Tim Holcomb

Linden High School

Email: tholcomb@voyager.net

 

Unit Title:  Whose Water Is It Anyway:

An Investigation Of Sediment Characteristics  & Algal Indicator Species

 

Subject:  Ecology, Biology

 

Target Grade:  9-10 Grade

 

Unit Overview 

This two-part unit is intended to: 

1) Provide students with a hands-on opportunity to determine water/sediment characteristics of lakes and rivers in the district by examining algae and growing plants; and

2) Enhance student awareness of how local water systems are connected to the Great Lakes.

 

Purpose:  To increase student knowledge of the origin of Lake Superior, its peoples and how the Great Lakes are impacted by local water systems.

 

Michigan Content Standards and Benchmarks

 

    I 1.1 Ask questions that can be investigated empirically

             1.2 Design and conduct scientific investigations

 

      II   Reflecting on Scientific Knowledge

1.1  Justify plans or explanations on a theoretical or empirical basis

1.2  Describe some general limitations of scientific knowledge

1.3  Show how common themes of science, mathematics and technology apply to real-world contexts.

1.4  Discuss the historical development of key scientific concepts and principles

1.5  Explain the social and economic advantages and risks of new technology

1.6  Develop an awareness of and sensitivity to the natural world

1.7  Describe the historical, political, and social factors affecting developments in science

 

II.  Ecosystems

5.1 Describe common ecological relationships between and among species and their environments

5. 2 Explain how energy flows through familiar ecosystems

5. 3 Describe general factors regulating population size in ecosystems

5.4 Describe responses of an ecosystem to events that cause it to change

5.5 Describe how carbon and soil nutrients cycle through selected ecosystems

5.6 Explain the effects of agriculture and urban development on selected ecosystems

 

V.  Geosphere

1.1  Explain the surface features of the Great Lakes region using Ice Age Theory

1.2  Use plate tectonics theory to explain features of the earth’s surface and geological phenomena and describe  evidence for the plate tectonics theory

1.3  Explain how common objects are made from earth materials and why earth material are conserved and recycled

1.4  Evaluate alternative long range plans for resource use and by product disposal in te4rms of environmental and economic impact

           

Most students will agree that the Great Lakes are “very old,” however to them, “old” is a relative term.  When discussing the geology of the Great Lakes region and numbers like three billion are used, “old” takes on a new meaning. With ten lakes, a river and a millpond all in the district, we have plenty of student interest in water, especially water sports.  Recently, several of these lakes have been closed for extended periods of time due to bacterial contamination.  Students are eager to use water chiefly as a recreational resource and therefore have a vested interest in maximizing the number of days to be in the water. This marriage of student leisure time interest with water provides for a fruitful learning opportunity.  Archean to Proterozoic through middle Proterozoic, the Paleozoic and Pleistocene are the backdrop for our discussion of the Great Lakes and the student’s home water. 

            For this unit, students arranged themselves into teams of two. Many group members live on a water source or live very near a body of water.  After an overview of the project, each group selected a suitable water test source, one with flowing water.  All locations were plotted with stickpins on a USGS map located in the classroom.  Next, the teams assembled their “algae collectors”. Dr. Matt Julius, St. Cloud University, provided this idea.   These consisted of Styrofoam pieces connected with four clean microscope slides.  The collection devices were then placed into the flowing water sources and allowed to stand for seven days. Would there be a difference in the alga samples?   In some cases, the collection devices did not survive the week, either being washed away or taken.

 

Following collection, the microscope slides were returned to the classroom and stored at 4ºC.  Alga samples were removed from slides and observed for diatom/algae types. Identification was made through the use of 1) algae/diatom color charts obtained from Michigan Technological University, 2) How to Know the Algae, Prescott, 1970, Wm. C. Brown Publisher.  Figure 1 lists some of the more common algae/diatoms, which were identified.  While most students believed there would be differences in algae/diatoms from different sites, many were convinced that their site would have the “best” algae/diatoms.  We discussed as a class the small but noticeable differences in data from some collection sites.  What might account for such differences and could we somehow investigate this?  Several worthy ideas were “hatched” which had significant funding attached.  How about sediments?  Would sediments from the collection sites provide an insight into growth potential?  What could we hope to grow?  How might we do this in the classroom?  What about all the variables.  “We” decided to collect sediments from their sites and use them to grow bean seedlings as a way to gather additional information about their collection sites.  Students collected sediments from each sample site.  (NOTE:  The collection produced several interesting stories from students and a couple of mothers.  No one was injured or harmed but many reported getting wet and dirty – the stories were enhanced as time went on.)  These sediments were allowed to air dry in the classroom.

           

  

 

Figure 2

Terraqua Columns “at work”.  These were moved on a daily basis to help ensure equal treatment.

 

Once dry, the sediments were used to construct a Terraqua Column. Fig 2.  To determine the “growth potential” of each sample site, students would follow the germination/growth of four bean seeds.  Prior to actually setting up their experimental models, each group had to construct a picture of the control column and identify possible variables.  Each seed was planted at a pre-determined depth and watered with identical amounts of water.  Columns were then placed where each would be exposed to consistent temperature and light conditions.  Student groups constructed data collection sheets so they could monitor the progress of each seed for fourteen days.   Students monitored germination, change in height, number of leaves, overall growth for fourteen days and mass of each seedling after fourteen days.  Summary chart Figure 3.

 

 

Figure 2

You always get results. 

           

            Following data collection, groups attempted to evaluate their collection sites for growth potential and algae/diatom types.  Site 10 was the control.  Students designed the control to contain potting soil and treated this the same as other samples.  While overall data proved to be somewhat inconclusive, a minor trend of more seeds germinating and developing to a greater mass was evident in collection sites away from the village.  However, to the surprise of some the collection from near a sewage treatment plant proved no “better” for growth than other locations.  Students discovered that with real research data provides some answers, but many questions are raised.  Why didn’t some seeds germinate?  What other materials are in the water contributing to algae/diatom growth?  Would all types of seeds respond the same way?  Why did some seeds grow so tall?  Why did some leaves get spots? What will happen if we do this next year?  The next phase of the unit consisted of posing the question, “So where does this water flow?” 

 

 

            This led to a discussion of the Great Lakes and our local impact on them.  What changes have the lakes gone through?  How does the cycling of nutrients impact the Great Lakes?  What about man’s historical impact?  What relationship did Native Americans have with the lakes?  From “A Face in The Rock” we discussed the Chippewa relationship with Lake Superior, the legend of Mishosha, the Battle of the Cavern, and later decline of the Chippewa.  Recent history and current information regarding the state of the Great Lakes was discussed as per information obtained from David Rockwell, U.S. EPA.   Discussion topics centered on water quality of the 1960s/1970s, DDT/PCBs, cycling of energy/nutrients and exotic species such as the spiny water flea, zebra mussel and lamprey.  We concluded with a discussion about, “Where will all of this lead us?”  Student response to the question “What do you think might be the greatest reason for not being able to make improvements to the waters of the Great Lakes in the future”, was clear.  We must cooperate and have people who care and are willing to working together both politically and financially.

Summary

 

            Student interest in this unit was very high and their enthusiasm was exciting to be part of.  They related much better to the hands-on part than the discussions of the Great Lakes.  Their responses to survey questions indicate improvement in their knowledge of the Great Lakes as discussed and in science.  While exotic species are somewhat important to them, the challenge remains to help them see into the future and beyond their own recreational water source.  Students were proud to be part of an initial research project, which impacts them.  In the future we have decided to purchase/burrow water test kits.  A joint venture with the ecology classes will allow us to follow the algae/diatoms as well as water quality at the same sites.  I believe students have a much better understanding/appreciation of their water and the Great Lakes as part of a system.  What they do does make a difference and they can have a positive impact.  The world is truly larger than their own backyard.

 

Resources/Sources Consulted

 

1.      A Face in The Rock, Loren Graham, University of California Press

2.      Great Lakes Aquarium- Duluth, www.glaquarium.org

3.      Geology of the Lake Superior Region, LeBerge, 1994, Geosciences Press Inc.

4.      Shoreline Processes of the Great Lakes, Department of Environmental Quality, EDC 2755

5.      State of the Great Lakes Annual Report 1995

6.      Understanding Lake Data, Shaw, Mechenich,  Klessig, cooperative extension publication

7.      A Primer on Limnology, 2nd ed. Monson, Water Resources Center

8.      Lake Effects, The Lake Superior Curriculum Guide for Grades k-8

9.      An Atlas of Biodiversity, Chicago Wilderness, EPA

10.  The Great Lakes – An Environmental Atlas and Resource Book, EPA, 3rd ed, 1995

11. Bottle Biology – Kendall Hunt, 1993, pages 61-62.

            12. The Life of The Lakes – A Guide to Great Lakes Fishery Education Materials,  Michigan Sea Grant

      Extension Publication

            13. How to Know The Algae, Prescott, 1970, Wm. C. Brown Company Publishers

 


Figure 1*

 

Collection sites 1, 3, 8, 9 were either in the village of Linden or just below the dam.

 

Collection Site

Algae

Diatom

1

Asteronella, Euastrum

 

2

 

Fraglaria, Navicula, Diatoma

3

Anabaena

 

4

 

Tabellaria

5

 

Asteronella, Navicula

6

 

Tabellaria

7

 

Scenedesmus, Navicula

8

Spirogyra

Tabellaria

9

Anabaena

 

 

* I did not personally view each sample and relied on student drawings/perceptions of images provided.

 

 

 

 

 

Figure 3                                              Summary of Bean Seedling Growth

* site 10 is the control

Collection Site

# germinated seeds

Av. Height 14 days

Total # leaves

Seedlings Mass

1

0

 

 

 

2

1

6.7cm

4

25.6g

3

3

12.5cm

12

31.2g

4

2

5.3cm

8

12.3g

5

3

3.8cm

12

10.8g

6

1

10.2cm

4

19.6g

7

0

 

 

 

8

2

14.6cm

8

16.4g

9

1

20.1cm

4

22.7

10*

3

18.5cm

12

24.7g

 


 

Pre-Post Content Survey

 

 

1. What is meant by a “rift” lake?

a. the age of the lake

b. how the lake was formed

c. the type of rock in the lake

d. the type of fish in the lake

 

2. Why did the Chippewa fight the Sioux?

a. they didn’t like the Sioux

b. the Sioux were taking Chippewa territory

c. Chippewa liked the white man and Sioux didn’t

d. no one knows

 

3. What led to the decline of the Chippewa culture?

a. lack of food

b. global warming

c. increased use of the land by the whiteman

d. competition from the Sioux

 

4. When the Chippewa fought the Sioux, why did one Chippewa survive?

a. he was bravest

b. Sioux let him go

c. to tell the story of the battle

d. to provide for the women and children

 

5. Why does the water of the Great Lakes “mix” twice a year?

a. the density changes with the seasons

b. due to boat traffic

c. the weight of the snow and ice

d. due to evaporation

 

6. Generally speaking, what has happened to the water quality of Lake Superior over the last 10 years?

a. improved

b. declined

c. remain unchanged

 

7. Which of these describes the difference between one part per billion compared to one part per million

a. 1000 times less

b. 100 times less

c. 10 times less

d. they are really the same

 

8. List three exotic species found in the Great Lakes.

 

 

 

9. The phytoplankton of the Great Lakes make their own food.

a. true

b. false

 

10. Lake Superior is described as an “oligotrophic” lake.  This means the lake is:

a. cold, deep, low in nutrients

b. warm, moderate amounts of nutrients

c. warm, rich in nutrients

d. cold, deep, rich in nutrients

 

11. The rock formations of Isle Royale and the Keewenaw are alike because they are:

a. opposite sides of a valley

b. luck

c. the glaciers left them there

d. volcanic deposits were made after the last ice age

 

12. Lake Superior might remain oligotrophic because of:

a. its temperature

b. the rocks located on its bottom

c. little boat traffic

d. a new ice age

 

13. Which of these is a forage fish of the Great Lakes?

a. pike

b. perch

c. bass

d. sculpin

 

14. When volume is compared to drainage size, which Great Lake has the smallest drainage area?

a. Superior

b. Huron

c. Erie

d. Michigan

e. Ontario