Changes Due to Population Growth Activity 15 Changes Due to Population Growth

Have you eaten fish or some other kind of seafood in the last week? Where do you think that fish or other seafood came from?

Would this help to prevent overfishing? Do you think we could have fish farms to grow fish instead of catching wild fish? Would this help to prevent overfishing? Do you think fish farming will be helpful, negative, or mixed? Tally the students’ responses to the last question on the board to revisit at the end of the activity. Brainstorm possible benefits and trade-offs of aquaculture with the students before they read the Introduction and list those on the board for later reference.

Read the introduction. What is Aquaculture Give examples of fish/seafood that are being raised through aquaculture methods in the US What are some benefits of aquaculture? What are some concerns with aquaculture? Explain why farmed oysters/clams/mussels has been successful Explain why farmed shrimp has not been sustainable Ask the students again “Do you think aquaculture will be helpful, negative, or mixed for preventing overfishing?

Aquaculture is the growing of fish and other aquatic species for human consumption.

How can the environmental harm from salmon farming be minimized? Challenge How can the environmental harm from salmon farming be minimized?

Comparing Wild and Farmed Salmon Populations You and your partner will simulate 20 generations of population growth in a wild population of salmon and a farmed population of salmon You will roll a number cube…each number will represent a particular event Record all information in data table

If at any point in the investigation you roll a 5 or 6 and your farmed population is not 1,400 or greater, roll again until you get a 1, 2, 3, or 4. A sample data table with student results can be found in your Teacher’s Edition for this Activity. Note that student results may vary greatly depending on what numbers they roll and in what order.

What kind of events affected your systems? How did the events affect the wild and farmed populations? Be sure students discuss what happened to population levels in relation to the events that happened.

How does this compare to the salmon farm in the activity? What are the benefits and trade-offs of the fish farm shown in the video? How does this compare to the salmon farm in the activity? Show students a video clip on sustainable fish farming. A link to the clip “Sustainable Ocean Fish Farming in Hawaii” can be found on the Science and Global Issues page of the SEPUP website (sepuplhs.org/sgi).

Let’s revisit our data from the beginning of the activity Do you think the results of fish farming will be helpful, negative, or mixed? Let’s revisit our data from the beginning of the activity Retake the poll from the beginning of class. Allow students to change their answers, and discuss the results with the class. Have the class return to the list of the benefits and trade-offs of aquaculture and add or subtract from it as appropriate. For more information on having this class discussion see your Teacher’s Edition for this activity.

Analysis 4 What are the benefits and trade-offs involved with aquaculture? Discuss at least two aquaculture systems. Analysis Question 4 can be used as a Quick Check to ensure that students understand the term, and can identify, trade-offs, which is a component of the Evidence and Trade-offs scoring variable. A sample student response and more information can be found in your Teacher’s Edition for this activity, and in Teacher Resources IV: Assessment.

How can the environmental harm from salmon farming be minimized? Revisit the Challenge How can the environmental harm from salmon farming be minimized?

density-dependent factors density-independent factors population Key Vocabulary aquaculture density-dependent factors density-independent factors population population growth rate See Teacher Resources III: Literacy for more information on key vocabulary and the most effective strategies to enhance student vocabulary learning. Note that bold words are formally defined in this activity. Words in regular font are used in the activity, but not formally defined. The definition of a key vocabulary word should not be discussed as a class prior to the formal definition being introduced.