Invasive Species

• Invasive Species: an organism that is not native to a specific location• Also called an introduced species• Often have a tendency to spread, which is believed to cause damage to the environment, human

economy and/or human health

• Asian long-horned beetle• Pest!• Cause death of elm, maple, poplar, and willow trees

Pollution

• https://www.youtube.com/watch?v=CVm1pB3iJOw

• https://www.youtube.com/watch?v=-OVNd6Fa9fg (0:27 – 4:10)

Acid Rain

• Overview of the water cycle:

Acid Rain

• What happens when pollutants from man-made and natural sources enter the water cycle?

Acid Rain

• Pollutants come from:• Natural sources, such as volcanoes and decaying vegetation• Man-made sources, such as exhaust from vehicles and burning fossil fuels

• Acid Rain: rain that is acidic and that is harmful to the environment

Acid Rain

• Sulphur dioxide and nitrogen oxides are the gases involved• Form sulphuric acid and nitric acid

• pH Scale: a scale to measure how acidic or basic something is• 0 = most acidic• 7 = neutral• 14 = most basic

Acid Rain

• Acid rain has a pH value of around 4.2-4.4• This is about 10

times higher than normal rain

Acid Rain

• Acid rain has many harmful effects on the environment• Forests• Ruins the soil• Trees grow more slowly• Lose their leaves• Die

Acid Rain

• Lakes and ponds• Fresh water

becomes more acidic• Fish and other

organisms living there can die

Acid Rain

• Human Life• Ruins metals and sculptures • Respiratory issues

Oil Spills

• Form of human pollution• Release of crude oil from tankers, drilling rigs and wells• Most spills occur in the water and ruin marine ecosystems• Can take years to clean up

Oil Spills

• Exxon Valdez (1989)• Approx. 100,000m3 of crude oil released• Wildlife was severely affected• Up to 250,000 seabirds• 300 seals• 247 bald eagles• 22 orcas

Oil Spills – Demonstration

• What happens to the feather when it is covered with oil?• Weight? Texture?

• What worked best in removing the oil?• What are some consequences of oil spills on birds? On the rest of the

ecosystem?

Pests and Pesticides

Pests & Pesticides

• Pest: any organism that is causing plants to produce less that they otherwise would

• Insects eat the plants• Weeds steal nutrients, light, and space from the plants• Fungi cause infections which can destroy a plant

Pests & Pesticides

Pests & Pesticides• What else could you consider a pest?

• Agroecosystem: unit of agricultural activity, including the living and non-living components involved and their interactions• Pesticides: substances meant for destroying insects or other

organisms harmful to cultivated plants

Pests & Pesticides

• Bioaccumulation: the build-up of toxic substances, such as pesticides, in an organism • Bioamplification (or Biomagnification): the concentration of a toxic

substance increases in organisms higher up in the food chain

Pests & Pesticides

• DDT dichlorodiphenyltrichloroethane • Colourless, tasteless insecticide

• Banned worldwide in 2001• Bald Eagles

Bioaccumulation

• Amount of DDT in prey (mg)• Ex. 5mg

• Number of prey organisms consumed• Ex. 10 mice

• Amount of DDT accumulated by predator (mg)• Ex. 50mg

Amount of chemical in prey x number of prey consumed = amount of chemical in predator