The use of benthic indicators in Europe: from the Water Framework Directive to the Marine Strategy Framework Directive.

The Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD) are the European umbrella regulations for water systems. It is a challenge for the scientific community to translate the principles of these directives into realistic and accurate approaches. The aim of this paper, conducted by the Benthos Ecology Working Group of ICES, is to describe how the principles have been translated, which were the challenges and best way forward. We have tackled the following principles: the ecosystem-based approach, the development of benthic indicators, the definition of 'pristine' or sustainable conditions, the detection of pressures and the development of monitoring programs. We concluded that testing and integrating the different approaches was facilitated during the WFD process, which led to further insights and improvements, which the MSFD can rely upon. Expert involvement in the entire implementation process proved to be of vital importance.

An adjustment of benthic ecological quality assessment to effects of salinity.

In the last decade a politically inspired marine protection movement arose in the European Union. This movement leads to an holistic strategy. Merging the Water Framework Directive (WFD) and the Marine Strategy Directive (MSD) along the European coastline demands sophisticated ecological classification procedures. The 'Benthic Quality Index' (BQI) is one of several indices created in view of the WFD. We used the dynamic species reference system ES(50)(0.05) to test the capability of BQI to exclude primary environmental factors including the salinity gradient and depth (a proxy for the oxygen regime) from the ecological quality (EcoQ) assessment. A macrozoobenthos dataset of the southern Baltic Sea spreading over more than 20 years and over 100,000 km2 was used for the EcoQ assessment. Quality assurance rules were applied to the record set and an analytical dataset of 936 sampling events with 20,451 abundance records was used in the analysis. We show that the natural salinity gradient has a severe impact on the BQI based EcoQ. We adapted the calculation procedure to reduce the salinity effects to a minimum. According to the adaptation 503 sensitivity/tolerance values for 87 species were computed. These values were calculated within seven salinity ranges from 0 to >30 PSU and two depth zones. These values can be used as a reference for further investigation in the Baltic and other areas with similar environmental conditions.

Performance comparison of two biotic indices measuring the ecological status of water bodies in the Southern Baltic and Gulf of Lions.

Two biotic indices, ATZI Marine Biotic Index (AMBI) and Benthic Quality Index (BQI) have been recently introduced within the EC Water Framework Directive to assess the quality of marine habitats: both are based on sensitivity/tolerance classification and quantitative information on the composition of soft-bottom macrofauna. Their performance, especially with regard to sampling effort was assessed based on two data sets collected in Southern Baltic and one from the Gulf of Lions Mediterranean. AMBI was not affected by sampling effort but BQI was. Two modifications were proposed for BQI (i.e., BQI) (1) the removal of the scaling term (i.e., BQI(W)), and (2) the replacement of the scaling term by different scaling term (i.e., BQI(ES)). Both modified BQIs were largely independent of sampling effort. Variability was slightly lower for BQI(W) than for BQI(ES). BQI was highly correlated with BQI(W) and with BQI(ES) both in the Southern Baltic and in the Gulf of Lions. However, the proportions of stations, which were not attributed the same ecological quality status (EcoQ) when using BQI and its two modified forms were always high. Differences in ecological classification were mostly due to the scales used to infer EcoQ. Based on this study we recommend to use BQI(ES) in future studies because it apparently constitutes the best compromise in (1) being independent of sampling effort, (2) limiting the variability in computation in relation with sampling effort, (3) being correlated with BQI and corresponding EcoQ.

Reduced repolarization reserve due to anthracycline therapy facilitates torsade de pointes induced by IKr blockers.

BACKGROUND: Cytostatic agents such as anthracyclines may cause changes in the electrophysiologic properties of the heart. We hypothesized that anthracyclines facilitate life-threatening proarrhythmic side effects of cardiovascular and non-cardiovascular repolarization prolonging drugs. METHODS AND RESULTS: The electrophysiologic effects of chronic administration of doxorubicin (Dox) were studied in ten rabbits, which were treated with Dox twice a week (1.5 mg/kg i.v.). A control group (11 rabbits) was given NaCl solution. Two of ten Dox rabbits died suddenly, the remaining animals showed mild clinical signs of heart failure after a period of six weeks. Echocardiography demonstrated a decrease in ejection fraction (pre treatment: 74 +/- 23% to post treatment: 63 +/- 16% (p <0.05)). In isolated hearts, action potential duration measured by eight simultaneously recorded monophasic action potentials (MAP) was similar in Dox and control hearts. However, in Dox rabbits, administration of the I(Kr)-blocker erythromycin (150-300 microM) led to a significant greater prolongation of the mean MAP duration (63 +/- 21ms vs 29 +/- 12 ms, p <0.05) and the QT interval (100 +/- 32ms vs 58 +/- 17 ms, p <0.05) as compared to control. Moreover, I(Kr)-block led to a more marked increase of dispersion of MAP(90) in the Dox group as compared to control hearts (23 +/- 7ms vs. 9 +/- 4 ms). In the presence of hypokalemia more episodes of early afterdepolarizations and torsade de pointes occurred (p <0.05). CONCLUSION: Even during the early phase of chemotherapeutic treatment,before significant QT-prolongation is present,anthracyclines lead to an increased sensitivity to the proarrhythmic potency of I(Kr)-blocking drugs. Thus, anthracycline therapy reduces repolarization reserve and thereby represents a novel contributing factor for the development of life-threatening proarrhythmia.

Divergent proarrhythmic potential of macrolide antibiotics despite similar QT prolongation: fast phase 3 repolarization prevents early afterdepolarizations and torsade de pointes.

Macrolide antibiotics are known to have a different proarrhythmic potential in the presence of comparable QT prolongation in the surface ECG. Because the extent of QT prolongation has been used as a surrogate marker for cardiotoxicity, we aimed to study the different electrophysiological effects of the macrolide antibiotics erythromycin, clarithromycin, and azithromycin in a previously developed experimental model of proarrhythmia. In 37 Langendorff-perfused rabbit hearts, erythromycin (150-300 microM, n = 13) clarithromycin (150-300 microM, n = 13), and azithromycin (150-300 microM, n = 11) led to similar increases in QT interval and monophasic action potential (MAP) duration. In bradycardic (atrioventricular-blocked) hearts, eight simultaneously recorded epi- and endocardial MAPs demonstrated increased dispersion of repolarization in the presence of all three antibiotics. Erythromycin and clarithromycin led to early afterdepolarizations (EADs) and torsade de pointes (TdP) after lowering of potassium concentration. In the presence of azithromycin, no EAD or TdP occurred. Erythromycin and clarithromycin changed the MAP configuration to a triangular pattern, whereas azithromycin caused a rectangular pattern of MAP prolongation. In 13 additional hearts, 150 microM azithromycin was administered after previous treatment with 300 microM erythromycin and suppressed TdP provoked by erythromycin. In conclusion, macrolide antibiotics lead to similar prolongation of repolarization but show a different proarrhythmic potential (erythromycin > clarithromycin > azithromycin). In the presence of azithromycin, neither EAD nor TdP occur. This effect may be related to a rectangular pattern of action potential prolongation, whereas erythromycin and clarithromycin cause triangular action potential prolongation and induce TdP.