Lake Rara Research Articles

Local Government’s Effort for the Conservation of Rara Lake, Karnali, Nepal

Rara, the largest Lake in Nepal, has enormous potential for the total development of the region. It is located in the Mugu district of Karnali region at an elevation of 2990 m. However, the federal and provincial governments’ current plans and strategies are ineffective in protecting and promoting the Lake from both present and future viewpoints. Participation theory was the most commonly used idea in this study. In order to provide baseline data for the formulation of efficient strategies and policies for the sustainable development of the Lake and its environs, this study intends to investigate the role of Rara Lake in the socioeconomic development of the Province. The study uses a questionnaire survey with a variety of stakeholders, including local people, business owners, and members of local political parties. The outcome shows that, in the current situation, the Lake’s promotion and conservation are solely dependent upon national park policies, as neither the provincial nor municipal governments have taken any direct action to further these goals. The results show that for the long-term conservation and promotion of the Lake, local inhabitants, and local government must adopt an integrated approach. The Lake would have a significant impact on the Province’s and the nation’s overall development if this strategy had been successfully applied.

Ornithological Survey and Habitat Quality Study in Rara Lake, Nepal

Rara Lake is situated in mountain ecoregion serves as staging post for the long range migratory wetland birds. The lake ambient forest bears the restricted range and globally threatened species. Bird species in the park is reported as unrecorded while habitat quality of the Rara lake providing the refuge to migratory and native bird species is degrading. Adherence to the statement, study was carried to gather the descriptive and evidence- based information on bird species and habitat quality was carried to understand bird status, its activities and habitat quality. Bird count was carried through line transect. Bird behavior, activities, stay-length and lake riparian habitat was noted through direct sighting. Water quality was assessed following American Public Health Association water quality test guideline. The study counted a total of 2415 bird individuals from listed 104 species including 16 migratory Waterfowls, 13 wetland dependent birds and 75 forest birds. The observed bird species ranged from frequent to very uncommon winter visitor stop in Rara lake primarily for fueling during migration. Observed that most of time birds were foraging at shallow water but merely outside lakes. Discarded trashes in the roosting and foraging site and around the lake circuit trail triggering threats to waterfowls and aquatic biodiversity while higher human movement through the trail causing disturbance to waterfowl. Water quality assessment revealed that Phosphorous and ammonia concentration in Rara lake were higher than the recommended level for freshwater/aquatic ecosystem connoting lake in the process of eutrophication and acute ammonia toxicity affecting aquatic life. Regular assessment of water quality is required preventing aquatic life from detrimental effects. Continuous monitoring to study their migratory behavior and habitat qualities would be essential to inform conservation policies also linking with eco-tourism activities.

Spatio-temporal hydrochemistry of two selected Ramsar sites (Rara and Ghodaghodi) of west Nepal

The present study was conducted in two Ramsar sites, Lake Rara and Lake Ghodaghodi, of the western Nepal covering pre-monsoon and post-monsoon seasons of 2019 to find out the dynamics of the hydrochemistry. A total of 11 major ions (Na+, K+, Ca2+, Mg2+, NH4+, F−, Cl−, SO42−, NO3−, NO2−, HCO3−) along with six on-site parameters (temperature, pH, electrical conductivity, total dissolved solids, dissolved oxygen, and turbidity) were sampled in replicates from 18 sites in Lake Rara and 13 sites in Lake Ghodaghodi. Major ions were analyzed using ion chromatography including field and procedural blanks to maintain quality standards, whereas on-site parameters were measured by using standard multi-meter probes. The most dominant cation and anions were Ca2+ and HCO3− in both lakes indicating rock dominance through carbonate weathering as the primary source of dissolved ions in the lake waters. Further analysis indicated that Rara belongs to Ca(Mg)HCO3 and Ghodaghodi belongs to Ca–HCO3 type. The higher concentrations of Na+ and Cl− during the post-monsoon indicates a possibility of long-range marine transport through monsoon precipitation.

Molecular and morphological identification of frog species collected at Rara Lake in Rara National Park, Nepal.

This study seeks to clarify the taxonomic identity of three adult frogs and two tadpoles from Rara Lake situated in Rara National Park, Mugu district, Western Nepal, using both phenotypic and mitochondrial sequence data (16S rRNA gene). Based on the molecular data, we determined our specimens belonged to two species; Paa cf. ercepeae (Dubois, 1974) and Paa rarica (Dubois, Matsui, and Ohler, 2001), and this assignment is also supported by morphology. Principal component analysis of phenotypic data clustered species into large-bodied (SVL > 55 mm) and small-bodied (SVL < 55 mm) groups. The molecular data suggest that Paa rarica belonged to a group that contains several undescribed lineages and that Paa liebigii (Gnther, 1860) hosts extensive cryptic diversity. Our study also documents that Paa species in the Himalayan region are more widely distributed than previously believed.

Lake Watershed Dynamics and Bathymetry Modeling of Rara and Begnas Lakes in Nepal

Lake evolution and its changes over time are an evident and easily measurable signal of human activities and climate change impacts in mountain regions. This study presents bathymetric modeling of permanent lakes (Begnas and Rara Lakes) located in two different geographic settings of Nepal. Moreover, temporal changes in land cover and soil erosion of the lake watersheds, as well as climatic trends around these lakes, are assessed. This study supports establishing reference sites for exploring scientific evidence on the impacts of anthropogenic and climate change on lake hydrological systems. Second-order polynomial models best represent the relationship between lake depth and volume. Rara Lake had a maximum depth of 169 m with an area of 10.52 km2 and a volume of 1013.305 million cubic meters (Mm3), whereas Begnas Lake had a maximum depth of 12.5 m with an area of 2.98 ± 0.10 km2 and a water volume of 13.539 Mm3 in the year 2019. Both lake regions are experiencing changes in temperature and rainfall. The area and volume of Rara Lake and its watershed have been relatively stable even with minimal land-cover change during the recent decades. Begnas Lake and its watershed have experienced significant changes in the last few decades. This study concludes that human activities in the Begnas Lake watersheds are the primary source of lake area variation rather than climate change.

Hydrochemistry of Rara Lake: A Ramsar lake from the southern slope of the central Himalayas, Nepal

High-altitude Himalayan lakes act as natural storage for environmental evidence related to climate change and environmental factors. A great number of lakes are distributed in the southern slope area of the central Himalayas; however, research concerning the hydrochemical processes of these lakes is still insufficient. Herein, we present a comprehensive study on the water chemistry of the lake waters and the inlet stream waters from Rara Lake in western Nepal based upon samples collected in November 2018. The pH, dissolved oxygen, chlorophyll-a concentration (chl-a), water temperature, electric conductivity (EC) and total dissolved solids (TDS) were measured in situ, and the concentrations of major ions (Ca2+, Mg2+, K+, Na+, Cl−, SO42−, and NO3−) were analyzed in the laboratory. The results revealed that the water in Rara Lake is slightly alkaline, with pH values ranging from 7.6–7.98. The cations, in decreasing order of concentration in the lake water, are Ca2+ >Mg2+ >K+ >Na+ with average concentrations of 20.64 mg·L−1, 11.78 mg·L−1, 1.48 mg·L−1 and 0.72 mg·L−1, respectively; the order and concentrations for the anions is HCO3−>SO42−>Cl−>NO3−, with average concentrations of 122.15 mg·L−1, 2.15 mg·L−1, 0.46 mg·L−1 and 0.55 mg·L−1, respectively. The dominant cation and anion in the lake water are Ca2+ and HCO3−, and they account for 48.14% and 71.8% of the totals, respectively. The range of lake water TDS is from 95 mg·L−1 to 98 mg·L−1, with an average of 96.85 mg·L−1. The high ratio of (Ca2+ + Mg2+) to total cations and the low ratio of (Na+ + K+) to total cations indicate that Rara Lake receives ions from rock weathering, especially from carbonate rocks. Similarly, Gibbs boomerang diagrams and Piper diagrams also support the hydrochemistry of Rara Lake as being dominated by rock-weathering patterns. Likewise, other statistical analysis tools, such as Principal Component Analysis (PCA) and correlation strongly suggest the dominance of weathering of calcium and magnesium bicarbonate rocks as the major source of ions in Rara Lake. However, several traces of anthropogenic inputs into the lake were noticed, and the hypolimnion in the lake appears to be oxygen deficient, which may not be an issue at present but cannot be ignored in the future.

Geometric morphometric analyses define riverine and lacustrine species flocks of Himalayan snowtrout (Cyprinidae: Schizothorax) in Nepal

Freshwater fishes in the river and lake systems in the Himalayas and Tibetan Plateau are morphologically diverged but the evolutionary relationship of putative subspecies separated in these freshwater systems has not been explored. Snowtrout(Schizothoraxspp.) are minnows (Cyprinidae) broadly distributed in Asia. Body shapes of 3 Lake Rara (northwest Nepal) endemics (S. macrophthalmus,S. nepalensis,S. raraensis) and 2 widely distributed riverine species (S. progastus,S. richardsonii) across 3 drainages in Nepal (i.e. Karnali, Gandaki, and Koshi Rivers) were studied using geometric morphometry. Data were derived from museum voucher specimens/tissues collected in 1984-1986 and 1996 (Lake Rara). Cartesian coordinates of 18 anatomical points (Type I landmarks) from 528 individuals were digitized; shape variation was then quantified with principal component analysis and visualized with thin-plate splines derived from a Procrustes analysis. Models of shape variation (i.e. taxonomy versus geography) were tested with a multivariate analysis of variance and a morphological distance matrix. Phylogeographic relationships were examined with a haplotype network (N= 115) derived from 1140 base pairs of the mitochondrial DNA cytochromebgene, and selected GenBank sequences (N = 5). Koshi River snowtrout diverged morphologically from conspecifics, consistent with the phylogeographic data. In contrast, Gandaki and Karnali River snowtrout grouped by morphotype (up- versus downstream) irrespective of geographic origin, yet clustered separately within the haplotype network. Lake Rara snowtrout were morphologically but not genetically distinct, due to incomplete lineage sorting. Morphological and genetic variability inSchizothoraxfrom Nepal represent a mosaic driven by isolation (= vicariance) and specialization (= adaptation), with taxonomy insufficiently reflecting diversity. Additional data are required to appropriately derive management and effective conservation plans.

Spatial and temporal dynamics of social-ecological resilience in Nepal from 2000 to 2015

Social-ecological resilience (SER) is the ability to recover from disasters from both social and ecological perspectives. Exploring the resilience of regions that have vulnerable ecosystem and are at high risk of natural disasters is of great significance to effective disaster risk reduction and sustainable development. Nepal has frequently experienced various natural disasters, such as earthquakes, mountain torrents and landslides in recent decades, which have tremendous impacts on the livelihood and socioeconomic development of local residents. This study seeks to generate more information about the spatial and temporal dynamics of SER in Nepal. Here, a SER assessment index was constructed at the village level for the entire country between 2000 and 2015 using the entropy weight method. The study further clarified the mechanisms of driving factors affecting SER based on the Obstacle Degree Model. The results showed that the SER in Nepal presented an uneven spatial distribution, where the northwest was generally lower than that in the east and south. The high-value areas were Kathmandu and areas surrounding Lake Rara in the northwest. The low-value areas were mainly located in mid-western Nepal near the Himalayas. Over the years, the maximum values of SER increased from 0.350 to 0.361, while the minimum reduced from −0.014 to −0.019. The main factors affecting the local SER were the proportion of built-up areas, cultivated land and surface water area. Therefore, it is important to promote agricultural modernization and rational land use planning, in order to reduce the pressure on land resources and enhance agricultural income.

Potentially large post-1505 AD earthquakes in western Nepal revealed by a lake sediment record

According to paleoseismological studies, the last earthquake that ruptured the Main Frontal Thrust in western Nepal occurred in 1505 AD. No evidence of large earthquakes has been documented since, giving rise to the concept of a seismic gap in the central Himalaya. Here, we report on a new record of earthquake-triggered turbidites from Lake Rara, western Nepal. Our lake-sediment record contains eight possibly moderate-to-large earthquake-triggered turbidites during the last 800 years, three of which overlap in age with previously reported Mw ≥ 7 events in western Nepal. Shaking intensity modelling, together with instrumental records, suggests that near-field earthquakes (≤15 km) should have a minimum Mw 5.6, and regional earthquakes (≤80 km) a Mw > ~ 6.5, to trigger turbidites. We present a likely scenario that western Nepal may be as seismically active as central Nepal; however, more data are needed to revaluate the seismic risk in the central Himalaya.

Diatom biodiversity in the lake littoral of Rara Lake, a high altitude lake in the Himalaya of western Nepal

Diatoms were investigated in the littoral of Rara Lake, Nepal, to investigate the impact of land use, substratum type and season. Species composition and diversity differed between areas, seasons and between stones, sediment and macrophytes. Both communities on stones and on sediment differed between the settlement and forested areas, but communities on stones showed the greatest differentiation between land use types.

Ecotone vegetation and water quality of Rara and Begnas Lakes, Nepal

Land-water interfaces of lakes are highly dynamic and are responsible for the stability and maintenance of ecosystems. This study was carried out to understand the ecotone vegetation and the physico-chemical characteristics of waters of Begnas and Rara lakes of Nepal. For vegetation survey, line transects (perpendicular bi-sector to lake boundary), were used along the lake boundaries at an interval of 500 m; three quadrats of 1 m x 1 m size were laid on each line transect (off shore, boundary line, and on shore). All vegetation species in the sample quadrates were recorded. For probing water quality, lakes were divided into three blocks, then sampling was conducted on a consecutive day. Physico-chemical parameters —temperature, pH, electric conductivity (EC), dissolved oxygen (DO), total dissolved solid (TDS), ammonia, and nitrate—were measured. A total of 55 species under 38 families and 28 orders were recorded from ecotone of Begnas lake. In Rara lake, 56 species of 41 families and 22 orders were recorded. Poaceae was the dominant largest family in Begnas which was followed by Asteraceae. In Rara lake, Rosaceae was the dominant family which was followed by Pinaceae. Temperature, pH, and DO values decreased with depth, but EC and TDS e increased with depth, in both Begnas and Rara lakes. Ammonia and Nitrate were below the detectable limit of the instrument, indicating low nutrient contents of both lakes. The study established the baseline information about the diversity of ecotone vegetation; both the lakes show clear changes in physiochemical parameters with lake depths.

The genus Gomphonema (Bacillariophyta) in Rara Lake, Nepal: taxonomy, morphology, habitat distribution and description of five new species, and a new record for Gomphoneis qii

During the first study of the diverse diatom assemblages in Rara Lake, the largest lake in Nepal, 11 species of Gomphonema, belonging to six morphological groups, and Gomphoneis qii could be investigated using light and scanning electron microscopy. Five new Gomphonema species are described: Gomphonema subodhii, Gomphonema parasundaense, Gomphonema raraense, Gomphonema parapygmaeum and Gomphonema himalayaense. Known species included Gomphonema sublaticollum, Gomphonema cf. capitatum, Gomphonema minusculum, Gomphonema lateripunctatum, Gomphonema tergestinum (the only one previously recorded from Nepal) and Gomphonema vibrio. The history of the latter name is explained in detail. The distribution of the Gomphonema species, number of species and records in the littoral of the lake shore varied and was related to the presence of suitable substrata, land use and season, with more records and species present in spring than in autumn.This publication is dedicated to the victims of the earthquakes which hit Nepal in 2015 and to their families.

Hydrochemistry of Lake Rara: A high mountain lake in western Nepal

AbstractHigh altitude ecosystems have important natural ecological functions but are under increasing impacts from human activities and climate change. A detailed analysis of the water chemistry of Lake Rara, a high mountain lake in western Nepal, was carried out in October 2015 and April 2016. A total of 31 water samples were collected. Major ions (Ca2+, Mg2+, Na+, K+, SO42−, NO3− and Cl−) were analysed by ion chromatography. Si and PO43− were analysed following the standard protocols. Conductivity, pH, total dissolved solids (TDS), turbidity and dissolved oxygen (DO) were measured on‐site. The lake is oligotrophic characterized by low PO43− concentration (0.06 ± 0.01 mg/L), high DO values (6.73 ± 0.06 and 10.89 ± 0.86 mg/L), alkaline pH (8.42 ± 0.3 and 8.32 ± 0.23) and low conductivity (189.93 ± 5.3 and 189.22 ± 5.8 μS/cm). The concentrations of the major cations were in the order of Ca2+ &gt; Mg2+ &gt; K+ &gt; Na+ (during both seasons), and for anions, it was HCO3− &gt; SO42− &gt; Cl− &gt; NO3− and HCO3− &gt; Cl− &gt; NO3− &gt; SO42− during postmonsoon and premonsoon, respectively. One‐way ANOVA revealed significant seasonal variations (p &lt; 0.05) in most of the physicochemical parameters. The increased concentrations of most of the ions in the premonsoon time probably reflect long‐range transport of materials through dry deposition, whereas higher concentrations of NO3− and Cl− in some sites possibly reflect the localized impacts of settlement and grazing. The lake water was classified as Ca(Mg)HCO3. High (Ca2+ + Mg2+)/Tz+ ratio (0.97 in postmonsoon and 0.95 in premonsoon) and low (Na+ + K+)/Tz+ ratio (0.03 in postmonsoon and 0.04 in premonsoon) confirm carbonate weathering as the principal source of major ions with bedrock geology governing the water chemistry. The findings of this study build on the baseline dataset for assessing future anthropogenic influence on the lake and subsequent development for future lake management strategies.

Landslide susceptibility mapping in eastern hills of Rara Lake, western Nepal

The tendency of occurrences of slope failures in future in an area is landslides susceptibility. This tendency in eastern hills of Rara Lake was analyzed through mapping process. Bivariate statistical index method was used to produce the susceptibility of landslides. Ninety six slope failures were delineated from Google Earth imagery. The ratio of landslide densities of each individual factor classes to that of whole area gave weight values necessary to produce landslide susceptibility index (LSI). East and South facing slopes, gradients of &lt;30o, elevation of 2000-2800 m, buffers closer to road and streams, grassland and cultivation lands, and lithology of pelitic metamorphic rocks were factor classes with positive weight values. The LSI values ranging from -7.12 to 5.45 were reclassified into five susceptibility classes. Landslide densities of 8.12 and 4.76 per km2 were observed for very high and high susceptible zones. Success rate curve, made from 35 landslides located in the field survey, showed 0.76 portion area under the curve. This gives 76% overall success rate. Higher susceptible areas are cultivated areas and grasslands, where most houses were located. Thus, knowing the landslide susceptibility of areas, necessary preparedness can be done to reduce the impacts.

Weak monsoon event at 4.2 ka recorded in sediment from Lake Rara, Himalayas

The strength of the Indian summer monsoon varied significantly on centennial- to millennial timescales during the Holocene. Among these variations, a weak summer monsoon event occurred approximately at 4 ka, the so called “4.2 ka event”. This event is considered to have been a relatively sustained and widespread phenomenon at regional scales across southern Asia to eastern Africa. However, little is known about the impact of such variations in the Himalayas, a key location for understanding the monsoon system. Here we present a record of changes in summer monsoon strength during the Holocene from Lake Rara, western Nepal, using redox sensitive elements (Mn/Ti and Mn/Fe) measured by X-ray fluorescence (XRF) core-scanner. In addition, organic matter properties (TOC, δ13C, and C/N) and changes in the 14C age offset between bulk organic matter and leaf matter – namely the old carbon offset – are used to augment the environmental reconstruction. Collectively, the data indicate a period of prolonged weak monsoon interval at around 4 ka. The timing of onset and recovery from the event observed at Lake Rara exhibits particular similarity with changes in the Indus River discharge. This is the first record of the “4.2 ka event” from the Himalayas based on a relatively well-constructed age model using 14C dates that are not influenced by reservoir effects. These findings provide an important step towards better understanding the spatial and temporal variability in the Holocene Indian Monsoon.

Documentation of flora of Rara lake and adjoining areas in mid-western region of Nepal

Rara National Park is the smallest national park of the country. It is rich in floral and faunal diversity. Rara is one of the sacred lakes and is listed as a Ramsar site. The aim of the study was to compile the representative flora of Rara lake and to present status of available vegetation. The research used both primary and secondary sources of data. Field visit was conducted in June, 2010 during which more than 300 plant specimens were collected. The secondary data were collected from Rara and adjoining area like Gamgadi. These data were thoroughly analyzed to understand the composition of vegetation. The study revealed the existence of about 224 flowering plant species in the area, under 173 genera and 67 families. Compositae was found to be the largest family (21 species and 17 genera) followed by Rosaceae (19 species and 10 genera). DOI: http://dx.doi.org/10.3126/banko.v21i1.9063 Banko Janakari, Vol. 21, No. 1 2011; 41-47

Late Holocene Asian monsoon variations recorded in Lake Rara sediment, western Nepal

AbstractThe Himalayas are a key location for understanding centennial‐ to millennial‐scale variations in the Asian monsoon, yet few studies of the late Holocene have been conducted in this sensitive area. Direct evidence for shifts in monsoonal wind strength is often limited to marine proxy records, while terrestrial reconstructions (e.g. lake levels and spleothems) focus on precipitation. Here, we present the first evidence of terrestrial summer monsoon wind strength changes from Lake Rara, western Nepal, based on Mn/Ti ratios, a proxy for lake stratification. These data indicate a link between the Arabian Sea and the Himalayas, suggesting that centennial‐ to millennial‐scale changes in wind strength occurred synchronously. Distinct similarity is also observed between Lake Rara and the southern part of China, which may support previous suggestions that the southern part of China is influenced by Indian summer monsoon. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Three New Species of the Cyprinid Genus Schizothorax from Lake Rara, Northwestern Nepal

Three New Species of the Cyprinid Genus Schizothorax from Lake Rara, Northwestern Nepal

Evolutionary genetics of the endemic Schizorathicine (Cypriniformes: Cyprinidae) fishes of Lake Rara, Nepal

The three endemic species of Schizothorax from Lake Rara, Nepal comprise a putative cyprinid species flock. Mitochondrial DNA sequences were compared for specimens of the endemic species S. raraensis, S. macrophthalmus, and S. nepalensis, and specimens of S. richardsonii and S. progastus from the Karnali River, Koshi River, and Kali Gandaki River drainages. An analysis of molecular variance demonstrated that S. nepalensis is genetically distinct from a group composed of S. raraensis and S. macrophthalmus. Phylogenetic analyses based on parsimony failed to corroborate or conclusively reject a hypothesis of monophyly for the three endemic species of Schizothorax from Lake Rara. The mtDNA haplotypes of S. richardsonii and S. progastus from the Karnali River drainage were not significantly differentiated from one another, but pairwise comparisons of haplotypes from the Lake Rara basin, Karnali River drainage, Koshi River drainage, and Kali Gandaki River drainage were significantly differentiated from one another.

Dendrochronology in Coniferous forests around Lake Rara, West Nepal

In two forest stands, one domonated byAbies spectabilis, and the other byPinus wallichiana-Picea smithiana, 198 cores were taken from 105 conifers in May 1983 and the annual ring widths were measured. The annual ring widths usually had significant similarities between cores taken from the same tree and with cores taken from different trees. these similarities increased with tree size. The climatic change affected the large trees more strongly than it did the small trees. Micro environmental changes, such as canopy gap affected the small trees more strongly. Annual ring widths were also correlated with the annual precipitations at Jumla 30 km south of the plots for a recent 20 year period. A multiple regression analysis between ring width and seasonal precipitation showed that the growth ofA. spectabilis was correlated primarily with the rain from May to August and secondarily with that from September to December in the previous year.