This study documents aquatic and terrestrial/riparian biodiversity in an anthropogenically disturbed Ramsar site, the Ghodaghodi Lake complex, in the Western Nepal surveyed during the summer season (March-April) of 2007. The study site comprises three major interconnected lakes: Ghodaghodi (138 ha), Nakharodi (70 ha), and Bainshwa (10 ha). Five transect lines for aquatic macrophytes and three transect lines and 37 sampling plots were laid to sample terrestrial/riparian plants, birds, and animals. Five sample plots were established for fish and aquatic bird. A total of 45 species of aquatic macrophytes, 54 species of terrestrial/riparian vegetation, 19 fish species, 41 bird species, 17 mammals (endangered and vulnerable), and 5 reptiles (critically endangered, vulnerable, and near threatened) were recorded at the lake complex. Local people have used most of the aquatic and terrestrial plants for different purposes while many of the potential medicinal plant species were still untapped. Persistent anthropogenic threats, like excessive harvesting and poaching, habitat destruction—population pressure, forest fragmentation, siltation, fertilizer and pesticide seepage, water pollution, overgrazing, and unmanaged irrigation system found over the lake complex, endangered the existing biodiversity. The suggested remedial measures are further exploration of medicinal potential, prioritization of in situ biodiversity conservation strategies, and implementation of awareness program at local level against anthropogenic threats.
Wetlands are defined as lands transitional between terrestrial and aquatic eco-systems where the water table is usually at or near the surface or the land is covered by shallow water [
Medicinal plants have contributed significantly to the livelihood of Nepalese people [
Biodiversity loss has become a major issue over the last few decades and its protection has emerged as a main agenda within national nature conservation policies, international conventions, conservation targets, and political programmes [
Ghodaghodi Lake complex is the largest interconnected natural lake system in the plain land of Nepal and was designated a Ramsar site in 2003 due to its high biodiversity value. Though it is a very important lake ecosystem, only a few studies [
The Ghodaghodi Lake complex (28°41′17′′ N, 80° 56′47′′ E) lies in the Kailali district of far Western Terai in Nepal (Figure
Map showing Ghodaghodi Lake complex and adjoining villages.
The lake system is connected with extensive forests along the Siwalik (Churia) Hills to the north and falls between two of Terai’s protected areas—the Royal Bardia National Park and the Royal Suklaphanta Wildlife Reserve—and functions as an important corridor for the movement of wildlife. The lake complex is characterised by three types of wetland habitats: (i) riverine including perennial rivers and river flood plain; (ii) lacustrine including oxbow lakes and ponds; and (iii) palustrine including marshes and swamps. Marshy areas on the fringes of the lakes are subject to periodic inundation. Only Ghodaghodi and Nakharodi Lakes are perennial while Bainshwa is seasonal and turns marshy during the dry season. Similarly, the wetland forest complex has three types of forest habitats:
The area has a tropical monsoon climate. The average annual rainfall ranges between 1630 mm (recorded at Tikapur, 35 km to the southeast of the lake) and 1705 mm (recorded at Dhangadhi) where about 80–85% of total rainfall occurs during the monsoon period (mid-June to late September). The average monthly maximum temperature ranges from 21°C to 38°C and minimum 6°C to 25°C (at Tikapur). At Dhangadhi, the maximum temperature ranges from 22°C to 37°C and minimum from 5°C to 25°C. The soil at the bed and surrounding area of the lake complex was almost of the same type with very little horizontal spatial variation. The predominant soil type was high in plasticity, of low permeability clay of yellowish to light brown colour. Low permeability of the soil was on the basis that loss of water through seepage and deep percolation seemed to be considerably low. No rock outcrop could be seen in the vicinity of the lake area. The lake is fed by direct precipitation during the monsoon season and by surface flows from the watershed area, ground water springs, and small streams. Water depth varies from 1-2 m during the dry period to 3-4 m during the monsoon season [
The wetland complex is bordered by three local politico-administrative units called Village Development Committees (VDC): Sandepani in the East, Darakh in the South, and Ramshikharjhala in the North and West. Around 60% of the total area is used as agricultural land, 37% land is under forest covers, lakes, common pastures, and scrubs; 2% percent under settlements and roads while rivers and streams cover 1% percent of the total land. Farming with traditional use of natural resources is the major occupation of the people living in the lake area. The present uses of lake resources include fishing, livestock grazing and collection of fodder, firewood, and nontimber forest products including medicinal plants. Tharus, an indigenous ethnic group of the lake area, comprising more than 50% of the total population, are the most dependent community on wetland resources [
Household and population increment in the lake adjoining villages.
VDC | Total household | Total population | ||
---|---|---|---|---|
2001 | 2011 | 2001 | 2011 | |
Darakh | 1,694 | 3,153 | 12,171 | 17,623 |
Ramsikharjhala | 1,824 | 3156 | 13,560 | 18,016 |
Sandepani | 2,592 | 4,278 | 17,956 | 24,892 |
|
||||
Total | 6,110 | 10,587 | 43,687 | 60,531 |
Source: CBS [
Data were collected during March-April 2007. Therefore the species documented in this study can only be validated in the summer months of Nepal. Data on both terrestrial/riparian and aquatic plants were recorded in the floral category. For aquatic plants, submerged, free-floating, floating leaves, and emergent plants were collected. Sampling was undertaken in such a way that it would cover all the representative habitats of aquatic flora. Shorelines as well as open water areas, floating as well as submerged vegetations were sampled across the lake in transect lines in a boat. Five transect lines, three at Ghodaghodi (719 m, 1673 m, and 1572 m), one at Bainshwa (460 m), and one at Nakharodi (960 m), were established; and quadrat method of random sampling as mentioned by Ludwig and Reynolds [
For terrestrial plants, trees, shrubs and herbs were surveyed. Three transect lines, each from eastern, western, and northern parts, passing through the surrounding forest of Ghodaghodi Lake complex, were demarcated. A total of 37 quadrat plots, also used by Dongol [
Field identification of the plant species was carried out using standard literature [
In the faunal category, the survey was undertaken for fishes, birds, mammals, and reptiles. For fish, five sampling areas were purposively identified, three in Ghodaghodi Lake and two in Bainshwa and Nakharodi. Fishing nets were kept overnight and the fish catch was collected next morning and repeated for three consecutive days. We followed Shrestha [
For terrestrial birds, the same plots of terrestrial vegetation assessment were considered. Bird surveys were carried out before vegetation surveys in the morning from 0500 hr to 0700 hr through direct observation via binoculars (8 × 30) and a call count method. Birds were surveyed for a total of five consecutive days. For aquatic birds, the same sampling points used for fish were considered. The survey procedure and period were similar to those of terrestrial birds and in both cases, we followed the literature of BCN and DNPWC [
For terrestrial wildlife, the transect lines setup for terrestrial plant assessments was used. Each transect was walked three times and wildlife species were observed. This survey was carried out before vegetation surveys so that habitats could remain undisturbed and animals could be spotted. Indirect methods such as faecal, hair, and horns were also used to determine the presence of wildlife species.
Anthropogenic threats as well as additional information on exiting biodiversity and local medicinal uses of plant species were observed and recorded through field observations, focus group discussions (FGDs), and key informant interviews (KII). A total of three focus group discussions, one at each VDC and six key informant interviews, two at each VDC, were conducted. Field observations were made using a recording sheet and camera while a checklist containing all aspects of biodiversity, medicinal uses, and existing threats was developed, pretested, and used for the FGD. A total of 8–10 people including ethnic traditional healers were made available for FGD in order to gather information, crosscheck, and validate. Older members of the community and local schoolteachers were selected for key informant interviews.
A total of 45 species of aquatic plants including 9 submerged, 6 free-floating, 21 floating leaved, and 9 emergent species (Table
Aquatic macrophytes recorded in the Ghodaghodi Lake complex.
Species | Potential uses | Existing uses by local people in the Ghodaghodi Lake area |
---|---|---|
Submerged | ||
|
Human medicine [ |
Fish food; duck food; green manure |
|
Fish food [ |
Fish food; duck food; fodder; green manure |
|
N/A | NONE |
|
N/A | NONE |
|
N/A | NONE |
|
N/A | NONE |
|
N/A | Human medicine; green manure |
|
N/A | NONE |
|
Fish food [ |
NONE |
Free-floating | ||
|
Green manure [ |
Fish food; duck food; green manure |
|
Fodder [ |
Food; fodder |
|
N/A | Fish food; duck food; green manure |
|
Human medicine [ |
Human medicine; green manure |
|
N/A | NONE |
|
N/A | NONE |
Submerged rooted with floating leaves | ||
|
N/A | NONE |
|
N/A | NONE |
|
Food [ |
NONE |
|
Human medicine [ |
Human medicine; food; fodder |
|
N/A | NONE |
|
Food [ |
NONE |
|
Duck food [ |
NONE |
|
Human medicine [ |
Human medicine; food |
Emergent | ||
|
N/A | NONE |
|
Human medicine [ |
NONE |
|
Human medicine [ |
Human medicine; food |
|
Fodder [ |
NONE |
|
Human medicine [ |
Human medicine; fodder |
|
Human medicine [ |
Human medicine; fodder |
|
Human medicine [ |
Human medicine; green manure |
|
Fodder [ |
NONE |
|
Human medicine [ |
Human medicine |
|
N/A | NONE |
|
Human medicine [ |
Human medicine; fish food; duck food; food |
|
Human medicine [ |
NONE |
|
Human medicine [ |
NONE |
|
Human medicine [ |
Food |
|
Human medicine [ |
Fodder; industrial use |
|
Food [ |
NONE |
|
Human medicine [ |
Human medicine |
|
Human medicine [ |
Food; green manure |
|
Human medicine [ |
Fodder; industrial |
|
Human medicine [ |
NONE |
|
Food [ |
NONE |
A total of 54 terrestrial/riparian plant species (Table
Terrestrial/riparian plants recorded within the forest adjacent to the Ghodaghodi Lake complex.
Species | Potential uses | Existing uses by local people in the Ghodaghodi Lake area |
---|---|---|
Herb | ||
|
Human medicine [ |
NONE |
|
Human medicine [ |
Human medicine; veterinary medicine |
|
Human medicine [ |
Human medicine |
|
Human medicine [ |
NONE |
|
N/A | Human medicine; fodder |
|
Food [ |
NONE |
|
N/A | NONE |
|
Human medicine [ |
Human medicine; fodder |
|
N/A | NONE |
|
Human medicine [ |
NONE |
|
N/A | NONE |
|
N/A | Human medicine; veterinary medicine; food; fodder |
|
N/A | NONE |
|
N/A | Human medicine |
|
Human medicine [ |
Human medicine; veterinary medicine; food; fodder |
|
N/A | NONE |
|
Human medicine [ |
Human medicine |
|
Industrial [ |
NONE |
|
N/A | Human medicine |
|
Human medicine [ |
Human medicine |
|
Human medicine [ |
NONE |
|
Human medicine [ |
Human medicine |
Shrub | ||
|
Human medicine [ |
Human medicine |
|
N/A | Human medicine; veterinary medicine |
|
N/A | NONE |
|
Human medicine [ |
Fruit; food; fodder; firewood |
|
N/A | NONE |
|
Human medicine [ |
Human medicine; veterinary medicine; industrial use |
|
Human medicine [ |
Human medicine; fruit; industrial use |
Tree | ||
|
Human medicine [ |
Human medicine; industrial |
|
Human medicine [ |
Human medicine; fruit |
|
Human medicine [ |
Human medicine |
|
Human medicine [ |
Human medicine; fodder; food; firewood; industrial use |
|
Human medicine [ |
NONE |
|
Human medicine [ |
Human medicine; firewood |
|
Human medicine [ |
Human medicine; timber; fodder |
|
N/A | Timber |
|
Food [ |
NONE |
|
Fodder [ |
Fodder |
|
Human medicine [ |
NONE |
|
Human medicine [ |
Timber; fruit |
|
Human medicine [ |
Human medicine; fodder; firewood |
|
N/A | NONE |
|
Human medicine [ |
Fruit |
|
Human medicine [ |
Timber; firewood; fruit |
|
Fodder [ |
Human medicine; timber |
|
Human medicine [ |
Human medicine; fruit |
|
Food [ |
Human medicine; timber; fruit; fodder |
|
N/A | NONE |
|
Human medicine [ |
Human medicine |
|
Fodder [ |
Human medicine |
|
Human medicine [ |
Human medicine; timber |
|
Human medicine [ |
Firewood; fodder |
|
Human medicine [ |
NONE |
Climber and vine | ||
|
Fodder [ |
Human medicine; fruit; fodder; industrial |
|
N/A | Fodder |
A total of 19 fish species were found in the Ghodaghodi Lake complex (Table
Fishes recorded in the Ghodaghodi Lake complex.
Scientific name | Family |
---|---|
|
Belonidae |
|
Claridae |
|
Channidae |
|
Channidae |
|
Cobitidae |
|
Channidae |
|
Cyprinidae |
|
Cyprinidae |
|
Cyprinidae |
|
Cyprinidae |
|
Cyprinidae |
|
Saccobranchidae |
|
Cyprinidae |
|
Mastacembelidae |
|
Belonidae |
|
Mastacembelidae |
|
Bagridae |
|
Notopteridae |
Wetland birds comprise a significant portion of the avian fauna recorded in Nepal [
Avifauna recorded in the Ghodaghodi Lake complex.
Scientific name | Family |
---|---|
|
Ardeidae |
|
Jacanidae |
|
Anatidae |
|
Rallidae |
|
Rallidae |
|
Ardeidae |
|
Anhingidae |
|
Phalacrocoracidae |
|
Accipitridae |
|
Ardeidae |
|
Accipitridae |
|
Anatidae |
|
Bucerotidae |
|
Ciconiidae |
|
Rallidae |
|
Ardeidae |
|
Rallidae |
|
Oriolidae |
|
Threskiornithidae |
|
Ardeidae |
|
Picidae |
|
Capitonidae |
|
Capitonidae |
|
Muscicapidae |
|
Meropidae |
|
Meropidae |
|
Alcedinidae |
|
Cuculidae |
|
Cuculidae |
|
Psittacidae |
|
Accipitridae |
Long-tailed shrike* | Campephagidae |
Rufous hooded oriale* | Oriolidae |
|
Campephagidae |
|
Corvidae |
|
Muscicapidae |
|
Nectariniidae |
|
Psittacidae |
|
Ciconiidae |
|
Accipitridae |
|
Corvidae |
A total of 17 species of mammals belonging to 12 families were recorded in the Ghodaghodi Lake complex (Table
Mammals recorded in the Ghodaghodi Lake complex.
Scientific name | Family | Common name |
---|---|---|
|
Cercopithecidae* | Rhesus monkey |
|
Cercopithecidae* | Hanuman langur |
|
Felidae** | Jungle cat |
|
Felidae** | Fishing cat |
|
Felidae** | Leopard cat |
|
Felidae** | Leopard |
|
Canidae* | Jackal |
|
Mustelidae* | Otter |
|
Pteropodidae* | Bat |
|
Sciuridae* | Squirrel |
|
Sciuridae* | Flying squirrel |
|
Leporidae* | Jungle hare |
|
Bovidae* | Blue bull |
|
Cervidae* | Spotted deer |
|
Suidae* | Wild boar |
|
Elephantidae** | Asian elephant |
|
Muridae* | Jungle rat |
EN: endangered, VU: vulnerable, NT: near threatened, LC: least concern (IUCN Red List Category); I, II: CITES categories (source: Jnawali et al. [
This study found a total of 6 species of reptiles representing 5 families in the Ghodaghodi Lake complex (Table
Reptiles directly observed in the Ghodaghodi Lake complex.
Scientific name | Family | Common name |
---|---|---|
|
Crocodylidae | Marsh mugger |
|
Pythonidae | Python |
|
Geoemydidae | Indian roofed turtle |
|
Geoemydidae | Red crowned roofed turtle |
|
Trionychidae | Flap shell turtle |
|
Varanidae | Golden monitor lizard |
V: vulnerable, CR: critically endangered, NT: near threatened, LC: least concern (IUCN Red List Category) (source: IUCN [
Freshwater ecosystems are affected by overharvesting of the resources and habitat destruction. The major drivers of the destruction are human demography, excessive resource use, increased water consumption, technological development, and social organization [
Local people heavily harvested aquatic and terrestrial plants and fishes. Illegal tree felling and smuggling of
Habitat destruction affects both harvested species such as aquatic plants and fishes and even nonharvested species of weeds, reptiles, and microorganisms. Large mammals like tiger, sloth bear, and most of the deer species were not sighted in the area for a couple of years. The current population pressure in the area and fragmentation of the forest and increased agricultural land have been identified as factors contributing to this degradation. The local people attributed this to the shrinkage and thinning of forest areas for the establishment of settlements around the lake that have heavily degraded the habitat of these mammals. The other drivers of habitat destruction in the lake complex include rites and rituals, unmanaged irrigation systems for agricultural fields, runoff from agricultural fields and siltation, and overgrazing.
The wastes generated from the rites and rituals performed by the religious pilgrims, especially indigenous Tharu community, on the shore of the lake, have contributed significantly to water pollution in the Ghodaghodi Lake complex. They celebrate by sacrificing domestic pigs, goats, chickens, and pigeons on the shore, which ultimately becomes a source of pollution. A few past studies [
During the last two decades, land use of the complex has changed due to the encroachment of migrants from the hilly districts of far western region. Forest area has decreased at the expense of agricultural land while forest cover has been converted into open grazing land, displacing the habitat of important birds and wildlife.
Water extraction for irrigation and water use for buffalo wallowing has severely affected the habitat. This study observed both Ghodaghodi and Nakharodi Lakes having a canal used for irrigation purposes, a practice that becomes even more intense during dry periods. Landowners and farmers downstream from the lake have a vested interest to secure water for irrigation. The lake complex does not have a permanent perennial source of water and this extraction system, especially in the dry season, greatly affects the aquatic life and migratory birds.
The southeastern part of Ghodaghodi Lake and eastern parts of Nakharodi Lake have been heavily affected by livestock grazing. As the occupation of most of the villagers used to be farming as well as rearing livestock, grazing the forests and open grasslands of the lake area is common. However, the trampling of soil and browsing of young palatable species from this traditional practice has damaged the regeneration capacity of native vegetation in the area.
Dichlorvos 76% EC and Endosulfan 35% EC were the major pesticides used, while urea and diammonium phosphate (DAP) were the major fertilizers used in crops near the lake vicinity. The seepage of such pesticides and fertilizers through agricultural runoff has caused eutrophication in the lake. As a result, excessive growth of aquatic macrophytes such as
Siltation emerging from the degradation of upper watershed areas is another reason for habitat destruction. Rapid deforestation and encroachment in the watershed area within Betini forest, a major source of water, is causing reduced water supply to the lake. Overgrazing of the grassland at the watershed has also increased soil erosion and siltation. This finding is similar to that of [
This study, a month long summer season survey, documents the existing biodiversity, the use pattern of floral diversity by the local people, and anthropogenic threats to the overall biodiversity of Ghodaghodi Lake complex. The Ghodaghodi Lake complex was found to be a very rich wetland diversity hotspot in the western low-land region of Nepal, though variations in the number of species than those of previous study by IUCN [
The paradox is however the threats in the area, mostly anthropogenic in nature, which could lead to an imbalance of the natural wetland ecosystem. If immediate conservation action is not put in place, then there is a likelihood that most of the threatened category animals will be in danger due to the anthropogenic threats identified by this study. The results show that Ghodaghodi Lake complex has an enormous economic and conservational potential and care should be taken to maintain its biodiversity value. The economic potential and multipurpose use of plant species, including medicinal values, could supplement the household income of the local people and be a good incentive for them for conservation. We recommend (1) more exploration of the indigenous lake resource uses including medicinal potential of available plant species, (2) prioritizing in situ biodiversity conservation, and (3) implementing awareness programs at local levels on the consequence of threats to lake biodiversity.
The authors declare that there is no conflict of interests regarding the publication of this paper.