ecosystem

Presentation Prepared by:MuhamadNabeelUddin

Syllabus objective/contentsSection E

4.1. Recycling of biodegradable and non-biodegradable materials

5.1 Negative impact of human activity on the environment

5.2 Pollution of marine and wetland environments

5.3 Conservation

Population growth

The table below shows the growth of human population from 1650 to 2012

Year Population (billions)

1650 0.5

1930 1

1965 3.5

1980 4.5

2012 7

Is such an increase in population beneficial or harmful?

Justify your response

Complete the table below- Benefits or harm of rapid human population growth

Benefits Harm

A typical growth curve e.g. of bacteria

What are some possible negative effects of rapid growth in human population?

Increase in demand for food, and increase in number of people dying of starvation and people suffering from deficiency diseases (demand more than supply)

Increase in demand for energy

More land space will be needed for housing and agriculture

Increase rate of deforestation increase effects of climate change

Factors affecting growth of Natural Populations

Competition for food, water, oxygen and space: Resources available can only support a finite number of organisms. However, competition may also help to keep the number of organisms in check (prevent overpopulation of one type of species). This is an advantage in some cases e.g. in human digestive system.

Effect of disease and pests: E.g. Black death/Bubonic plague killed 30-60% of Europe's population in the 14th Century. Pest may damage crops causing famine

1918 Flu pandemic-Killed over 50 million persons worldwide (wikipedia)

Factors affecting growth of Natural Populations

Natural Disasters: Fires, flood, hurricanes and volcanoesfor example can wipe out severalpopulations at once in ashort time (overnight maybe). E.g. Tsunami (causedby anearthquake) in Indian Ocean in 2004 killed more than230,000 humans and many other species of livingorganisms.

2004 Tsunami

Is Georgetown in a suitable location?

Waste products from Human Activities

Biodegradable

Can be recycled by biological means e.g. by bacteria

They are generally organic matter e.g. plant matter or animal waste

Can be recycled to make fertilizers (organic), or biofuel(e.g. methane gas)

Simple method: Compost

Non-Biodegradable wastes

Cannot be decomposed by biological means

E.g. synthetic plastics, metals, synthetic Styrofoam

Can be recycled e.g. Plastic bottles

When recycling, one need to considerCost of recycling

Storage cost/space

Collection and transport

PollutionTypes

Water pollution: e.g. chemical, thermal, or physical.

Air pollution: release of harmful gases

Land pollution: disposal of solid waste

Negative impact of Human Activities on the environment-Water pollution

Pollution by agricultural activities

Pesticide runoffs affects aquatic organisms and humans who consume them

Eutrophication : process where water bodies receive excess nutrients that stimulate excessive plant or algae growth (algal bloom)

Eutrophication

Some harmful effects of Inorganic/synthetic pesticides

Death of aquatic organisms

Cancer/tumors in animals or humans who consume affected animals

Reproductive problems and birth defects

Genetic change (Mutation)

Nerve disorders

Industrial WasteMercury in gold mining may affect aquatic organisms (cause mental retardation and paralysis in humans)

Heated water into river: from power stations

Other chemicals in river, streams e.g. oils used in heavy duty machines

Any other ?

Oil spillsToxic to marine life, and birds

Prevent flight in birds

Damage beaches and surrounding ecosystem

Water pollution-Industrial Waste

Improper sewage and garbage disposal

Release of raw, untreated sewage can cause Eutrificationbut more importantly, lead to spread of water borne disease

Improper disposal of garbage may lead to blockage of drainages, causing flooding. Flood may lead to loss of livestock, spread of diseases and loss of property

BiomagnificationsConcentration of pollutants increase at each trophic level of the food chain.

ReviewHuman population growth is very rapid

Large population increases demand for resources

Factors such as food, competition, disease and natural disasters affects/limits population growth

Water pollution can cause Eutrophication and Biological Oxygen Demand (BOD)/lack of oxygen in water

Heavy metals e.g. Mercury and lead are toxic, and may result in Biomagnifications

TodayAir Pollution

Climate change

Reducing pollution and conservation

Air PollutionMainly from burning of fossil fuels, release of gases from factories, or dust particles

E.g. of air pollutants: Carbon dioxide (Greenhouse gas)

Carbon monoxide

Oxides of sulphur (results in?)

Oxides of nitrogen (results in?)

Lead from car exhaust

CFC in aerosols. Break down ozone layer

What does air pollution cause?Acid rain

Global climate change/global warming

Affects health: increase asthma, respiratory disorder, cardiovascular disease

Effect of Acid rain on Monuments

Both marble and limestone consist of

CaCO3, which reacts with acid rain in an acid base

reaction to produce CaSO4. Because CaSO4 is

somewhat soluble in water, significant damage

to the structure can result.

Marine PollutionMarine ecosystem: includes oceans, estuaries and lagoons, mangroves and coral reefs, the deep sea and the sea floor

Marine pollution

occurs when harmful chemicals, particles, industrial, agricultural and residential waste

Noise (due to industrial activities)

invasive organisms enters into the marine habitat

A lagoon- a shallow body of water separated from a larger body of water by barrier islands or reefs.

Examples of Marine PollutionInvasive species can take over an ecosystem (dominate) and facilitate the spread of new diseases, jeopardize the ability of native species to obtain food.

Due to climate change

ocean water is becoming more acidic (suggest effects)

Water temperature is increasing

WetlandsA wetland is a land area that is saturated with water, either permanently or seasonally e.g. mangroves

Destruction and pollution to wetlands may be due to:

Commercial development : tourism

Drained wetland for agriculture

Polluted water affects entire ecosystem

Sea level rise: species of mangrove become submerged and die

Wetland

Wetland