The Feeding Frenzy : Seasonal Upwelling (6-8)
Overview of the box
Concepts and Standards
Lessons:
1 Marine food webs &
energy flow
2 Primary production
& upwelling
Activities:
1 Phytoplankton &
primary production
2 Colorful convection currents
3 Upwelling & wind patterns
3 Seasonal upwelling
4 An assessment:
Read all about it!
Online resources
Student Web Page
Teaching Boxes Home
Lesson 2: Primary Production and Upwelling in the Ocean

Activity 1

Phytoplankton and Primary Production in the Ocean

Materials / Preparation

  • Make sure you have the Making Algae Grow experiments easily accessible for the students to observe.
  • Print a copy of the Phytoplankton in the Ocean Worksheet for each student.
  • Students will need access to computers to work in pairs. The two web sites that students will be using can be accessed at Phytoplankton on the Exploring Oceans Student Web Page.
  • Alternately, the on-line resources could be printed and copied for each student.
  • The lesson includes an MP3 audio clip Ocean Currents: Sinking Nutrients at the end of class. If you do not have a subscription or wish to pay the fee, the web page for the audio clip also contains a transcript of the program.

Grouping

Class discussions and groups of two

Teacher tips

Students should have a firm grasp of the concept that food webs in the ocean are dependent upon photosynthetic organisms such as phytoplankton.

Procedures

  1. Begin the lesson by asking the students: “What is the most important organism in a food web? What is the one organism that everything else is dependent upon?” Next ask the students what phytoplankton/algae need in order to successfully photosynthesize and reproduce. Students should be able to generate a list that includes water, sunlight, and nutrients (including Carbon Dioxide). Ask students how plants get these resources on land. Then ask how phytoplankton get these resources in the ocean.

  2. Remind students that they set up an experiment some time ago to determine the conditions under which algae will grow best. Have students look at the results of their algae/sunlight/nutrients experiments. Ask students to summarize their results from the Making Algae Grow Worksheet . Under what conditions did the algae grow? Under what conditions did they grow best? Under what conditions was there no growth? What does this tell us about the needs of phytoplankton in the ocean?

  3. Pass out the Phytoplankton in the Ocean Worksheet . Give students about 5 minutes to think about the needs of phytoplankton/algae: sunlight, nutrients, and water. Have them hypothesize with a partner about where they would live if they were phytoplankton? And why?

  4. After forming their hypotheses, students should go online to the two resources listed on the worksheet: Allow students to complete the worksheets with a partner.
    NOTE    : These two sites can also be accessed at Phytoplankton on the Exploring Oceans Student Web Page.
  5. Have a class discussion about resources for phytoplankton in the ocean. Ask questions that guide students to think about the challenges faced by phytoplankton in the open ocean such as:
    • Where do you think the most plants and algae would live? (Answer: near the shore where nutrients are more abundant and the shallow water provides more sunlight)
    • Do any producers live in the open ocean? (Answer: yes)
    • What were the results of your experiments? Can algae grow without sunlight? Can they grow without nutrients? Under what conditions do they grow best? (Answer: cannot grow without sunlight, limited growth without nutrients, abundant growth with both sunlight and nutrients)
    • Would phytoplankton in the open ocean live near the surface or near the bottom? (Answer: near the surface so they can get sunlight)
    • What are some of the nutrients phytoplankton need? (Answer: If students don’t list all of these, add them at the end: Carbon Dioxide, Phosphates, Nitrates, Iron, Silicates)
    • What challenges do phytoplankton face by living on the surface? (Answer: nutrients are not readily available, decomposition is taking place at the bottom of the ocean—unlike a forest floor, plants can’t access both nutrients and sunlight in the same part of the ocean)
    Allow students to hypothesize about how phytoplankton might solve this problem.
  6. End the class by listening to the Pulse of the Planet audio clip Ocean Currents: Sinking Nutrients. If playing the audio is not possible, have the students read the transcript of the program available on that page.

Resources used

Making Algae Grow
http://www.teachingboxes.org/upwelling/lessons/lesson1_supplement/MakingAlgaeGrow.pdf

Ocean Currents: Sinking Nutrients
http://www.teachingboxes.org/catalog.jsp?id=DLESE-000-000-006-920

Temperate Oceans: Light Zones
http://www.teachingboxes.org/catalog.jsp?id=TBOXR-000-000-000-056

Seawater Composition
http://www.teachingboxes.org/catalog.jsp?id=DLESE-000-000-008-938

 

up