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They can be changed and inactivated by heat, oxygen, light and chemical processes. Chemical forms of nitrogen are most often of concern with regard to eutrophication, because plants have high nitrogen requirements so that additions of nitrogen compounds will stimulate plant growth. August 23, at 9: Although eutrophication is commonly caused by human activities, it can also be a natural process, particularly in lakes. Micro Core Reinforced areas at 10 and 2 o'clock provide greater stability, power and spin in the functional areas of the upper hoop where many advanced players make contact. This is absolutely horrible!
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This process causes shifts in the species composition of ecosystems. For instance, an increase in nitrogen might allow new, competitive species to invade and out-compete original inhabitant species. This has been shown to occur  in New England salt marshes. In Europe and Asia, the common carp frequently lives in naturally Eutrophic or Hypereutrophic areas, and is adapted to living in such conditions.
The eutrophication of areas outside its natural range partially explain the fish's success in colonising these areas after being introduced. Some algal blooms , otherwise called "nuisance algae" or "harmful algal blooms", are toxic to plants and animals. Toxic compounds they produce can make their way up the food chain , resulting in animal mortality. When the algae die or are eaten, neuro - and hepatotoxins are released which can kill animals and may pose a threat to humans.
Examples include paralytic , neurotoxic, and diarrhoetic shellfish poisoning. Other marine animals can be vectors for such toxins, as in the case of ciguatera , where it is typically a predator fish that accumulates the toxin and then poisons humans.
In order to gauge how to best prevent eutrophication from occurring, specific sources that contribute to nutrient loading must be identified. There are two common sources of nutrients and organic matter: Point sources are directly attributable to one influence.
In point sources the nutrient waste travels directly from source to water. Point sources are relatively easy to regulate. Nonpoint source pollution also known as 'diffuse' or 'runoff' pollution is that which comes from ill-defined and diffuse sources. Nonpoint sources are difficult to regulate and usually vary spatially and temporally with season , precipitation , and other irregular events. It has been shown that nitrogen transport is correlated with various indices of human activity in watersheds,   including the amount of development.
There are three reasons that nonpoint sources are especially troublesome: Nutrients from human activities tend to accumulate in soils and remain there for years. It has been shown  that the amount of phosphorus lost to surface waters increases linearly with the amount of phosphorus in the soil. Thus much of the nutrient loading in soil eventually makes its way to water. Nitrogen, similarly, has a turnover time of decades. Nutrients from human activities tend to travel from land to either surface or ground water.
Nitrogen in particular is removed through storm drains , sewage pipes, and other forms of surface runoff. Nutrient losses in runoff and leachate are often associated with agriculture. Modern agriculture often involves the application of nutrients onto fields in order to maximise production. However, farmers frequently apply more nutrients than are taken up by crops  or pastures. Regulations aimed at minimising nutrient exports from agriculture are typically far less stringent than those placed on sewage treatment plants  and other point source polluters.
It should be also noted that lakes within forested land are also under surface runoff influences. Runoff can wash out the mineral nitrogen and phosphorus from detritus and in consequence supply the water bodies leading to slow, natural eutrophication. Nitrogen is released into the air because of ammonia volatilization and nitrous oxide production.
The combustion of fossil fuels is a large human-initiated contributor to atmospheric nitrogen pollution. Atmospheric nitrogen reaches the ground by two different processes, the first being wet deposition such as rain or snow, and the second being dry deposition which is particles and gases found in the air.
Any factor that causes increased nutrient concentrations can potentially lead to eutrophication. In modeling eutrophication, the rate of water renewal plays a critical role; stagnant water is allowed to collect more nutrients than bodies with replenished water supplies.
It has also been shown that the drying of wetlands causes an increase in nutrient concentration and subsequent eutrophication blooms. Eutrophication poses a problem not only to ecosystems , but to humans as well. Reducing eutrophication should be a key concern when considering future policy, and a sustainable solution for everyone, including farmers and ranchers, seems feasible.
While eutrophication does pose problems, humans should be aware that natural runoff which causes algal blooms in the wild is common in ecosystems and should thus not reverse nutrient concentrations beyond normal levels. Cleanup measures have been mostly, but not completely, successful.
Finnish phosphorus removal measures started in the mids and have targeted rivers and lakes polluted by industrial and municipal discharges. One proposed solution to eutrophication in estuaries is to restore shellfish populations, such as oysters and mussels. Oyster reefs remove nitrogen from the water column and filter out suspended solids, subsequently reducing the likelihood or extent of harmful algal blooms or anoxic conditions.
Nonpoint pollution is the most difficult source of nutrients to manage. The literature suggests, though, that when these sources are controlled, eutrophication decreases. The following steps are recommended to minimize the amount of pollution that can enter aquatic ecosystems from ambiguous sources.
Studies show that intercepting non-point pollution between the source and the water is a successful means of prevention. Creating buffer zones near farms and roads is another possible way to prevent nutrients from traveling too far.
Still, studies have shown  that the effects of atmospheric nitrogen pollution can reach far past the buffer zone. This suggests that the most effective means of prevention is from the primary source. Laws regulating the discharge and treatment of sewage have led to dramatic nutrient reductions to surrounding ecosystems,  but it is generally agreed that a policy regulating agricultural use of fertilizer and animal waste must be imposed.
In Japan the amount of nitrogen produced by livestock is adequate to serve the fertilizer needs for the agriculture industry. Policy concerning the prevention and reduction of eutrophication can be broken down into four sectors: Technologies, public participation, economic instruments, and cooperation. As mentioned before, nonpoint sources of pollution are the primary contributors to eutrophication, and their effects can be easily minimized through common agricultural practices.
Reducing the amount of pollutants that reach a watershed can be achieved through the protection of its forest cover, reducing the amount of erosion leeching into a watershed. Also, through the efficient, controlled use of land using sustainable agricultural practices to minimize land degradation, the amount of soil runoff and nitrogen-based fertilizers reaching a watershed can be reduced.
Because a major contributor to the nonpoint source nutrient loading of water bodies is untreated domestic sewage, it is necessary to provide treatment facilities to highly urbanized areas, particularly those in underdeveloped nations, in which treatment of domestic waste water is a scarcity.
The role of the public is a major factor for the effective prevention of eutrophication. In order for a policy to have any effect, the public must be aware of their contribution to the problem, and ways in which they can reduce their effects. Programs instituted to promote participation in the recycling and elimination of wastes, as well as education on the issue of rational water use are necessary to protect water quality within urbanized areas and adjacent water bodies. Economic instruments, "which include, among others, property rights, water markets, fiscal and financial instruments, charge systems and liability systems, are gradually becoming a substantive component of the management tool set used for pollution control and water allocation decisions.
By internalizing the costs associated with the negative effects on the environment, governments are able to encourage a cleaner water management. Because a body of water can have an effect on a range of people reaching far beyond that of the watershed, cooperation between different organizations is necessary to prevent the intrusion of contaminants that can lead to eutrophication. Agencies ranging from state governments to those of water resource management and non-governmental organizations, going as low as the local population, are responsible for preventing eutrophication of water bodies.
In the United States, the most well known inter-state effort to prevent eutrophication is the Chesapeake Bay. Soil Nitrogen Testing N-Testing is a technique that helps farmers optimize the amount of fertilizer applied to crops. By testing fields with this method, farmers saw a decrease in fertilizer application costs, a decrease in nitrogen lost to surrounding sources, or both. There has been a study that found that organically fertilized fields "significantly reduce harmful nitrate leaching" over conventionally fertilized fields.
Dredging helps in reduction of soil contamination that was caused by sewage sludge like fecal sludge , wilted plants, or chemical spill. Bokashi is a modern method of eutrophication prevention to decrease smell and toxic materials. After a few weeks, they would bury the waste. From Wikipedia, the free encyclopedia. Causes, Consequences, and Controls in Aquatic Ecosystems".
Retrieved 10 March Nasir and Mohammad, F. Department of Botany, Aligarh Muslim University. Skulberg Chapter 1. Toxic Cyanobacteria in Water: A guide to their public health consequences, monitoring and management. Encyclopedia of Quaternary Science , Vol. Impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems".
Environmental pollution Barking, Essex: Eutrophication, Causes, Consequences, Correctives. National Academy of Sciences, Washington D. A view from space". South African Journal of Science. A review of realities and challenges". Transactions of the Royal Society of South Africa.
Sitting on the Horns of a Dilemma: Water as a Strategic Resource in South Africa. In Liberty, No 6, Issue South African Institute of Race Relations. The signature technology remains the Isometric head shape, which is designed to feel roomier than conventionally shaped equivalents.
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