1. Ecology
Activity 6

2. What have we been studying?
Refer back to the Graphic Organizer Chart (Observation-Thought-Question, Claim-Evidence) Student Page 5A
We have been examining normal interactions and patterns that happen in ecosystems

3. List
What kinds of human actions might alter or disturb interactions and patterns in an ecosystem?
Think of good impacts as well as negative impacts. Accept all answers.
Helping endangered species, running over wild animals, fire burns in forests, erecting buildings in areas where wildlife live, oil spills, pollution

4. What activities could impact your Lake Ecosystem?
Adding invasive species? Prob wont suggest it but its ok.

5. Student page 6a; fish only die once
Read the story and consider how humans might “inadvertently” change an ecosystem
allow them to discuss their ideas about what might happen in this Lake Ecosystem when their baitfish get dumped. Tell students to assume that the type of baitfish that gets dumped from the bucket are mosquitofish.

6. Student page 6b: mosquitofish behavior
Underline every place where there is a possible interaction with another organism.
“Non-native” or “exotic species” means an organisms that is introduced to an ecosystem where it has never lived.
It becomes an “invasive” species if it aggressively establishes itself in an ecosystem by interfering with the natural interactions between the native species and its normal functions.
Would you consider the mosquitofish an invasive species?

7. If the mosquitofish eats ___________________ then this will affect _________________________. As a result, the population of ______________________ may (increase or decrease). The mosquitofish will compete with _________ because they will both try to prey upon ____________. This may lead to ________________________. The predator prey relationship that usually exists between ________ and _____________ may be changed and this may affect ________________________.

8. Student page 6c: Mosquitofish trophic level card
Read and compare the feeding and nesting behaviors of mosquitofish and bluegill in a Lake Ecosystem.
Discuss whether you believe there would be any competition between mosquitofish and bluegill.

9. How might the trophic level pyramid be affected?
Draw the lake organisms into the pyramid including mosquitofish

10. Niche- role an organism plays in the food chain
Compare the role that bluegill play and the role that mosquitofish play
How will this impact the normal patterns and interactions between the largemouth bass and the bluegill?

11. think
Describe how these two organisms might compete for the same resources
How might this affect your food chain diagrams and energy flow through the ecosystem?

12. Could your pond ecosystem support both bluegill and mosquitofish
Could your pond ecosystem support both bluegill and mosquitofish? Why or why not?
They have overlapping behaviors/niche. Both feed on plankton and insect larvae. Abundance of mosquitofish could cause declines of the bluegill population

13. Draw this chart
What I see
What it means

14. What do you think “carrying capacity” means
What do you think “carrying capacity” means? (Tell them to write definition) Ask Why did the graph stop showing steep growth and level off?

15. Carrying capacity
What’s the carrying capacity of largemouth bass? What’s the carrying capacity of bluegill?
70-80 lbs, based on the 10% rule lbs

16. What might happen if more fish were added into the system?
Not be able to support them b/c environment will exceed carrying capacity

17. Closing thought
How do human interactions disrupt normal patters and interactions in ecosystems?
It disrupts energy flow, predator-prey interactions, population cycles may be impacted