Spatial distribution of 0+ juvenile fish in differently modified lowland rivers
2006
Valova, Z.(Akademie Ved, Brno (Czech Republic). Ustav Biologie Obratlovcu) E-mail:[email protected] | Jurajda, P.(Akademie Ved, Brno (Czech Republic). Ustav Biologie Obratlovcu) E-mail:[email protected] | Janac, M.(Masarykova Univ., Brno (Czech Republic). Ustav Botaniky a Zoologie) E-mail:[email protected]
Juvenile 0+ fish communities in three adjacent stretches of two lowland rivers with different degrees of habitat modification were surveyed using electrofishing and evaluated as indicators of fish assemblage reproductive success and spatial distribution. The Czech stretch of the Morava River (69.4-92.8 r. km) was regulated by five weirs and completely separated from its floodplain. The Slovak stretch of the Morava River (33.5-69.4 r. km) and the stretch of the Dyje River (0-26.7 r. km) were not interrupted by weirs and their floodplain areas remained connected, though partially modified. The total number of 0+ fish species in all of the stretches recorded over three years was similar (22, 23 and 25 spp., resp.). The lowest value of the Shannon index of species diversity and the highest value of total relative density were documented in the Czech channelized stretch of the Morava River. Significant differences in species richness and relative density were documented among habitats.
显示更多 [+] 显示较少 [-]