelagia).

Beschreibung: Rising stable nitrogen isotope ratios (d15N) in dated sediment records of the German Bight/SE North Sea track river-induced coastal eutrophication over the last 2 centuries. Fully exploiting their potential for reconstructions of pristine conditions and quantitative analysis of historical changes in the nitrogen cycle from these sediment records requires knowledge on processes that alter the isotopic signal in non-living organic matter (OM) of sinking particles and sediments. In this study, we analyze the isotopic composition of particulate nitrogen (PN) in the water column during different seasons, in surface sediments, and in sediment cores to assess diagenetic influences on the isotopic composition of OM. Amino acid (AA) compositions of suspended matter, surface sediments, and dated cores at selected sites of the German Bight serve as indicators for quality and degradation state of PN. The d15N of PN in suspended matter had seasonal variances caused by two main nitrate sources (oceanic and river) and different stages of nitrate availability during phytoplankton assimilation. Elevated d15N values (〉 20 per mil) in suspended matter near river mouths and the coast coincide with a coastal water mass receiving nitrate with elevated isotope signal (d15N 〉 10 per mil) derived from anthropogenic input. Particulate nitrogen at offshore sites fed by oceanic nitrate having a d15N between 5 and 6 per mil had low d15N values (〈 2 per mil), indicative of an incipient phytoplankton bloom. Surface sediments along an offshore-onshore transect also reflect the gradient of low d15N of nitrate in offshore sites to high values near river mouths, but the range of values is smaller than between the end members listed above and integrates the annual d15N of detritus. Sediment cores from the coastal sector of the gradient show an increasing d15N trend (increase of 2.5 per mil) over the last 150 years. This is not related to any change in AA composition and thus reflects eutrophication. The d15N signals from before AD 1860 represent a good estimation of pre-industrial isotopic compositions with minimal diagenetic overprinting. Rising d13C in step with rising d15N in these cores is best explained by increasing productivity caused by eutrophication.

Beschreibung: The University of Hamburg is part of environmental studies in the INDEX Program, which was establishes by the BGR (Federal Institute of Geosciences and Natural Resources) in Hanover to explore Massive Sulphides with regard to a potential future deep sea mining. The INDEX license area is located in the oligotrophic subtropical gyre of the South Indian Ocean. The water samples were collected with a CTD water rosette during two ship cruises with R/V Merian in 2016 (MSM 59/2 "INDEX 2016-2"; November−December 2016) and R/V Sonne in 2017 (SO 259 "INDEX 2017"; August−October 2017) and were analysed for nutrients and stable isotopes of nitrate.