1. Cycles & Bioaccumulation

2. Water Cycle
Describes the circulation of water on, above and below the Earth’s surface.
Surface: ponds, lakes, rivers, ocean, snow, ice…
Under: ground water
Above: water vapour H2O(g)
All this water continuously cycles through ecosystems by:
Evaporation
Condensation
Precipitation

3. Water Cycle Heat from the sun causes water on the surface to evaporate
Warm air rises, cools and condenses, forming clouds
Water fall back as rain, snow, sleet or hail
Water moves over the surface as “run-off” and will move to the lowest point
Note: your first skill refers to
solar energy and gravity

4. Transpiration
Water is absorbed by roots of plants, carried through the plant, and lost as H2O(g) through small pores in the leaves

5. Water Pollution
Any physical, biological, or chemical change in water quality that has an adverse effect on living things or makes the water unsuitable for desired uses.
Can happen naturally with volcanic eruption, earthquakes, tornadoes, etc.
Humans: factories, power plants, sewage treatment, oil wells, etc
Most challenging is pollution in the atmosphere: pollutants can be carried great distances by wind then eventually fall to earth as rain, snow etc. far from the original point of origin.

6. Biomagnification
The increase in concentration of pollutants in tissues of organisms that are at successively higher levels in the food chain/food web

7. Bioaccumulation

8. Example of Bioaccumulation
The PCB concentrations in the orca’s food web
When orcas consume food contaminated with PCBs, they store some of the PCBs in their blubber.
When salmon (their primary food) is not available, orcas use their blubber for energy.
This releases PCBs into their system.
Pollutants can build up to toxic levels in organisms at the top of the food chain.
They can also affect entire ecosystems when keystone species, species that greatly affect ecosystem health, or the reproductive abilities of species are harmed.

9. Organisms Magnify Water Pollutants
Chemicals like PCBs (polychlorinated biphenyls) and DDT (9- Dichlorodiphenyltrichloroethane), are called persistent organic pollutants (POPs)
POPs contain carbon, like all organic compounds, and remain in water and soil for many years.
Many POPs are insecticides, used to control pest populations.

10. Heavy metals (high density toxic elements) also bioaccumulate.
DDT was introduced in 1941 to control mosquito populations,
and is still used in some places in the world.
Like PCBs, DDT also bioaccumulates and has a long half-life.
At even low levels (5 ppm*), DDT in animals can cause nervous,
immune and reproductive system disorders as well as cancers.
*The unit ppm means “parts per million” of the pollutant
Eg. one ppm is like one car in bumper-to-bumper traffic from Vancouver to Toronto
Heavy metals (high density toxic elements) also bioaccumulate.
Lead, mercury and cadmium are the most
polluting heavy metals.

11. Reducing the Effects of Chemical Pollution
1. Trapping chemicals in the soil means they cannot enter the food chains as easily.
2. Bioremediation is also used: micro-organisms or plants are used to help clean up, and are then removed from the ecosystem.
The oil industry will often use bacteria to “eat” oil spills.
DDT, Hg, PCBs (production of DDT and PCBs now banned)
Bioaccumulation and biomagnification work together
to magnify certain water pollutants in large predators.

12. Biotic and Abiotic Parts of the Environment
All living things in the environment are its biotic parts
All non-living things in the environment are its abiotic parts

13. The Earth’s Spheres
Natural processes move matter in continuous cycles from the biotic and abiotic parts of the environment and back again. At any time, matter occupies one of Earth’s four spheres (systems): 1. atmosphere: the gaseous part of Earth, which is concentrated within about 10 km of the surface but also extends hundreds of kilometres higher 2. geosphere: (or lithosphere): the solid, mainly rocky part of Earth 3. hydrosphere: all of the water (liquid, as well as solid and gaseous) that exists on and within the geosphere 4. biosphere: all of the areas on and under the geosphere, in the atmosphere, and in the hydrosphere that are inhabited by and support life

14. The Earth’s Spheres Earth’s spheres are interconnected. For example:
The atmosphere interacts with the hydrosphere, resulting in weather.
The hydrosphere interacts with the geosphere when floods wash away soil.
The biosphere interacts with the geosphere when plant roots break apart rocks.

15. QUIZ NEXT DAY ON SKILLS 1 AND 2
LESSON ON POLLINATORS
MONDAY: REPORT TO CLASS FOR ATTENDANCE BEFORE HEADING UP TO THE FIELD TO MEET MARIKA FROM THE ENVIRONMENTAL YOUTH ALLIANCE…WE’RE GOING TO LOOK AT POLLINATORS!
WEDNESDAY: QUIZ ON POLLINATORS