bleof content Introductiona)EutrophicationEutrophication or moreprecisely hypertrophication, is a water body enriched withnutrients,with an excess amount of it.Certain nutrients are needed for survival of theliving thing.Primarily,nature is efficient enough to provide right amount ofnutrients,not less nor too much. This is absolutely true in aquatic ecosystemsbecause they are so dynamic.Water will be oligotrophic if there is too muchnutrient.Consequently,serious problems will occur if there is no nutrients in theaquatic environment of the organisms.
However,problems can also occur when there is too much nutrients too. When this occurwe get eutrophication. A eutrophic stream, river or lake occurs when too many nutrients,suchas nitrogen and phosphorous, are present, usually as a result of overflow ofthe land. Algae, plankton and other microorganisms attracted to these types ofnutrients, and when they are too much these aquatic organisms can take over.When eutrophication occurs in a lake, river or other aquatic system,it gives anegative impact on the organisms itself including humans,birds and fishes.b)DeforestationClearing of trees or removalof trees from the forest to make it into non-forest is called deforestation andit is also used for urban development.
Conversion of forestland to farms, ranches, or urban use are also examplesof deforestation.Tropical rainforests are the most commondeforestation area.One of the largest and severe issue in global land is noneother than deforestation. Croplands and grazing lands are estimated arearegarding deforestation which includes cutting down trees for wood products andso on due to urban usage.Due to this,whole forest is no more and wiped out dueto no more trees left in the forest.
In some cases,forest structure would bealtered if illegal logging and so called accidental fire occurs.The practiceof slash-and-burn agriculture isthe major contributor for deforestation.Small-scale farmers clear land producesfor only a few years and then must forests by burning them and then grow cropsin the soils fertilized by theashes.In Southeast Asia such as Indonesia, tropical Africa, and the Americasfor permanent oil palm plantations practiceopen fire burning to clear out the forests. c) Global WarmingTheobserved century-scale rise in the average temperature of the Earth’s climate system andits related effects called Global warming commonly known as climate change,The increase of average world temperatures as a result ofwhat is known as the greenhouse effect is global warming too. Ingreenhouse,certain gases in the atmosphere acts like glass, sunlight is allowedto heat the earth’s surface but it radiates back to the space if we trap theheat. The Earth gets hotter when the greenhouse gases build up in theatmosphere.
Consequently,this phenomena is called climate change.Sincethe mid-20th century the Scientist have gathered detailed observations ofvarious weather phenomena(such as temperatures, precipitation,and storms) and of related influences on climate (suchas oceancurrents and the atmosphere’s chemical composition).Earth’s climate indicated that it has changedover almost every conceivable timescale since the beginning of time and thatthe influence of human activitiessince at least the beginning of the IndustrialRevolution has been deeply contributed to the climatechange.d) Ozone depletionOzone is very importantand crucial to us and gives us the pros and cons.Asa result of many chemical reaction regarding air pollution which caused byheavy traffic and UV light formed ozone near the ground which eventually causeda lot of respiratory problems particularly for children and the elderly.However,the stratosphere, ozonefilters out incoming radiation from the Sun in the cell-damaging ultraviolet (UV)part of the spectrum are known as high up in the atmosphere in a region.Life onearth would not have evolved in the way it has without this ozone layer.
Single-celled organisms such as algae that make upthe bottom rung of the food chain inhibits the reproductive cycle ofphytoplankton with the help of extra UV B radiation shone onto Earth.The onlything fears the Biologist is that reductions in other animals due to low numberof phytoplankton..Excess ultraviolet B.
Chlorofluorocarbons (CFCs), chemicalsfound mainly in spray aerosols heavily used by industrializednations for much of the past 50 years, are the primary culprits in ozone layerbreakdown which ultimately causes the change in the reproductive rates of youngfish, shrimp, and crabs as well as frogs and salamanders.UV breaks down into substancesuch as chlorine due to CFC in the upper atmosphere exposed to UV.Chlorinereacts with the oxygen particle and tears down the ozone. e)PollutionWhen pollutants contaminate the naturalsurroundings; which changes our normal lifestyles quickly is called pollution.Ourecosystem and the balance in the environment are disturbed due to pollution.
Pollution occurs in Different forms of pollution can be found such as air,water, soil, radioactive, noise, heat/ thermal and light.There are two sourcesof pollution occurrence; the point and the non-point sources.The non-pointsources are hard to control whereas the point sources are easier toidentify,monitor and control.
Firstly,Air pollutionis a contamination of natural air with dangerous gases.It is one of the majorcontributor to environmental pollution. Landpollution occurs due to excess of dumping of toxic waste. This can be achemical or other waste material.
Sound pollution calledas noise pollution is a disturbance of silent environment with loudnoises.Radiation pollution is the pollution due to abnormalradiation in the environment. This occurs due to use of radioactive elementsfrom atomic energy stations.Thermal pollution arises becauseof excess heat from thermal power plants,industries involved in metal molding.
Water pollution is mainly aboutharmful toxic substances thrown by ignorant humans or released as residue byirresponsible companies.In other cases,ships release their unwanted oil intothe sea.f) Acid depositionAny other form of precipitation that is unusually acidic, elevated levels of hydrogen ions(low pH) is known as Aciddeposition.Plants, aquatic animals and infrastructure had negative impacts dueto acid deposition.Emissions of sulphur dioxide and nitrogen oxide, which react withthe water molecules in the atmosphere to produceacids is called acid deposition.
Wet and dry are the two types of deposition.Rain, snow, fog, hailor even dust that is acidic are included in the type of acid deposition.Dry deposition consist of acidicparticles and gases from atmosphere in the absence of moisture.
Duringatmospheric the acidic particles and gases may deposit to surfaces (waterbodies, vegetation, buildings) quickly or may react to form larger particlesthat can be harmful to human health. This acidic water flows over and throughthe ground, and can harm plants and wildlife, such as insects and fish when theaccumulated acids are washed off a surface by the next rain.The amount ofrainfall an area receives depends on the amount of acidity in the atmosphere thatdeposits to earth through dry deposition.For instance,the ratio of dry to wetdeposition is higher than an area that receives several inches of rain each yearin the desert areas.Causes and why it happensA)EutrophicationFertilizers (nitratesand phosphates)Ignorant human actions predominantly causes Eutrophication.Nutrientaccumulation consists of agriculturalpractices and the use offertilizers on lawns, golf courses, and other fields.
Surface runoff intolakes, rivers, oceans and other surface waters washes away these nutrients withhigh concentrations of phosphorous and nitrogen when it rains, photosynthesisactivity of the hungry plankton, algae and other aquatic plant life increases andwell fed.Dense growth of algal blooms and plant life in the aquaticenvironments are the consequence of this.Concentrated animalfeeding operationsPhosphorus and nitrogen nutrients and Concentrated animal feedingoperations (CAFOs) are the main contributor for eutrophication. The nutrients arenormally discharged through animal feeding that finds way into rivers, streams,lakes, and oceans whereby accumulation occur in large quantity with recurringcyanobacterial and algal blooms plaguing the water bodies.Direct sewagedischarge and industrial waste into water bodies Sewagewater is directly discharged into water bodies such as rivers, lakes, andoceans in some parts of the world, especially thedeveloping nations. As a result, it stimulates the dense growth of algal bloomsand other aquatic plants which threatens survival of aquatic life in many waysdue to the newly introduced high amounts of chemical nutrients.The sewage water may also be treated by some countries,but it is stilldischarged into the water after the treatment.
Causing of the accumulation ofexcess nutrients, ultimately bringing about eutrophication,as much as the wateris treated. Similar outcomes are present when direct discharge of industrial wastewater into water bodies. Natural eventsFloods and thenatural flow of rivers and streams are natural events which can prevent excessivegrowth of algal blooms by washing away the excess nutrients off the land intothe water systems.Accumulation of sediments as well as phosphorus and nitrogennutrients which contribute to the explosive growth of phytoplankton andcyanobacterial blooms will occur as lakes grow old.
The process of EutrophicationTwo essential nutrients such as Nitrogen (N) and Phosphorus(P) are needed by aquatic plants (like any other plants) to grow.Small amountsof nutrients required and occur in a healthy lake. But,major water pollution problem will be created if inlarge quantities.
The rapid growth of plants and algae, clogging waterways andsometimes creating blooms of toxic blue-green algae due to stimulation of toomany nutrients.Eutrophication is the processs.Result of this, largeamount of oxygen (O2) are used up due to thedeath of plants and decomposition of algae.So.
fish and other aquatic speciesoxygen level will be reduced from the availability.A complete oxygenlessenvironment that can support nothing except a few species of anaerobic bacteriawill occur in extreme cases.Fish and other aquatic life will be killed and theaesthetic and recreational value of the lake would be reduced.Nitrates are thenutrients found in sewage and fertilizers, and phosphates found in detergentsand fertilizers.A process called cultural eutrophication is the human inputs of nutrients fromthe atmosphere and from nearby urban and agricultural areas can acceleratethe natural eutrophication of lakes.Domestic sewage, industrial wastes and stormdrainage are the examples where nutrients from urban sources derived.
There is aconsiderable range where the contribution of nitrogen and phosphorus per person per day averages 10.8 gN and 2.2 g P.Detergents were developed containing sodium tripolyphosphate,which softens water by neutralizing calcium and keeps dirt in suspension onceit has washed off clothes in the 1940s.Cultural eutrophication in lakes happens due to the principalsources of nutrient overload.Types and amounts of human activities occurring ineach airshed and watershed varied according to amount of each source.Refer to Appendix A for further information B) DeforestationAgricultural Activities One of the major factors affecting Deforestationis agricultural activities.
Huge amount of tress are fell down to grow crops andfor cattle gazing due to overgrowing demand for food products.Illegal Logging Substantialamount of wood supply are prominent for wood based industries like paper,match-sticks, furniture etc., Therefore trees are chopped for supplies since woodis used as fuel both directly and indirectly.Examples of wood being used asfuel are firewood and charcoal.
These industries thrive on illegal wood cuttingand felling of treesUrbanizationTheconstruction of roads are undertaken; here again trees are chopped to createroads in order to gain access to the forest.Forest covers, as with the expansionof cities more land are affected by too direct overpopulation needs toestablish housing and settlements.Hence,forest land is reclaimed.Desertification of landDesertificationof land is the some of the other factors that lead to deforestation are alsopart natural and part anthropogenic.Growth of trees is not possible due to landabuse making it unfit.Soil erosion occurs and making it unfit to growplants and trees due to many industries in petrochemicals release their wasteinto rivers.MiningAconsiderable amount of forest land is required for oil and coal mining.
Apart from this,roads and highwayshave to be built to make way for trucks and other equipment.Pollution of theenvironment occurand affects the nearby species due to the waste that comes out from the mining.Forest FiresAnotherexample would be forest blazes;Forest fires in various portions of the worlddestroys hundreds of trees each year.Extreme warm summers and milder winters.Fires, whether causes by man or nature results in huge loss of forest cover dueto this. Palmoil Palm oil has its potentialas a biofuel and nowadays packaged foods and beauty products are using palm oil init.Another cause of deforestation is palm oil.Many Indonesian and Malaysian farmersdestroy acres of trees to harvest it due to rising prices make it morevaluable.
Several countries are currently debating a ban on palm oil as abiofuel for this reason.Trees are cut down tomake more room for houses and roads as cities grow larger to accommodate morepeople. Now that 50 percent of the world’s population lives in cities, this urbansprawl deforestation is occurring worldwide. Process of Deforestation Firstly, the main method of clearing trees for small farmers and plantation owners in the tropics Slash and Burn agriculture. This is because to remove unwanted parasites and organisms that reside in the desired land is the only way to do effectively.During season between June and October the burning usually happens. 20% of the fires in the world can be attributed to deforestation during this period. In order to release the minerals in the trees back into the soil, the trees are cut down and then later burned.
Soil in the tropics so very poor and nutrient deficient hence minerals are needed in the soil. After the first burn which only lasted for a few years due to the nutrients that are released into the soil due to the rain washing them away and their use for agriculture. Between 3 and 20 years after the trees removed,this can happen anywhere.
In order for the farmer to keep turning a profit, he will need to clear a new section of land and start over again at this time. Removing all the trees and vegetation, regardless of species, leaving the land completely bare is example of clear-cutting a forest.Scientists have no idea how long it takes the forest to recover since nothing is left on the land.
A method used both to clear the land and harvest trees for commercial logging purposes is Clear-cutting.The most destructive of all methods because nothing is left but the soil which is not even replenished by a burn is clear cutting. Only certain trees are chosen to be cut down in selective logging.
Research shows that during Selective logging, only about 3% of the trees are harvested are shown during the research. About 3%, and 49% of the trees are damaging in the process of harvesting. Selective logging is a relatively short 50 years,the period that it takes for vegetation to grow back in. This is because there are patches of tree left to disperse seeds and provide shade for the developing seedlings from too much sun. Perennial shade agriculture, like selective logging, leaves large areas of forest intact, so the period of regrowth is also relatively short. Only small areas of trees and vegetation are removed in order to leave adequate shade for the crops. This method of deforestation is employed by farmer of crops such as coffee and chocolate, which need the shade of large canopy trees.
Perennial shade agriculture has one of the fastest recovery periods of all the processes of destruction. Refer to Appendix B for furtherinformation C) GlobalWarmingThe main cause of the current global warming trend is human expansion ofthe “greenhouse effect” agreed by the most scientist.Heat is blocked incertain gases at atmosphere from escaping.Climate change are the long-livedgases that remain semi-permanently in the atmosphere and do not respondphysically or chemically to changes in temperature.Feedbacks are the gases,such as water vapor, which respond physically or chemically to changes intemperature.
Gases that contribute to the greenhouse effect include:Water vaporThe most abundant greenhouse gas, butimportantly, it acts as a feedback to the climate is water vapour.As theEarth’s atmosphere warms, but so does the possibility of clouds andprecipitation, making these some of the most important feedback mechanisms tothe greenhouse effect,as the water vapour increases.Carbon DioxideA minor but very important componentof the atmosphere, carbon dioxide is released through natural processes such asrespiration and volcano eruptions and through human activities such asdeforestation, land use changes, and burning fossil fuels is Carbon dioxide (CO2).Atmospheric CO2 concentration increased by humans by more thana third since the Industrial Revolution began. Climate change is the mostimportant long-lived.
MethaneA hydrocarbon gas produced boththrough natural sources and human activities, including The decomposition ofwastes in landfills, agriculture, and especially rice cultivation, as well asruminant digestion and manure management associated with domestic livestockproduce a hydrocarbon gas through natural resources and human activities.Methaneis a far more active greenhouse gas than carbon dioxide, but also one which ismuch less abundant in the atmosphere for a molecule-for-molecule basis. Nitrous Oxide The use of commercial and organicfertilizers, fossil fuel combustion, nitric acid production, and biomassburning by a powerful greenhouse gasproduced by soil cultivation practices.