Tidal Estuaries: manual of sampling and analytical procedures

This "Manual" refers to a set of methodological descriptions of sampling strategies, sampling tools and methods for the study of chemical and biological variables in water and sediments of tidal estuarine environments

Mesocosm validation of the marine No Effect Concentration of dissolved copper derived from a species sensivity distribution

The Predicted No Effect Concentration (PNEC) for dissolved copper based on the species sensitivity distribution (SSD) of 24 marine single species tests was validated in marine mesocosms. To achieve this, the impact of actively maintained concentrations of dissolved copper on a marine benthic and planktonic community was studied in 18 outdoor 4.6 m3 mesocosms. Five treatment levels, ranging from 2.9 to 31 µg dissolved Cu/L, were created in triplicate and maintained for 82 days. Clear effects were observed on gastropod and bivalve molluscs, phytoplankton, zooplankton, sponges and sessile algae. The most sensitive biological endpoints; reproduction success of the bivalve Cerastoderma edule, copepod population development and periphyton growth were significantly affected at concentrations of 9.9 µg Cu/L and higher. The No Observed Effect Concentration (NOEC) derived from this study was 5.7 µg dissolved Cu/L. Taking into account the DOC concentration of the mesocosm water this NOEC is comparable to the PNEC derived from the SSD

Toxicity of bioavailable copper in relation to surface water organic matter: biological effects to Daphnia magna

Water quality standards for copper are usually stated in total element concentrations. It is known, however, that a major part of the copper can be bound in complexes that are biologically not available. Natural organic matter, such as humic and fulvic acids, are strong complexing agents that may affect the bioavailable copper (C

Copper toxicity in relation to surface water-dissolved organic matter: biological effects to Daphnia magna

Water quality standards for copper are usually stated in total element concentrations. It is known, however, that a major part of the copper can be bound in complexes that are biologically not available. Natural organic matter, such as humic and fulvic acids, are strong complexing agents that may affect the bioavailable copper (Cu2+) concentration. The aim of this study was to quantify the relation between the concentration of dissolved natural organic matter and free Cu2+ in surface waters, and the biological effect, as measured in a standardized ecotoxicological test (48 h¿median effective concentration [EC50] Daphnia magna, mobility). Six typical Dutch surface waters and an artificial water, ranging from 0.1 to 22 mg/L dissolved organic carbon (DOC), were collected and analyzed quarterly. Chemical speciation modeling was used as supporting evidence to assess bioavailability. The results show clear evidence of a linear relation between the concentration of dissolved organic carbon (in milligrams DOC/L) and the ecotoxicological effect (as effect concentration, EC50, expressed as micrograms Cu/L): 48-h EC50 (Daphnia, mobility) = 17.2 × DOC + 30.2 (r2 = 0.80, n = 22). Except for a brook with atypical water quality characteristics, no differences were observed among water type or season. When ultraviolet (UV)-absorption (380 nm) was used to characterize the dissolved organic carbon, a linear correlation was found as well. The importance of the free copper concentration was demonstrated by speciation calculations: In humic-rich waters the free Cu2+ concentration was estimated at ¿10¿11 M, whereas in medium to low dissolved organic carbon waters the [Cu2+] was ¿10¿10 M. Speciation calculations performed for copper concentrations at the effective concentration level (where the biological effect is considered the same) resulted in very similar free copper concentrations (¿10¿8 M Cu) in these surface waters with different characteristics. These observations consistently show that the presence of organic matter decreases the bioavailability, uptake, and ecotoxicity of copper in the aquatic environment. It demonstrates that the DOC content must be included in site-specific environmental risk assessment for trace metals (at least for copper). It is the quantification of the effects described that allows policy makers to review the criteria for copper in surface waters

Collaborative Study to Improve the Quality Control of Rare Earth Element Determinations in Environment Matrices.

Abstract not availableJRC.D-Institute for Reference Materials and Measurements (Geel

Laser granulometry of Holocene estuarine silts: effects of hydrogen peroxide treatment

The Holocene estuarine silts of the Severn Estuary Levels (southwest Britain) are representative of their kind in northwest Europe. They contain two broad types of plant material: particles codeposited with mineral grains from the estuarine water body, and extraneous debris (stems of indigenous prior plants; post depositional root matter) which is difficult to remove completely by physical means. Treatment with hydrogen peroxide before laser granulometry removes all plant material regardless of kind, drastically reduces values for the mean grain size and median size relative to untreated samples, but has little effect on the mode, except for a restricted group of bimodal-platykurtic, medium-coarse silts. It is concluded that, in the case of sediments of the general kind examined, no advantages acrue from the treatment of samples with hydrogen peroxide prior to analysis. Although a discrete rather than continuous variable, values of the mode obtained from untreated sediments are suggested to be acceptable for most purposes where a measure of central tendency is required

Towards a New Certified Reference Material for Butyltins, Methylmercury and Arsenobetane in Oyster Tissue

Increasing awareness of the determination of chemical species in the environment evolves jointly with the need to control the validity of analytical measuremetn in a wide variety of matrices. There are few Certified Reference Materials (CRMs) available for various chemical species, and they are certified for species of one single element (e.g. species of tin and mercury). Three years of collaboration within the framework of EU research programmes involving more than 20 laboratories have made it possible to produce an oyster reference material for species of tin, mercury and arsenic (BCR-710) and to perform the necessary experimental work for its certification. This articles summarises the feasibility study and describes the various steps in the peparation, production and characterisation of this material for its content of arsenobetaine, methylmercury, tributyltin and dibutyltin. These steps included stability and homogeneity testing as well as value assignment based on a collaborative approach involving a group of European laboratories. Further work is going on to certify total contents for a range of trace metals.JRC.H.6-Spatial data infrastructure