FLOW OF ENERGY IN AN ECOSYSTEM
BACKGROUND:
In this simulation, students will play the roles of organisms found in a kelp forest ecosystem of the Pacific Ocean. Each student will represent a different organism. You will get colored chips to represent the amount of energy you have based on your organism. You will roam around the room and ask other students what organism they represent. A chart that follows describes what you eat and the amount of energy you get from eating that organism. The organism you are has to give up energy (chips) each time you ask and an organism you cannot eat. The purpose of this simulation is to observe how energy is transferred (and lost) from organism to organism during feeding in an ecosystem food web.
PROCEDURE:
1. Your teacher will assign you to represent one of nine organisms living in the ecosystem.
2. Read the information in the chart that follows to find out what you can eat and what can eat you.
3. Blue chips = 50 EU Red chips = 25 EU Yellow chips = 5 EU
Get the appropriate chips needed for your organism. For example, if you represent a sea snail, you are to obtain 20 energy units (EU) in chips, or 4 yellow chips. This is the total amount of energy you have to start the simulation. Memorize what you eat and what eats you!
4. When your teacher gives the signal, all students are to stand and move about the room. When searching for food, you will ask others what organism they represent. When you tell others who you are, discreetly show them your paper or whisper. This way others will not know and won’t come after you! If you can eat them, collect the appropriate EU. If they can eat you, give them the appropriate EU. If you can’t eat them place the appropriate EU in the ENERGY LOST PER ENCOUNTER POT. You can only have a total of 10 encounters and you cannot ask the same person twice.
5. When you lose all your energy sit down. After you have asked 10 people and you can no longer ask any one else you must sit down. Others who are walking can still ask people sitting down!
6. After the simulation is over your teacher will ask you to fill in the EU you have left (if any) in the table on the overhead. Copy this data into your Data Sheet. EU= Energy units
ORGANISM ENERGY FOOD SOURCE ENERGY OBTAINED ENERGY LOST AT START FROM FOOD PER ENCOUNTER KILLER WHALE 400 EU* Sea otters and - Sea lions provide a killer A killer whale will California sea lions whale 200 EU lose 50 EU - Sea otters provide 150 EU CALIFORNIA 300 EU Señorita fish and - Señorita fish provide a A California sea SEA LION California squid sea lion 15 EU lion will lose 45 - Squid provide 40 EU EU NORTHERN SEA 250 EU Sea snails, - Squid provide a sea otter A Northern sea OTTER California squid, 40 EU otter will lose 25 and Purple sea - Purple sea urchins EU urchins provide 10 EU - Sea snails provide 5 EU CALIFORNIA 75 EU Señorita fish - Señorita fish provide a A California squid SQUID squid 15 EU will lose 15 EU SENORITA FISH 40 EU Northern kelp - Crabs provide a señorita A señorita fish will crabs fish 5 EU lose 5 EU PURPLE SEA 25 EU Kelp - Kelp provides a sea A purple sea URCHINS urchin 5 EU urchin will lose 5 EU NORTHERN 25 EU Kelp - Kelp provides a crab 5 A northern kelp KELP CRAB EU crab will lose 5 EU SEA SNAIL 20 EU Kelp - Kelp provides a sea snail A sea snail will 5 EU lose 5 EU KELP 250 EU Kelp does not eat Plants only lose energy when they are eaten NAME ______PER ______DATE ______
~DATA COLLECTION AND ANSWER SHEET~
FLOW OF ENERGY IN AN ECOSYSTEM
TOTAL ENERGY IN THE ECOSYSTEM BEFORE THE SIMULATION: ______
L E P H P A A A A I
L L I S L E E E A I E A N N S S E S F I
D N
K H I R K S E R A N H
A I U O L E C W B N R N A T
F N Q P I T R E A I O E R R S R I R T R S L U E R H E L O U O O A C T L H F P C L N I R T I E L R O K S A N O C N TOTAL ENERGY LEFT
TOTAL ENERGY IN THE ECOSYSTEM AFTER THE SIMULATION: ______
1. Create a food web diagram for the kelp forest ecosystem simulated in this activity. Just write the names and do not use pictures. USE PENCIL!!!
2. Label the producers (P), the primary consumers (PC), the secondary consumers (SC), and tertiary consumers (TC).
3. What could you eat and what could eat you?
4. The law of conservation of energy states that energy can be neither created nor destroyed; it can only be transferred to another form. In living things energy is transferred as organic matter (molecules of carbohydrate, fats, starch, etc.). Below is a diagram of an animal “Herbivore A” and its daily diet. Energy is measured as biomass.
a) How many grams of grass does herbivore A eat each day?
b) How much did herbivore A grow and increase its biomass from eating this grass?
c) Is all of the mass of the ingested grass accounted for in the growth and waste of herbivore A? If not, how much is “missing”? Write a mathematical calculation to support your answer.
d) In addition to growth and waste production, what else does herbivore A’s body do with the food it ingests? Think back to the simulation to answer this question.
e) Egested waste from an organism is not always wasted energy. Describe how this energy (organic matter) might be used in a useful way.
5. What organism did you represent and how much energy did you begin with?
6. How much energy were you left with at the end of the 10 encounters?
7. Why do you have to put EU in the energy lost per encounter jar even thought you weren’t eaten? What does this represent? 8. The diagram above does not show biomass but energy moving. What are the three ways that the energy taken in by the herbivores is used?
9. How much energy was in the total ecosystem before the simulation began? ______
How much energy was left in the ecosystem after the simulation? ______In nature, where does all this energy go?
What processes is this energy lost to?
10. About one third were assigned as plants and only one assigned as the killer whale. Why was this important?
11. Why did some organisms start out with more EU than others?