FROM SOURCE TO SINK - ELEMENTAL AND ISOTOPIC DISTRIBUTION MAPS IN THE GERMAN WADDEN SEA CATCHMENT


Johanna Irrgeher1, Thomas Prohaska2, Andreas Zitek2, Ulrike Kleeberg1, Tristan Zimmermann1, Daniel Proefrock1
1: Helmholtz-Centre Geesthacht, Institute of Coastal Research, Marine Bioanalytical Chemistry, Germany;

2: University of Natural Resources and Life Sciences, Dept. of Chemistry, Division of Analytical Chemistry, VIRIS Laboratory, Vienna

Environmental monitoring of complex ecosystems requires reliable sensitive techniques based on sound analytical strategies to identify the source, fate and sink of elements. The Wadden Sea represents an enduringly contaminated and highly anthropogenically impacted ecosystem.

The presented approach is based on the assessment of elemental and isotopic variation of Sr and Pb by (MC) ICP-MS in different marine and estuarine compartments covering the catchment of the Wadden Sea and one of its main tributaries, the Elbe River, in order to trace samples such as sediments or contaminants to their origin. The varying elemental concentrations, the complex matrix and the expected small variations in the isotopic composition required the development of reliable analytical measurement approaches as well as suited metrological data evaluation strategies. Aquatic isoscapes were created by using ArcGIS®, which was also used as a tool to spatially relate isotopic data with geographical and geological maps.

Elemental as well as Sr and Pb isotopic composition of sediment fields in the German Bight indicate significant variation in the signatures, which make a clear differentiation possible. Elemental and Sr isotopic patterns along the German Elbe River catchment show significant variation along the river. A clear influence by seawater mixing and the tributaries on both the elemental and isotopic composition was detected.

These results are very promising in terms of using these selected isotopic systems to trace the origin of the different sediments as well as to characterize the resulting transport processes of both sediments and anthropogenic contaminants within the investigated aquatic ecosystem.

Johanna Irrgeher

Johanna Irrgeher is currently postdoctoral researcher in the field of analytical chemistry at the Helmholtz Centre for Materials and Coastal Research Geesthacht in Germany with her research focus set on analytical method development for elemental and isotopic analysis in the field of analytical ecogeochemistry dealing with aquatic and terrestrial ecosystems. She holds a master degree in biotechnology from BOKU Vienna and obtained her PhD granted by the Austrian Academy of Sciences in 2013 with honours for her work on stable strontium isotope ratio analysis by (LA)-MC ICP-MS. She was a visiting researcher at the Institute of Isotopes in Budapest (Hungary), the National Cheng Kung University in Tainan (Taiwan) and the National Research Council Canada in Ottawa (Canada). Since 2014 she has been an associate member of the IUPAC committee on isotope abundances and atomic weights as well as chair of the IUPAC subcommittee on isotope abundance measurements for the period 2015-2016.