This paper reports the results from mobile hydroacoustic surveys carried out between 1994 and 2018, to assess fish stocks in four impounded reaches, covering 19.8 km of River Thames, England. The data are complemented with electric fishing boom boat results, collected at same study reaches time periods. Hydroacoustic used inter-calibrated dual split-beam scientific echosounders, transducers bea...

To test the hypothesis that different species have similar responses to local and regional environmental constraints, we modelled the occurrences of 13 species using a data set of 413 undisturbed river reaches. Three environmental descriptors were considered at the local scale (river slope, river width, and upstream drainage area) and three at the regional scale (mean annual and mean range air ...

Intensive agriculture increasingly depends on chemical fertilizers and pesticides. Considerable amounts of these substances persist in the soil and, then, they reach surface water bodies, favouring eutrophication phenomenon or adversely affecting aquatic life. The existence and evolution of aquatic organisms decisively depend on the environment they live in water. This paper presents the result...

The ichthyological biodiversity of Polish lakes is poorly understood, even in not used for fishing and those under strict protection. With this mind, the aim study was to conduct a comprehensive survey several Wolin National Park (Poland). conducted Domysławskie Gardno anthropogenic Stara Kredownia reservoir. Each exercise using benthic nets over 12 h period. fish caught were measured weighed, ...

Statement of problem and methods employed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538 Pollen-tube growth in diploid plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pollen-tube growth in tetraploid plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tetraploid...

The chromosomal spread and karyotype of Bleak (Alburnus alburnus) from Anzali lagoon were identified using tissue squashing techniques with injection of 0.5ml/100g body weight of 0.01% Colchicines solution in fish fingerlings. Kidney and gill tissues were then extracted and chopped in KCl 0.045M for 20 min and fixed in Carnoy solution in 3 stages. The chromosomal spreads were stained in 20% Gim...