Fish community structure along altitudinal gradients with relation to environmental variables in Ratuwa River of Eastern, Nepal

Studies on fish community structure along altitudinal gradients of rivers are lacking in Nepal. This study was carried out to gauge the fish diversity and composition along elevational gradient in Ratuwa River. The altitudinal gradient varies between 70 m to 1300 m. Fish samples were collected based on habitat representativeness from April (spring) 10-18, July (summer) 10-18, October (autumn) 10-18, 2020 and January (winter) 10-18, 2021. A total of 3447 specimens representing 4 orders, 14 families and 36 species were identified. Both fish diversity and abundance of studied ichthyofauna vary with altitudinal gradient. The present study affirmed that fish species of Opsarius bendelisis, Schistura multifasciatus, Garra annandalei, Brachydanio rerio, Aspidoparia morar, and Schistura scaturigina are the major contributory species (>1%) for both space and time spectrums. Fish community structure testing for both to space and time showed significant difference in spatial spectrum (R=0.72, P<0.01) but no significant difference in temporal variation (R=-0.034, P>0.05). The present results hinted that fish assemblage structure varied significantly from low to high elevations, altitude, water temperature, water velocity, dissolved oxygen and pH was found as major influential factors (P<0.05) for species distribution.

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

Borneo Journal of Resource Science and Technology ◽

10.33736/bjrst.2954.2021 ◽

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.

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Fish Community Structure and Environmental Correlates in Nepal’s Andhi Khola, Province No. 4, Syangja

Borneo Journal of Resource Science and Technology ◽

10.33736/bjrst.2510.2020 ◽

2020 ◽

Vol 10 (2) ◽

pp. 85-92

Author(s):

Jash hang Limbu ◽

BISHNU BHURTEL ◽

ASHIM ADHIKARI ◽

PUNAM GC ◽

MANIKA MAHARJAN ◽

...

Keyword(s):

Community Structure ◽

Spatial Variation ◽

Fish Assemblage ◽

Environmental Variables ◽

Fish Community ◽

Mesh Size ◽

Fish Diversity ◽

Fish Assemblage Structure ◽

Fish Community Structure ◽

Significant Difference

The study of correlations between fish diversity, environmental variables and fish habitat aspects at different space and time scales of Nepal’s rivers and streams is scanty. This study investigated spatial and temporal patterns of fish assemblage structure in Nepal’s Andhi Khola. The field survey was conducted from September 2018 to May 2019 and the fishes were sampled from three sites using a medium size cast net of mesh size ranging from 1.5 to 2.5 cm and gill net having 2-3 cm mesh size, 30-35 feet length and 3-4 feet width, with the help of local fisher man. A total of 907 individuals representing 15 species belonged to four orders, six families and 11 genera were recorded during the study time. To detect the feasible relationships between fish community structure and environmental variables, we executed a Canonical Correspondence Analysis (CCA). Based on similarity percentage (SIMPER) analysis, the major contributing species are Barilius barila (26.15%), Barilius vagra (20.48%), Mastacembelus armatus (8.04%), Puntius terio (6.64%), and Barilius bendelisis (5.94%). One-way analysis similarity (ANOSIM) tried out for both time and space variations in fish community structure suggested that there was a significant difference in temporal variation (R = 0.794, P = 0.0037) but no significant difference in spatial variation (R = -0.18, P = 0.923). Results from the Canonical Correspondence Analysis (CCA) vindicated that dissolved oxygen, free carbon-dioxide and total hardness were the principle physio-chemical correlates of fish assemblage structure. One-way analysis of similarity (ANOSIM) on the Non-metric Multidimensional Scaling (NMDS) showed significant difference between spring, autumn and winter season but no significant difference was found in spatial variation. The extraction and transportation of boulders, cobbles, pebbles, sand mining, haphazard ongoing road development and dam construction for the irrigation without fish ladders were found to be existing threats to the fish diversity of Andhi Khola. Keywords: Fish assemblage, multivariate analysis, rivers, spatio-temporal, streams

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

Borneo Journal of Resource Science and Technology ◽

10.33736/bjrst.2048.2020 ◽

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

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Characterization of Fish Community Structure And Development of An Estuarine Fish Community Index For Temporarily Closed Estuaries (TCEs) From India’s Western Coast

10.21203/rs.3.rs-402316/v1 ◽

2021 ◽

Author(s):

Kiranya Bella ◽

Pramila Sahadevan ◽

Sreekanth Giri Bhavan ◽

Appukuttannair Bijukumar ◽

Rajeev Raghavan

Keyword(s):

Community Structure ◽

Fish Community ◽

Estuarine Fish ◽

Feeding Guilds ◽

Western India ◽

Western Coast ◽

Anthropogenic Pressure ◽

Fish Assemblage Structure ◽

Ecological Quality ◽

Fish Community Structure

Abstract We present for the first-time data on fish assemblage structure for ten temporarily closed estuaries (TCEs) along the western coast of India. Fish community structure differed significantly between TCEs based on species presence/absence, estuarine use and feeding mode - differences based on estuarine surface area and geographical position (northern and southern locations). Marine migrant and freshwater stragglers dominated the ‘fish guilds’ in all estuaries, while piscivores and zoobenthivores were the major feeding guilds. We used the estuarine fish community index (EFCI) and a combined anthropogenic pressure index (CPI) to determine ecological quality of the TCEs. The application of functional guilds and EFCI could represent the use of TCEs by fish communities, and functional similarities existing between fish assemblages of these estuaries, despite considerable taxonomic, physical and chemical differences. Analysis of EFCI indicated that the ecological health of TCEs in south-western India ranges from “poor” to “good”. Through this index, we also established a significant relationship between CPI, EFCI and ecological quality in various TCEs (EFCI = A + (b X CPI)). Thus, the EFCI provides an integrated measure of the ecological status of fish community for TCEs along Indian coast.

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Environmental Determinants Influencing Fish Community Structure and Diversity in Two Distinct Seasons among Wetlands of Northern Region (Ghana)

International Journal of Ecology ◽

10.1155/2016/1598701 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Collins Ayine Nsor ◽

Edward Adzesiwor Obodai

Keyword(s):

Community Structure ◽

Fish Community ◽

Nitrate Nitrogen ◽

Grazing Intensity ◽

Distribution Patterns ◽

Northern Region ◽

Fish Distribution ◽

Fish Diversity ◽

Fish Community Structure ◽

Dca Ordination

Fish community structure was assessed in six wetlands using cast nets, to correlate with environmental variables with diversity and distribution patterns, from 2010 to 2012. A total of 2,239 individuals belonging to 44 species and 1,938 individuals belonging to 40 species were sampled in the dry and wet seasons. Mochokid and Mormyrid families dominated fish community and constituted 14.8%, respectively, followed by Alestids (12.9%) and Chlariids (11.1%). Rarer taxons were centropomids, channids, malapteruds, and oesteoglossids and represented 1.9%, respectively. Overall, CPUE per net did not vary significantly (Tukey HSD test,p=0.27) in the dry and wet seasons. Wuntori marsh consistently showed dominance in mean monthly CPUE per net (dry =115±4.5; wet =107±7.7seasons), while Bunglung constructed wetland was the least recorded (dry =56.5±6.2; wet =58.3±4.1seasons). Fish diversity and richness differed significantly (F=0.11,p=0.03) among seasons. Environmental disturbances were season-specific and did not differ significantly (F=0.16,df=14,p=0.97) among sites. A DCA ordination explained 69% variability in fish distribution patterns, while PCA showed that 81.8% of nitrate-nitrogen, phosphate, and grazing intensity on axis 1 and conductivity, temperature, and turbidity on axis 2 influenced fish community structure. Wetland conservation must be promoted to sustain fish abundance and overall ecosystem stability.

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Marine Fishes of Caño Island Biological Reserve: Reef fish community structure and updated list for the coastal fish.

Revista de Biología Tropical ◽

10.15517/rbt.v63i1.23098 ◽

2016 ◽

pp. 97-116

Author(s):

Eva Salas ◽

Cristina Sánchez-Godínez ◽

Andrea Montero-Cordero

Keyword(s):

Community Structure ◽

Reef Fish ◽

Fish Species ◽

Fish Community ◽

Coral Cover ◽

Fish Diversity ◽

Fish Community Structure ◽

Coastal Fish ◽

Reef Fish Community ◽

Biological Reserve

Biogeographically, the Caño Island Biological Reserve (CIBR) is of strategic importance, since it is located in the center of the Panamic Province (Costa Rica and Panama), characterized by a peak in fish species richness within the Tropical Eastern Pacific (TEP). Despite its importance, fish community structure around the island has not been deeply studied, and coastal fish diversity records need to be updated. The aims of the study were: 1) to describe the community structure of the reef fish community of CIBR and 2) to update the list of the coastal fish species recorded until today. For the first objective, 50 stationary fish counts were conducted at 10 locations around Caño Island, in which 79 species, belonging to 32 families, were registered. The most abundant family was Pomacentridae, and the most abundant species was Chromis atrilobata. Planktivorous and carnivorous fish were the most abundant. The existence of a relationship between coral cover and the presence of herbivorous grazers was highlighted within the analysis. Additionally, species composition was compared by site and this revealed that “El Barco” has an abundant presence of snappers. For the second objective, published fish species records were collected for the CIBR and 35 new records were added, for a total of 212 coastal fish species, which represents approximately 17% of coastal fish diversity in the TEP. This work presents a baseline for fish monitoring and mangement measures in this marine protected area.

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Fish community structure, habitat complexity, and soundscape characteristics of patch reefs in a tropical, back-reef system

Marine Ecology Progress Series ◽

10.3354/meps12829 ◽

2019 ◽

Vol 609 ◽

pp. 33-48 ◽

Cited By ~ 7

Author(s):

RP Lyon ◽

DB Eggleston ◽

DR Bohnenstiehl ◽

CA Layman ◽

SW Ricci ◽

...

Keyword(s):

Community Structure ◽

Habitat Complexity ◽

Fish Community ◽

Back Reef ◽

Fish Community Structure ◽

Patch Reefs ◽

Reef System

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Dissolved oxygen and temperature best predict deep-sea fish community structure in the Gulf of California with climate change implications

Marine Ecology Progress Series ◽

10.3354/meps13240 ◽

2020 ◽

Vol 637 ◽

pp. 159-180

Author(s):

ND Gallo ◽

M Beckwith ◽

CL Wei ◽

LA Levin ◽

L Kuhnz ◽

...

Keyword(s):

Climate Change ◽

Community Structure ◽

Community Composition ◽

Environmental Conditions ◽

Deep Sea ◽

Gulf Of California ◽

Fish Community ◽

Demersal Fish ◽

Fish Community Structure ◽

Explained Variance

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.

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