Over 200,000 kilometers of free-flowing river habitat in Europe is altered due to impoundments.

European rivers are disconnected by more than one million man-made barriers that physically limit aquatic species migration and contribute to modification of freshwater habitats. Here, a Conceptual Habitat Alteration Model for Ponding is developed to aid in evaluating the effects of impoundments on fish habitats. Fish communities present in rivers with low human impact and their broad environmental settings enable classification of European rivers into 15 macrohabitat types. These classifications, together with the estimated fish sensitivity to alteration of their habitat are used for assessing the impacts of six main barrier types (dams, weirs, sluices, culverts, fords, and ramps). Our results indicate that over 200,000 km or 10% of previously free-flowing river habitat has been altered due to impoundments. Although they appear less frequently, dams, weirs and sluices cause much more habitat alteration than the other types. Their impact is regionally diverse, which is a function of barrier height, type and density, as well as biogeographical location. This work allows us to foresee what potential environmental gain or loss can be expected with planned barrier management actions in rivers, and to prioritize management actions.

The effect of cannabinoid CB(1) receptor antagonist rimonabant (SR-141716) on ethanol drinking in high-preferring rats.

The present study investigated the effect of the cannabinoid CB(1) receptor antagonist, rimonabant (SR-141716) on ethanol intake in selectively bred alcohol-preferring Warsaw High-Preferring rats. Ethanol (10% vol/vol) and food were available in daily 4-h limited access period while water was available ad libitum. The administration (i.p.) of single 2.5 and 5.0-mg/kg doses of rimonabant preferentially reduced ethanol intake, whereas a 10 mg/kg dose of rimonabant similarly reduced both ethanol and food intake. Our result extends the suppressive effect of cannabinoid CB(1) receptor antagonist to the ethanol drinking behavior in Warsaw High-Preferring line of rats. The result also supports a growing body of literature indicating that the cannabinoid CB(1) receptor is involved in motivational and appetitive properties of ethanol.