European marine waters were the scene of many sea battles and war events throughout the two World Wars, during which a high number of ships were sunk. The German Maritime Museum in Bremerhaven suspects that there are still approx. 680 wrecks from the two World Wars in the North Sea alone, many of which were partially or fully loaded with munition by the time of the sinking. The increasing corrosion of munition shells in the saline environment leads to increased leakage of chemical substances into the marine ecosystem posing risks to marine organisms, because the chemicals preserved in the munitions are toxic and classified as CMR substances (carcinogenic, mutagenic, toxic for reproduction). Particularly, the 2,4,6 - trinitrotoluene (TNT) is of great concern here, since it has been the most commonly used explosive during the World Wars.

To investigate the biological effects of the dumped ammunition on marine organisms, field studies were conducted on selected wrecks (UC30, SMS Mainz, and SMS Ariadne) from the First World War in the southern North Sea. Therefore, non-migratory dabs (Limanda limanda) were caught as close as possible to the wreck sites and investigated using a multi-biomarker approach. The dabs were first examined for obvious diseases before being dissected for subsequent assessment of relevant tissues.

First preliminary results show a significantly increased incidence of liver diseases including tumors in the dab fished at the wreck sites, compared to the fish caught at a reference area (Borkum Reef) most probably free of munition remains. Up to 65% of the examined dab (SMS Ariadne) showed at least one nodule in their liver. These results correlate with the TNT concentrations detected in the surrounding waters of the wreck site suggesting that wrecks are a point source for dissolved explosives having negative impacts on exposed marine organisms, including fish.

How to cite: Schuster, R. M., Binder, F., and Brenner, M.: Are war wrecks and their munition cargo posing health risks to fish? – A multi-biomarker assessment of dabs (Limanda limanda) living at wreck sites in the southern North Sea, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-1515, https://doi.org/10.5194/egusphere-egu23-1515, 2023.

The North Sea was the scene of many naval battles during both World Wars. As a result, military ships, civilian merchants, and cargo vessels sank. Today, the German Maritime Museum in Bremerhaven, Germany, suspects approx. 240 wrecks in Danish, at least 100 in Belgian and about 120 military wrecks including airplanes in the German EEZ and territorial waters. Many of these wrecks were partially or fully loaded with munition at the time of the sinking. However, based on archive information, visible inspections or survey reports only rough estimates about remaining quantities of munition on or in the vicinity of these wrecks can be made. After 75-100 years in the marine environment munition shells are corroding and start leaking chemicals of their explosive cargo into the marine environment. They main component of munition is 2,4,6 trinitrotoluene (TNT). Next to its ability to explode, TNT is also known for its toxicity and for being carcinogenic and mutagenic. In order to test for leaked explosives in the surrounding waters, sediments and biota field studies were conducted on wrecks sites in Belgium, Germany and Denmark. The measured concentration of explosive were subsequently correlated with potential health impairments, using blue mussels (Mytilus edulis) deriving from munition free site. These mussels were exposed for several weeks in steel cages on or near three wrecks sites. In Belgian waters the KW 58 Hendricus a transport vessel loaded with several tons of landmines sunken during WW II was selected for this investigations. In German waters the light cruiser SMS Mainz laying approx. 40sm west of the island of Heligoland was chosen and in Danish waters a German mine laying submarine (UC30) situated a few miles west of Esbjerg was investigated using caged blue mussels. Three to four cages filled with blue mussels were placed at different locations on each of the three wrecks. At the end of the exposure time mussels were retrieved and first examined for mortality, subsequently dissected and analysed in the lab for biomarker responses according to a multi-biomarker approach. First results show very different water concentrations around the wreck sites ranging from low ng/L of dissolved TNT up to the µg/L and mg/L level. Further, also the uptake of TNT by mussels could be proven resulting in measurable biomarker responses of the exposed blue mussels.

How to cite: Brenner, M., Schuster, R., and Binder, F.: Biological effects of munition left on war wrecks on the health of caged blue mussels (Mytilus edulis, L.)  in the southern North Sea, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-2746, https://doi.org/10.5194/egusphere-egu23-2746, 2023.

Explosive chemicals released by dumped warfare material pose a threat to the marine environment and can enter the marine food web. These chemicals are toxic and are suspected to be carcinogenic, mutagenic and have also genotoxic effects. 2,4,6-Trinitrotoluene (TNT) is one of the most used explosives in munitions and therefore of special interest. To test the potential uptake, bio-concentration or bio-accumulation, and metabolism or depuration of TNT in marine organisms two lab exposure experiments were conducted using common blue mussels (Mytilus edulis). Mussels were exposed to different TNT concentrations for a specific period of time. The first experiment ran for a total of 120 hours, with 48 hours of exposure to different TNT concentrations (0 mg/L, 0.625 mg/L, 1.25 mg/L and 2.5 mg/L) followed by a 72 hours recovery phase in clean artificial seawater. Mussel sampling took place during the recovery phase.

The second experiment was performed as follow up to the first experiment and was conducted over 36 hours, with 24 hours of exposure and 12 hours of recovery. Water and mussel samples were taken during exposure and recovery phase with a higher sampling resolution within the first hours of the recovery phase. GC-MS/MS was used to determine the mussel tissue and water concentration of TNT and its metabolites 2-amino-4,6-dinitrotoluol (2-ADNT), 4-amino-2,6-dinitrotoluol (4-ADNT) and 2,4-diamino-6-nitrotoluene (2,4-DANT).

Results of the first experiment showed a rapid decrease in TNT and metabolite concentrations in mussel tissues over time. Overall, 57 to 76 % of the detected concentration was metabolised within the first four hours after the exposure. Analysis of samples of the second experiment verified the results from the first experiment showing clear linear digression of the two ADNTs within the first four hours of the recovery phase and a more or less complete metabolism of the parent compound TNT.

In summary, uptake of TNT in relation to the exposure concentration could be proven and first insights concerning the metabolism and depuration velocity could be shown.

Keywords: TNT, metabolites, 2-ADNT, 4-ADNT, metabolic rate, depuration

How to cite: Binder, F., Bünning, T., Strehse, J., Maser, E., and Brenner, M.: Depuration kinetics of TNT and its metabolites in lab exposed blue mussels (Mytilus edulis, L.), EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-5211, https://doi.org/10.5194/egusphere-egu23-5211, 2023.

Over 38000 tons of chemical munitions were dumped in the Baltic Sea after World War II. They rest on the bottom of the Gotland and Bornholm Deeps. Studies performed between 2011 and 2019 show that those munitions are largely corroded, and chemical warfare agents (CWA) are released to the environment. Biomarker studies indicate, that they adversely affect marine biota from the dumpsites. Hydrodynamic models suggest that they can be transported with currents to adjacent areas. CWAs are transformed in the environment producing a variety of different degradation products, some of them characterized by higher toxicity than the parent compounds. An effort was undertaken to summarize the studies performed in three EU Interreg and one NATO SPS projects focusing on this problem.

How to cite: Bełdowski, J., Jakacki, J., Vanninen, P., Lehtonen, K., Brenner, M., Fabisiak, J., Popiel, S., Czub, M., Nawała, J., and Dziedzic, D.: Chemical munitions in the Baltic Sea – growing evidence of environmental impact, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6163, https://doi.org/10.5194/egusphere-egu23-6163, 2023.

The German waters of the North and Baltic Sea contain over 1.6 million tons of dumped munition, mostly left after the first and second World Wars. Some of the dumpsites consist of old mines and shells containing TNT, which is known to have toxic effect on marine organisms. The objective of this study was to investigate whether the structure and composition of benthic macrofauna is influenced by the munition.

Two munition sites were chosen in the western Baltic Sea – Kolberger Heide (=‘KH’, Kiel Bay) and Haffkrug (=‘H’, Lübeck Bay). Samples were taken with 0.1 m² van-Veen grab (two replicates per station), sieved through 1 mm sieve and fixed with formalin. Stations were taken at several areas near the munition dumpsites, each time arranged in two short parallel transects with ~100 m step (6-10 station per area). In addition, samples in the background areas away from munition were taken. A total of 19 stations (37 samples) were taken in ‘KH’ and 25 stations (50 samples) were taken in ‘H’. Environmental values used in this study included depth, TNT-content in bottom water layer, distance from the maximum concentration of the munition objects, latitude and longitude.

A total of 118 taxa were found in ‘KH’ and 121 taxa in ‘H’. Abundance and biomass values varied among the samples greatly in both areas (from 10 to 1730 ind. 0.1 m^-2 and from 0.09 to 155.37 g wet weight 0.1 m^-2 respectively), although the dominant taxa were similar in all samples, including polychaetes Scoloplos armiger, Pygospio elegans, Dipolydora quadrilobate and Lagis koreni and gastropods Peringia ulvae.

In ‘KH’ notably higher abundance and biomass values were observed in the control sites, while the diversity expressed in different indices (Shannon index, Rarefaction curves, Pielou’s evenness etc.) was relatively higher in the munition sites. According to the canonical correspondence analysis, species and samples were grouped along two axes, roughly corresponding to the larger TNT content and shallower depths. Linear mixed-effect model showed statistically significant values for TNT content vs. Shannon diversity index with negative linear relation.

In ‘H’ the results were different with no clear abundance biomass or diversity relations to the environmental factors. However, this can be connected to a different munition distribution within the Lübeck Bay, which is more dispersed through the area, without such clear concentration area as in ‘KH’. Further possible conclusions will be discussed.

How to cite: Vedenin, A., Kröncke, I., and Greinert, J.: Impact of munition dumpsites on the benthic macrofauna in the western Baltic Sea, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6236, https://doi.org/10.5194/egusphere-egu23-6236, 2023.

There is about 1,6 million tons of dumped ammunition lying in the German Baltic and North Sea waters, which is not only toxicologically threatening the aquatic ecosystems, but also hindering anthropogenic off-shore activities such as construction of wind parks, pipelines and fisheries. Although, the German federal government is committed to providing considerable funds, the large amount of munition in the German Seas and the complexity of retrieving it, make remediation efforts time consuming and costly. An important question is therefore, “How should dumped munition sites in the German Baltic Sea be prioritized for clearance?”. The focus on the Baltic sea results from the amount of available data.

This poster will showcase how a priority list for the remediation of dump sites of conventional munition in the German Seas will be generated using multi-criteria analysis. This decision depends on a multitude of factors, ranging from the availability of information, geophysical features, collected biological, chemical and toxicological data, level of corrosion, proximity to beaches, severity of contamination, distance to infrastructure as well as the preferences of the stakeholders involved.

To structure the multiple factors and to capture preferences of diverse stakeholders, the Analytic Hierarchy Process (AHP) will be used. AHP helps guide complex decisions regarding a set of alternatives for dealing with a particular problem. This is done by structuring relevant criteria within a hierarchy tree and comparing them pairwise through stakeholder participation. This procedure will aid the computation of a final priority list of which dumping sites to clear first. This result will reflect the priorities of the different groups of involved stakeholders, the multiple factors and it will indicate what kind of additional information may need to be generated for future analysis. The poster will therefore, exemplify how geophysical and geochemical data can be used to assist political decision making.

How to cite: Ensenbach, S., Pechmann, A., and Frey, T.: Implementing geophysical and geochemical data in multi-criteria analysis for prioritization of munition dump site clearance, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14271, https://doi.org/10.5194/egusphere-egu23-14271, 2023.