Effects of a micro hydroelectric power plant upon population abundance, mobility and reproduction behaviour of European grayling T. thymallus and brown trout S. trutta in a salmonid river

peer reviewedThis study examines the potential effects of a new micro hydroelectric power plant (MHPP) on the behaviour (habitat use, movements) and population abundance of European grayling (T. thymallus) and brown trout (S. trutta) in the Lhomme (Belgian Ardennes). Thirteen grayling and five brown trout were captured before their spawning period and were manually radio-tracked up to 6 times a week. Population density and biomass were estimated into two different sampling sectors with electric fishing, before and after the MHPP started up. The mobility patterns of grayling and trout in the reach of the river Lhomme influenced by the MHPP strongly contrasted with results obtained in an undisturbed river of the same type in the Belgian Ardennes. Movements were mostly restricted and rarely increased during the spawning period. Spawning took place, but was disturbed by hydropeakings. The population biomass of grayling and trout decreased by 61 % and 23 % respectively, five months after the start-up of the MHPP exploitation

Reactions of polycyclic thioketones with a phosphonylated carbanion

ABSTRACT: Polycyclic, non enolizable cycloaliphatic thioketones 1a and 1b react smoothly with the lithium salt of diethyl methylphosphonate 7 in THF solution at –40°C to afford products of the carbophilic attack exclusively. Quenching of the obtained lithium thiolates with alkyl iodides yields sulfanes of type 9 or 11, respectively, in good yields. 1-Fluoro-2,4-dinitrobenzene was shown to act as an arylating agent. In the case of the ‘cage’ thioketone 1b, the carbanion of salt 7 approaches the C=S bond from the exo-side exclusively. In contrast to the parent carbonyl compounds, thioketones 1 show no tendency to undergo the conversion analogous to the Horner-Wadsworth-Emmons reaction, which would result in the formation of an olefinic product