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In this activity, learners examine the properties of different seaweeds, investigate what happens when powdered seaweed (alginate) is added to water, and learn about food products made with seaweed. Instructions are provided for facilitating three stations at a table in an aquarium or museum, but the activities can be done anywhere. Background information is provided about seaweed and its use in foods, and learners realize how common it is (it's in toothpaste, ice cream, pudding, and even chocolate milk).

Quick Guide

  • Preparation Time: 30 to 45 minutes
  • Learning Time: 10 to 30 minutes
  • Estimated materials cost: $5 - $10 per group of students
  • Age Range: Ages 4 - adult
  • Resource Type: Activity
  • Language: English

Materials List (per group of students)

  • 6 foot table
  • Chair (optional)
  • Table cover
  • 1-2 stools
  • Small samples of brown, red and green seaweed
  • Plastic animal tub, small or large, 1/4 full of seawater
  • Dried seaweed, natural and/or packaged (optional)
  • Alginate (powdered brown seaweed)
  • 1 oz. plastic cups with lids (enough for one set per participant) or 3 oz. paper cups
  • Beaker or jar of fresh water
  • Wooden stir sticks, 3-4 depending on number of participants
  • Damp cloth
  • 5-6 Product containers/boxes with seaweed in ingredients
  • 3-4 Magnifying lens
  • Laminated list of seaweed “code names” found in ingredients lists
  • Directions for reading lists (used if only one presenter)

Informal Categories

  • Food and Cooking
  • Nature and Environment


  • Earth and Space Science
    • Earth Structure
      • Oceans and Water
  • Life Sciences
    • Diversity of Life
      • Plants
    • Ecology
      • Ecosystems

To use this activity learners need to

  • see
  • hear
  • be mobile
  • smell
  • taste
  • touch

Learning styles supported

  • Involves hands-on or lab activities
Includes alignment to state and/or national standards:

This resource is part of


Birch Aquarium


All Rights Reserved, Birch Aquarium at Scripps, ©2009

Funding sources

  • National Science Foundation, NSF OCE-0731338



Deborah Lee Rose
Seaweed snack time

This activity includes a list of many kinds of food items that are made with some form of seaweed. If educators or learners bring not only empty, used containers from seaweed products, but new, full bags or containers, this activity can be followed by—or include—a seaweed snack time or "smorgasbord."