Student Experience 6: More of the story

Description

Provide students with the full story for Part One of the pathway:
[stextbox id = “info”] Farmers at Sunrise Farm are planting crops for the season. They spread fertilizer on the field. The fertilizer contains chemical nutrients that help plants grow. Much of the fertilizer is used by the plants or absorbed by the soil, but not all. When it rains, some of the fertilizer goes into the stream by the field and flows into the pond.

Sunrise Farm Pond, like all ponds, has some algae growth. The algae grow slowly and have a very short lifespan. When the fertilizer runs into the pond, the chemical nutrients that help the crops grow also help the algae grow and reproduce much faster than they had previously.

The algae grow thick at the top of the water, which makes the water cloudy and blocks the sunlight from getting to the bottom of the pond where many producers live. As a result, it is difficult for the producers to grow, and they eventually die. The producers at the bottom of the pond make much of the oxygen that the pond needs, and as they die, the amount of oxygen in the pond from these producers decreases.

When one of the farmers checks on the pond a few months after planting the crops, she finds that several of the fish have died.

Why are the fish dying at Sunrise Farm Pond?
[/stextbox] After sharing the full Part One story, use the Questions to Ask Students in a class discussion to encourage students to consider how their models relate to events in the story. Finally, tell students that they will explore how decreased oxygen is connected to fish dying at Sunrise Farm Pond.

Questions to Ask Students

How does the story compare with your thinking about why the fish are dying in Sunrise Farm Pond?
How does your model represent what is described in the story?
What impact do you think the decreased oxygen will have on the organisms living in the pond?

Science Practices

Developing and Using Models After students have made initial revisions to their model in the previous student experience, they hear more of the story and have an opportunity to reflect on how their model represents what is known so far about the mystery at Sunrise Farm Pond.

Engaging in Argument from Evidence Consider having students work in pairs to explain how their models demonstrate what they think is happening at Sunrise Farm Pond. Providing an opportunity for students to examine and pose questions about a peer’s model will help students consider further revisions to make (e.g., adding clarification or evidence to support their ideas). Encourage students to use evidence to support their models when explaining them to a peer.

Asking Questions Now that students have had experiences in Part 1 gathering evidence related to producers and their role in the pond, have students revisit the class-generated list of sticky-note questions from Student Experience 2 to see which, if any, they are now able to answer. In addition, provide an opportunity for students to add questions that have emerged based on what they now understand about the mystery and what they think will be important to investigate. For example, students may pose questions such as, “What happens to the producers at the bottom of the pond when they die?” or “What organisms in the pond eat the producers?”, questions that students will gather evidence to answer in Part 2 and Part 3, respectively.

Crosscutting Concepts

Cause and Effect Students can compare their thinking from the initial experience with what they have heard in the story to see the extent to which the causal relationships described in the story are reflected in their model.

Systems and Systems Models Hearing more of the story about the system under investigation (Sunrise Farm Pond) enables students to reflect on how their model represents this system.

Student Thinking

At this point in the pathway, some students may think that the lack of oxygen from the underwater plants is the sole reason for fish death.

Implementation Tip

It is okay that students have an incomplete understanding at this point in the pathway. Parts Two and Three will address the other causes.