Fish community structure of the middle course of the Bečva River

Abstract

Fish communities of the Bečva River were studied in summer and autumn 2000 and 2001. Electric fishing gear (Honda EX 1000, DC 230 V, 0.75-0.9 kW) was used for sampling. Four sampling sites (Grymov 19.6 r. km, Rybáře 35.8 r. km, Hustopeče 50.7 and Choryně 54.7 r. km) were selected. Total of 23 fish species representing 5 families were determined. The family Cyprinidae with 15 species was dominant while Salmonidae, Balitoridae, Percidae and Gadidae were the other recorded families. Species diversity ranged from 9 at Hustopeče to 20 at Grymov localities. The lowest biomass and abundance were observed at Hustopeče locality (28.93 kg/ha and 336 fishes/ha) and the highest at Choryně locality (612.90 kg/ha and 7 367 fishes/ha). Barbus barbus, Chondrostoma nasus and Leuciscus cephalus contributed 87.73-97.55% and 60.5%-87% to total biomass and abundance in different samplings, respectively. The Chondrostoma nasus population was dominated by fish of total length over 300 mm. We believe that river fragmentation, trapping and blockade of fish are the main reasons for this irregular distribution. Index of diversity ranged from 0.811 to 2.05 and equitability index from 0.449 to 0.821. Physical and chemical parameters were also measured, pH value ranged from 7.8 to 9.8, DO (7.62-12.15 mg/l), conductivity (450-639 µS/cm), N-NH 4 (0.65-2.39 mg/l), P-PO 4 (0.12-0.68 mg/l) and alkalinity (2.55 to 3.40 mg/l).

Density and biomass of fish populations in kirmir stream of Sakarya river, Turkey

“…The comparative analyses of fish density and biomass in streams studied by Ölmez (1992), Korkmaz & Atay (1997), Dikov & Zikov (2004), Namin & Spurny (2004), Vlach et al (2005), Korkmaz (2005) for 13 species in Úpoř Brook were higher than our results. These differences can be said to be caused by the fact that selective fishing or catch efficiency.…”

“…Where A is area of sampling sites (in ha) (Bohlin et al 1989). Number of fish species of Kirmir Steam is fewer than the most studies such as Guadina Basin (Portugal, 16 species) (Pires et al 1999), Veleka River (Bulgaria, 16 species) (Dikov & Zıkov 2004), Bečva River (Czech Republic, 23 species) (Namin & Spurny 2004), Úpoř Brook (Czech Republic, 13 species) (Vlach et al 2005); more than Sakarya Basin (Turkey, 4 species) (Ölmez 1992), Sugul Brook (Turkey, 4 species) (Korkmaz & Atay 1997), Hatilla Brook (Turkey, 2 species) (Korkmaz et al 1998) and Kadıncık Brook (Turkey, 2 species) (Korkmaz 2005). In freshwater, comparisons of the difference between the numbers of species are difficult.…”

Freshwater fish biodiversity in the River Ganga (India): changing pattern, threats and conservation perspectives

“…Overall, the fish community indices across the river was low (Table 2) when compared to larger rivers in the world. Based on Namin and Spurny (2004) category, the low Shannon diversity index (H = 2.85) indicates that the river Ganges is moderately impacted. The low evenness index (0.27) across all the stretches may be due to phenomenon that river Ganges covers a great variation of latitude and altitudes (10,000 ft), which mean that the some species are restricted to particular geographical area and do not appear in other areas especially, the cold water species in upper stretch.…”

Ichthyofaunal Survey in Selected Freshwater Habitats in Camarines Sur, Philippines

“…Our computed H', however, was comparatively lower than any of those measured in the streams in Sorsogon (richness = 16, mean H' = 2.41), and Pansipit River in Batangas (richness = 21, mean H'= 3.05) (Corpuz et al 2010(Corpuz et al , 2011. According to Namin and Spurny's (2004) method of categorizing the estimated H' values based on the impact of anthropogenic disturbances, the computed H' in Bato's lakes and streams are considered moderately impacted. The species distribution exhibited low dominance and relatively high evenness signifying that the allocation of niche space is distributed equitably for dominant and non-dominant fish species (Begon et al1996), albeit a very high dominance of a single species was determined in Bagacay.…”