Human induced, or cultural eutrophication, is usually due to the discharge of fertilizers , sewage, or detergents which contain high levels of phosphates [1].
There are a number of things that you can do to prevent eutrophication if you care about the environment, including:. The best, easiest, and most efficient way to prevent eutrophication is by preventing excess nutrients from reaching water bodies. This can be done in a number of ways, the simplest of which is just being aware of the chemicals and fertilizers that we are using. If you put your fertilizer on just before a big rain storm, then most of it will be lost and will probably end up in the nearest waterway due to runoff.
In the same way, if you put too much fertilizer on then some of it will not be bound to the soil. We can also reduce the nutrient load due to sewage disposal by stopping our expulsion of it directly into waterways.
In developed countries this is a relatively minor problem, but many poor areas still release untreated human waste directly into rivers [3]. Once more, the easiest way of stopping excess phosphates associated with detergents entering waterways is by stopping the detergent itself entering the waterway.
How do we do this? By not using them at all! Trends in Ecology and Evolution 24 , Role of sediment and internal loading of phosphorus in shallow lakes. Tillmanns, A. Meta-analysis of cyanobacterial effects on zooplankton population growth rate: species-specific responses. Fundamental and Applied Limnology , Turner, A.
Blinded by the stink: nutrient enrichment impairs the perception of predation risk by freshwater snails. Ecological Applications 20 , Introduction to the Basic Drivers of Climate. Terrestrial Biomes. Coral Reefs. Energy Economics in Ecosystems.
Biodiversity and Ecosystem Stability. Biological Nitrogen Fixation. Ecosystems Ecology Introduction. Factors Affecting Global Climate. Rivers and Streams: Life in Flowing Water. The Conservation of Mass. The Ecology of Carrion Decomposition. Causes and Consequences of Biodiversity Declines. Earth's Ferrous Wheel. Alternative Stable States. Recharge Variability in Semi-Arid Climates.
Secondary Production. Food Web: Concept and Applications. Terrestrial Primary Production: Fuel for Life. Citation: Chislock, M. Nature Education Knowledge 4 4 Eutrophication is a leading cause of impairment of many freshwater and coastal marine ecosystems in the world. Why should we worry about eutrophication and how is this problem managed? Aa Aa Aa. Figure 1. Aquaculture ponds, such as these channel catfish production ponds, typically contain high concentrations of nutrients, such as nitrogen and phosphorus, due to regular feeding of the fish.
Figure 2. Figure 3. Helisoma trivolvis left and Physa acuta right are two of the most common freshwater snails in North America. Figure 4. A dead African buffalo Syncerus caffer found in a reservoir with a dense bloom of the toxic cyanobacterium Microcystis at the Loskop Dam Nature Reserve in South Africa. Given the widespread extent of water quality degradation associated with nutrient enrichment, eutrophication has and continues to pose a serious threat to potable drinking water sources, fisheries, and recreational water bodies.
Figure 5. Daphnia are generalist herbivores that play a powerful role in the structure and function of lake ecosystems and can have large effects on phytoplankton abundance, water clarity, and water quality when abundant. Despite dramatic improvements in water quality as a result of large-scale efforts to reduce nutrient enrichment e. Given that the demand for freshwater resources is expected to increase dramatically, protecting diminishing water resources has become one of the most pressing environmental issues and will likely become more complicated as climate change, species invasions, and pollution further degrade water quality and quantity Schindler Control and management of cultural eutrophication is a complex issue and will require the collective efforts of scientists, policy makers, and citizens to reduce nutrient inputs, to develop effective, long-term biomanipulation techniques, and to eventually restore aquatic communities.
References and Recommended Reading Arend, K. Francis, G. Poisonous Australian lake. Nature 18 , Wilson, A. Effects of cyanobacterial toxicity and morphology on the population growth of freshwater zooplankton: meta-analyses of laboratory experiments.
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No topic rooms are there. Lead Editor: Ecosystem Ecology. Or Browse Visually. Other Topic Rooms Ecology. Consequently, the accumulation of sediments starts to fill the basin and, increasing the interactions between water and sediment, the resuspension of nutrients present at the bottom of the basin is facilitated N. Sechi, This phenomenon could in fact lead to a further deterioration of water quality, accentuating the processes connected with eutrophication V.
Tonolli, Eutrophication is characterised by a significant increase of algae microscopic organisms similar to plants due to the greater availability of one or more growth factors necessary for photosynthesis, such as sunlight, carbon dioxide and nutrients nitrogen and phosphorus.
When algae start to grow in an uncontrolled manner, an increasingly large biomass is formed which is destined to degrade. In deep water, a large amount of organic substance accumulates, represented by the algae having reached the end of their life cycle. To destroy all the dead algae, an excessive consumption of oxygen is required, in some cases almost total, by microorganisms. An anoxic oxygen-free environment is thus created on the lake bottom, with the growth of organisms capable of living in the absence of oxygen anaerobic , responsible for the degradation of the biomass.
The microorganisms, decomposing the organic substance in the absence of oxygen, free compounds that are toxic, such as ammonia and hydrogen sulphide H 2 S. The absence of oxygen reduces biodiversity causing, in certain cases, even the death of animal and plant species. All this happens when the rate of degradation of the algae by microorganisms is greater than that of oxygen regeneration, which in summer is already present in low concentrations.
An aquatic environment with a limited availability of phosphorus and nitrogen is described as "oligotrophic" while one with high availability of these elements is called "eutrophic"; a lake with intermediate availability is called "mesotrophic".
When the eutrophication phenomenon becomes particularly intense, undesirable effects and environmental imbalances are generated. The two most acute phenomena of eutrophication are hypoxia in the deep part of the lake or lack of oxygen and algal blooms that produce harmful toxins, processes that can destroy aquatic life in the affected areas www.
The main effects caused by eutrophication can be summarised as follows N. Sechi, : abundance of particulate substances phytoplankton, zooplankton, bacteria, fungi and debris that determine the turbidity and colouration of the water; abundance of inorganic chemicals such ammonia, nitrites, hydrogen sulphide etc. These substances, moreover, form complex chemical compounds that prevent normal purification processes and are deposited on the walls of the water purifier inlet tubes, accelerating corrosion and limiting the flow rate; the water acquires disagreeable odours or tastes of earth, of rotten fish, of cloves, of watermelon, etc.
In the light of these significant repercussions and serious consequent economic and naturalistic damage, there is a clear need to curb the progress of eutrophication, avoiding the collapse of the affected ecosystems. Control In the past, the traditional eutrophication reduction strategies, including the alteration of excess nutrients, physical mixing of the water, application of powerful herbicides and algaecides, have proven ineffective, expensive and impractical for large ecosystems Michael F.
Chislock, Today, the main control mechanism of the eutrophic process is based on prevention techniques, namely removal of the nutrients that are introduced into water bodies from the water. It would be sufficient to reduce the concentrations of one of the two main nutrients nitrogen and phosphorus , in particular phosphorus which is considered to be the limiting factor for the growth of algae, acting on localised loads loads associated with waste water and widespread loads phosphorus loads determined by diffuse sources such as land and rain.
The load is the quantity milligrams, kilograms, tons, etc. The possible activities to be undertaken to prevent the introduction of nutrients and to limit phosphorus loads can be summarised as follows www3. In cases where water quality is already so compromised as to render any preventive initiative ineffective, "curative" procedures can be implemented, such as: removal and treatment of hypolimnetic water deep water in contact with the sediments rich in nutrients since in direct contact with the release source; drainage of the first cm of sediment subject to biological reactions and with high phosphorus concentrations; oxygenation of water for restore the ecological conditions, reducing the negative effects of the eutrophic process, such as scarcity of oxygen and formation of toxic compounds deriving from the anaerobic metabolism; chemical precipitation of phosphorous by the addition of iron or aluminium salts or calcium carbonate to the water, which give rise to the precipitation of the respective iron, aluminium or calcium orthophosphates, thereby reducing the negative effects related to the excessive presence of phosphorus in the sediments.
Conclusions Water is not a commercial product like any other but rather a heritage which must be defended and protected, especially in the presence of a global decline in the availability of drinking water and increase in its demand. Despite the considerable efforts made to improve the water quality by limiting nutrient enrichment, cultural eutrophication and the resulting algal blooms continue to be the main cause of water pollution.
The prevention and protection action that countries must adopt to safeguard the quality of surface water as requested not only by the scientific community and other experts, but to an increasing extent also by citizens and environmental organisations, is therefore increasingly important ec.
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