scholarly journals Relationships between environmental conditions and fish assemblages in the Lohore River of Dailekh, Western Nepal

Our Nature ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 18-26
Author(s):  
Sushil Shrestha ◽  
Dipak Rajbanshi ◽  
Dil Kumar Limbu ◽  
Jash Hang Limbu
Keyword(s):  
Fish Species ◽  
Environmental Conditions ◽  
Fish Assemblages ◽  
Mesh Size ◽  
Influential Factors ◽  
Fish Diversity ◽  
Fish Community Structure ◽  
Aquatic Communities ◽  
Riverine Ecosystems ◽  
Fish Samples

The Lohore River is one of the important riverine ecosystems of Dailekh which support diverse aquatic communities. The present study was carried out to assess the fish diversity status with relation to environmental conditions in both to space and time. The survey was conducted at three different sampling stations in three different seasons. For the fish sampling, two cast nets of different mesh sizes were used, one having large mesh size of 2 cm, 6 m diameter and 6 kg weight and another having mesh size of 0.5 cm, 3 m diameter and 2 kg weight. Moreover, drag net and gill net were also used to collect the fish samples. A total of 11 fish species belonging to 2 orders, 3 families and 7 genera. Results from the similarity percentage analysis (SIMPER) suggested that fish species of Puntius gelius, Schizothorax plagiostomus, Tor chelynoides and Schistura sovana were major contributing species each contribute more than 9%. An analysis of similarity (ANOSIM) pointed that fish community structure in the Lohore River differ in spatial scale (p<0.01) but not in temporal scale (P>0.01). Water temperature, dissolved oxygen and water velocity was found as influential factors for fish species distribution.

scholarly journals Fish Community Assemblages of Mining-Impacted Freshwaters at Prestea, Ghana

2018 ◽  
pp. 1-9
Author(s):  
Osei O. Antobre ◽  
Nat Owusu-Prempeh ◽  
Michael J. Twumasi-Ankrah
Keyword(s):  
Fish Community ◽  
Average Length ◽  
Mesh Size ◽  
Fish Diversity ◽  
Freshwater Ecosystem ◽  
Fish Community Structure ◽  
Average Width ◽  
H Index ◽  
Community Assemblage ◽  
Fish Samples

The study evaluated the fish community assemblage in the sections of the Subri river, the Ankobra river, and the “galamsey” pond within the Prestea community as impacted by alluvial mining activities. Gill nets of length 10 m and mesh size 1.27 cm were used to trap fish of average length 25.25 cm whilst cane baskets were used to trap fish of average width 10.40 cm using the catch and recapture method. All the 46 fish samples identified belong to 10 genera and 5 families. The Chichlidae was the dominant family, accounting for 60% of the total families observed. With an H’ index of 1.57 the Subri river had the most fish diversity in comparison with the Ankobra river and the “galamsey” pond, which had 1.21 and 0.71, respectively. Similarly, the Subri river had a more complex fish community structure than the Ankobra and “galamsey” pond. The dominant species, Oreochromis niloticus, has not yet been evaluated by the IUCN, but the least dominated Brienomyrus brachyistus could be regarded as “least concern”. Notwithstanding, these fish are essential for food by the local communities. There is a possibility that the alluvial mining might have influenced the complexities of fish species communities. Thus conservation efforts must be promoted to sustain fish communities and overall freshwater ecosystem health.

scholarly journals Environmental Variables and Fisheries Diversity of the Nuwa River, Panchthar, Nepal

2020 ◽  
Vol 13 (13) ◽  
pp. 69-74
Author(s):  
Jash Hang Limbu ◽  
Archana Prasad
Keyword(s):  
Dissolved Oxygen ◽  
Fish Species ◽  
Environmental Variables ◽  
Diversity Index ◽  
Environmental Parameters ◽  
Influential Factors ◽  
Water Volume ◽  
Fish Diversity ◽  
Fish Assemblage Structure ◽  
Fish Samples

The fish samples were collected from October 2017 to June 2018 in Nuwa River from four sampling stations by using cast net, bamboo fish trap and mosquito nets. Environmental parameters: water temperature, dissolved Oxygen (DO), CO2, pH, hardness and water velocity were analyzed during each field visit. Eight fish species were collected in present study. The most copious species were Schizothorax plagiostomus, and Schistura multifaciatus. Shannon-Weiner fish diversity index and species richness recorded were highest at station I and lowest at station III, similarly, evenness index was highest at station I and lowest at station III. The water volume, water depth, and the availability of substrates were found to be major influential factors for the weight and length of the fishes. The redundancy analysis (RDA) portrayed that environmental variables like dissolved oxygen, free- carbon dioxide, and pH were found to be pivotal variables to shape the fish assemblage structure of Nuwa River. The cluster analysis delineated that similarity between fish species subsided as the distance of sites turgid.

scholarly journals Fish Diversity and Water Quality Parameters of Mechi River, Jhapa, Province No. 1, Nepal

2021 ◽  
Vol 11 (1) ◽  
pp. 24-34
Author(s):  
ASHIM ADHIKARI ◽  
JASH HANG LIMBU ◽  
SOMIKA PATHAK
Keyword(s):  
Fish Community ◽  
Mesh Size ◽  
Quality Parameters ◽  
Fish Diversity ◽  
Fish Assemblage Structure ◽  
Fish Community Structure ◽  
Brachydanio Rerio ◽  
Significant Difference ◽  
Fish Samples ◽  
Spatio Temporal

Species diversity is widely recognised as an important trait of functioning and resilient ecosystem. Spatio-temporal patterns of fish community structure in the Mechi River was studied based on stratified random survey, conducted between September 2018 and April 2019. The survey was conducted at three different sampling stations in three different seasons. For the fish sampling, two cast nets of different sizes were used, one having large mesh size of 0.5 cm, 3 m diameter and 2 kg weight and another having mesh size of 2 cm, 6 m diameter and 6 kg weight. In addition, drag net and gill net were also used to collect the fish samples. A total of 1,772 fishes belonging to 4 orders, 8 families, 16 genera and 33 species were documented. The results from the similarity percentage analysis indicated that, the species Schistura devdevi, Brachydanio rerio, Puntius sophore, Barilius barila, Schistura beveani and Puntius terio were the most copious fish species recorded from the Mechi River. One-way analysis of similarity testing for space and time variations in fish community indicated that there was a significant difference in space (R = 0.66, p<0.01) but no significant difference in time (R = -0.0123, p>0.433). The Canonical Correspondence Analysis hinted that dissolved oxygen, water velocity and pH have shown to influence the fish assemblage structure in Mechi River.

Estuarine characteristics, water quality and heavy metal contamination as determinants of fish species composition in intermittently open estuaries

2017 ◽  
Vol 68 (5) ◽  
pp. 941 ◽  
Author(s):  
K. O'Mara ◽  
A. Miskiewicz ◽  
M. Y. L. Wong
Keyword(s):  
Water Quality ◽  
Species Composition ◽  
Fish Species ◽  
Metal Contamination ◽  
Fish Assemblages ◽  
Anthropogenic Activities ◽  
Estuarine Fish ◽  
Fish Diversity ◽  
Eastern Australia ◽  
Fish Species Composition

Estuaries are critical aquatic environments that are used by many fish during their life cycle. However, estuaries often suffer from poor water quality as a result of anthropogenic activities. Fish diversity studies in estuaries are common, although few have examined whether correlations exist between water quality, metal contamination and fish assemblages. In the present study we investigated the effect of abiotic conditions, heavy metals and estuary characteristics on the abundance, diversity and composition of fish in four intermittently open estuaries along the Illawarra coast of south-eastern Australia. The heterogeneity of environmental conditions was reflected in the fish assemblages in each estuary. Environmental variables predicted fish species composition, and estuaries in particularly poor condition contained few species (estuarine residents) in high abundance, indicating their ability to acclimatise and survive in conditions that are hostile to other species. Overall, these findings demonstrate that estuarine fish assemblages may be useful indicators of estuary condition and reveal the importance of managing anthropogenic activities in the surrounding catchment to improve water quality so that biodiversity of fish can be restored in these estuarine environments.

scholarly journals Patterns of Fish Assemblage, Growth, and Diet Composition in a Tropical River between Two Cascading Hydropower Dams

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lee Nyanti ◽  
Chen-Lin Soo ◽  
Afina-Yian Chundi ◽  
Elsa-Cordelia-Durie Lambat ◽  
Alvinna Tram ◽  
...  
Keyword(s):  
Fish Species ◽  
Diet Composition ◽  
Fish Assemblages ◽  
Condition Factor ◽  
Dry Season ◽  
Growth Patterns ◽  
Native Fish ◽  
Wet Season ◽  
Fish Samples ◽  
The Impact

Construction of cascade dams has been shown to have impacts on fish assemblages and biodiversity. Yet, there is no literature on fish assemblages in the Murum River that connects the cascading Bakun and Murum dams in Sarawak, Malaysia. Hence, study on this modified ecosystem is necessitated to better understand the effects of the cascade dam construction on fish fauna. For this, fish samples were caught at five stations located along the river during both dry and wet seasons. Environmental parameters were taken concurrently with fish sampling. Length-weight relationship, condition factors, and diet composition of selected fish species in the river were also determined. The present study demonstrated that there are indications of the impact of cascading dams on the formation of a complex ecosystem in the Murum River, that is, changing from the shallow downstream of the Murum Dam to the deep transitional and inundated zone of the Bakun reservoir. The transitional zone in the Murum River exhibited the lowest fish species diversity, richness, and evenness during the dry season due to low pH and DO coupled with high turbidity. The biological indices improved when the water quality improved during the wet season. On the contrary, the diversity and evenness indices at the inundated tributary station decreased remarkably during the wet season, likely due to the migration of fish during the onset of the rainy season. This study showed that Barbonymus schwanenfeldii has a wider feeding habit which contributes to its higher distribution and abundance in the Murum River. The growth patterns of B. schwanenfeldii, Cyclocheilichthys apogon, Hampala macrolepidota, Lobocheilos ovalis, and Osteochilus enneaporos were better during wet than dry season. Overall, the condition factor of all native fish species in the Murum River was in poor to fair condition, whereas the exotic species, Oreochromis mossambicus, exhibited excellent condition (K value > 2) for both seasons. The increase in the number of O. mossambicus coupled with its high condition factor indicates biological intrusion and a potential threat to the native fish species in the Murum River. Continuous monitoring is essential to detect in-time risk issues associated with environmental degradation and biological invasion in this regulated and inundated river ecosystem.

scholarly journals Spatial and Temporal Variation of Fish Assemblages in Seti Gandaki River, Tanahu, Nepal

2020 ◽  
Vol 10 (2) ◽  
pp. 93-104
Author(s):  
ARCHANA PRASAD ◽  
ANJANA SHRESTHA ◽  
JASH HANG LIMBU ◽  
DEEP SWAR
Keyword(s):  
Community Structure ◽  
Fish Community ◽  
Fish Assemblages ◽  
Mesh Size ◽  
Spatial And Temporal Variation ◽  
Total Hardness ◽  
Medium Size ◽  
Fish Community Structure ◽  
Space And Time ◽  
Significant Difference

The space and time variations of the fish community structure in hill streams of Nepal are poorly understood. This research aims at studying the space and time variation of fish community structure in the Seti Gandaki River, Tanahu, Nepal. The field survey was conducted from July 2017 to June 2018 and the fishes were sampled from six sites using a medium size cast net of mesh size ranging from 3 mm to 6 mm mesh size, 25-33 feet length and 3.5-5 feet width, with the help of local fisher man. A total of 1,440 individuals were caught representing 46 species belonging to three order, nine families and 23 genera. The analysis of similarity (ANOSIM) showed significant difference in space (R = 0.824, P = 0.001) but not in time (R = 0.135, P = 0.021). On the basis of similarity percentage (SIMPER) analysis, 85.43% similarity was found among the seasons and major contributing species were Barilius bendelisis (8.44%) followed by B. vagra (7.79%), Tor putitora (7.27%), Garra gotyla (7%), Acanthocobotis botia (6.7%), Neolissochilus hexagonolepis (6.64%), Barilius shacra (6%), B. barila (4.5%) and Opsarius barna (4.37%). On the other hand, 85.24% similarity was found among the sites and major contributing species were B. bendelisis (8.8%) followed by B. vagra (7.6%), G. gotyla (7.27%), T. putitora (7.17%), A. botia (6.97%), N. hexagonolepis (6.7%), B. shacra (6.34%), B. barila (4.7%) and O. barna (4.39%). Results from the Canonical Correspondence Analysis indicated that the environmental variables, such as pH, total hardness, alkalinity, dissolved oxygen and water temperature have shown to determine the fish community structure of Seti Gandaki River. Keywords: Fish diversity, freshwater, habitat, spatio-temporal, stream

scholarly journals Evaluating the influence of environmental variables on fish assemblages along Tropical Andes: considerations from ecology to conservation

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Rafael Miranda ◽  
Blanca Rios-Touma ◽  
Ana Falconí-López ◽  
Andrea Pino-del-Carpio ◽  
Sergio Gaspar ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Abiotic Factors ◽  
Regional Scale ◽  
Conservation Strategies ◽  
Fish Diversity ◽  
Fish Community Structure ◽  
Tropical Andes ◽  
Freshwater Biodiversity ◽  
Elevation Gradients ◽  
Ecological Features

AbstractThe lack of knowledge about freshwater biodiversity in remote areas like montane Andean rivers is noticeable and hinder the development of efficient conservation plans for aquatic ecosystems. Habitat requirements of tropical Andean fishes have been poorly analysed, despite the relevance of these ecological features on the fish conservation strategies. The present study aimed to examine fish assemblages along the altitudinal gradient in tropical Andean rivers and their relationship to habitat features to detect the most relevant abiotic factors and their implication on conservation. This study was conducted on a regional scale, along six basins located in tropical Andes (500 to 2,692 m a.s.l.). We studied fish diversity and distribution and their habitats along these elevation gradients. We found 6,320 specimens from 53 genera. Our analysis for the six most common and widely distributed genera (Astroblepus, Brycon, Bryconamericus, Chaetostoma, Pimelodella and Trichomycterus) underlines the relevance of hydromorphological variables on fish community structure in the Andean montane rivers, whereas human alterations seem to be less significant. These findings could be useful for current management and conservation strategies considering present threats over tropical montane rivers.

scholarly journals Long-term study of reservoir cascade in south-eastern Brazil reveals spatio-temporal gradient in fish assemblages

2018 ◽  
Vol 69 (12) ◽  
pp. 1983 ◽  
Author(s):  
Raquel Coelho Loures ◽  
Paulo Santos Pompeu
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Fish Assemblage ◽  
Native Species ◽  
Fish Assemblages ◽  
Native Fish ◽  
Fish Diversity ◽  
Fish Assemblage Structure ◽  
Long Term Study

In reservoir cascades, effects on fish assemblages are expected to strengthen over time and transfer from one reservoir to an adjacent one. To test this, fish-assemblage data from 23 years of monitoring in the Araguari reservoir cascade system, upper Paraná River basin, were analysed. The results showed a clear reduction in richness of native and migratory fish species and an increase of non-native species, following reservoir formation. Migratory species richness was higher in reservoirs that presented habitats similar to lotic stretches or tributaries upstream of the impounded area. There was a clear tendency for native species to decline and non-native fish species to increase, in a downstream direction. Fish assemblages became increasingly dissimilar as reservoirs became more distant from each other (longitudinal gradient) and were dominated by small and medium-sized species. Alongside longitudinal position, reservoir area, age and the presence of herbivorous non-native fish were found to be important predictors of variation in fish-assemblage structure. Results from the present study help clarify the potential accumulated impacts of reservoir cascades on fish diversity, which must be carefully considered in river-basin inventories for hydropower plants, and reinforce the importance of long-term monitoring, considering longitudinal and lateral dimensions of the basin.

scholarly journals Fish and macrozoobenthos in the Vlára stream drainage area (Bílé Karpaty Mountains)

2008 ◽  
Vol 52 (No. 7) ◽  
pp. 214-225 ◽  
Author(s):  
P. Jurajda ◽  
Z. Adámek ◽  
M. Janáč ◽  
Z. Valová
Keyword(s):  
Salmo Trutta ◽  
Fish Assemblages ◽  
Fish Fauna ◽  
Mesh Size ◽  
Drainage Area ◽  
Aquatic Communities ◽  
Similar Frequency ◽  
Gammarus Fossarum ◽  
A Minor

Fish fauna and macrozoobenthos were surveyed at 51 and 32 sampling sites, respectively, in mountain and submountain streams of the Vlara stream drainage area in the Bílé Karpaty Mountains. The aim of the study was to bring wide knowledge of their aquatic communities with their indicative value of the ecological quality of particular sites. Fish were sampled by electrofishing and macrozoobenthos was collected by kick-sampling using a bottom net (mesh size 500 &mu;m) at the majority of the respective sites. In total, 15 fish species were registered in all profiles. At four headwater sites no fish were recorded at all. Brown trout (<i>Salmo trutta</i> m. <i>fario</i>) and stone loach (<i>Barbatula barbatula</i>) were the most frequent species at the sites under study (73% and 67%, respectively). A similar frequency (41%) was documented for chub (<i>Leuciscus cephalus</i>), gudgeon (<i>Gobio gobio</i>) and minnow (<i>Phoxinus phoxinus</i>). The species richness increased downstream in the mainstream of the Vlára stream with the maximum of 10 species found at the lowest study site. Qualitative data on fish assemblages did not fully correspond with the environmental stress. On the other hand, macrozoobenthos indicated a minor decrease in water quality downstream of small villages and farms. Larvae of dipterans (Chironomidae and Simuliidae in particular) and mayflies (Ephemeroptera) dominated among the temporary water macroinvertebrates while numerous populations of <i>Gammarus fossarum</i> (Amphipoda) and in some cases also of <i>Asellus aquaticus</i> (Isopoda) were recorded as permanent inhabitants of clean and polluted stretches, respectively.

scholarly journals Population Aspects of Fishes in Geba and Sor Rivers, White Nile System in Ethiopia, East Africa

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Simagegnew Melaku ◽  
Abebe Getahun ◽  
Mulugeta Wakjira
Keyword(s):  
Sex Ratio ◽  
Fish Species ◽  
Condition Factor ◽  
Diversity Index ◽  
Abundant Species ◽  
Fish Diversity ◽  
Reproductive Behaviors ◽  
Fish Samples ◽  
The Mean ◽  
White Nile

This study was carried out to assess the diversity, condition factor, length-weight relationship, and sex ratio of fishes in Geba and Sor Rivers located in Baro-Akobo Basin, White Nile system within Ethiopia. Fish samples were collected in one wet and one dry season. The length-weight relationships were fitted using power equation for the most abundant species. A total of 348 fish specimens were collected using gillnets and hooks. These were identified into eight species and one Garra sp. representing seven genera and four families. Family Cyprinidae was the most dominant with six species (66.7%). Labeobarbus intermedius, Labeobarbus nedgia, and Labeo cylindricus were the most abundant fish species, respectively, with 60.72%, 16.83%, and 14.66% index of relative importance (IRI). The diversity index was higher for Geba River (H′ = 1.50) than for Sor River (H′ = 1.10). All the three most abundant species had negative allometric growth. Seasonal variations in the mean Fulton condition factor (FCF) were statistically significant for L. cylindricus (p<0.05). There was variation in the sex ratio with the females dominating in all the three most abundant species. Further investigation into the fish diversity, food, feeding, and reproductive behaviors of fish species especially in the tributaries of these rivers and their socioeconomic aspects is recommended.

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