A5002636491- Marine Biology and Ecology Research
- Marine and coastal ecosystems
- Heavy metals in environment
- Electrochemical Analysis and Applications
- Geochemistry and Elemental Analysis
- Mercury impact and mitigation studies
- Ocean Acidification Effects and Responses
- Analytical chemistry methods development
- Geochemistry and Geologic Mapping
- Environmental Toxicology and Ecotoxicology
- Microbial Community Ecology and Physiology
- Oceanographic and Atmospheric Processes
- Water Quality and Pollution Assessment
- Geology and Paleoclimatology Research
- Hydrocarbon exploration and reservoir analysis
- Paleontology and Stratigraphy of Fossils
- Radioactive element chemistry and processing
- Methane Hydrates and Related Phenomena
- Analytical Chemistry and Sensors
- Water Quality Monitoring and Analysis
- Electrochemical sensors and biosensors
- Minerals Flotation and Separation Techniques
- Mine drainage and remediation techniques
- Microbial Fuel Cells and Bioremediation
- Chromium effects and bioremediation
GEOMAR Helmholtz Centre for Ocean Research Kiel
2021-2024
Kiel University
2024
University of Otago
2014-2023
Australian National University
2022
International University of Monaco
2017-2022
Scientific Committee On Oceanic Research
2020
National Institute of Water and Atmospheric Research
2016-2019
Universität Ulm
2014
Zimmer Biomet (Germany)
2014
Clausthal University of Technology
1999-2000
An improved knowledge of iron biogeochemistry is needed to better understand key controls on the functioning high‐nitrate low‐chlorophyll (HNLC) oceanic regions. Iron budgets for HNLC waters have been constructed using data from disparate sources ranging laboratory algal cultures ocean physics. In summer 2003 we conducted FeCycle, a 10‐day mesoscale tracer release in SE New Zealand, and measured concurrently all (with exception aerosol deposition) to, sinks from, rates recycling within,...
Research Article| August 01, 2008 Hydrothermal venting at pressure-temperature conditions above the critical point of seawater, 5°S on Mid-Atlantic Ridge Andrea Koschinsky; Koschinsky 1School Engineering and Science, Jacobs University Bremen, 28759 Germany Search for other works by this author on: GSW Google Scholar Dieter Garbe-Schönberg; Garbe-Schönberg 2Institute Geosciences, Kiel, 24118 Sylvia Sander; Sander 3Department Chemistry, Otago, Dunedin, New Zealand Katja Schmidt; Schmidt...
Diatom blooms play a central role in supporting foodwebs and sequestering biogenic carbon to depth. Oceanic conditions set bloom initiation, whereas both environmental ecological factors determine magnitude longevity. Our study reveals another fundamental determinant of dynamics. A diatom spring offshore New Zealand waters was likely terminated by iron limitation, even though diatoms consumed <1/3 the mixed‐layer dissolved inventory. Thus, duration were primarily competition for between...
The role of heterotrophic bacteria in iron recycling, the influence complexation on remineralization, and mobilization rates from lithogenic vs. biogenic particulate (PFe) were examined using field experiments modeling simulations. During summer, we measured rate algal by mixed layer at a polar subpolar site south Australia, conducted shipboard incubations to track release dissolved (DFe) iron‐binding ligands subsurface settling particles sampled 120‐m depth. Bacteria mobilized > 25% PFe...
Ocean warming (OW), ocean acidification (OA) and their interaction with local drivers, e.g., copper pollution, may negatively affect macroalgae microscopic life stages. We evaluated meiospore development of the kelps Macrocystis pyrifera Undaria pinnatifida exposed to a factorial combination current 2100-predicted temperature (12 16 °C, respectively), pH (8.16 7.65, two levels (no-added-copper species-specific germination Cu-EC
Though it is clear that plankton in oceanic regions access iron bound to strong organic ligands, the mechanism mediating release of from these complexes remains unresolved. In this study, we aim elucidate mechanisms acquisition by subantarctic waters. particular, investigated importance photochemistry reductive dissociation complexes, using naturally occurring and model with different iron‐binding groups photoreactivities. Our results demonstrate within ligands available for uptake growth...
The effect of volcanic activity on submarine hydrothermal systems has been well documented along fast‐ and intermediate‐spreading centers but not from slow‐spreading ridges. Indeed, eruptions are expected to be rare axes. Here we report the presence venting associated with extremely fresh lava flows at an elevated, apparently magmatically robust segment center southern Mid‐Atlantic Ridge near 5°S. Three high‐temperature vent fields have recognized so far over a strike length less than 2 km...
Significance The supply and bioavailability of dissolved iron sets the magnitude surface productivity for approximately 40% global ocean; however, our knowledge how it is transferred between chemical states pools poorly constrained. Here we utilize isotopic composition particulate to fingerprint its transformation in ocean by abiotic biotic processes. Photochemical biological reduction dissolution appear be key processes regulating marine biota. Iron isotopes offer a new window into...
The microbial degradation of marine particles is an important process in the remineralization nutrients including iron. As part GEOTRACES study (FeCycle II), we conducted incubation experiments with obtained from 30 and 100 m depth at two stations during austral spring subtropical waters east North Island New Zealand. were collected using in-situ pumps, comprised mainly suspended slow sinking populations along associated attached heterotrophic bacteria. In treatments live bacteria,...
With the common goal of more accurately and consistently quantifying ambient concentrations free metal ions natural organic ligands in aquatic ecosystems, researchers from 15 laboratories that routinely analyze trace speciation participated an intercomparison statistical methods used to model their most type experimental dataset, complexometric titration. All were asked apply techniques they familiar with synthetic titration data are typical those obtained by applying state-of-the-art...
Abstract Although the supply of iron generally limits phytoplankton productivity in Southern Ocean, substantial seasonal blooms are observed over and downstream Kerguelen plateau Indian sector Ocean. Surprisingly, oceanic blooms, those associated with deeper southern last much longer (~3 months) than northern bloom (~1‐month plateau). In this study, mechanisms around were investigated, obtaining profiles dissolved (<0.2 μm, dFe) to 2,000‐m deep at 25 stations during austral summer 2016....
Hydrothermal vent fluids are highly enriched in iron (Fe) compared to ambient seawater, and organic ligands may play a role facilitating the transport of some hydrothermal Fe into open ocean. This is important since limiting micronutrient for primary production large parts world`s surface We have investigated concentration speciation several fluid plume samples from Nifonea field, Coriolis Troughs, New Hebrides Island Arc, South Pacific Ocean using competitive ligand exchange - adsorptive...
The nature of interparticle forces acting on colloid particle surfaces with adsorbed surface films the internationally used humic acid standard material, Suwannee River Humic Acid (SHA), has been investigated using an atomic force microscope (AFM). Two were used, alumina and a hydrous iron oxide film coated onto silica particles. Adsorbed SHA dominated interactive for both types when present. At low ionic strength pH >4, curves by electrostatic repulsion electrical double layers, extent...
Environmental context. Deep-sea hydrothermal vents represent a natural habitat for many extremophile organisms able to cope with extreme physical and chemical conditions, including high loads of heavy metals reduced gases. To date, no information is available on the level role organic complexation in these systems, which will have consequences bioavailability precipitation or mineralisation metals. In this work, we give evidence presence molecules, thiols, capable forming complexes copper...