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To highlight the changes in the structure of fish communities through the advent of Bicaz lakes and Poiana Teiului samples were taken both from the two lakes, using trammel and the upstream river areas (Bistrita - Galu) and downstream (Bistrita - City Bicaz) them. The two lakes were identified higher valences species to environmental conditions and food (perch, bleak, chub) except nase identified Bicaz lake, which with the advent dam at Poiana Teiului, probably will not be able to migrate on the river, leading to the reduction and disappearance of the numbers of the lake. By sampling upstream and downstream, by calculating some ecological indices in the two collection points is apparent influence they have two lakes on the fish fauna of the river. Fish community structure is slightly modified in the upstream of the two lakes. Downstream river course due to strong fragmentation and water pollution, fish community structure is changed by the dominance resistant species with broad valences. [ABSTRACT FROM AUTHOR]

This paper tries to highlight the extent to which were affected fish communities on the Bistrita River tributaries in the upper basin. For this purpose samples were taken from 10 collection points both on tributaries of right and left of the Bistrita River. Sampling was done in the spring and summer when fish species are active foraging and reproduction. In each collection point were recorded a number of physico-chemical water parameters (temperature, conductivity, pH, amount of O2 dissolved in water), habitat status data (collected surface, water depth, speed, altitude and GPS coordinates) and raw data on fish samples (number of specimens per species and biomass). Through data processing and calculation of indices ecological, biodiversity index could highlight the current status of fish fauna, which was comparable to that existing before the human impact after 1960. By determining the IBI was revealed that the fish communities of the Bistrita river tributaries, upstream from Lake Bicaz, were the least affected, except tributary Neagra Şarului. [ABSTRACT FROM AUTHOR]

This article represents a comparative study on the fish fauna from the Bistricioara River before the anthropic impact that took place after 1960 and the present fauna. The evaluation of the present status of the fish communities was performed in 4 collecting points on the main course of the river, by highlighting the abundance and absolute biomass, the numeric stock and gravimetrical stock at each collecting point. The ecological rang of every species in the structure of fish communities and the present zoning fish of the river were determined by calculating the ecological indices (constancy, dominance, ecological significance). The biodiversity index and the biological integrity index (IBI), which are the best indicators of the degree to which the fish fauna is affected by the anthropic impact, were also calculated. [ABSTRACT FROM AUTHOR]