This assignment was designed for a lab but could be done in a regular classroom. It is intended to take at least three weeks. This assignment focuses on lake ecology and the use of data sets to define the ecology of a selected lake. Students will select a lake from a list at the Water on the Web internet site and use the data provided there to describe various features and conditions of that lake. That description will be provided to the instructor in a written report and an oral presentation in class.
Minimum of three weeks.
Use of computer, including browser, excel and word processor software.
1. Understand the basics of lake ecology to include physical and geologic characteristics, chemistry, productivity, annual turnover of nutrients and oxygen, food webs, and trophic status. 2. Estimate land use surrounding the lake selected and its impact on the lakes functioning. 3. Acquire and present data in graphic form to support conclusions.
Text of Learning Exercise:
This exercise starts with the concept of a problem space (BioQUEST Notes, Spring 2004). A problem space is the intersection of three separate sets of information and tools that will allow you to explore, ask, and answer questions about that space.
Area of Research
The area of research in this investigation is lake ecology. Lakes are complex, freshwater ecosystems that exemplify the interaction of biotic and abiotic factors to form a dynamic, interdependent system. As in any ecosystem, energy flow through the system will result in a definite trophic structure (food webs), biotic diversity (range of different types of organisms),
and material cycles (cycling of elements through the system). These interactions result in a continually changing set of conditions that are also impacted by the use of the surrounding land. While more detail will be in the procedures portion of this exercise, you will work in groups of one to three individuals to characterize a specific lake and present that characterization with supporting data to the lab section in written and oral formats.
To assist you in this exercise, you will be provided with three sets whose intersection will define the problem space. These sets will all the found at the Water On the Web internet site (http://www.waterontheweb.org). The first set is background information on the biological principles underlying lake ecology and is found under the heading Understanding. You may use other sources to supplement this site as desired. The second set will be data sets collected on a variety of parameters on indicated lakes in Minnesota, New York, and Washington. These lakes have (or have had) automated sensors that collected a set of information up to three times per day. The data sets are also located at the Water On the Web site under the heading Data. The third set consists of several analysis tools for accessing and displaying the data for your use. The intersection of these biological principles, data sets, and analysis tools defines your problem space.
Questions to answer before starting exercise:
1. Describe the concept of a problem area and the sources of data you will be using to complete this lab exercise. 2. Briefly explain what the elements of an ecosystem are and how they interact. 3. List the abiotic factors that determine where and what type of life will be found in a lake ecosystem.
1. Using the information given below,
your group will research a particular lake and answer the questions presented in the procedures below. The results of this lab will be presented in a report done on a word processor that should be no less than three (3) double spaced pages with one (1?) inch margins and using the Times New Roman font in a size not larger than twelve (12). Graphs and data tables are expected as part of the report. They will be placed in appendices to the paper and are not included as part of the page count for the paper. In addition each group will do an oral presentation giving the results of their research. This presentation will be no less than ten minutes per group. All group members will participate in the presentation. You may present your tables and graphs either on a poster or in an electronic display. Part of your grade will be a peer grading sheet where the other group members will evaluate your contributions to the group. Obviously this sheet will not be required if you work alone. 2. Determine group members. Provide instructor with a list of the members of your group. 3. View video on pond/lake ecology. This video will serve as an introduction to lake ecology and the problems that humans cause. Suggest a worksheet to be completed individually and turned in for grading. Possible videos are "A New England Pond" (available from Hawkhill Associates) or National Geographic: A rocky Mountain Beaver Pond. 4. The rest of the class time is available for the group to organize their research plans and do a preliminary review of the data available at the web site. Make sure you understand how to find and what data is found in the three sets of information/data/tools at the Water On the Web site. a. Background information: Go to the web site and click on the heading ?Understanding?. This will take you to a Lake Ecology Primer. Make sure you read all
parts of the primer?this is your basic background information. Without this information you will not be able to understand and interpret the data in this exercise. Topics include the following: i. Overview ii. Lake Variability iii. Physical Structure and Geological Characteristics iv. Light v. Density Stratification vi. The Watershed vii. Chemical viii. Dissolved Oxygen ix. Nutrients x. Biological?Lake Zones xi. The Food web xii. Primary Producers xiii. Chlorophyll?A Measure of Algae xiv. Algal Succession xv. Consumers xvi. Trophic Status xvii. Eutrophication xviii. Biological Differences xix. Water Quality: Non-Point Pollution and, Exotic Species b. Data Sets: Go to the web site and click on the heading ?Data?. This will take you to the data sets and the analysis tools. You will not actually view tables of raw data. The analysis tools will analyze the data for you. c. Analysis Tools: Go to the web site and click on the heading ?Data?. Select the first sub-heading that will display a map showing the sites available. From that page you will see a link to a WOW Tutorial that will explain use of the data analysis tools available. In addition, when you select a lake, in the left margin you will see heading ?Data Visualization Tools?. Click on that and then click on ?Overview? in the drop down menu. This page will also give you an overview of the tools. Explore what each set of tools will show you before you do your final selection of a lake.
5. Required Topics To Be Covered in Paper/Report: a. When you select a lake, look at the Depth vs. Time (DxT) Plotter for the lake and select a lake that has at least one complete year of mostly unbroken data. In some cases,
you will find only one complete ice-free season?that will suffice. However, you may NOT copy the DxT plot directly into the paper as your only graph or data source. You will need to use the Profile Plotter and/or Color Mapper to extract specific sets of data to use to support the conclusions in your paper. This data should then be presented in both tabular and graphic form. b. The following topics should be described/explained as appropriate in your characterization of the lake you selected: i. The location and physical structure (size, depth, etc) of the lake. Include whatever geological data is provided about the lake and how it was formed. ii. Describe the abiotic conditions of the lake. This section would include chemistry (use at least pH) of the lake, light, density stratification and annual changes in this stratification, anoxic zones and seasonal changes in these zones, temperature. This portion would include turnover times for the lake; explain why turnover occurs. Use appropriate quantitative data (tabular and graphs of the data in the tables) to support your discussion. iii. Describe the biotic conditions of the lake. This section would include typical lake zones and food web for the lake you chose. In addition, discuss the trophic status of the lake. Is it oligotrophic or eutrophic? Support your position with data from the site. This section should also include changes by season. iv. Define what is meant by pollution. What kinds of things constitute pollutants and are they always ?man-made? chemicals? Describe any evidence that there are pollutants in the lake and their sources. Based on development around the lake and past trends, predict what you think the condition of the lake will be in 2015.
1. Review progress on your report with the instructor. Provide the instructor with an outline of your paper and presentation with the name ofall students working in your group. The outline needs to have some data to support it at this point. 2. Recommend the video ?Clear Water,
Cloudy Future.? This video is about the cleanup of Lake Erie and the new problems created by the attempt to restore the ecosystem. Suggest a worksheet to be completed individually and turned in for grading.