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Mobility and bioavailability of metals in continental surface waters; an integrated approach - Part 4: narrowing the laboratory vs. field gap

English title Mobility and bioavailability of metals in continental surface waters; an integrated approach - Part 4: narrowing the laboratory vs. field gap
Applicant Dominik Janusz
Number 117942
Funding scheme Project funding (Div. I-III)
Research institution Institut F.-A. Forel Université de Genève
Institution of higher education University of Geneva - GE
Main discipline Hydrology, Limnology, Glaciology
Start/End 01.10.2007 - 30.09.2010
Approved amount 424'689.00
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Keywords (9)

bioavailability; bioaccumulation; microcosm; colloid; sediment; mercury; chromium; Chironomus; field study

Lay Summary (English)

Lay summary
Significant deposition of trace metals and persistent organic compounds (POPs) in sediments represents a true risk for aquatic organisms and has encouraged environmental managers to develop risk assessment procedures and sediment quality guidelines using a variety of laboratory- and field-based approaches. Insufficient field-evaluation of laboratory-based mechanistic knowledge of contaminant bioaccumulation and toxic effects remains the major obstacle towards the coherent interpretation of laboratory and field results within comprehensive mechanistic frameworks. Such situation is particularly critical in “promising” research areas such as Tissue Residue Approaches (TRA), which hold great potential for improving current fundamental knowledge on contaminant bioavailability and effects, risk assessment procedures and environmental quality guidelines.
TRA are based on establishing cause-effect relationships between the quantity of contaminants accumulated by aquatic organisms and the organisms’ response. This strategy is attractive because, by definition, it takes into account variations in exposure conditions and hence greatly reduces the interspecific variability of biological responses. On the other hand, field verification of the available knowledge is still required since the theoretical assumptions of TRA (i.e., independence of bioaccumulation from exposure matrices and time; direct relationship between bioaccumulation and responses) may be questionable outside laboratory settings.
Based on past experience and state of the art, we propose to perform detailed investigations in two areas:
•Evaluation of metal accumulation kinetics by benthic organisms (mainly Chironomus riparius) under field conditions and comparison with microcosms experiments
•Combined study of the interactions between nutritional and other biotic and abiotic factors under field conditions and in microcosms

The research will be focused on chromium and mercury; the latter is one of the most hazardous elements due to its environmental mobility and biomagnifying potential. Some work on PCBs, for which the state of the art is more advanced, will also be carried out.Experiments will involve the study of bioaccumulation kinetics directly in the field using customized exposure chambers and under varying feeding conditions. Similar studies will be carried out in the microcosms using unperturbed sediment cores. Field experiments will be limited to bioaccumulation in the larval stages; while some laboratory experiments will be conducted over an entire life cycle of C. riparius. Besides providing additional endpoints to relate metal bioaccumulation and organism response, these experiments will allow to evaluate the contaminant load potentially removed from the sediment compartment via aquatic insects.
The results of this project are expected to improve the understanding of the factors affecting contaminant bioavailability in field conditions and to help verifying the predictive power of laboratory-based results for various TRA.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants


Associated projects

Number Title Start Funding scheme
109608 Mobility and bioavailability of metals in continental surface waters; an integrated approach - Part 3: role of colloids in metal uptake and toxicity 01.10.2005 Project funding (Div. I-III)
136134 Mercury and methyl-mercury in the Lagoon of Venice: biogeochemistry and bioaccumulation. 01.03.2011 International short research visits