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(Note: our usual Tuesday feature, Seed of the Week, will be back next week. Today we are going to visit the ocean. )

Algae and oceans go hand in hand, but what exactly are algae anyway? Are they plants? What are seaweeds and are they related to algae?

seaweed(Public domain photograph of seaweeds by Axel Kuhlmann)

Although algae may be large and appear plant-like, they are actually protists (belong to the Kingdom Protista). They have chlorophyll like plants so they can make their own food from the energy of sunlight, but they lack common plant structures like roots or leaves. Seaweeds, like that shown in the foreground of photograph above, are large forms of algae, also called "macroalgae." The small forms that float around in the water are often called "microalgae" or "phytoplankton."

You may be wondering why anyone would care about algae. Turns out, algae are important in a lot of ways. First of all, algae are the basis for aquatic food chains in both seawater and freshwater. They are also used for food, as fertilizer, and as a source of products such as agar and carrageenan. Algae are being studied as a potential source of biofuel. Let's not forget, they make a significant amount of oxygen. In fact, it is not too farfetched to think that algae might be the most important organisms on the planet!

Activities for kids:

1. Investigate seawater under a microscope

If you have access to a microscope, obtain a sample of seawater (or pondwater) and take a look at what is in it. Look for green, blue-green or even brown or red organisms that are algae. Examining samples under a microscope is fun because it often leads to surprises.

2. Make an algal collection

You can make a collection of pieces of algae or seaweed you find at the beach, similar to the way you make a plant collection. Some of them can have beautiful shapes and colors.

640px-Adolphe_Millot_algues(Illustration Adolphe Millot algues public domain from Wikimedia)

Gather pieces of algae on the beach and keep it moist in seawater. Once you are home, float the seaweed/algae onto a piece of heavy paper. Press the paper between layers of felt to remove the water and allow it to dry. The Hawaii Botany Department has step-by-step instructions on how to make an algal herbarium.

 

example-image(Figure 3 - Seaweeds are pressed on herbarium sheets for further study and repository in botanical Herbaria. The species that Dr. Suzanne Fredericq is pressing was found at about 66 m depth (200 ft) in the West Flower Garden Banks, and represents a new record for the Gulf of Mexico. -From NOAA)

If you don’t want to disturb nature, which is a good idea, you can take close up photographs of what you find instead. You can share what you discover via blogs, websites or photo streams.

Once you have a collection, visit some of these websites to help you identify what you have. Seaweeds are not too easy to identify, but you might at least figure out which group your sample belongs to.

Biomara has an extensive booklet of activities/lessons about algae to download (30.3 MB). The link for the "entire teaching resource" is right above the "Information for Teachers" bold header. It contains large color photographs of many common "macroalgae."

Who knows where studying algae might lead you. Perhaps you will be inspired to become a marine botanist, like Sylvia Earle (previous post).

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This post is part of our ocean science series. Visit the landing page for links to all the related posts.

ocean-science-week-badge

 

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This week we are continuing our series at the beach. Check previous posts for sand science and seawater science.

Have you ever found something plant-like on the beach and wondered what it was?

algae

beach stuff

Seems like a lot of beach plants are hard to classify. Are they algae, a sort of seaweed, or are algae and seaweed the same thing? Are algae plants or do they belong to a different kingdom? These are all good questions, and scientists are just beginning to answer some of them.

Many of the plants and plant-like creatures you see at the beach are technically algae. For example, kelp are giant brown algae.

kelp

kelp

Algae come in many colors, like these red ones.

algae

The green algae are often found in freshwater ponds and lakes.

algae

Ready to learn more? Here are some suggestions for activities to investigate algae. I'd love to hear your ideas, as well.

Activity 1. Make an algal collection

Gather algae on the beach and keep it moist in seawater. If you have never worked with algae, the Hawaii Botany Department tells you how to make an algal herbarium. Or if you don't want to disturb nature, you can take close up photographs of what you find.

Once you have a collection, visit these websites to help you identify what you have.

Michael Guiry's Seaweed Site covers all things seaweed and the identification of algae.

Life on the Australian Shores and Algae: The Forgotten Treasure of Tidepools are also helpful, although the later tends to get a bit silly at times.

You may be wondering why anyone would care about algae. Turns out, algae are important in a lot of ways.

Activity 2. Investigate food chains.

Algae are the basis for aquatic food chains in both seawater and freshwater.

If you are unfamiliar with the concept of food chains, this book is a great introduction to food chains and food webs. It has been a family favorite.

Who Eats What? Food Chains and Food Webs (Let's-Read-and-Find-Out Science, Stage 2)by Patricia Lauber and illustrated by Holly Keller


Find out as much as you can about food chains in the oceans. Gather, print and cut out pictures of ocean critters to illustrate your own posters of food chains or webs.

Activity 3. People eat algae too.

You have probably eaten algae and didn't even know it. Carrageenan, a thickener used in a variety of foods, is extracted from a red alga. For more information, see http://encarta.msn.com/encyclopedia_761573848_3/algae.html.

Once you have an idea what to look for, head to your kitchen and check to see if you have any foods that contain carrageenan or other products made from algae. Look at the cookbook listed below (or a similar one), and make some of your own dishes using algae. Asian markets are often an excellent source of ingredients.

If you are interested, a fun research project would be to investigate all the ways people use algae for food throughout the world.

Activity 4. Other important uses for algae.

See if you can make a list of other uses for algae. Here are some I found:

Algae are thought to make much of the oxygen we breathe.

This video shows a camera zooming in on the leaves and then the cells of a common water plant, Elodea. In the cells you can see the chloroplasts moving around. The chloroplasts are the sites of photosynthesis, the process that turns sunlight into chemical energy we can use as food. A by-product of photosynthesis is the release of oxygen. Although Elodea is actually a vascular plant, the process in green algae is the same.

If providing food and oxygen weren't enough, now scientists have discovered ways to use the oils found in algae to make biodiesel. In fact, algal oils can be made into jet fuel. See this previous post for more information about algal research at ASU.

If you are interested in algae, here are a few books you might want to try:

The Seaweed Book: How to Find and Have Fun With Seaweed by Rose Treat and Randy Duchaine


For Adults:
Seaweeds of the Pacific Coast: Common Marine Algae from Alaska to Baja California
by Jennifer Mondragon and Jeff Mondragon


Have fun with some seaweed science and let me know what you discover!

Edit: To check the rest of the posts on beach science, follow these links:

Sea Horses and Other Fish

Shore Birds

Tide Pool Invertebrates

Beach Science- Boats

Beach Science-Sand

Beach Science-Seawater

In a previous post, I mentioned two Arizona State University scientists have a project to grow algae to convert into fuel, particularly jet fuel. They made the news again this week because they just got a $3 million-dollar grant to start a pilot project. Exciting stuff!

Follow the link to the newspaper article:
Algae-to-fuel work gets $3 mil
ASU spinoff believes organisms key to renewable energy for jets
by Ken Alltucker - Sept. 2, 2008 12:00 AM
The Arizona Republic