HEALTH, NUTRITION & FITNESS • EDIBLE SEA LIFE

Title: Algae is Um, Um Good!

(Health & Nutrition)

Grade(s): 6

Introduction: Many kinds of seaweed are edible and rich in vitamins and iodine. They are as common in many Asian Countries as green beans and carrots are in the United States. But until more people here develop a taste for sea vegetables, it is alginates, carrageenan, and beta carotene — seaweed derivatives that act as stabilizers, thickeners, and colorants — that end up on our dining room tables. Seaweeds are not really weeds but large forms of marine algae that grow in the coastal ocean waters of many countries. They include thousands of species ranging from microscopic plants called phytoplankton to giant floating or anchored plants.

The three main groups of seaweed are brown, red, and green algae, each providing important ingredients for the manufacture of food and other products. Carrageenan is a generic term for compounds extracted from species of red algae. Carrageenans are used in stabilizing and gelling foods, cosmetics, pharmaceuticals, and industrial products. From brown algae come alginates. They make water-based products thicker, creamier, and more stable over extreme differences in temperature, ph, and time. For example, alginates prevent ice crystals from forming in ice cream. Beta Carotene, a natural pigment derived from green algae and numerous other land plants, is used as a yellow-orange food coloring and may help prevent certain types of cancers.

These seaweed derivatives represent only a small part of the many living and nonliving products we derive from ocean plants, animals, minerals, and sea water. Together, they provide an important reason to protect the oceans.

Learner Objectives:

• The student will be able to demonstrate that, although we sometimes can neither smell or taste them, many ingredients in our foods and household products come from the sea.
• The student will be able to investigate the foods that you eat to determine what algae derivatives they contain.

Florida Sunshine Standard(s): Science: SC.G.2.3.2 Math: MA.E.1.3.1

Competency Based Curriculum: Math: M/J-I-V-1-A/M/J-3-VI-1-A
Science: M/J-I-VII-4-A

Materials:

Collection of food items containing algae derivatives
Copies of Home Algae Products survey
Samples of brown, red, and green algae

Activity Procedures:

1. Look through your own kitchen and find a few food products that contain algae derivatives. Show these items to your class, without mentioning that they come at least partially from the sea. Ask students to guess what the foods have in common.
   
   
2. Explain that each product contains algae in the form of seaweed, which is now used in many everyday foods and household items. Hold up one of the products that you brought in and show the students where they can find the nutrition label on the packaging. Show students pictures or samples of brown, red, and green algae, from which ingredients in the foods on display are derived. To find these different types of seaweed, check an Asian supermarket or specialty food store.
   
   
3. Distribute copies of survey, Home Algae Products, and tell them to complete the survey at home. Remind them that not all brands of the product contain seaweed derivatives.
   
   
4. The following day, divide the class into groups of three and give each group a few minutes to compare the results of its members’ survey.
   
   
5. Ask if any of the groups found information on all of the foods listed on the survey. Ask them if any of the foods contained two or more of the algae ingredients.
   
   
6. Allow students to consider whether they would eat the whole seaweed plant, knowing now that they already eat algae extracts in many foods. Offer samples of dried, edible seaweed (nori, kombu, dulse, kelp), if available, for students to smell and taste. Explain that algae are rich in vitamins and iodine and, in Asian cultures especially, are used in wrapping to hold together rice, meat, and vegetables (for example in sushi). Ask students what food they use to hold these ingredients together and what makes bread so much more readily available in the United States than in Japan and other Asian countries.

Student Assessment:

Allow students to answer critical thinking questions assigned by the teacher during the class activity.

1. Scientists use marine organisms for research. For example, sea urchins are used in embryology, and sharks are studied in immunology. Explain your feelings regarding this issue.
2. Classify consumer goods that come from the ocean into groups and identify their source.

Students will be assessed on their group participation when comparing the results of their respective surveys.

Activity Extension(s):

1. Provide the opportunity for students to investigate how one change in a freshwater environment can affect everything that lives in that environment by discovering how the amount of fertilizer affects algae growth (Environmental Science).
   
   
2. Allow students to discuss why many seafood products and seaweed derivative foods are healthy meals for people all over the world (Health/Nutrition).

Home Learning Activity:

Home Algae Products survey

Look for the following ingredients which come from seaweed, in the foods that you have in your home: carrageenan, alginates, beta carotene. Place a check mark in the appropriate box to indicate which of these ingredients are listed in each food’s label. There may be more than one per food.

Vocabulary: alginates, carrageenan, beta carotene

References/Related Links:

www.aquariumteacher.com
http://seawifs.gsfc.nasa.gov/ocean_planet.html