Where shall we go swimming?
Marj Ostgaard, Marshall Public High School, Marshall MN
Author Profile
Summary
In this water study lab students investigate how water samples from a variety of local lakes differ. Students will observe a variety of water samples macroscopically, microscopically, and chemically. Students will be taught how to identify various macroscopic and microscopic organisms found in wetlands. They will also be trained to do various types of chemical water tests. Then students will be instructed to compare and contrast two different bodies of water using one of the three areas or combinations of them. Students will create a complete lab report and share their findings with the class. This can be used to lead into discussions of water quality and the factors that affect it. Next students will be given maps of the area the sample came from and asked to determine how the surrounding land contributed to the lake's environment.
Learning Goals
Students will use critical thinking, data analysis, questioning, writing, communicating skills. They will also be using various laboratory apparatus including microscopes, magnifying glasses, and water testing kits. The concept they will learn is that there is interrelationship between biotic organisms and abiotic factors in their environment, and that both are affected by human actions.
Context for Use
This would be taught after a unit on erosion and deposition has been covered. Students will have already learned how to use the microscope. This would be primarily lab with some lecture. I estimate the activity to take about 5 to 7 ninety minute periods. I think this activity could be modified to various grade levels by giving more structure to the investigation.
Description and Teaching Materials
There will be about 6 numbered water samples the teacher has obtained from various bodies of water in the local area. Students will be instructed to use two different samples to observe macroscopically and microscopically. They will be instructed to draw at least 6 different organisms they can see from the samples. Then they will be given keys and asked to identify them. Next the students will be taught how to follow the instructions in the Hach water testing kits and test the same two samples for pH, nitrates, and phosphates and then record their data. Students will share their findings by compiling the data on a giant grid on the board or on a smart board. The teacher will facilitate a discussion of the correlation between the organisms that have been identified and the chemical test results if any. Students will be asked to brainstorm and discuss where the chemicals that have been found originated. Then students will be told the original location of their sample. They will be instructed to go to the internet and find maps and infer why they obtained the results testing their sample. (Websites below) They will create a visual presentation and present an oral defense of their findings. Suggested web sites:
http://cfpub.epa.gov/surf/state.cfm?statepostal=MN
http://water.umn.edu/cgi-bin/mapserv http://www.dnr.state.mn.us.lakefind/index.html
This activity is a water study investigation of how biotic and abiotic factors are influenced by human activity. (Microsoft Word 28kB Jun3 11) Teaching Notes and Tips
Collect the water samples ahead of time so you can insure they are collected in clean containers and refrigerated. Color keys would be useful in helping identify organisms. You might want to add a substance to slow down the organisms for observation. Before I would teach the concept, do a lab, give a test.
Now I will do the lab, teach, then assess. This lab activity is more guided and less structured than what I have done in the past.
Assessment
go to
http://rubistar.4teachers.org
you can create your own assessment easily or use mine
Standards
Earth Science: 9-12.111.A.1. and B.4. Life Science: 9-12.1V.C.4.
References and Resources
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