Taudaha Lake is one of the important wetlands in Nepal, as it provides critical habitats for thousands of migratory birds and fishes. Despite being a critically important water body, there is a lack of detail chemical...Taudaha Lake is one of the important wetlands in Nepal, as it provides critical habitats for thousands of migratory birds and fishes. Despite being a critically important water body, there is a lack of detail chemical and biological studies on this lake. The present study investigates the effects of seasonal water quality variations in distribution and abundance of macroinvertebrates in Taudaha Lake, during four different seasons in 2006. The results indicate that all the water quality parameters, except secchi depth, and total alkalinity, significantly varied among seasons. The gross primary productivity of the lake also significantly varied among the seasons, with highest primary production during summer (3.92 ± 0.18 gC/m<sup>3</sup>/day) and lowest during spring (2.44 ± 0.67 gC/m<sup>3</sup>/day). A total of 2166 individual benthic macroinvertebrates from 10 families and 7 orders were collected during the study period. Unlike water quality parameters, the macroinvertebrate species composition did not vary significantly among the seasons. The results suggested that the change in lake water quality did not have significant impacts on community metrics such as species diversity, species richness, and species evenness.展开更多
Spatial and temporal variation in planktons and water quality parameters were investigated in order to determine the effects of seasonal water use on reservoir water quality and planktons’ diversity in Kulekhani Mult...Spatial and temporal variation in planktons and water quality parameters were investigated in order to determine the effects of seasonal water use on reservoir water quality and planktons’ diversity in Kulekhani Multipurpose Reservoir, Nepal. This study also focuses on interactions among various water quality parameters with planktons and how such interactions can affect the second major utility, the fish farming in the reservoir. The analyses of seasonal water samples collected from three different sampling locations in the reservoir showed that select water quality parameters varied significantly (P < 0.05) with sampling seasons (transparency: 30 - 250 cm, pH: 7 - 7.5, alkalinity: 30 - 120 mg/L, DO: 6 - 11.5 mg/L, CO2: 0.1 - 1.1 mg/L) and sampling locations (phosphate: 0.1 - 0.25 mg/L, nitrate 0.01 - 0.19 mg/L) in the reservoir. Three groups of zooplankton and four classes of phytoplankton, respectively with eleven and twelve genera, were identified and quantified in the reservoir. Among them, Cyclops, Asplanchana, and Keratella were most dominant zooplanktons while Synedra, Melosira and Peridinum were the most dominant phytoplankton in the reservoir water. The abundance of select zooplanktons (Cyclops, Keratella, Polyanthra), and phytoplankton (Navicula, Melosira, Amphora, Chroococcus, Staurastrum, Scendesmus) showed significant interaction between sampling sites and sampling seasons, while the other varied only with sampling seasons and/or sites. These results showed that seasonal water level fluctuations, along with the variation of water quality parameters, change the abundance and diversity of planktons’ in the reservoir. Such changes can negatively impact the fish in cage culture, affecting the livelihood of people extensively relying on these fish farming.展开更多
文摘Taudaha Lake is one of the important wetlands in Nepal, as it provides critical habitats for thousands of migratory birds and fishes. Despite being a critically important water body, there is a lack of detail chemical and biological studies on this lake. The present study investigates the effects of seasonal water quality variations in distribution and abundance of macroinvertebrates in Taudaha Lake, during four different seasons in 2006. The results indicate that all the water quality parameters, except secchi depth, and total alkalinity, significantly varied among seasons. The gross primary productivity of the lake also significantly varied among the seasons, with highest primary production during summer (3.92 ± 0.18 gC/m<sup>3</sup>/day) and lowest during spring (2.44 ± 0.67 gC/m<sup>3</sup>/day). A total of 2166 individual benthic macroinvertebrates from 10 families and 7 orders were collected during the study period. Unlike water quality parameters, the macroinvertebrate species composition did not vary significantly among the seasons. The results suggested that the change in lake water quality did not have significant impacts on community metrics such as species diversity, species richness, and species evenness.
文摘Spatial and temporal variation in planktons and water quality parameters were investigated in order to determine the effects of seasonal water use on reservoir water quality and planktons’ diversity in Kulekhani Multipurpose Reservoir, Nepal. This study also focuses on interactions among various water quality parameters with planktons and how such interactions can affect the second major utility, the fish farming in the reservoir. The analyses of seasonal water samples collected from three different sampling locations in the reservoir showed that select water quality parameters varied significantly (P < 0.05) with sampling seasons (transparency: 30 - 250 cm, pH: 7 - 7.5, alkalinity: 30 - 120 mg/L, DO: 6 - 11.5 mg/L, CO2: 0.1 - 1.1 mg/L) and sampling locations (phosphate: 0.1 - 0.25 mg/L, nitrate 0.01 - 0.19 mg/L) in the reservoir. Three groups of zooplankton and four classes of phytoplankton, respectively with eleven and twelve genera, were identified and quantified in the reservoir. Among them, Cyclops, Asplanchana, and Keratella were most dominant zooplanktons while Synedra, Melosira and Peridinum were the most dominant phytoplankton in the reservoir water. The abundance of select zooplanktons (Cyclops, Keratella, Polyanthra), and phytoplankton (Navicula, Melosira, Amphora, Chroococcus, Staurastrum, Scendesmus) showed significant interaction between sampling sites and sampling seasons, while the other varied only with sampling seasons and/or sites. These results showed that seasonal water level fluctuations, along with the variation of water quality parameters, change the abundance and diversity of planktons’ in the reservoir. Such changes can negatively impact the fish in cage culture, affecting the livelihood of people extensively relying on these fish farming.
