Archives of Environmental Contamination and Toxicology (2022) 82:481—492 
Conclusion 
Within this work, a time series of ten years of sediment 
samples at two different locations in the German North 
Sea were analyzed for their mass fractions of the TCEs Ga, 
Ge, Nb, In, REEs, and Ta to investigate the occurrence and 
temporal variation of these elements. The regional scale 
and period of 10 years of the analyzed samples enabled the 
determination of robust threshold values for the analyzed 
TCESs within the German Bight. Even though the data do 
not indicate significant anthropogenic inputs of TCEs into 
the German North Sea up to now, this is likely to change 
over the next years to decades. Exact knowledge of mass 
fractions of TCEs in sediment samples will be of great 
benefit to gain better insights into the behavior of these 
elements in the marine environment and for the determina- 
tion of their origin, fate, and distribution within complex 
land-river-sea systems. 
Therefore, the reference values determined in this study 
will be very valuable for future environmental studies 
investigating the input of TCEs into the environment. One 
of which may be emissions of TCEs from offshore wind 
farms in the German Bight, which play a key role in the 
ongoing energy transition in Germany. 
Supplementary Information The online version contains supplemen- 
tary material available at https://doi.org/10.1007/s00244-022-00929-4. 
Acknowledgment The authors greatly acknowledge the Bundesamt 
für Seeschifffahrt und Hydrographie (BSH) for providing sieved sedi- 
ment samples. Anna Ebeling was funded by the BSH through the pro- 
ject OffChEm (BSH contract code: 10036781, HZG contract code: 
17/2017). Ole Klein is funded by the project MetroCycleEU of the 
European Metrology Programme for Innovation and Research (Funder 
[D: 10.13039/100014132, Grant number: 20INDO0O1 MetroCycleEU). 
Author Contributions Conceptualization: D.P, A.E, O0.K; Formal anal- 
ysis: MK, O.K; Funding acquisition: T.K., D.P.; Investigation: M.K., 
O.K.; Methodology: A.E, O.K., T.Z.; Resources: D.P.; Supervision: 
O.K., A.E, D.P.; Validation: M.K., O.K., A.E; T.Z.; Visualization: 
O.K., M.K., T.Z.; Writing-original draft preparation: 0.K.; Writing- 
review and editing: T.Z., A.E, D.P., M.K., T.K. 
Funding Open Access funding enabled and organized by Projekt 
DEAL. Anna Ebeling was funded by the BSH through the project Off- 
ChEm (BSH contract code: 10036781, HZG contract code: 17/2017). 
Ole Klein was funded by the European Metrology Programme for 
Innovation and Research (EMPIR) project MetroCycleEU (Funder 
[D: 10.13039/100014132, Grant number: 20INDO1 MetroCycleEU). 
Declarations 
Conflict ofinterest The authors have no competing interests to declare. 
Open Access This article is licensed under a Creative Commons 
Attribution 4.0 International License, which permits use, sharing. 
491 
ıdaptation, distribution and reproduction in any medium or format, 
as long as you give appropriate credit to the original author(s) and the 
s0uUrce, provide a link to the Creative Commons licence, and indicate 
ıf changes were made. The images or other third party material in this 
article are included in the article's Creative Commons licence, unless 
indicated otherwise in a credit line to the material. If material is not 
included in the article's Creative Commons licence and your intended 
use is not permitted by statutory regulation or exceeds the permitted 
use, you will need to obtain permission directly from the copyright 
holder. To view a copy of this licence, visit http://creativecommons. 
org/licenses/by/4.0/. 
References 
Ackermann F, Bergmann H, Schleichert U (1983) Monitoring of 
heavy metals in coastal and estuarine sediments - a question 
of grain-size: <20 um versus <60 um. Environ Technol Lett 
4(7):317-328. https://doi.0rg/10.1080/09593338309384212 
BaCic N, Mikac N, Lucie M, Sondi I (2021) Occurrence and dis- 
tribution of technology-critical elements in recent freshwater 
and Marine Pristine Lake sediments in Croatia: a case study. 
Arch Environ Contam Toxicol 81(4):574-588. https://doi.org/ 
10.1007/s00244-021-00863-x 
Barth MG, McDonough WF, Rudnick RL (2000) Tracking the 
budget of Nb and Ta in the continental crust. Chem Geol 165(3- 
4):197-213. https://doi.0rg/10.1016/S0009-2541(99)00173-4 
Birch GF (2017) Determination of sediment metal background con- 
centrations and enrichment in marine environments - a criti- 
cal review. Sci Total Environ 580:813-831. https://doi.0org/10. 
1016/j.scitotenv.2016.12.028 
Bu-Olayan AH, Thomas BV (2020) Bourgeoning impact of the tech- 
nology critical elements in the marine environment. Environ 
Pollut 265(Pt A):115064. https://doi.0org/10.1016/J.envpol.2020. 
115064 
Deng F, Hellmann S, Zimmermann T, Pröfrock D (2021) Using Sr-Nd- 
Pb isotope systems to trace sources of sediment and trace metals 
to the Weser River system (Germany) and assessment of input to 
the North Sea. Sci Total Environ. https://doi.org/10.1016/j.scito 
tenv.2021.148127 
Dolor MK, Helz GR, McDonough WF (2009) Sediment profiles of less 
commonly determined elements measured by Laser Ablation ICP- 
MS. Mar Pollut Bull 59(4-7):182-192. https://doi.0org/10.1016/7. 
marpolbul.2009.03.027 
Ducrotoy J-P, Elliott M, de Jonge VN (2000) The North Sea. Mar Pollut 
Bull 41(1):5—23. https://doi.org/10.1016/S0025-326X(00)00099-0 
Ellison SLR, Williams A (2012) Quantifying Uncertainty in Ana- 
lytical Measurement, 3rd edition. Teddington, UK, Eurachem/ 
CITAC, 141pp. (CITAC Guide Number 4). http://doi.org/10. 
25607/0BP-952 
Federal Maritime and Hydrographic Agency (BSH) (2009) System 
Nordsee — Zustand 2005 im Kontext langzeitlicher Entwicklun- 
gen (System North Sea - State 2005 in the context of long-term 
developments). Hamburg and Rostock 
Federal Maritime and Hydrographic Agency (BSH) (2016) Nordsee- 
zustand 2008-2011 (Condition of the North Sea 2008-2011) 
Hamburg and Rostock 
Federal Ministry for the Environment Nature Conservation Nuclear 
Safety and Consumer Protection (BMUV) (2018) Zustand der 
deutschen Nordseegewässer 2018 (State of the German North 
Sea Waters 2018). In: Bundesministerium für Umwelt NunSB 
(ed) Bonn 
Filella M, Rodriguez-Murillo JC (2017) Less-studied TCE: are their 
environmental concentrations increasing due to their use in new 
2 Springer