Core
Curriculum Objective: Analyze the effects of pollutants on the functioning and health of organisms within ecosystems.
Focus/Overview: The class will discuss the components of an ecosystem. They will examine cause and effect relationships in various ecosystems. Students then will examine the cause and effect of pollutants that once existed in Lake Erie. Pollutants will be traced throughout food chains and various cycles, (oxygen, nitrogen, water). The class will work in groups of three and come up with possible causes and effects of the pollutants given.
Essential Questions: What are the components of an ecosystem? What pollutants can effect an ecosystem? What are the causes of these pollutants? What are the effects of these pollutants?
Time Frame: One 70-minute class.
Resources/Materials:
nternet access
Large white paper
Rulers
Assessment: Each group will identify the causes of pollutants in an ecosystem and the effects to the functioning and health of the organisms within the ecosystem. They will be graded satisfactory for reasonable causes and effects and unsatisfactory for unreasonable causes and effects, as well as incomplete work.
Instructional Activities:
Do It Now: Define ecosystem
What kind of things makes up an ecosystem?
What are some effects of pollutants to the organisms within an ecosystem?
Ask the class what is an ecosystem? (The interaction of a community of organisms within its environment).
Ask the class, "what kinds of interactions occur in an ecosystem?" (Food chains, oxygen cycle, water cycle).
Review these cycles with the class, you may even want to draw them on the board so they can refer back to them as they are working on their assignment.
Now ask the class, "what would happen if one of these cycles, or the food chain was some how interrupted or tainted?" (Other parts of the cycles, or food chain would also be effected).
Now give an example:
Benzene leaks in a pond:
Effects: Harm fish gills, eat away at frog's sensitive skin, poisons other animals further down the food chain. Destroys plants, oxygen supply in pond decreases, amount of bacteria decreases, pond can become "dead."
Cause: possible causes may be a leaky gas tank, or a gas spill.
Put the students in groups of 3. One student should be the recorder. Pass out the large sheet of paper and rulers. Have students divide the paper into a matrix grid. There should be 6 columns down and 3 rows across. Label the columns pollutant, possible cause, effects to living organisms, effects to food chain, effects to oxygen cycle, effects to water cycle.
Pass out a copy of the Lake Erie pollution problem,
(www.ec.gc.ca/water/index.htm), have each group read the article about Lake Erie's nitrogen and phosphate problem.
Have students complete the first row of their matrix.
Answers
Pollutants-nitrogen, phosphate
Possible causes - fertilizers, laundry detergents).
Effects to living organisms - stimulates plant growth, fish suffocate due to lack of oxygen, bacterial activity decreases
Effects the oxygen cycle - oxygen cycle stops due to lack of oxygen.
Effects to the food chain food chain in the lake will stop, the area surrounding the lake will also be effected - answers may vary
Effects to the water cycle - slows it down due to the lake drying up.
Go over the answers. Tell students to use oil in the water and gas in the soil as their last two pollutants. Go over at the end of class. Their answers may vary due to the specifics of the ecosystem they choose to relate to.
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