A Brief Description: A long term lab investigating biotic and abiotic influences on an ecosystem.

Transcription

1 Biology Standard 1: Objective 3 Title: Brine Shrimp Inquiry Lab A Brief Description: A long term lab investigating biotic and abiotic influences on an ecosystem. Materials needed: 36 quart jars, brine shrimp cysts (available at salt water aquarium stores), algae (from a salt water tank) or yeast culture, slides, coverslips, plastic pipettes, microscopes, rock salt, microscope camera, incandescent light bulbs to provide heat, I make students provide anything else they would like to include Prior to Assessment: An understanding of the Great Salt Lake ecosystem and also interactions within ecosystems. They should be able to draw a food web of the GSL. Students should also know how to use a microscope and estimate microscopic lengths (to estimate the size of their shrimp and track growth). Students should also understand population survey techniques to estimate the size of their brine shrimp populations. Students should also understand the terms bias, biotic, and abiotic. Time Needed: Activity Approx Time Allotment Introduction and Lab Design 55 minutes Lab Set Up 55 minutes Observations (every 2-3 days) 20 minutes x 6 days Lab Clean Up 30 minutes Lab Analysis Questions/Conclusions 55 minutes Total: 3 weeks Notes to Teacher: A warm temperature is key to having the shrimp hatch quickly. Place all mini ecosystems under some sort of heat lamp to ensure hatching. For the short duration of this experiment the brine shrimp actually don t need an outside food source, they will feed on their molted exoskeletons or fecal matter. If you are unfamiliar with the GSL, you may want to look at for some background information. Just search under Great Salt Lake. Teacher Procedures: 1. Obtain all needed supplies. 2. Hook-When students enter the classroom pass around an unmarked jar of brine shrimp cysts. Let the students examine them. Ask if anyone knows what they are. Explain to the students that cysts are a strategy to save energy. In hostile conditions cysts form so energy is not wasted.

2 3. Introduce students to this lab through a review of the GSL and some of the environmental issues surrounding the ecosystem. Some of these include the salinity changes in the N and S because of the railroad tracks, pollutions from boats/cars etc, rising temperatures, drought conditions, influxes of nitrogen and phosphorus from sewage and agriculture, loss of surrounding wetlands to urban development and how this affects water filtration etc. 4. Give them a copy of the student sheet 5. Go over the entire lab with them. 6. Allow them to choose groups of 3-4 students 7. Have students develop hypotheses, this may take some time 8. Let students design their lab and then get an approval signature from you 9. On Lab set up day you may want to go over how to create a percent solution (100 x percent = # g of salt). Those not investigating salinity should have around 5-6% salt solution. 10. Be sure to let your water sit overnight before using (unless using distilled water) 11. The shrimp should be placed under a heat lamp to ensure hatching 12. When students observe their shrimp, have them examine them under a microscope. Encourage students to use all of their senses when making their observations. 13. Set up a microscope camera to the television and allow students to view the shrimp on the TV. This is very high interest. 14. Allow students time to work on lab questions. Answers: All answers will differ. You should grade based on completion, thoughtfulness and understanding. Possible Grading Rubric: See following page.

3 Requirement Points Received Points Possible Relevant problem selected 2 Variable relates to problem 2 Creative title 2 Design the investigation: control described that mimics GSL and factors listed which remain constant in both jars Materials listed and justified 4 Thorough procedures listed from beginning of lab until completion 6 Experimental design, clear and labeled 4 Errors anticipated and documented 4 Hypothesis covers all jars and is detailed 6 Data Table 1: number of shrimp estimated daily 6 Data Table2: length of shrimp estimated daily 6 Pictures are neat, and detailed 12 Written observations are detailed, all senses were used, changes were noted with each observations (5 pts per obs) Graphs are neat and accurate 6 Error analysis: detailed and thoughtful (3 pts per question) 9 Conclusions: detailed, thoughtful (3 pts per question) 36 Summary Analysis: used complete sentences, provided thoughtful analysis and shows clear conceptual understanding Total

4 Name: Period: Brine Shrimp and the Great Salt Lake Inquiry Lab Purpose: To better understand the GSL ecosystem and how it is influenced by abiotic and biotic factors. Select a Problem: State the problem, in general terms, you and your group would like to investigate. This should be something that relates the effects of abiotic or biotic factors on the ecosystem of the GSL. These factors could include human activity, birds, insects, weather, nutrients etc. Choose a Variable: Once you have chosen your problem, decide on one variable that will help you investigate it. Relate that variable to a real life variable introduced by humans to the Great Salt Lake. For example you might test how different concentrations of chlorine affect the growth of Brine shrimp. This corresponds to the chemical dumping of chlorine done by Magnesium Corp. Title: Come up with a creative title for your lab that relates to the problem and the hypothesis. Design the Investigation: Describe the conditions of your control jar. A control should mimic the actual GSL ecosystem as closely as possible. Also list everything you will be keeping the same in each of your jars. Materials: List all the materials you will need for your lab. Next to each material please explain what part of the GSL ecosystem it is representing. Material Light What it represents Sun

5 List any other materials needed: Procedures: List all the steps you will take to complete your lab. Experimental Design: Draw a picture and label how you will set up your lab. Errors: List 4 possible sources of error in your lab and how they might influence your results. (hint: think about how your lab is different than what is actually happening in the GSL) Write a Hypothesis: Create a hypothesis related to the problem. Remember a hypothesis is what you think the answer to your problem is. A hypothesis may be written as, if this happens, then this will happen. Example: If brine shrimp eggs are exposed to...then... will occur. Approval Signature

6 Set up the experiment: Pay special attention to any sources of error that you make (did you spill some water or squash your cysts...). Make sure that you record these in the space below. Data Collection: Collect data and record observations 6 times. These should be in the form of tables. Record number of hatched, length in mm, smells, water condition and quality and any other changes you may notice. Make sure you include a drawing for each observation also. Quantitative Data: (numerical data) Number of Hatched Shrimp Day Jar Jar Jar Length of Shrimp in millimeters Day Jar Jar Jar

7 Qualitative Data: (written observations using all 5 senses) Pictures: Day Jar # Jar # Jar #

8 Written Observations (use additional paper as necessary) Day Jar # Jar # Jar #

9 Analyze the data: This is where you graph your results from your tables and interpret them. A line graph will probably work best. length in mm time in days time in days # of shrimp time in days

10 Error Analysis 1. Discuss all possible errors that you encountered with your lab and how they may have affected your results. 2. Is it normal to have errors in a lab? What should you do if you make an error? 3. Explain 3 reasons why you think that your shrimp did not hatch and what you could do next time to assure that they did. (ONLY answer this question if no shrimp in any of your jar hatched,including your control.) Conclusions 1. Did your results support your hypothesis? Why or why would this be the case? 2. How does your experimental variable (salt levels, acid levels etc) relate to the variable effecting the Great Salt Lake in reality? 3. How would you interpret your results. Are you concerned about the results of your experiment and the implications for the GSL? Why or why not? 4. Explain what would happen to your ecosystem if the problem you investigated goes unchecked? 5. In order to obtain more data describe another experiment you could perform.

11 6. Draw a picture and explain how the water cycle was functioning in your jar. 7. Draw a picture and explain how the carbon cycle was function in your jar. 8. Please list the abiotic and biotic factors that were a part of your ecosystem. 9. Please list the abiotic and biotic factors that were missing in your ecosystem but are present in the actual GSL ecosystem. 10. How do these missing factors influence the ecosystem? 11. Explain how environmentalists would feel about the results of your experiment? What would be their bias when interpreting the results? 12. Explain how a nonenvironmentalists would feel about the results of your experiment? What would be their bias when interpreting the results? Summary Analysis: Please explain in complete sentences 4 things you learned from this project.