Eutrophication - A Global Aquatic Environmental Problem: A Review
Eutrophication has become a global aquatic environmental problem because of its ecological consequences, such as frequent outbreaks of algal blooms threatening the reliable supply of drinking water. Eutrophication increases biological oxygen demand (BOD) of water, release toxic gases, encourage profuse growth of aquatic weeds and all these have adverse effects on fish growth, fish spawning, domestic use and even navigation. Eutrophic water favours the growth of disease causing agents of health hazards. The enhancing rate of deposition of silt and organic debris in the eutrophic water body makes the water body slowly becomes shallower and shallower and as a result the water body slowly transforms into a wetland and finally converts into a dry land which ultimately leads to water crisis of the environment. As eutrophication is a global aquatic environmental problem, so currently our attention at the global level is how to minimize eutrophication through sustainable management of conservation of water resource. Minimization of eutrophication requires holistic efforts of some parameters such as physico-chemical factors of water should be analysed regularly, developing phosphate-free detergents for domestic use, removal of algal bloom by dredging, reducing the excessive use of fertilizers in the agricultural practices, mechanical aeration, effective waste water treatment etc. Recent research shows that climatic factors have profound impact on eutrophication. When the nutrient load is reaching a constant level in water bodies, increasing temperature, precipitation, wind speed and solar radiation from sunlight are generally expected to increase the risk of water eutrophication. Therefore, it infers that even if the external sources of nutrients are controlled by implementing governance measures, such as the control of waste discharges and non-point pollution, under climate change water could still become eutrophic due to the release of nutrient loading from internal sources.