Seaweeds

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"The Gardens of the Sea"
Basic: Grades K-2
Intermediate: Grades 3-5
Advanced: Grades 6-8

Seaweeds are the garden of the sea. Students see, touch and taste these fascinating marine algae that range from tiny one-celled plants to tall kelps. Seaweeds are used in many of our foods and are vital to the ocean food chain.

The Seaweed Program combines hands-on activities for the students with explanations of the principle characteristics of seaweeds and their role in the marine ecosystem. Samples of many types of seaweeds are collected before the session so that the students can see and touch many different species.

Sample of seaweed taken from the Great Bay during a Floating Lab excursion.

Program Outline

The Seaweed program begins with a discovery session. Students have small bowls with a variety of seaweed samples and are encouraged to study the samples and figure out the differences among them in terms of color, texture and size.

Then, a presentation is given emphasizing these key topics:

  • Classification of seaweeds as aquatic plants called algae.
  • Comparison of seaweeds with land plants. 
  • Explanation of Photosynthesis as a source of algae nourishment and the production of excess oxygen.
  • Location of various seaweeds in the tidal zones of the seashore.
  • Description of the major types of seaweeds – brown, red and green.
  • The value of seaweeds in the marine ecosystem including the production of oxygen and as food and shelter for marine animals. 

The presentation is interactive and uses Q &A to involve the students.

Seaweed on the shore of the Great Bay
  • After the presentation, students perform several reinforcement activities:
  • A Felt Board depicts the Rocky Shore and the various zones. Students place pictures of seaweeds in the appropriate zones.
  • Students make a Medallion by mounting a piece of seaweed on construction paper.
  • Zone Quiz: Each student receives a diagram of the Rocky Shore showing the various zones. Students connect seaweed names to the appropriate zones.
  • Advanced students learn to use a Dichotomous Key (a roadmap of Yes/No questions) to identify various species of seaweeds.
  • Finally, we review the vocabulary used in the presentation and the answers to the zone quiz.