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1

Fish diversity in different habitats in the streams of lower middle Western Himalayas

100%
Singh J. M., Krishan Tandon K., Kumar Tyor A., Kumar Rawal Y.
Polish Journal of Ecology
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2002
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tom 50
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nr 1
The present study was carried out in the lower middle Western Himalayan streams in the Indian state of Himachal Pradesh of the three river basins namely the Ghaggar, the Sutlej and the Yamuna. The main aim was to study fish assemblage structure/composition, fish diversity in different habitats and the habitat preference of the fishes. The different habitats like pools, riffles, runs and rapids were sampled over a 2 km stretch at all the sites with the help of cast net of 1 cm mesh size having a diameter of I-2 meter on a fixed day every month between mid morning and late afternoon. All the sites when broadly delineated at level-I fall into type - B except site II that is an F - type stream. A total of 23 species belonging to four orders were recorded of which the cyprinids were the most dominant group. According to Shannon-Weaver diversity index, the pool habitat supports greater diversity (H' = 0.72-0.97). Runs (H' = 0.24-0.87) and riffles (H' = 0.22-0.81) have diversity very near to each other at all the sites whereas rapids have significantly lower fish diversity (H' = 0.00-0.58). The pool is the preferred habitat for most of the cyprinid fishes recorded in the present study especially the minnows.
2

Impact of engineering on fish diversity and community structure in the Gwda River basin, North Poland

84%
Penczak T., Gomes L. C.
Polskie Archiwum Hydrobiologii
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2000
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tom 47
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nr 1
3

The alpha and beta diversities in the fish assemblages of the Promissao Reservoir [SP-Brazil]: scales, complexities and ecotone heterogeneity

84%
Amaral B. D., Petrere M.,Jr.
International Journal of Ecohydrology and Hydrobiology
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2001
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tom 01
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nr 1-2
This paper characterizes the fish community and its interaction with different ecotones within the reservoir. The transformation of a river basin into a cascade of reservoirs produces new ecotones which interact differentially with the spatial\temporal distribution of fish species, their diversity, trophic structures, etc. So the variations of the fish fauna are described to understand better the practices of conservation and management of these reservoirs. The concepts of α and β diversities are related to the concepts of scale, complexity and heterogeneity. Scale comprises the longitudinal, horizontal and vertical variation which are represented by the complexity and heterogeneity of the fish community in the reservoir. Complexity exhibits the variations in ecological data interpretation according to environmental variability or type of data. Heterogeneity describes the variations in species assemblages related to different ecotones. The sampled ecotones were: forest, agricultural land, beaches and mouths of tributaries, each with three replications. Cluster analysis of the environmental factors revealed two distinct ecotonal groups: i) forest, agricultural land and beach; and ii) the tributary mouths. The ANOVAS indicated two possible patterns of α diversity: 1- heterogeneity within the fish community represented by number of species, and differences between the ecotones; 2- homogeneity within the fish community described by the biomass of different species. The β diversities were congruent with environmental factors giving evidence of the horizontal scale within the reservoir. The forest ecotones revealed higher heterogeneity in the coexistence of fish species than did the with other ecotones. This fact is explained by the littoral areas close to the forest fragments with more refuge, increasing the environmental structural diversity. So it reinforces the importance of the forest as refuge enhancing fish dispersal. The fish assemblages related to agricultural land and beaches were more similar. Agricultural land and pasture ware the dominant ecotone on the reservoir margins.
4

The state of inland fisheries in Ethiopia: a synopsis with updated estimates of potential yield

67%
Tesfaye G., Wolff M.
International Journal of Ecohydrology and Hydrobiology
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2014
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tom 14
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nr 3
5

Ecotones and hydrology: key conditions for fish in large rivers

67%
Schiemer F., Keckeis H., Flore L.
International Journal of Ecohydrology and Hydrobiology
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2001
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tom 01
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nr 1-2
6

The importance of floodplains for the dynamics of fish communities of the upper river Parana

67%
Agostinho A. A., Gomes L. C., Zalewski M.
International Journal of Ecohydrology and Hydrobiology
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2001
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tom 01
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nr 1-2
The last free stretch of the River Paraná inside of Brazilian territory, about 230 km of the former 810 km, runs in a wide floodplain, which flood regime is controlled in part by upstream dams. Aim to evaluate the impacts of different levels of hydrological control on the regional fish diversity, nutritional condition, trophic categories proportion, reproduction and young abundance monthly sampling were carried, between 1986 and 1993, during three annual periods with different flood duration and intensity. Lagoons, secondary channels and river channel was sampled with gillnet of different mesh size and standardized effort. Diversity, evenness indexes and number of species increased with the occurrence of floods. The trophic category proportions varied among the periods considered, with a decrease in piscivores participation and an increase of iliophages, herbivores and insectivores (terrestrial) participation in big flood years. The tendencies for piscivores guild were not uniform to every pecies. The variations on the nutritional condition reveal that the absence of flooding has a negative effect on greater migratory species and positive on sedentary ones. The young abundance shows, however, that fail in the flooding has a strong negative impact on de recruitment of all the reproductive strategies. It’s stressed the operational procedures in the upstream dams and the maintenance of the floodplain integrity is essential to preserve the regional biodiversity, fisheries and particularly the greater migratory fishes population.
7

Populations of fish in relation to riparian ecotone development in the Narew River catchment

67%
Penczak T.
International Journal of Ecohydrology and Hydrobiology
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2001
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tom 01
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nr 1-2
Number of species (S), density (N) and standing crop (B) were investigated in 331 sites in the catchment of the Narew River, the biggest tributary of the Vistula, against 4 categories of riparian ecotone intensity in various-width rivers. All populations were first analyzed together, then within the scope of three most abundant ecological spawning groups. The image obtained is to some extent blurred by anthropogenic alterations as well as humancreated ecotones, yet it is evident that a total lack of bankside trees had a negative impact on the values of S, N and B of all investigated populations. Exceptions are only small streams of the Bialostocka Upland, where at a high percentage of submerged vegetation and occasionally stony bottom (washed away moraine bars), the lack of riparian trees did not cause any decrease in any of the three populational parameters. The uninterrupted compact forestation of the banks was positively correlated with S, N and B only in the lower Narew River, where the river bed was more than 100 m wide, hence where the access of light was not already limited. For lithophilous species a river's naturalness was a more important factor conditioning their abundance than the development of riparian ecotones. Indifferent species displayed a high, positive dependence on the development of ecotones, while phytophils (whose development is vegetation-dependent) formed the most qualitatively and quantitatively abundant populations at a weak, and in some rivers, even medium forestation of the banks.
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