Runoff, Algae and Fish: Reading a Lake Data Set

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Science · Biology
SP-BIO-012 · Free to print and use in your classroom · substituteplans.com
Page 2
Runoff, Algae and Fish: Reading a Lake Data
Set
Science · Biology · Grades 10 · 50 minutes
Time needed
50 minutes (one class period)
Prep
Copy the 2-page worksheet (one per student). Calculators are optional.
Technology
Optional: calculators.
Student
independence
High. Individual work with a partner discussion.
Copies to make
One 2-page worksheet per student
Materials
Pencils, Worksheet, Calculators (optional)
Goal for today: Students will interpret data trends, calculate percent change, identify variables and propose
evidence-based solutions for a human-caused environmental problem.
Before the bell
☐ Copy the worksheet, one per student (2 pages).
☐ Write on the board: Percent decrease = (old − new) ÷ old × 100.
☐ Keep the answer key on your desk. The lake and numbers are made up for practice.
Say this to start
Today you are an environmental scientist. A town near a lake has been watching the water change over five years, and
you have the data. Your job is to read the numbers, find patterns and explain what might be happening. Use the data
to back up every answer.
Run of show
Minutes
What you do
What students do
0–5
Take attendance. Hand out the worksheet and read the
directions aloud.
Look over the worksheet.
5–13
Tell students to read the passage silently and underline the
chain of events that leads from fertilizer to fish loss.
Read silently and underline.
13–40
Tell students to study the data table and answer questions
1–9. Walk the room and point students to the table.
Use the data to answer each question.
40–46
Read the answers aloud from the key. Students check their
own work.
Correct mistakes in a different color.
46–50
Collect the worksheets and place them in a stack for the
teacher.
Hand in the worksheet.
If things go wrong
• If students say they have not learned about this: the passage explains the cycle. Have them read it twice.

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Science · Biology
SP-BIO-012 · Free to print and use in your classroom · substituteplans.com
Page 3
• If students ask whether farms or lawns are to blame: this lesson is about how nutrients affect the lake, not
about blaming anyone. Many sources, including towns, farms and homes, can add nutrients.
• If a student finishes early, use the early finisher list.
• If the room gets loud, move to silent work for five minutes.
Early finishers
• Design a poster slogan and a three-point action plan to protect a lake from runoff.
• Describe what you would measure if you wanted to test whether lawn fertilizer or road salt harms a nearby
stream.
Support and challenge
• Support: Let students highlight one trend per column in the table (up, down) before answering the questions.
• Challenge: Ask students to explain why correlation in this data set does not prove cause, and what extra
evidence would help.
Notes for the teacher (you fill this in)
Jot a few lines before you leave. A full Daily Sub Report is in the free Sub Survival Kit at SubstitutePlans.com.
How far the class got / what to pick up next:
Students who were especially helpful:
Anything the teacher should know: