Wetlands are the dynamic ecosystems with high yielding capacity which are considered very prolific from view point of biodiversity. With prime functioning of water supply, wetlands are well known for supplementary functions of providing ecosystem services viz., groundwater recharge, carbon sequestration, preventing water logging and flooding etc. Total ten wetlands sites of Nepal are included in Ramsar List till 2019, Koshi Tappu being the first listed wetland and Lake Clusters of Pokhara Valley being the latest included wetland which covers 60,561 hectares area of the total area of the country. Ramsar sites in Nepal are distributed throughout the country and are classified as high altitude wetlands, mid hill wetlands and terai wetlands. The Ramsar Site hosts endemic species of floral species some of which are endangered. It too serves as excellent habitat as water hole and corridor for numerous digits of threatened and endangered faunal diversity. Besides this, they serve as excellent habitats for migratory birds as well. Being such integral portions of biosphere, wetlands are under constant threats like eutrophication, siltation, invasion of alien species, pollution, agricultural runoff etc. This review article is based upon desk review different published and unpublished literatures from national level and provides detail information on updated wetlands of international importance of Nepal, along with present scenario, biodiversity value and threats that the wetlands are facing and is expected to help in shaping future course actions for wise use and sustainable management of wetlands in Nepal.
Wetlands are significant to the environment and economic survival of people most especially in the rural areas of the tropical world; their sustainability is however threatened by agricultural drainages and demographic pressure. The detrimental influence of agricultural expansion on wetland loss was examined using both primary and secondary data. The primary data was collected through questionnaires administration and interviewing of hundred members of Fadama Users Group (FUG) (i.e. 10%). The secondary data included satellite images of 1972, 1984, 2000 and 2015 analyzed using GIS technique and corresponding census data by simple descriptive percentage method. The results revealed that marginal wetlands lost about; 3180.60 ha between 1972 and 1984, 1936.08 ha between 1984 and 2000 and 805.32 ha between 2000 and 2015, to farmlands intensification throughout the periods of study. Wetlands ecosystem was also expected to lose more ground as the population growth is unabated and, more so, with the projected farmlands growth of about 4730.04 ha i.e. about 36.36% in 2030; there is, therefore tendency for serious depletion of marginal wetlands in the future.
This study examined the distribution of Escherichia coli (E. coli) resistant to eleven antibiotics and possible relationships among physico-chemical parameters and these resistances. It was carried out over two years during four climatic seasons in five lakes of the Yamoussoukro lake system in Côte d'Ivoire. The physicochemical parameters of the lakes studied are temperature, pH, dissolved oxygen (DO), dissolved organic carbon (DOC), turbidity, nitrates, orthophosphates and ammoniacal nitrogen. A total of 744 water samples were collected from five (5) lakes belonging to the lake system, over a two-year period, during four dry and four wet seasons. Escherichia coli loadings were evaluated after isolation on specific chromogenic medium COMPASS ECC Agar and the susceptibility to antibiotics by the agar diffusion method. Physico-chemical parameters were evaluated according to international standards. The physico-chemical results showed that the nutrient contents evolved generally from upstream to downstream of the lake system, independently of the sources of pollution of five lakes of system. However, the lake B, in upstream of the lake system, showed levels of nitrate, orthophosphate and ammoniacal nitrogen often similar to the downstream lakes. This demonstrates a source of chemical pollution in this lake, which flows to lakes D and E, which are themselves subject to other pollution. Bacterial loads and bacterial resistance to antibiotics have strictly evolved from upstream to downstream of the system. Most isolates were resistant to ampicillin (16.46%), tetracycline (12.87%), ciprofloxacin (12.86%) and sulfamethoxazole (10.14%). Antibiotic resistance patterns of E. coli isolates were similar in both years studied, but higher during rainy seasons (GRS and SRS). The spearman rank correlations and the principal component analysis (PCA) revealed significant correlations between bacterial resistance to antibiotics in lakes and water physico-chemical parameters. Turbidity and DOC can help to determine the main resistances in the lake D. Orthophosphates can help to understand the resistance of chloramphenicol and the nitrates can help to understand the resistance of ampicillin in the lake B. Resistance in the lakes A, B and C can be influenced by dissolved oxygen. Overall, this study provided baseline information on bacterial resistance in the lakes of Yamoussoukro in Côte d'Ivoire, showing that these lakes could be reservoirs of antibiotic resistance, potentially dangerous to public health.
Amongst three species of otters, the Asian Small-clawed Otter has not been recorded since Hodgson (1839). Since 1991, the Eurasian Otter has neither been photographed nor sighted in the country. Recently, the Smooth-coated Otter has been reported only from Bardia National Park and its west. In this chaotic situation, a volunteer project was initiated for otter conservation in Nepal three years ago. 1000 copies of an otter conservation awareness poster were printed in 2017 and a second set of posters in 2019. Posters were distributed to local communities while communicating with the local people along the way and during stays. Thus far, we have conducted awareness activities at selected sites in nine districts and four protected areas. Over three years, we have talked with more than 2000 local people about otters and disseminated more than 1300 posters. At all sites, local communities responded that they had not seen otters for 20 to 30 years or more and for the last 10 years, even in protected areas. However, there are hopes that the last scarce individuals or populations of otters remain at very few sites. Overfishing, river poisoning and pollution, hydropower dams and station construction, and sand and pebble extraction from rivers, are the major causes for depletion of otters in these areas. In the past, trapping by Tibetans for otter pelts and by nomads from the plains of Nepal and India were major causes for population declines. In conclusion, we convey a conservation message that humans must learn to co-exist with otters if the species are to survive.
Mangrove forests provide valuable ecosystem services but are declining in many tropical locations. The abundance of mangrove species in coastal fringe forests is related to biotic processes such as species succession or competition and abiotic factors, including nutrient availability, physiochemical water quality, soil composition, and tidal inundation. We examined the abundance of Rhizophora mangle and Avicennia germinans relative to environmental factors, including porewater chemistry, soil substrate, and distance from the ocean, on Bahamas Island. In this system, R. mangle were primarily found in litter-dominated soils and abundances were positively related to distance from the ocean, while A. germinans was only found in sandy soils closest to the ocean. Although phosphate, alkalinity, and salinity in porewater did not explain the distribution of species, free chloride varied significantly with distance from the ocean. These results suggest that soil conditions and tidal inundation may help determine the distribution of mangrove species on Caribbean islands. DOI: http://dx.doi.org/10.3126/jowe.v6i0.6081 J Wet Eco 2012 (6): 16-24
