WHOLE ISSUE \u3ci\u3eNebraska Bird Review\u3c/i\u3e (March 1974) 42(1)

Table of Contents 1973 Treasurer\u27s ........................................... 2 1973 Nebraska Nesting Survey ...................................... 3 1973 Christmas Count ...................................... 10 Canyon Wren in Nebraska ......................... 16 A Nebraska Swainson\u27s Thrush Nest .................................... 17 Another Black-throated Sparrow in Nebraska ................................. 18 Notes .......................................................... 1

Upstream migration of fish at natural obstructions and fish passes efficiency in Southern Belgium.

Fragmentation of rivers by physical obstacles has resulted in the drastic range reduction or extinction of numerous diadromous and potadromous species of fish worldwide. In order to implement to partially or completely re-establish the free movements of fish in the entire watercourse, the Walloon regional government (Southern Belgium) initiated an integrated restoration project whose objectives are 1) To perform a complete inventory of all obstacles that may potentially interfere with the longitudinal connectivity and the free movements of fish, 2) To test, using radio telemetry, the ability of representative fish species (Salmonidae, Thymallidae, Cyprinidae, Esocidae and Cottidae) to clear different typologies of physical obstacles, 3) To determine the problematic sites that should be improved with priority. 4) To construct fish passage facilities and to examine their biological efficiencies. During our talk we will synthesize the results of ten years of research and define the different options for the future

Behavioural adaptations of rheophilic fish radio-tracked in a river highly fragmented by hydroelectric plants. Outcomes of a partial reopening of their migration routes.

peer reviewedUsing water resources for hydroelectricity production influences and limits the quality and quantity of habitat available for use by fishes and influences fish mobility. In the Amblève (River Meuse basin, Belgium), the major part of the river is fragmented by hydroelectric power plants that largely prevent the biological movements of the fish population. In 2007, in the hydroelectric site of Lorcé, a modern pool-type fish pass was constructed, re-establishing the upstream movements of fish after more than 80 years of total obstruction. Sixteen different fish species promptly used the new fish pass and the objective of our study was to analyse their behavioural tactics and spawning activity once released upstream of the dam in a previously inaccessible environment. The study focussed on rheophilic holobiotic species, the nase (Chondrostoma nasus), the barbel (Barbus barbus), the European grayling (Thymallus thymallus) and the brown trout (Salmo trutta), which are highly representative of the fish population of the river. The fish were radio-tagged and intensively located using manual tracking techniques during their circum reproduction periods. The results indicate that most individuals of the different species seem to have found usable spawning areas and exploited a large part of the newly usable river stretch (as well as tributaries) located upstream of the fish pass. However, a major problem was observed during the post-spawning period, when the tracked individuals tried to reach their original departure sites (located downstream of the fish pass). The absence of a downstream migration device combined with the passage of all the water through the turbine severely disrupted their post-reproductive movements