Bio Ringkas No9

7/27/2019 Bio Ringkas No9

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Chanpter 9: Endangered ecosystem

The impact of human activities on the ecosystem in the ecosphere.

a) Pollution

The desire of humans to overcome their limiting factors have resulted heavy damage to nature.

Constant deposal of human waste has taken the toll on nature as humans dump rubbish and chemicals

in the river and more. To be more specific, there are 4 kind of common pollutions that are caused by

human activities.

Water pollution

Mainly caused by chemical factories with an irrational waste dumping management system. Spillage

of oil tankers in the seas also causes heavy damage to the seas like what happened at the Gulf of

Mexico. Domastic waste like synthetic foams and solutions like hard and soft detergents would

effect the oxygen supply of aquatic organisms.Water pollution causes an heavy imbalance and

damage to the ecosystem of aquatic life. Corals, which are sensitive animals and slight pollution to the

aquatic system would cause all of them to die. The niche of plankton that lives in the sea would not be

able to cope with the changes of the water and a big amount of them would die. Since plankton is the

most important organism in the aquatic food chain, this would indirectly cause most the aquatic life to

face extinction and this shall devastate the livelihood and economy of humans. Mercury is even worst,

as humans dump mercury into the aquatic ecosystem, the mercury content would not be lost and

would accumulate and become a large amounts. When humans consume large amounts of mercury

seafood, the neuron system would have some side effects, aka mental retardation.


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Noise pollution

Noise caused by vibrations of air that are caused by the discharge or energy by something. Humans

use a lot of machines that cause noise pollution and this annoys the organisms in a ecosystem. Car

engibes and engineering appliances caused a lot of annoying noises and this might cause confusion

to animals that depend on sound reflection to communicate. Bats, whales and dolphins would not

be able to navigate themselves efficiently. Also, animals that are sensitive to noises such as dogs and

cats would get annoyed and would go into a frenzy. Loud noises also increases the secretion of

andrenaline which increases the heartbeat and respiration of a human and this would lead to shock.

This is not good for health.

Thermal pollution

Caused when power stations discharges hot water without cooling into nearby streams and lakes.

Hot water would cause the change of temperature in the streams and aquatic life would experience

a sudden increase iof external temperature and may get cooked underwater. Hot water also

encourages the growth of algae and the increase of algae causes a higher biological oxygen demand

(B.O.D) and this would cause aquatic life to get lesser oxygen. To make things worst, oxygen is not

able to diffuse through hot water efficiently. The lack of oxygen in the water would cause a

permanent change in the ecosystem of the stream or lake.


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Air pollution

Happens when irresponsible factory owners discharge smokes of pollutants like sulphur monoxide

and sulphur dioxide gases and also nitrogeneous gases. The discharge of this poisonous gases

without filtering them would cause these gases to participate the hydrological cycle, which would

cause devastating effects. As sulphur dioxide combines with water, it forms sulphuric acid and when

it rains, in literally rains sulphuric acid. Acid rain would cause corrotion of manmade structures and

would also effect the plant life of the planet. Plants cannot grow in an acidic medium, which means

they are finished when sulphuric acid rains down upon them.

b) Deforestation

Caused by humans who wanted to remove a limiting factor --- livings space. As the population of

humans grow on the planet, humans need more space so that the population can have more space

to live. Also humans need to clear land to raise food stock to the humans would have a constant

food supply so that they have enough to eat. Forests are also seen as money makers because woodcan be made into expensive appliances and rare plants can be sold for a high price and can be used

to conduct medical research. But, the removal of forests causes a large imbalance to the ecosystem

because this would cause the ecosystem to become less diverse because of the lack of niches. Less

communities of animals would exists and also the nitrogen and phosphorous cycle would suffer

displacement. Also, the lack of trees means water does not have a water catchment area after a rain

has occurs in the area. As a result, during the runoff, stilt and mud would also flow with the water at

a higher speed. As a result, the soil would be solf and dry very fast. Soft soil has a potential danger to

cause land slides to occur in high areas which would endanger peoples lives. And also, the lack of

trees would also mean that the soil would become infertile. This would not benefit the humans at all.

Also, as more mud and stilt gather at the base of the lake or river, the lake/river would become

more shallow and would eventually lead to flash floods during the monsoon period.


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c) Flash floods

Flash floods are not only caused by a shallow river/lake, but also a poor management system. As the

human population grows, human waste would increase day by day. Not only that, there are also

humans who just love to throw rubbish into the water flow area (the drains). Poorly managing this

would cause flash floods to just happen when there is rain because water has no place to flow in the

drains. Flash floods cause heavy property damage as what happened in Singapore and Kuala Lumpur.

e) Eutrophication (healthy development)

When humans do agricultural activities, this inadvertly happens. Phosphorous and nitrogen

fertilizers, when used in excess, shall flow with water into the river or lakes. Nitrogen and

phosphorous are both nutrients required by plants so that they grow better. But for algae that grow

by the sides of the river or lakes, it works too well. Excessive growth fertilizer would cause these

algae too bloom at alarming rates. When algae blooms at a very fast rate, it would cover the surface

of the river/lake and this would prevent underwater autotrophs to undergo photosynthesis, thus

making aquatic life has lesser food resourse. Also, after the algae blooms and then dies,

microorganisms and bacteria would decompose these algae, but the need for oxygen to decompose

the dead algae would then increase the biological oxygen demand (B.O.D) of the ecosystem. With

the oxygen supply depleted, all underwater organisms would face difficulty in doing respiration and

would eventually die. Also, some microorganisms, when faced with lack of oxygen, would do

anaerobic respiration and would release byproducts harmful to the underwater inhabitants. Even

though the algae are finally cleared one day, the ecosystem of aquatic organisms would have

changed forever.


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g) Extinction

Extinction, a common thing among k-type selective organisms. The rapid change of the natural

ecosystem caused by humanity has landed a blow to them because these organisms need a longer

time to adapt to the environment properly. Other than that, they have low birth rate, and even

though having long life expectancies, it doesnt help because continuous poaching would eventually

kill them off without them having a chance to produce. This makes r-type selective organisms on the

other hand, have a better chance to survive in the narural system that is being alter too fast because

they reproduce a lot at once. Currently, around 1 million species have gone extinct and another

20million are considered endangered today. What a future there is for these organisms! They would

all be gone by another 2 millenniums I think.


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The greenhouse effect and the thinning of the ozone layer

a) The greenhouse effect

What is the green house effect? To explain this, we hould explain that is a greenhouse first. A

greenhouse is a specially build glass house usually found in the botanical gardens. Its exterior iswholly made up of glass so that heat from the sun would be trapped and ventilated inside the

glasshouse through radiation. Basically it works like a thermal ventilation system to sustain heat

internally and this is particularly useful when doing agriculture during wintertime and at night. Plants

need suitable temperatures to grow properly, and this application of thermal convection is pretty

useful for increasing the food supply of humans. Also, to return the temperature back to normal,

one just has to open its vents to let outside cool down the place. Some shopping malls and theme

parks in other countries install glass frame so that the place wont be cold during wintertime. Quite

innovative isnt it?

But when this thermal ventilation effect happens on a very large scale, really bad things happen.

Most people regard carbon dioxide as a harmful gas, in reality, it actually isnt. It is only harmful in

when there is a sudden large quantity of it being produced. The same thing goes for oxygen, duringthe carboniferous period 3 billion years ago, the amount of oxygen in the air actually brought a mass

extinction of plants because the overproduction of oxygen gas inadvertaly cooled down the planet

because of the decrease of the carbon dioxide gas. Why is carbon dioxide important then? Because

it acts as the temperature regulator of the planet and it matters. Inversely, if there was more carbon

dioxide in the atmosphere, then the planet shall eventually become hotter, isnt that right? How

does carbon dioxide trap heat? Well, when the sun radiates radiation (electromagnetic energy) to

planet earth, the radiation is usually reflected back to space as infrared radiation. Other cases do not

react with infrared radiation, but carbon dioxide does! Carbon dioxide absorbs the infrared radiation

and the electromagnetic energy is converted into kinetic energy via molecular vibration. Heat energy,

that is still present, doesnt escape the Earth but instead kept inside and heat is transferred through

molecular vibrations. This makes the heat unable to escape; instead it goes back to the Earth, thus

increasing the temperature of Earth.


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The words global warming and climate change seems to be very important words since the 21st

century and everybody has pointed their fingers to carbon dioxide as the main culprit. Well, it is

certainly true that it seems hotter these days, way above than before. Now, it is about 30 Celsius

everyday and the planet is certainly getting hotter. If carbon dioxide is the one causing all of this,

then where did this large amount of come from, an amount so big that it actually heated up the

planet!

Carbon dioxide is a covalent compound that consists of carbon and oxygen. To make this, we must

have carbon FIRST. Carbon has been log here since the birth of planet Earth, but the large amounts

of carbon dioxide now doesnt make sense, cause we have plants.. No, we have lesser plants

now! NOOOOOO.


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The industrial revolution is the root of all these carbon problems we have now. Smart animals called

homo sapiens managed to figure out how to make stuff do things without needing themselves to do

stuff. How lazy of them. Sapiens created machines that do their bidding, from draining water out

before to having a vehicle today. Thats right, the sapiens manage to find out stuff that produce

energy to do work-----coal. Coal is made up of carbon of course, and also a little bit of exerted

pressure is done. Basically, to power up machines. Coal has to be oxidized to create energy, but as

coal get oxidized and BANG you get carbon dioxide. And thus carbon dioxide is released into the

atmosphere and the sapiens get the energy they want.

Industrial revolution: 18XX. Current year :2013. Its almost a century since sapiens thought up of

great things to do stuff. After coal, they got their hands on unrefined petroleum and later on,

natural gas. All of these are made up of carbon whether in molecules or atoms. And when they all

get oxidized, all of them grant carbon atoms which just love to form carbon dioxide with the oxygen

in the air. Oxygen is just lovable to carbon. Annnd as the human growth population keeps growing (7

billion ++ today) = more machines must use more energy to support everybody = more

hydrocarbons are needed = more carbon dioxide in the air. DAMN

So where in the name of ---- did all these coal, petroleum and natural gas come from? A these

carbon compounds were form at the end of the carboniferous period. Thats right, after all, trees are

all made from carbon ( their lignin, their wood). When all of these trees in the rainforest collapsed 3billion years ago, all these trees sank into swampland, where all the soil sendimentation eventusally

piled up and later on exerting pressure on them. Thats where all the coal, petroleum and narutal

gas came from, and now we are technically releasing all of the carbon back into the atmosphere.


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As the temperature of planet increases, of course there would be some side effects on our planet. It

would feel hotter by the way, of and the increase of temperature by just 1 Celcius is capable of

throwing the ecosphere off balance. Some organisms are just so sensitive and they arent able to

cope with the temperature changes. Not only that, the higher the carbon dioxide content in the air,

that would mean more carbon dioxide would diffuse into the seas, forming acidic seas. Yeah, carbon

dioxide is quite soluble in water. And so the seas get acidic, and the first ones to suffer? The ones at

the bottom at the food chain, the autotrophic phytoplankton (must pH7!) , soon this would affect all

of the consumers of the world, including us, the sapiens. There would be lesser natural fish because

there arent enough producers. As we all know, the polar icecaps are melting and scientists are

estimating it would only take a mere 70 years for the artic to shrink into half if the temperature keep

rising. The sinking of countries has already happened and low lying areas like India, China and

especially South East Asia is going to get submerged. Billions killed by water! Nice headlines there.

Not only that, there is also carbon dioxide trapped in the ice since the last ice age and also

permafrost in the northern hemisphere. Once the temperature goes up, carbon dioxide gets

released by the ice and by the decomposing of dead plants, leading to a positive feedback system.More carbon dioxide=more heat=more carbon dioxide. Worst case scenario, the shutdown of the

thermohaline system, that is the global conveyer belt that keeps everything on Earth running

properly. With the thermohaline system shut downed (due to temperature increase that leads to

disturbance of climate that makes the system become more undynamic), underwater aquatic life

(those very deep down) would be unable to obtain food. Also there would be no more waves and

the seas would become literally a still body aka a lake. A big body of water with no movement and

no oxygen (cause system down) = all fishes are dead = Goodbye marine species. Not only that, when

bacteria are desperate to live in an oxygenless place, they resort to anaerobic respiration. As how

natural selection works, favorable traits are more favorable for reproduction, which leads to more of

these kinds of bacteria. Just to note that these bacteria are similar to the ones I stated in

eutrophication, yeah they have hydrogen sulphide as by byproducts (toxic that smells like rotten

eggs). Resulting a really big heap of poison gases in the atmosphere. Oh yeah, just forgotten to

mention that the shutdown of the thermohaline system shall result in climate change or some

bizarre environmental changes. A good example of this is show in the movie The Day After

Tommorow.

Nice job breaking it homo sapiens, how are we ever gonna fix this?


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b) The depletion of ozone layer

The ozone layer is a layer of ozone that is found in the stratosphere. It absorbs penetrating

ultraviolet radiation the sun. There are 3 types of ultraviolet rays that are emmited from the sun

based on their wave length, namely ultraviolet A (400-315nm), ultraviolet B (315-280nm) and

ultraviolet C (280-100nm). The ozone layer usually totally screens out ultraviolet C and partially

screen out ultraviolet B. Ultraviolet A is the ones that usually reach the surface of the planet but it is

not as harmful as its other 2 counterparts.

Ultraviolet A is the kind of radiation we feel on the earth, which, although not as harmful, but also

can cause skin diseases and other kinds of related stuff that we shall talk about below. Ultraviolet B

however is only partially screened because the ozone layer is able to absorb radiation wavelengths

between 200nm to 310nm with maximum absorption when it is 250 nm. The absorbed radiation

energy is usually converted into heat and shall disperse onto the Earth. Ultraviolet B with higher

wavelengths is able to penetrate the atmosphere and it usually causes sunburn and skin cancer to

the Earths inhabitants if exposed long enough. Ultraviolet C is the most harmful ultraviolet ray

emitted, with its small wavelength and thus higher frequency, it can penetrate the organisms and

would most probably cause genetic damage. Luckily, most ultraviolet C is totally screened out by the

ozone and also the dioxygen in the stratosphere.


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Ozone is a covalent compound formed by the bounding between 3 oxygen atoms (so its literally O3).

The ozone layer in our atmosphere was created when a diatomic oxygen molecule is photolysed by

higher frequency ultraviolet rays into 2 singular oxygen atoms. These oxygen atoms would go on to

bound with another oxygen molecule reacts with it (again energies form sun!!) and thus ozone is

formed. The ozone molecule enters a cycle called the Chapman cycle as it dissociates and discharges

from ozone back to oxygen molecules and then reforming ozone until it either reacts with an

oxygen atom or oxygen atoms are expelled from the cycle. When forming ozone molecules in the

cycle, inert gases (nitrogen, noble gases) take part in absorbing the excess energy released by the

formation to prevent the spontaneous decomposition of the ozone molecule.

The ozone molecule itself is quite special as it consists of a double bond and also a single bond. This

molecular structure is what makes it easier to dissociate back into dioxygen and oxygen atom. As

such, this occurrence within the Chapman cycle also brings a downside. Due to the pollution of the

environment, humans are releasing chemical radicles into the atmosphere, most notably chlorine

atoms (from CFC) and also nitrogenous oxides (NOX).


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Chlorofluocarbons, with the molecular structure of CFCl3 only consists of single covalent bonds. This

substance is relatively inert, non-toxic, non-combustible and also volatile. They were once used as

coolants in refrigerators and air conditioners. Most CFCs, after used are discharged into the

atmosphere due to their volatile nature. Since CFCs are inert, it reaches the stratosphere and is

photolysed by the suns UV radiations (by ultraviolet C), and this causes the CFCl3 to dissociate into

CFCl2 and a Cl atom. All hells break lose as the chlorine enters the chapman cycle as a radical

inhibitor that would disturb the single bonded oxygen in the ozone molecule. The reaction between

the chloride atom and the ozone molecule would cause the ozone molecule to dissociate back into a

dioxygen molecule and a chloride atom after 2 reactions.The overall result is the net removal of an

ozone molecule from the atmosphere. This single chloride atom would cause a chain of destruction

and is capable to destroy as much as 1x105

molecules of ozone unless removed by some other

reaction (methods shall be stated later).

Nitrogenous oxides (NOX) on the other hand are also capable of destroying the ozone layer as stated

above. (The group NOX may consist of NO, NO2,N2O, N2O5 etc.) These compounds are come from

the exhaust of high-altitude supersonic aircrafts and also from human activities. Similarly, the

nitrogenous oxide gets photolysed into nitric oxide (NO) at a certain wavelength and would

participate the Chapman cycle as a radical catalyst, thus producing nitrogen dioxide which would

then react with oxygen to return back to nitrogen oxide. And thus nitrogen would cause havoc at the

ozone layer repeatedly.

If chlorine monoxide is present in the atmosphere, then the nitrogen dioxide above shall combine

with it to produce Chlorine nitrate (ClONO2). Annnd molecule would then play a deadly role in the

depletion of ozone specifically in the poles. Chlorine nitrates reserves 2 atoms of chlorine in its

molecular structure. But why is the ozone layer at the poles dealt with large depletion of the ozonelayer as shown in the reports in the 1990s?

During the late winter solstice, atmospheric changes occurs and there is something called the polar

vortex is formed. Air that gets trapped in this vortex shall become extremely cold and this would

result in the formation of a kind of ice particles called the polar stratospheric clouds. These clouds

would act as a medium in converting hydrogen chloride (from volcanic gases)and chlorine nitrates

into a diatomic chlorine molecule and nitrite acid and this just keeps accumulating. In the spring

equinox, sun comes back, and everything get totally #### again. Photolysis of diatomic chlorine

atoms, formation of chlorine inhibiting radicals,the Chapman cycle get imbalanced, net loss of ozone

begins.


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So, what happens to us humans if the natural filter is gone? Lets talk about the good news first!

Firstly, ultraviolet (UVB) exposure increases the rate of production of vitamin B in our body, thus

promoting calcium metabolism. Well thats it. Now for the bad news: overexposure to ultraviolet B

would cause sunburn or maybe some other forms of skin cancer (like malignant melanoma).

Prolonged exposure to ultraviolet rays would also result in chronic and acute effects on our eyes

(retina ,lens ,cornea damaged), skin and our immune system. As stated above, ultraviolet C is a high

energy radiation wave and is also dangerous. Effects of ultraviolet C reportedly are carcinogenic and

mutagenic (mutates genetics). Ultraviolet A, B and C are all able to cause damage to the DNA. Well,

there is a lot more harmful stuff to talk about but I do not have time to talk about them.

There are ways that one can protect oneself from the ultraviolet radiation. Such instances including

applying sunblock to protect your skin and also wearing sunglasses to reduce the intensity of

untraviolet radiation entering the eye. But to obtain long term effects in reducing the depletion of

the ozone layer, steps must be taken. One way is by using a CFC substitute such as

hydrochlorofluocarbon -123 that would react with a hydroxyl radical decompose in the troposphere

before it even reaches the stratosphere to be photolysed. The product, chlorofluocarbon -123 would

not be able to react and released back into the environment. Side effects to humans is still

uncomfirmed. Other alternatives inclu the usage of hydrofluocarbons (HCFs). As they do not contain

the chlorine radical, they technically do not damage the ozone layer. Currently, we are using HCFs

instead of CFCs. CFCs is already banned in most parts of the world, with most developed nations

(including Malaysia) signed an international treaty called The Montreal Protocol that targets on

reducing CFC emission to complete elimination by the end of the 20th

century.


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Steps and ways to maintain a stable environment

a)Biological control

Cost-effective. Has lasting effects. Hell, maybe even cheaper than pesticides! Hurry and get your

very own owl or snake at the nearby exotic pet store now to get rid or control of these pesky pests.

Overbloomed flowers or annoying plants, go to the insect store to get some plant destroying insects!

Your life would be so much easier and you wouldnt need to use energy or hire others to get rid of

these plants.

Warning: If pets not selected properly to suit your needs, it might cause imbalance to ecosystem and

harm populations of other organisms that you never intend to harm. Might become another pesky

pest to you if not managed properly. So think twice before purchasing.

Laws and conditions apply.

b) Implementation of laws (Malaysian laws)

All below are obtained/directly copied from the Success reference book:

Environmental Quality Act 1974 and 1989

Legislation that regulates and governs the prevention and control of pollutions well as enhancement

of the environment.

National Forestry Act 1984

Act that aims to protect and preserve the forest and wildlife of the country.

Protection of Wildlife Act 1972

A law that aims to consolidate the laws relating to and to further provide the protection of wild life

and for purposes connected with it.


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c) Technological advancement

Ever heard of catalytic converters? They are specialized devises that are installed in the vehicles

exhaust system that catalyze (increase the rate of reaction) harmful exhaust gases into less harmful

gases.

d) Increase energy efficiency

If humans manage to create a perfect machine that can fully utilize the imput energy into the

machine, there would be less energy being wasted. This would maximize output and there would be

a more net amount of gain compared loss. Good examples include hybrid cars.


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e) Preservation and conservation

As responsible homo sapiens, we have to play our part in conserving and preserving the natural

ecosystem. We should do stuff like planting more good shady trees but nobody does that except

botanists and hired workers. Homo sapiens can also work together to conserve the environment and

to protect it from other homo sapiens to balance the equilibrium of nature. Recycle too.

f) Resource management education

Factory managements should have environmental officers that receive professional training to

ensure that they would not break the law and also protect the dignity of their employees. Good

training programs like ISO14001 should be able to produce a responsible and disciplined

environmental worker that cares about the environment and strive to protect it.

Bio Ringkas No9

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