Visbestandopnames op enkele wateren in het bekken van de Zeeschelde (2009): meting nulsituatie in het kader van de monitoring van het Sigmaplan

INBO researchers surveyed fish assemblages in several future flood control areas along the Zeeschelde estuary (Fig. 1, Table 1). Two survey periods were performed at 11 sites (117 surveys in toal). Fish assembvlages were assessed using electric fishing and fyke netting. Physical and chemical recordings showed that the 25% of the sites had a too low oxygen concentration. Some sites had no fish.In total 25 fish species were recorded. In the text fish results are explained for each area. In genral bitterling, stone moroko, Prucian carp, three-spined stickleback, roach and pumpkinseed dominate in numbers. The results indicate the presence of a diverse fish assemblage of mainly eurytopic and limnophilic species in some sites

ß-Methylphenylethylamines: Common fragmentation pathways with amphetamines in electrospray ionization collision-induced dissociation

β-Methylphenylethylamines are positional isomers of amphetamines and have been discovered in sporting supplements. Although the fragmentation of the β-methylphenylethylamine and N-methyl-β-methylphenylethylamine in gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) systems is significantly different to their amphetamine and methylamphetamine isomers, under electrospray ionization commonly used in liquid chromatography-mass spectrometry (LC-MS) systems, the fragmentation of each of the isomeric pairs is almost identical. The similarities in fragmentation make it possible for the misidentification of the β-methylphenylethylamines as the illicit amphetamines. It is proposed that the similarities are due to a fragmentation pathway involving a common phenonium ion intermediate. By careful control of fragmentation energies in liquid chromatography-tandem mass spectrometry (LC-MS/MS) systems and/or close examination of the relative abundances of product ions formed by collision-induced dissociation (qualifier ratios), it is possible to distinguish the β-methylphenylethylamines from the amphetamines, even if significant retention time separation is not achieved. In liquid chromatography-electrospray ionization-quadrupole time of flight (LC-ESI-QTOF) systems the mass spectra of the β-methylphenylethylamines are identical to their amphetamine isomers. In such systems, retention time separation of the isomers is critical to avoid misidentification. During this study β-methylphenylethylamine and N-methyl-β-methylphenylethylamine have been identified in commercially available sporting supplements and oral fluid samples taken during the course of road-side drugs-in-drivers and workplace testing programmes

Interpretation of urinary concentrations of pseudoephedrine and its metabolite cathine in relation to doping control

Until the end of 2003 a urinary concentration of pseudoephedrine exceeding 25 microg/mL was regarded as a doping violation by the World Anti-Doping Agency. Since its removal from the prohibited list in 2004 the number of urine samples in which pseudoephedrine was detected in our laboratory increased substantially. Analysis of 116 in-competition samples containing pseudoephedrine in 2007 and 2008, revealed that 66% of these samples had a concentration of pseudoephedrine above 25 microg/mL. This corresponded to 1.4% of all tested in competition samples in that period. In the period 2001-2003 only 0.18% of all analysed in competition samples contained more than 25 microg/mL. Statistical comparison of the two periods showed that after the removal of pseudoephedrine from the list its use increased significantly. Of the individual sports compared between the two periods, only cycling is shown to yield a significant increase.Analysis of excretion urine samples after administration of a therapeutic daily dose (240 mg pseudoephedrine) in one administration showed that the threshold of 25 microg/mL can be exceeded. The same samples were also analysed for cathine, which has currently a threshold of 5 microg/mL on the prohibited list. The maximum urinary concentration of cathine also exceeded the threshold for some volunteers. Comparison of the measured cathine and pseudoephedrine concentrations only indicated a poor correlation between them. Hence, cathine is not a good indicator to control pseudopehedrine intake. To control the (ab)use of ephedrines in sports it is recommended that WADA reintroduce a threshold for pseudoephedrine.status: publishe

Risk-benefit analysis regarding seafood consumption: a tool for combined intake assessment

The aim of food consumption is to provide people with the daily necessary energy, macro- and micronutrients in order to meet recommendations and to be able to execute daily tasks. What people need are the beneficial compounds that can be found in food products. Nevertheless, people risk to ingest simultaneously compounds that can have toxicological effects. These harmful compounds can on the one hand occur naturally in food, but on the other hand anthropogenic or man-made processes can lead to contamination of food products1. As such, food items can contain benefits as well as risks for consumers. A food group for which this nutritional-toxicological conflict is well-known and largely discussed in the scientific world and in the media is fish and shellfish, also named seafood or marine food. On the one hand, fish and shellfish represent a unique source of long chain poly-unsaturated fatty acids of the omega-3 family, particularly EPA and DHA. Moreover, they also contain a number of other valuable nutrients, like high quality amino acids and micronutrients like vitamin D and iodine. Therefore, it is generally accepted that seafood is important in a healthy and balanced omnivorous human diet. But on the other hand, this favourable health perception of seafood is troubled by less favourable information regarding the potential adverse health impact of chemical contamination of marine foods. Persistent organochlorine compounds, like PCBs, dioxin-like substances, and organochlorine pesticides (DDT/DDE) as well as heavy metals, e.g. mercury, accumulate in the marine food chain. This overall picture forms the basis for a conflictuous model between dietary recommendations and toxicological safety assurance. Therefore, it is useful to carry out a risk-benefit analysis to quantify the nutritional-toxicological conflict linked with seafood consumption. One important step in this risk-benefit analysis is a detailed intake assessment of nutrients and contaminants of interest by fish consumption. The model used for this intake assessment as well as the created output is described in this abstract, with a focus on the methodology and not on the results as such

KRW doelstellingen in Vlaamse getijrivieren: afleiden en beschrijven van typespecifiek maximaal ecologisch potentieel en goed ecologisch potentieel in een aantal Vlaamse getijrivier-waterlichamen vanuit de - overeenkomstig de Kaderrichtlijn Water - ontwikkelde relevante beoordelingssystemen voor een aantal biologische kwaliteitselementen

The European Water Framework Directive came into effect December 2000 in all member states. According to this directive, all European waters should reach ‘good status’ by the end of 2015. In order to assess the ecological status of their surface waters, member states have to act in concordance to a well-established step-wise plan and have to develop monitoring programs and valuation systems for a number of biological quality elements, which have been specified for each water category.This report deals with step 3 (delimitation of a reference) and step 4 (development of a score system). Subsequently, the ecological status is assessed. Assessed biological quality elements are phytoplankton, other aquatic flora, benthic invertebrates and fish. Hydromorphological status, as a supporting element for the biological quality elements, isalso assessed. Earlier studies served as a baseline to extend this research to all Flemish transitional water bodies within the Schelde basin (Van Damme et al., 2003; Brys et al., 2005) and results and insights gained from the conservations goals for the estuary where used (Adriaensen et al, 2005). While this report primarily deals with the tidal tributaries of the Zeeschelde (Flemish part of the Schelde River that has tidal regime), we tried to fill the gaps left by Brys et al. (2005), in order to obtain a comprehensive view at the entire estuary.All Flemish transitional waters have been identified as heavily modified water bodies. Therefore, maximum and good ecological potential (MEP/GEP) set the reference goals, not pristine conditions. These MEP and GEP were defined from an ecosystem perspective as an optimal functioning estuarine ecosystem. Thus, the ecological potential is conceived as the potential for natural physical, chemical and biological processes to deploy as good as possible within certain (achievable) boundaries. Attaining this potential requires an approach that surpasses the local level and individual quality elements. Therefore, an integrated, hierarchical and scale-dependent approach was chosen to establish the reference framework, including essential habitat characteristics besides the biological quality elements.At the ecosystem level, habitat area was considered, as it is a parameter relevant to all biological quality elements. Surface area of salt marsh, mudflat and shallow subtidal is also used to assess the hydromorphological status of the transitional waters. To obtain the MEP, a hydromorphological approach was used. Threshold band width was calculated as a quantifier for the space that is needed to maintain typical estuarine habitats (mudflats, salt marshes and shallow subtidal areas) in a sustainable and dynamic equilibrium of sedimentation and erosion. Along the estuary, this ‘equilibrium band width’ is proportional to the elevation range difference between the channel bottom and the mean high tide level (MHW) and the mean highest high water level (MHHW). The GEP for mudflats and salt marshes originates from the conservations goals set for the Schelde estuary: the minimum surface area of mudflat providing sufficient carrying capacity for macrobenthos, serving as (sufficient) food source for fish and birds (given good water quality). Salt marshes act as a source of dissolved silica. The minimal area of salt marshes, needed to provide sufficient amounts of silica for primary production of diatoms, is used to calculate the GEP for these marshes. The Zeeschelde and her tidal tributaries are, as a single ecosystem, in poor status, regarding the hydromorphological conditions. Dijle, Zenne, Getijdenetes and the upper Zeeschelde (Zeeschelde I) are in bad hydromorphological status. Zeeschelde II,III and Durme are also of poor status and Zeeschelde IV is in moderate status.To assess the phytoplankton of Durme and Rupel, the Flemish metric was used (Van Damme et al., 2003; Brys et al., 2005; Van Wichelen et al., 2005): chlorophyl a-concentration linked to the broader context of light climate, nutrient cycling and run-off time. The other tributaries were assessed by means of a German method (Mischke & Behrendt, 2007) comprising submetrics for phytoplankton biomass and species composition. Durme and Rupel were classified as ‘bad’, Dijle and Zenne as ‘moderate’ and the Getijdenetes as ‘good’.The macrobenthos metric consists of parameters at two scale levels:- habitat level: mudflat and shallow subtidal area- community level: application and evaluation of a number of available methods (AeTV, Dutch method, IOBS)These submetrics are subsequently integrated into a single indicator value (score). All fresh Schelde water bodies were scored ‘bad’.The macrophyte metric contains three levels:- ecosystem level: total salt marsh area- water body level: total salt marsh area and average quality of indivual marshes per water body- individual marsh level: (i) current area versus desired area (GEP) required for a sustainable development and conservation of the existing salt marshes, (ii) vegetation diversity, (iii) species richness and (iv) floristic quality index (FQI).These submetrics are subsequently integrated into a single indicator value (score), whereas the submetric values allow specific identification of bottlenecks and mitigating measures. The tributary macrophytes are scored as ‘poor’ or ‘bad’.In the fish assessment, species were selected per water body based on their discriminating power. According to their ecological demands, these species were grouped into guilds. From these guilds, relevant metrics were selected, based on their sensitivity towards anthropogenic pressures. Determination of class boundary values is based on the GEP reference list, providing the number of species per guild (metric). This number was used within each zone in order to calculate the maximum number of species and relative percentage in the total number of species for the selected guilds. Validation of the new index was based on catch data. The obtained score for the fish fauna within the studied tidal water bodies ranged from ‘bad to ‘poor’.Applying the WFD principle ‘one out, all out’, all of the 7 tidal water bodies of the Zeeschelde basin scored ‘bad’. Improvement is possible by means environmental measures which improve water and soil quality, as well as measures that provide sufficient amounts of space to the estuary, in order to allow natural functions and processes to develop naturally. Analysis of the impact of execution of the Most Desirable Alternative of the updated Sigma Plan, shows clear improvement for almost all of the considered water bodies and 3 of those 7 would rise above the GEP level boundary for the habitat area parameter