6 threats to biodiversity and biodiversity crisis2
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UNIVERSITI TUNKU ABDUL RAHMAN
FACULTY OF ENGINEERING AND GREEN TECHNOLOGY (FEGT)
BACHELOR OF ENGINEERING (HONS) ENVIRONMENTAL
ENGINEERING
UGNA 1053 Biodiversity and Concept of Ecology
Group Assignment
Assignment Title : The Six Threats of Biodiversity and Biodiversity
Crisis
Date : 08 August 2011
Group Member & ID : Tan Yi Mi 11AGB01150Lee Pei Ing 11AGB00069
Lecturer : Ms. Wong Lai Peng
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ContentNo. Index Pages
1. Introduction 2
2. The Six Threats to Biodiversity
2.1Introduced and Invasive Species2.2Habitat Destruction2.3Overpopulation2.4Overexploitation2.5Pollution2.6Climate Change
3-16
3. Biodiversity Crisis 17
4. Conclusions 18
5. References 19-20
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Figure 1.1 Pie Chart of the number and percentage
of species in each IUCN Red List category for all
mammal species.
1.0 Introduction
Biological diversity, or biodiversity, is the variety of the earths species, the genes
they contain, the ecosystems in terms in which they live, and the ecological processes such as
energy flow and nutrient cycling that sustains all life. Biodiversity is a renewable resource.
Biodiversity makes up the structure of the
ecosystems and habitats that support essential
living resources, including wildlife, fisheries and
forests. It helps provide for basic human needs
such as food, shelter, and medicine. It composes
ecosystems that maintain oxygen in the air,
enrich the soil, purify the water, protect against
flood and storm damage and regulate climate.
Biodiversity also has recreational, cultural,
spiritual and aesthetic values.
The earths biodiversity is a vital part of nature that keeps us alive.
However, unfortunately, many plant and animal species on Earth are facing severe threats to
their survival and are disappearing at alarming rates. This is referred to as the biodiversitycrisis. Every day biodiversity is being lost at up to 1,000
times the natural rate and this is a rate that is rarely seen in
history as generally a species will last for an average of 2-10
million years (The IUCN Red List, 2010). On average, one
extinction happens somewhere on earth every 20 minutes.
Ecologists estimate that half of all living bird and mammal
species will be gone within 200 or 300 years (Phillip &Donald, 2002). This is mainly a result of human actions.
Over the last century, humans have come to dominate
the planet. Ecosystems are being rapidly altered for numerous
reasons, and the planet is undergoing a massive loss of
biodiversity due to the six major threats to biodiversity.In
this assignment, the discussion will mainly focus on the
six major threats of biodiversity and will briefly discuss
about the biodiversity crisis, its global effect and the ways to overcome it.
Figure 1.2 Proportion of all assessed
species in different threat categories
of extinction risk on the IUCN Red
List, based on data from 47,677
species. Source: IUCN
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2.0 The Six Threats to Biodiversity
2.1 Introduced and Invasive Species
Introduced species and invasive species are two different term. Introduced species are
species which live outside their native distribution range by human activity, either
deliberately or accidentally. Invasive species are introduced species which are harmful to
others local species and bring adverse affect to economic, environment, and ecology.
So, not all introduced species are invasive but all invasive species are introduced
species. For example oil palm in Indonesia and Malaysia are introduced species but not
invasive species because palm oil brings economic benefits to local. The Asian Long-horned
beetles in US are invasive species because the introduction of them caused thousands ofornamental trees has been destroyed, and harmed local environment. Most of invasive species
are introduced deliberately.
The growth and reproduction of the
introduced and invasive species may loss
control and become a threat to local biodiversity, and will bring negative effect to ecological
value, economic value and cultural value of biodiversity.
2.1.1 Study Case: Introduced and invasive speciesLamprey
Figure 2.1.1 Oil palm in Malaysia and Indonesia
Figure 2.1.2 Asian Long-horned beetle in US
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Lampreys are vertebrates under phylum
chordate which dont have jaws or paired fins.
Half of the lampreys are parasites. They attach
on fish with a sucking disk and sharp teeth then
suck fishs blood as food. They often scarring
and killing host fish. Lampreys originate from
Atlantic Ocean. They can live in both salt and
fresh water. Sea lampreys were accidentally
introduced into the Great Lakes in the early 20th century through shipping canals. Today, sea
lampreys can be found all over the Great Lakes.
As mention above, lampreys are so destructive. Introduction of lampreys into lake
cause many fish die under the attack of lamprey. Introduction of lamprey bring negative
effect to local ecosystem and economy. According to the statistics, each lamprey can kill 18.2
or more kilograms of fish. Even more, only one of
seven fish attacked by a lamprey will survive
(Great Lakes Fishery Commission, 2010). In some cases, lampreys start to attack human and
cause series injuries. Nowadays, human spent millions of dollars each year to control lamprey
population especially in North American Great Lakes.
Three major methods to control lamprey are:
1. Set up barrier between streams that feed the lake and lake to prevent lamprey distribute.
Figure 2.1.3 sucking disk and sharp teeth of
lamprey
Figure 2.1.4 Fish attack by
lamprey
Figure 2.1.5 Fish attack by lamprey
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2. Apply a type of toxicant called lampricides which are harmless to most other aquatic
species to kill lamprey.
3. Use chemically sterilized male lamprey in a method akin to the sterile insect technique.
2.2 Habitat destruction
Habitat destruction is the process by which natural habitat is damaged or destroyed to
such an extent that it is no longer is capable of supporting the species and ecological
communities that naturally occur there (Butler, 2006). It often results in the extinction of
species and loss of biodiversity. Habitat destruction can occur through natural processes or
human activity. Volcanism, fire and climate change may cause habitat destruction but human
activities are the major cause.
The growth curve above shows the shape of the increasing of human population in
20th century. But animal populations do not usually rise sharply. The increasing of human
population is putting pressure on natural resources. Hence, to get more resource we need to
exploit more and cause habitat destruction.
Below are some major causes of habitat
destruction:
Figure 2.2.1 The Graph of of Year Versus Human Population
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1. Logging: Product of trees are widely use in construction, furniture and our daily
life. In some developing country wood are uses as fuel. Collecting wood for fuel does
not necessarily destroy rain forests, but it does damage or degrade them. People are
cutting down the forest for wood and wood produce. Commonly only large prime tree
are cut down but smaller trees can be destroyed in process.
2. Urbanization: For more places to live human start to clear forest to develop city.
Cities replace the natural habitat of
animal and plant. Highways and
freeways can destroy plants and also keep animals from safely traveling through their
natural habitat.
3. Agriculture: For more food resource, land is clearing to plant crop and domestic
animal such as chicken, pig and cow. It will destroy natural habitat of wildlife.
2.2.1 Study Case : Tropical Rainforest in Malaysia
As we now, rainforest have most plentiful natural resource in the world. Almost 40%
to 75% of all biotic species are habitat in rainforest (Butler, 2006). Rainforest also play acritical role in oxygen and medicines provide. So, tropical rainforest have been called The
Jewels of the Earth.
Malaysia is covered with tropical rainforest
which have plentiful natural resource. According to
survey, Malaysia is home to 15,500 species of
plants, 746 birds, 300 mammals, 379 reptiles, 198
amphibians, and 368 species of fish (Butler, 2006).
But this few years, Malaysias deforestation rate is
accelerating faster than of any other tropical
country in the world. Malaysia annual
deforestation rate jumped at almost 86% between
the 1990-2000 period and 2000-2005. In total, Malaysia lost an average of 140200 hectares,
which is 0.65% of its forest area per years since 2000 compare to the Southeast Asian country
with a loss of an average of 78500 hectares, which is 0.35% of its forests per years since 1990
Figure 2.2.2 logging
Figure 1 Large scale of rainforest in
Malaysia are destroy to plant oil palm
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(Butler, 2006). The main factor cause deforestation in Malaysia is logging, mining,
agriculture and incomplete government policy to protect primary forest.
2.3 Overpopulation
Overpopulation is a condition when an organisms population numbers exceed the
carrying capacity of its habitat. Overpopulation here refers to human overpopulation. As we
know, human have a highly developed brain, capable of abstract reasoning, language,
introspection, and problem solving. But as a most successful developed species in the earth,
overpopulation of human became a major threat to biodiversity nowadays.
As mention above, human population have a shape increase since 20 century.
Nowadays the numbers of human in the earth are exceeding the carrying capacity of
environment. Humans are 10,000 times more common than we should be (Beliuz, 2008).
Exceeding the carrying capacity of environment causes the short supply of essential natural
resource including clean water, food, shelter, warmth and others resources to sustain life.
Short supply of essential natural not only affect human, but the others species too, and this
become threat to global diversity.
Human expend natural resource more than other species in the earth require making
their life more easy and comfortable but they dont cherish resource they get from earth. As a
result, the rate of human expend natural resources exceed the rate of replenishment and
reproduction of the natural resources. In addition, human activity such as agriculture, fishing,
manufacturing will cause environment pollution and accelerate natural resource depletion
(Beliuz, 2008).
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2.3.1 Study Case: Overpopulation in Singapore
Overpopulation often occurs in developed urban such as Singapore. Abundant people
immigrated into urban from working chance, completed medical care and education. As an
island country, Singapore geographically lack of natural resource such as fresh water, shelter,
forest product, and agriculture product. Hence, effect of overpopulation more obvious in
Singapore. For an example, Singapore lack of
terrace house, most Singapore public live in
flat because lacking of land to build house in
Singapore. Singapore government control
overpopulation through immigration control
and education.
1. Immigration control
Singapore has a set of complete immigration
control. To immigrate to Singapore, one
person has to pass a set of test such as English test and has to be professional with high
education level. People who are not Singapore residents cant buy house in Singapore. The
increasing of hardness to immigrate to Singapore directly decreases the immigrationpopulation size. Besides, according to survey, higher educational group will give birth to less
offspring compare to lower educational group. Less offspring helps to decrease pressure at
require natural resource.
2. Education
As mentioned above, higher educational group will birth less offspring compare to low
education group as people who receive high education spent more time to focus on their job
and have higher demand to their mate.
Women have a direct role in regulating the size of their family (Beliuz, 2008).
Women who receive high education will focus more on their child quality than quantity.
They will give their child the best education and resource. So they have no more remaining
economy ability to burden more children.
Figure 2.3.1 lack of shelter in Singapore
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Figure 2.4.1 This female rhino was chased off a cliff
by poachers armed with dogs.Her calf was left
orphaned and refused to leave its mother's body.
(Photo via Protrack Anti-Poaching Unit)
2.4 Overexploitation
Overexploitation is also called overharvesting.It is the over use of wildlife and plant
species by people for food, clothing, pets, medicine and many other purposes, and occurs
whena resource is consumed at an unsustainable rate. As an illustration, 25,000 species ofplants are recognised as threatened in this way by the Convention on International Trade in
Endangered Species (CITES)( Kew, 2011). Overexploitation occurs in the form of illegal
overhunting, wildlife trade,excessive logging and over-collection of plants from the wild.
Overhunting
Over-hunting has been a significant cause of the extinction of hundreds of species and
the endangerment of many more, such as whales and many African large mammals (Allan,
J.David; Fathom, 2001). Over-hunting can lead to extinction because the animals cannot
reproduce fast enough to keep up with human demand.From the earliest of times, hunting for
wild mammals and birds for food has been an important human activity as a means of
survival.More recently, however, hunting of animals for food has taken a back seat, and
hunting for their skin, tusks or bones has gained prominence. Besides, the animals are also
hunted for sports, zoos, pet trades, ornaments and jewelleries, biomedical researches and
education (some animals such as frogs are dissected in many biology classes).The way of
hunting also can threaten the biodiversity. Hunters sometimes seek animals far into remote
areas and use extreme methods, such as laying mines and traps rather than using the more
commonly used methods and tools such as guns, nets and dogs. This may caused non-
targeted species being captured.
Illegal Wildlife Trade
Some protected species are
illegally killed for their valuable parts or
are sold live to collectors and may
endanger many larger animals and some
rare plants. Globally this illegal trade in
wildlife earns smugglers at least $10 billion
a year-an average of $19,000 a
minute(Miller & E.Spoolman, 2009).
Rapidly growing wildlife smuggling is a high profit, low risk business because few of the
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smugglers are rarely caught or punished. At least two-thirds of all live animals smuggled
around the world die in transit(Miller & E.Spoolman, 2009). Joe Walston, director of the
Wildlife Conservation Societys Asian programs, called the illegal trade in wildlife the
single largest threat to biodiversity in Asia(Rudolf, 2010).Excessive Logging and Over-Collection of Plants from the Wild
Plants are vital to our survival and
are the foundation of most of the Earths
ecosystems. People harvest plants for
food, medicine, building materials, and as
raw materials for making other products.But too many plants are taken from the
wild can lead to extinction.Some plants
which are collectedfor ornamental uses,
such as orchids, are so prized by
collectorsthat they are now endangered
and legally protected from poaching by
international law. Forests are overexploited when they are logged at a rate faster thanreforestation takes place. Tropical forests are so important because they harbour at least 50%,
and perhaps more, of world's biodiversity (Miller & E.Spoolman, 2009). Direct observations
reinforced by satellite data, documents that these forests are declining and thecurrent rate of
loss is estimated at near 2% annually and caused the diminishing of biodiversity (Allan,
J.David; Fathom, 2001).
Overexploitation of species can result in knock-on or cascade effects. This can
particularly apply if, through overexploitation, a habitat loses its apex predator. Because of
the loss of the top predator, adramatic increase in their prey species can occur. In turn, the
unchecked prey can then overexploit their own food resources until population numbers
dwindle, possibly to the point of extinction.
2.4.1 Study case: Malaysias Fisheries
As fishing gear and boats have improved, the fishing industry has become very
efficient at harvesting fish and shellfish. The industrialization of the fishing industry and the
Figure 2.4.2 Excessive logging in the Temengor
Forest Reserve has resulted in erosion and damage to
nature.Picture courtesy of Malaysian Nature
Society.
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increasing world demand for seafood have people taking more fish from oceans, lakes and
rivers than is sustainable. As a result, 53% of the worlds fisheries are fully exploited and 32%
are overexploited, depleted, or recovering from depletion and as many as 90% of all the
oceans large fish have been fished out(WWF, 2010).
In Malaysia, fisheries play an
important role in culture and economy.
Malaysia is a nation with more sea than
land and there are more than 120,000
licensed fishermen and aquaculture
operators within the fisheries sector in
2007(WWF & Society, 2010). Despite
increase in revenue over the years, the
situation on the ground is worrying.
Fisheries resources have depleted since
1970, so much so that fish biomass has
declined as much as 90% between 1971 and 1997 in some fishing areas(WWF & Society,
2010). This is based on the Department of Fisheries' decadal resource survey that concludes
that the demersal resources in west coast and east coast of Peninsular Malaysia, the reefs offSabah and Sarawak was already over-exploited in 1997(WWF & Society, 2010).
The main threats to the fisheries resources are overfishing, which is harvesting the
fish resources more than its sustainable level, and the environmentally damaging fishing
practices as many fisherman uses non selective gears such as trawl nets which results in high
catch of non-targeted species and using cyanides and bombs to catch fish which can results in
the devastating of coral reefs and the marine environments.
Of course, it isnt the consumption of seafood that is to blame, but if the consumers
decide to stop buying threatened and undersized fish, the fishermen will have no reason to
catch those fish. The choice of the right ways of fishing is also important. This will reduce
the pressure on the species and allows it to restock. .
Figure 2.4.3 A trawling boat in the Indo-Pacific
fishing for orange roughy, Hoplostethusatlanticus.There is one orange roughy in the top left-hand
corner. (photograph courtesy of Right Bite program,
John G. Shedd Aquarium).
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Figure 2.5.1 Water Pollution due to
toxic discharges
Figure 2.5.2 Emissions from industrial factory
2.5 Pollution
Pollution is one of the most serious threats, as it is a prominent factor when it comes
to extinction of animal and plant species. Species with limited geographical range are the
most affected when it comes to extinction due to pollution. Pollution occurs when substancesare released into an environment where they can have a harmful effect on living and non-
living things. Human activities can pollute both on a local and global scale and may affect
water, soil and air, three of the most important natural resources.
Water pollution often occurs due to
industrial and municipal toxic discharges, bacterial
contamination, and nutrient buildup which the
nutrients are often originate as run-off from
fertilizers applied on agricultural fields. The excess
nutrients can cause algal blooms and deplete
dissolved oxygen levels.
Water Pollutants can sway the balance of an
ecosystem resulting in danger to natural wildlife of
aquatic environments. Amphibians tend to be very
sensitive to pollution due to the fact that they absorb chemicals in the water through their
skins. With addition of detergents to the eco-system, insects that normally have the ability to
walk on water will be unable to. Younger animals also have a greater sensitivity to chemical
compounds, especially those that mimic organic
compounds, since they are still undergoing the
physiological changes associated with maturation
(Fears, 2009). Water Pollution can also lead to
Biochemical Oxygen Demand which results to the
aquatic animals thriving on the dissolved oxygen
from air die of suffocation.
Air pollution can originate from many
sources, and most is caused by factories, power
plants, transportation engines, power and heat generation and even things like windblown
dust and wild fires. Air pollution is a great threat because all the living things breathe air. If
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Figure 2.5.3 This composite image shows the world light
use at night. (Credit: Data courtesy Marc Imhoff of NASA
GSFC and Christopher Elvidge of NOAA NGDC. Image by
Craig Mayhew and Robert Simmon, NASA GSFC.)
polluted air is breathed, the chemicals and fumes get into the bodies and make them
extremely sick.
Acid rain which caused by air pollution can caused a significant impact on
biodiversity as it will make the surrounding environment become acidic. Species that do not
tolerate acidic environments, especially those which live in the aquatic environment, will first
begin to lose the ability to reproduce. Even if a female is able to spawn, the young of the year
might not be able to survive the harsh acidic environment, and may be more susceptible to
disease or deformity (U.S Environmental Protection Agency, 2010).
Others pollution such as light pollution and soil pollution are also a great threat to
biodiversity. Soil acidification creates ecological dead zones, leaving areas unfit for plant life
and the animals that depend upon them as sensitive plant species are especially vulnerable to
changes in soil chemistry, causing plant die-offs and lower biodiversity.
2.5.1 Case Study : Decreasing Population of Birds and Light Pollution
Light pollution is defined as the
over emission of light from artificialsources in wrong directions, amounts or
spectra. The physiology and ecology of
species, the interactions between species,
and functioning of ecosystems is governed
in part by light. They have evolved to cope
with, depend on and take advantage of
natural darkness. A night sky without
artificial light is therefore vital to the proper
functioning of natural ecosystems. In
modern times, humans have developed and deployed extensive outdoor and indoor electrical
lighting. The outline of these lights is now visible from space and this shows that the light
pollution is getting worse nowadays.
Artificial lighting seems to be taking the largest toll on bird populations. In a light
polluted site, birds are continuous chirping throughout the night, in anticipation of a dawnthat will not arrive for many hours. This seriously disrupts their sleep patterns, preventing
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Figure 2.5.4 A bird hitting a window
due to light pollution
them from resting(British Astronomical Association, 2010). Night time lighting is adversely
affecting insect species upon which some birds feed and causing the declination of some
birds population .Light pollution also reduces the suitable area of feeding habitat for owls
and other night-hunting birds.
Nocturnal birds use the moon and stars for
navigation during their bi-annual migrations. When
they fly through a brightly-lit area, they become
disoriented, as they mistaken the illumination for
stars or the moon. The birds often crash into
brilliantly-lit broadcast towers, skyscrapers or buildings,
or circle them until they drop from exhaustion.
Sometimes whole flocks collide with over-lit structures. In 1981, over 10,000 birds slammed
into floodlit smokestacks at the Hydrox Generating Plant near Kingston, Ontario(Guynup,
2003). In 2000, volunteers gathered over 3,000 dead and wounded birds of 138 different
species in Toronto. In 2006, a further 2,000 dead birds from 89 different species were put on
display at the Royal Ontario Museum to encourage people to turn off unnecessary
lights(British Astronomical Association, 2010).
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2.6 Climate Change
Another threat that needs to be concern is climate change. People have added carbon
dioxide, nitrous oxide, methane and other greenhouse gases to the atmosphere by extracting
and burning fossil fuels such as coal, oil and natural gas.The effect of these gases has been to trap heat and
accelerate the rate of global warming and rapid climate
change.
Climate change is a major threat to terrestrial and
marine biodiversity and ecosystem function and itis
predicted to be the greatest long-term threat to
biodiversity in many regions and is listed as a key
threatening process under the Threatened Species
Conservation Act 1995 and the Environment Protection
and Biodiversity Conservation Act 1999
(Commonwealth)(NSW Government, 2011).
Global climate change threatens biodiversity
worldwide because it is modifying average
temperatures and rainfall patterns, and thereby
shifting climate zones.Although throughout Earths
history the climate has always changed with
ecosystems and species coming and going, rapidclimate change affects ecosystems and
species ability to adapt and so biodiversity loss increases. This can lead to a change in the
abundance and distribution of individual species around the globe and cause a rise in sea
levels and problems to many coastal ecosystems. An average increasing of 1.8 degree Celsius
of the global surface temperature over the last few decades is causing the water bodies in the
tropical areas to evaporate at a faster rate, thus results in loss of habitat for fish and
amphibian species in these areas.
A 2004 study by Conservation International predicted that climate change caused
mostly by global warming could drive more than a quarter of all land animals and plants to
extinction by the end of this century(Miller & E.Spoolman, 2009). Some scientific studies
indicate that polar bears and 10 of the worlds 17 penguin species are already threatened
because of higher temperatures and melting sea ice in their polar habitats.
Figure 2.6.1 Climate change is
contributing to the bleaching of coral reefs.
The top photo shows a healthy staghorn
coral reef, and the bottom one shows one
that's been bleached. Photos by NOAA and
Dave Burdick
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Figure 2.5.2 By fitting a GPS collar to a
female bear, the researchers found out that
this bear swam continuously for 232 hours
and 687 km and through waters that were 2-6
degrees Celsius (Davies, 2011).
2.6.1 Case Study : Polar Bears and Global Warming
Polar bears are mammals which live in one of the earths coldest environments, the
Arctic Circle. Evidence shows that the Arctic warming as twice as fast as the rest of the world,
and that the average annual area of floating summer sea ice in the Arctic is declining and is
breaking up earlier and earlier each year, and this has become a great threat to the polar bears.
According to a new report from WWF,climate
change is the number one threat to the 22,000
polar bears that remain in the world(Young,
2002).
Polar bears hunt, feed and give birth on
ice or on land, and are not naturally aquatic
creatures. As the melting of ice is getting
earlier and the forming of ice is getting later,
this means that, the time bears have on the ice
is shorter making it more difficult for them to
store the energy they need to survive the summer. As the periods without food become longer,
the overall body condition of these polar bears declines. This is particularly serious for bears
that are pregnant or have cubs, and for the cubs themselves.
The increased sea ice melts also pushed polar bears to swim greater distances to find
enough food and to spend more time during winter hunting, risking their own life. Although
polar bears are strong swimmers, they are adapted for swimming close to the shore. Their sea
journeys leave them vulnerable to exhaustion, hypothermia or being swamped by
waves. Severalstudies link global warming and diminished sea ice to polar bears starving or
drowning while in search of prey. The researchers were startled to find bears having to swim
up to 96.6km across open sea to find food(Iredale, 2005).
According to a 2006 study by the IUCN-World Conservation Union, the worlds total
polar bear population is likely to decline by 30-35% by 2050, and by the end of this century,
the bears may be found only in zoos. In 2007, the IUCN listed polar bears as threatened in
their annual red list of endangered species, and in 2008, the U.S. government listed the polar
bears as threatened under the Endangered Species Act(Miller & E.Spoolman, 2009).
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Figure 3.1 Graph of species extinction since 1800
based on a mathematical model linking species tohabitat loss developed by Edward O. Wilson and
others.
3.0 Biodiversity Crisis
Loss of biodiversity on which so much of human life depends, is one of the worlds
most pressing crises. Species have appeared and disappeared continually throughout Earth's
history, with extinctions occurring on average at arate of 0.1 to 1 species per million species-years.
However, nowadays every day species extinctions
are continuing at up to 1,000 times or more the
natural rate. Many scientists believe that the Earth
is heading into the sixth great period of extinction,
where up to a fifth of all species will be lost.
Geological and other records indicate that
the earth has experienced five mass extinctions
throughout global history and after each mass extinction, biodiversity eventually required
million of years to return to equal or higher levels (Miller & E.Spoolman, 2009). The crisis
facing species today differs in one fundamental way from the earlier five mass extinctions:
they have come about as the result of climatic change, a natural geological change or some
cataclysmic event. The present crisis, however, is being driven by human influences.
Biological diversity is the resource upon which families, communities, nations and
future generations depend. It is the link between all organisms on earth, binding each into an
interdependent ecosystem, in which all species have their role. It is the web of life. If human
activities continue to cause extinctions and the loss of biodiversity, this will threaten the
continuity of ecosystems and limit provision of goods and services to humans affecting
global economies and societies. Millions of people will face a future where food supplies are
vulnerable to pests and disease, and where fresh water is irregular or short supply. The
vulnerability of plants and animals to pests and diseases will also be increased. Ultimately, all
ecosystems will suffer by the loss of biodiversity and the balance of life on earth will be lost.
For example, damaged ecosystems lose the capability of soaking up and cleaning water,
leading to devastating floods and mudslides and poisoned and diminished ground water all
around the world; the extinctions of birds that play key and specialized roles on pollination
and seed dispersal, especially in tropical areas, may lead to extinctions of plants dependant on
these ecological services, and some specialized animals that feed on these plants may also
become extinct.
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4.0 Conclusion
The biodiversity crisis and threats may sound like yet another doom-and-gloom-
scenario. But biodiversity scientists are making progress in finding solutions to avoid this
crisis. Foremost, the major solution is reducing human population in sharp increasing rate.
Decreasing of birth rate is an important step to slow down population growth in each country
as it cans temporary slowdown natural resource consumption, but it was not enough. Human
need to reduce their consumption of natural resources (such as forest product, meat, water
and soil) to let renewable natural resources have enough time to replenish.
Since 20th century, rate of extinction increase obviously because rapid evolution of
science and technology. Although science and technology nowadays improve human life
causes the depletion of natural resource, it also can help in saving our biodiversity. For an
example, selective breeding technology can produce plants and animals species which more
adaptive to environment and produce high quality and quantity offspring accelerate natural
resource replenish rate. By help of technology, concept of environment protection and
important of biodiversity can dispersal through media such as ratio, television and most
efficiency way is internet. Video or news about environment protective or after effect of
pollution may dispersal rapid through social network like Facebook, Youtube, and Twitter.
Moreover, government can use existing environmental laws and treaties and work to
enact new laws designed to prevent premature species extinction and protect overall
biodiversity. Creating and maintaining wildlife refuges, gene banks, botanical gardens, and
national park is also another way to protect the biodiversity.
Another step toward a solution to the loss of biodiversity is education. There are many
small steps that seem far too simple to work but which, if practiced by everyone, would go a
long way toward solving some of the problems. Walking or bicycling instead of driving,
using energy-efficient appliances, cutting down our dependence on fossil fuels are part of a
solution to biodiversity that almost anyone can put into practice easily. Problem of pollution
will more easy to solve, and reduction of consumption of natural resource will be more
efficiency if everyone have concept of environment protection.
From time immemorial, nature has fed us, cured us, and protected us. But today the
roles have switched. We need to feed nature, we need to cure it and protect it if we want to
secure a healthy and prosperous future for our next generation
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5.0 Reference
1. Kew. (2011). Over-exploitation . Retrieved from Royal Botanic Gardens:http://www.kew.org/msbp/why/overexploitation.htm
2. Allan, J.David; Fathom. (2001). Threats to Biodiversit. Retrieved from The University ofMichigan: http://www.fathom.com/course/21701785/session2.html
3. Beliuz, J. (2008, October 7).Leading geneticist Steve Jones says human evolution is over.Retrieved from The Sunday Times:
http://www.timesonline.co.uk/tol/news/science/article4894696.ece
4. British Astronomical Association. (2010). The Treats to Wildlife. Retrieved from BritishAstronomical Association's Campaign of Dark Skies: http://www.britastro.org/dark-
skies/wildlife.html
5. Butler, R. A. (2006, February 4).Malaysia's Tropical Rainforest. Retrieved fromMongabay.com: http://rainforests.mongabay.com/20malaysia.htm
6. Davies, E. (2011, January 25). Polar bear's epic nine day swim in search of sea ice.Retrieved from BBC Earth News-Reporting Life on Earth:
http://news.bbc.co.uk/earth/hi/earth_news/newsid_9369000/9369317.stm
7. Eldredge, N. (2005). The Sixth Extinction. Retrieved from ActionBioscience.org:http://www.actionbioscience.org/newfrontiers/eldredge2.html
8. Fears, S. (2009, January 12).Effects of Water Pollution on Aquatic Ecosystems.Retrieved from Bright Hub: http://www.brighthub.com/environment/science-
environmental/articles/13705.aspx
9. Great Lakes Fishery Commission. (2010). Sea Lampreys: A Great Lakes Invader.Retrieved from Great Lakes Fishery Commission.org: http://www.glfc.org/lampcon.php
10.Guynup, S. (2003, April 17).Light Pollution Taking Toll on Wildlife, Eco-Groups Say.Retrieved from National Geographic News:
http://news.nationalgeographic.com/news/2003/04/0417_030417_tvlightpollution.html
11.Iredale, W. (2005, December 18). Polar bears drown as ice shelf melts. Retrieved fromThe Sunday Times: http://www.timesonline.co.uk/tol/news/uk/article767459.ece
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8/3/2019 6 Threats to Biodiversity and Biodiversity Crisis2
21/21
20
12.Miller, G., & E.Spoolman, S. (2009).Essentials of Ecology. United States: YolandaCossio.
13.National Wildlife Federation. (2010). Overexploitation. Retrieved from WildlifeConservatiion: http://www.nwf.org/Wildlife/Wildlife-Conservation/Threats-to-
Wildlife/Overexploitation.aspx
14.NSW Government. (2011, April 11). Climate change impacts on biodiversity. Retrievedfrom Office of Environment Heritage:
http://www.environment.nsw.gov.au/biodiversity/climatechange.htm
15.Rudolf, J. C. (2010, September 3). Vietnam Raids Restaurants Selling Exotic Meats.Retrieved from The New York Times:http://green.blogs.nytimes.com/2010/09/03/vietnam-raids-restaurants-selling-illegal-
exotic-meats/?partner=rss&emc=rss
16.The IUCN Red List. (2010, September 03). Why is Biodiversity in Crisis? Retrievedfrom The IUCN Red List of Threatened Species:
http://www.iucnredlist.org/news/biodiversity-crisis
17.U.S Environmental Protection Agency. (2010).Air Pollution. Retrieved from AquaticBiodiversity: http://www.epa.gov/bioiweb1/aquatic/airpoll.html
18.WWF. (2010). Unsustainable Fishing - Our Ocean has Plundered. Retrieved from WWFGlobal: http://wwf.panda.org/about_our_earth/blue_planet/problems/problems_fishing/
19.WWF, & Society, M. N. (2010). Fisheries Scenario. Retrieved from S.O.S Save OurSeafood: http://www.saveourseafood.my/about/fisheriesScenario.html
20.Young, E. (2002, May 15). Climate change threatens polar bears. Retrieved from NewScientist: http://www.newscientist.com/article/dn2285-climate-change-threatens-polar-
bears.html
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