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
Objective:To measure the productivity of water on the floodplain land in terms of fisheries and living aquatic resources based on two floodplain beels in Bangladesh.Methods:Among two beels,beel Mail is practicing comm...Objective:To measure the productivity of water on the floodplain land in terms of fisheries and living aquatic resources based on two floodplain beels in Bangladesh.Methods:Among two beels,beel Mail is practicing community based fish culture management,and beel Chandpur is open access and improperly managed.The production and market price data of fish,snail,and aquatic plants were collected by direct observation based on 30 samples fishers in the year 2006-2007.This study also collected production related water quality data,such as water temperature,pH and dissolved oxygen.Results:The water quality data are found within the normal range.Net aggregated water productivity values based on production costs were TK 8016.23 ha^(-1)and TK 3912.9 ha^(-1)and based on all cost TK 7160.97 ha^(-1)and TK 3741.13 ha^(-1)at beel Mail and beel Chandpur,respectively.The contribution of fish,snails and aquatic resources were 96.50%,3.10%,and 0.40%of the gross aggregated water produced in beel Mail and 87.85%,8.38%,and 3.77%in the beel Chandpur.The water productivity values in beel Mail are higher than in beel Chandpur due to the intervention of community based fish culture.Conclusions:The proper management and techniques of harvesting fish through appropriate number of fish fingerlings stocked,good quality of fish fingerlings,size of beel,good fencing and well defined embankment,etc.can help to improve the productivity of water in the beel areas.展开更多
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.
基金Supported by the World Fish Center,and Malaysian Commonwealth Scholarship(MCS),Ministry of Higher Education,Malaysia.
文摘Objective:To measure the productivity of water on the floodplain land in terms of fisheries and living aquatic resources based on two floodplain beels in Bangladesh.Methods:Among two beels,beel Mail is practicing community based fish culture management,and beel Chandpur is open access and improperly managed.The production and market price data of fish,snail,and aquatic plants were collected by direct observation based on 30 samples fishers in the year 2006-2007.This study also collected production related water quality data,such as water temperature,pH and dissolved oxygen.Results:The water quality data are found within the normal range.Net aggregated water productivity values based on production costs were TK 8016.23 ha^(-1)and TK 3912.9 ha^(-1)and based on all cost TK 7160.97 ha^(-1)and TK 3741.13 ha^(-1)at beel Mail and beel Chandpur,respectively.The contribution of fish,snails and aquatic resources were 96.50%,3.10%,and 0.40%of the gross aggregated water produced in beel Mail and 87.85%,8.38%,and 3.77%in the beel Chandpur.The water productivity values in beel Mail are higher than in beel Chandpur due to the intervention of community based fish culture.Conclusions:The proper management and techniques of harvesting fish through appropriate number of fish fingerlings stocked,good quality of fish fingerlings,size of beel,good fencing and well defined embankment,etc.can help to improve the productivity of water in the beel areas.
