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Item type:Publication, Access status: with files , Sustainable decision making under uncertainty: A case study in dredged material managementBackground: The port of Lübeck is one of Germany's most important harbours for goods traffic to and from the Baltic Sea Region. Sedimentation from the River Trave requires regularly maintenance dredging as well as capital dredging operations in order to maintain the operational capability of the port. A range of solutions for sustainable dredged material handling exist and an assessment of these options often proves to be challenging for decision makers. Multi-criteria decision analysis (MCDA) provides decision support by processing different data sets and evaluating suitable options in a rational way. Using the stochastic multi-criteria acceptability analysis (SMAA)-TRI method with a modification of a previously developed computerised model for decision support in dredged material management, this study was performed to test decision support under uncertainty. Results: The analysis endorsed that relocation to a dredged discharge pool and capping of an ammunition disposal site are viable options for Lübeck port. On the other hand, the use of dredged material from port expansion and its disposal on land are considered to be of very low sustainability under the given circumstances. Conclusions: The case study demonstrates capabilities as well as boundaries of computer-aided decision making under the premise of incomplete information. Despite uncertainties, sustainable decision making is possible with appropriate MCDA methodologies although minimum requirements concerning both data quality and data quantity must be fulfilled. Consequently, one possible alternative could not be integrated into the case study due to incomplete information. © 2014 Scheffler et al.Publicationtype: Journal ArticleScopus© Citations 13 254 188 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Assessing the risk of a 50-year-old dump site in the Baltic Sea by combining chemical analysis, bioaccumulation, and ecotoxicity(Springer, 2013-06-11); ; ; ; Purpose: During the late 1950s and early 1960s, industrial waste material highly enriched with various contaminants (e.g., heavy metals, polycyclic aromatic hydrocarbons (PAHs)) was dumped in the inner Bay of Mecklenburg, western Baltic Sea. Between 2002 and 2004, a research program was initiated using chemical analysis in combination with bioanalytical techniques to assess the extent and variability in contamination at this dump site (DS). The data were compared to a reference area (RS) with similar environmental conditions, which is representative of the western Baltic Sea. Materials and methods: Twelve PAHs were investigated to assess their ecological hazard, as they were identified as major pollutants in the dumped material. In addition to analyzing the actual PAH contamination status in the sediments, PAHs measured in the soft tissue of Arctica islandica were also used as an indicator of contaminant bioaccumulation. A biotest battery was applied to determine the toxic effects of contaminants in the sediment. Results and discussion: Significantly elevated PAH concentrations (sum of 12 PAHs) of ∼3,000 ng g-1 dw and higher bioaccumulation factors (BAFs) were determined in the soft body tissue of A. islandica collected at DS (t test, p = 0.025). The results also showed that the sediment PAH contamination was significantly higher at DS (1,952-5,466 ng g-1 dw) than at RS (1,384-2,315 ng g-1 dw). The results revealed a major heterogeneity in the PAH concentration at DS due to an attempt to cover the toxic material with clean clay. This resulted in a more heterogeneous distribution of the dump material rather than covering it up completely. However, not all relevant contaminants were included in this study, not only because it is too costly to determine them all but also because unidentified contaminants present at concentrations below the limit of detection cannot be measured. Bioassays were used to fill this gap in the hazard assessment in a cost-effective way by investigating the possible effects of sediment contamination on benthic organisms. The results showed a high variability and magnitude of growth and luminescence inhibition. Bacterial contact tests with marine organisms showed a high toxicity response (>80 % inhibition) from DS sediments. In contrast, the luminescent bacteria test (Vibrio fischeri) showed equivalent effects of sediments from both DS and RS. Conclusions: The spatial distribution of toxicity in DS, the bioaccumulation in mussels and the analytical evidence of PAH pollution clearly show that the dumped material still represents a potential risk even after 60 years.Publicationtype: Journal Article76 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Sediment contact tests as a tool for the assessment of sediment quality in German waters(Elsevier, 2013); ; ; ; A sediment contact test (SCT) battery consisting of five ecotoxicological test systems was applied to 21 native freshwater sediments characterized by a broad variety of geochemical properties and anthropogenic contamination. Higher plants (Myriophyllum aquaticum), nematodes (Caenorhabditis elegans), oligochaetes (Lumbriculus variegatus), zebrafish embryos (Danio rerio), and bacteria (Arthrobacter globiformis), representing various trophic levels and exposure pathways, were used as test organisms. The test battery detected sediment toxicity caused by anthropogenic pollution, whereas the various tests provided site-specific, nonredundant information to the overall toxicity assessment. Based on the toxicity pattern derived from the test battery, the sediments were classified according to a newly proposed classification system for sediment toxicity assessment. The SCT-derived classification generally agreed well with the application of consensus-based sediment quality guidelines (SQGs), especially with regard to sediments with high toxic potential. For sediments with low to medium toxic potential, the SQGs often underestimated the toxicity that was detected by the SCTs, underpinning the need for toxicity tests in sediment quality assessment. © 2012 SETAC.Publicationtype: Journal ArticleScopus© Citations 53 28 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Strategien zur Sedimentbewertung : ein Überblick(Springer, 2009-04-01); ; ; ; Background Being an important determinant in aquatic ecosystems, sediments have gotten more and more into focus of scientific and public discussions. While water quality has been significantly improving during recent years, highly contaminated sediments in many European rivers will still have ongoing impact for several centuries from now. Hence, monitoring and assessment of sediment quality are crucial for national legislation as well as the implementation of the European Water Framework Directive (WFD). Aim On the occasion of the retirement of Prof. Dr. Dr. h. c. Volker Storch, this article reviews the various concepts of sediment assessment and introduces case studies in sediment toxicology which have been carried out in Heidelberg and surrounding areas. Results and Discussion Initially, the article portrays benefits and drawbacks of chemical analytics and biotest systems. The individual approach has only limited informative value, but combiningbothperspectives allows fora comprehensive characterization of the state of sediments. As examples of toxicity evaluation based on this strategy, weight-of-evidence studies for tiered investigations and integrated sediment assessment are presented. In addition, a combination of chemical fractionation, bioanalytic investigations and chemical analysis - known as 'effect-directed analysis' (EDA) - is discussed. This integrated concept eventually aims at the identification of hazardous substance classes or even of single compounds. Finally, the article raises the issue of sediment mobility as an important parameter for risk analyses of highly contaminated legacy sediments within further WFD implementation. Outlook Using various case studies, the article outlines the potentials of integrated approaches for cause-effect analysis of complex environmental samples within aquatic ecosystems as well as for action programs of management plans dealing with chemically polluted rivers. Effect-directed analysis in particular, but also the combined application of acute and mechanism-specific bioassays together with in-situ investigations, complemented by investigations on sediment mobility, appear promising with regard to comprehensive sediment assessment weight-of-evidence studies.Publicationtype: Review Article121 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Entwicklung von ökotoxikologischen Instrumenten und ihre rechtliche Implementierung zur marinen ökologischen Risikobewertung von Chemikalien, Pestiziden und BaggergutBackground, aim, and scope The marine environment is often the final sink for pollutants, especially for persistent organic pollutants (POPs) and for persistent, bio- accumulative and toxic (PBT) substances. The body burden of marine top predators in the Baltic Sea, in the North Sea and also in the Arctic seas is alarming. Thus, the question was investigated if the European environmental law considers a prospective marine ecological risk assessment of chemicals, pesticides and dredged material before they are launched on the market or disposed to the sea. Results The analysis of European environmental law showed that the European environmental protection goals demand a good quality status of coastal waters until 2015 (Waterframework Directive) and a good quality status of European seas until 2020 (Marine Strategy Directive), but a specific marine ecological risk assessment of chemicals and pesticides is not sufficiently required in current European legislation. Discussion It was shown that the ecological risk assessment for freshwater ecosystems is, due to the pecularities of pollutant impacts in the marine environment, not adequate to predict marine effects and to protect the marine environment sufficiently. A statistical analysis of international databases on the relative toxicity of narcotics revealed that marine organisms can be significantly more sensitive than freshwater organisms towards substances with an unspecific mode of action (narcotics). Approximately 60 % of the industrial chemicals are classified as narcotics by their mode of action. Thus, this substance class is of environmental importance. Due to the hydrophobic properties and the low solubility of narcotics in seawater, the ecotoxicological assessment of marine sediments was of interest. An estuarine and marine bioassay test set was established and further developed to assess the ecotoxicological potential of brackish and seawater sediments. It was important that the test procedures were adapted to brackish and marine conditions and were harmonised between each other as well as on the international level. Conclusions Beside two bioassays for the ecotoxicological assessment of elutriates of marine and brackish sediments (bacteria bioluminescence test and marine algae test), the implementation and further development of the whole sediment bioassay with the marine amphipod Corophium volutator was important for enhancing the risk assessment. In order to gain a more standardised, all-season available test organism the marine amphipod was for the first time reproduced under laboratory conditions the whole year round (also in winter), which is the essential basis for the urgently needed chronic whole sediment bioassay. The results of this investigation were implemented in the international (ISO), European (EN) and national (DIN) standardisations. Therefore, a standardised test set is ready for the implementation in the marine ecological risk assessment of chemicals, pesticides and dredged material in international, European and national legislation. Recommendations and perspectives Recommendations to mprove the implementation of a marine risk assessment in European regulations are given with the goal to reach the internationally required objective of a sustainable development of the seas.Publicationtype: Journal Article73 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Sediment quality objectives and criteria development in GermanyNew objectives regarding the improvement of water quality as well as problems with the resuspension and land deposition of dredged materials require a standardized assessment of sediment quality. Numerical approaches are based on the accumulation, pore water concentrations, solid/liquid partition and elution properties of contaminants; these non-biological schemes can be extended and completed by additional biological criteria. Specific biological approaches have been combined with chemical surveys (for example Sediment Quality Triad). In Germany, numerical criteria are based on the background approach. Biological criteria approaches include bioassays on sediment, porewater and elutriates; recent developments are directed towards microbial solid phase bioassays. Special emphasis is placed on the characteristics of the mineral and organic solid substrate, in particular, buffer capacity against pH-depression; these components should be classified on the basis of the carbonate and sulfide inventories.Publicationtype: Conference Paper587 917 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Chemical mobility and bioavailability of sediment-bound heavy metals influenced by salinity(1992-07); ; The transfer of metals from contaminated sediments to algal cell walls (Scenedesmus quadricauda) and organisms from various trophic levels (euryhaline osmoconform hydroid Cordylophora caspia and algae Brachiomonas submarina) was studied with a multichamber device. The system consists of a central chamber which contained the mud suspension and six external chambers containing the different biological indicators. The solids in the central and external chambers are separated by 0.45 µm-diameter membranes which allow diffusion of the mobilized, dissolved metal compounds. Experiments were performed with dredged sediments at various salinities (0.5, 1.0, 1.5, and 2.0 percent, respectively) and the kinetic of re-adsorption was obtained by taking samples after different time intervals. High enrichment of Cd was found in the living alga Brachiomonas submarina, but on the other side only a weak influence of salinity on re-adsorption could be observed. Model experiments with ionic Cd showed a clear dependency on Cd-sorption on the algae, Cd-concentration in solution, and salinity. These results indicate that the transfer of metals mainly depends on the specific surface properties of the substrates and on the specific chemical form of the dissolved mobilized metal.Publicationtype: Journal Article479 497 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Assessment of metal mobility in sludges and solid wastesAmong the criteria to assess which element or elemental species, beside its toxic potential, may be of major concern in ecological evaluations, one question deserves primary attention: Is the element mobile in geochemical processes because of either its volatility or its solubility in natural water, so that the effect of geochemical perturbations can propagate through the environment? (...) Problems with solid "speciation" (...) are connected to the complexity of heterogenous systems, e.g. of soils, sediments and aerosol particles, and to disequilibria between dissolved and particulate fractions. It has been stressed, that due to the important role of kinetically controlled processes in these systems, the actual speciation is often different from what can be expected. Particularly in polluted solid systems, an even greater increase of entropy will induce a concominant increase in instability in both physical and chemical context (...) On the other hand, it is just these systems, where action is immediately needed and where for an assessment or prognosis of possible adverse effects the species and the transformations of pollutants have to be evaluated. The present review on metal mobility in relation to "speciation" in typical examples of solid waste materials is a follow-up study to our earlier compilations (...) Here we will focus on the progress, which - to our opinion - has been achieved since the latter conference with respect to the conceptual aspects and operational procedures in the subject area of distribution and transformation of metal species in solid waste materials.Publicationtype: Conference Paper555 595 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Biogeochemical studies on the distribution of heavy metals in the Elbe estuary[Introduction] The mixing of riverwater and seawater in an estuary is accompanied by a large number of biogeochemical and physical processes which change the distribution, partitioning and bioavailability of contaminants. Superimposed particulates may take place, which cause deviations from the theoretical mixing curve between dissolved metal ions and salinity. Seasonal fluctuations and year-to-year variations in concentrations of trace metals must be considered in characterizing the importance of biogeochemical processes for the distribution of anthropogenic metals in estuaries. We undertook the present study to interpret the time and space variability of metal concentrations within the Elbe estuary and its relationship with physical and biogeochemical processes of metal distribution. The data also provided information on the role of particulate components in the distribution process.Publicationtype: Conference Paper270 156 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Sediment criteria development : contributions from environmental geochemistry to water quality managementThe role of sediments as carriers and potential sources of contaminants is reviewed. A program of sediment studies will normally consist of a series of objectives of increasing complexity, each drawing part of its information from the preceding data base. The study of dated sediment cores has proven particulary useful as it provides a historical record of the various influences on the aquatic system by indicating both the natural background levels and the man-induced accumulation of pollutants over an extended period of time. Since adsorption of pollutants onto particles is a primary factor in determining the transport, deposition, reactivity, and potential toxicity of these materials, analytical methods should be related to the chemistry of the particle's surface and/or to the pollutant species highly enriched on the surface. New objectives regarding the improvement of water quality as well as problems with the resuspension and land deposition of dredged materials require a standardized assessment of sediment quality. Biological criteria integrate sediment characteristics and pollutant loads, while generally not indicating the cause of effects. With respect to chemical-numerical criteria immediate indications on biological effects are lacking; major advantages lie in their easy application and amendment to modeling approaches. Numerical approaches, on the one hand, are based on (1) accumulation; (2) pore water concentrations; (3) solid/liquid equilibrium partition (sediment/water and organism/water); and (4) elution properties of contaminants. The second component in an assessment scheme would include characteristics of the solid substrate, in particular, buffer capacity againt pH-depression. At the present stage of criteria development we propose that the substrate properties should be classified on the basis of the carbonate and sulfide inventory, whereas the pollutant load is advantageously assessed by the accumulation rate multiplied with a toxicity factor for the respective substance.Publicationtype: Book Part575 346