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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

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In addition to cicadas and tree crickets, toads also sing at night in the desert. Because it so dry here for most of the year, these toads stay dormant in underground chambers until the summer rains come. When the rains start the toads erupt from the ground, rush to puddles and attempt complete their entire life cycle before the puddles dry out, sometimes in only 7 days. We have several common species of frogs and toads, but one of the most amazing is the Couch's spadefoot toad.

In this video you can see and hear the adult males calling, tadpoles in temporary puddles, and "toadlets" hopping away. Note: If you have young, sensitive children be aware that cannibalism of tadpoles is mentioned, although not shown.

Sounds like sheep baaing? Well, maybe.

In this video a spadefoot toad is digging into soil. Spadefoot toads may stay underground as long as two years if the rains don't come. This video is silent.

Activities:

1. Get to know your local frogs and toads.

First of all, what is the difference between a frog and a toad?

As it turns out, the terms "frog" and "toad" are common names, they are not scientifically-based groups. According to frog taxonomists, all frogs and toads belong to a group called "frogs." Although many people call the bumpy, dry land-dwelling creatures "toads" and the smooth-skinned, pond-dwelling creatures "frogs," there are a number of species that are hard to place into one of those groups, such as the smooth-skinned spadefoot toads shown above. Check Frogs and Toads for more information.

To learn more about frogs, take a field trip to a pond or wetland.

frog

Gather:

  • Boots
  • Pictures of frog and toad life stages
  • Identification guides if available
  • Camera and/or paper and pencil to record what you see

What you may see:

frog eggs

When I see frog eggs, I always think of punctuation. They start out a dark round periods, and then right before they hatch they turn into commas. Always leave eggs alone because handling them may damage their jelly coating.

tadpoles

tadpole

The larvae, commonly called tadpoles, are often easy to spot along the shore. Sometimes you may see a mix of different kinds. In this case the larger light-brown tadpoles are bullfrogs.

If you are very lucky, you may discover some of the tadpoles beginning to grow legs.

Ask everyone to be quiet and stand still in order to see adult frogs. Typically the adults swim away quickly when there are rapid movements nearby.

frog

Can you identify the adults? Are they common species?

Frog fact: Frogs regularly live 4-15 years, and sometimes much longer. Keep this in mind if you decide to raise one.

2. Frog Songs

Visit the same wetlands or pond at night to listen to frogs and toads singing. Ever hear the spring peepers? These tiny frogs can make a tremendous racket early in the spring.

If possible, make recordings of different types of frogs and toads singing. Or listen to recordings, such as at Sing to me baby! ...Ribbit!

Try to mimic the calls yourself. Can you tell the different kinds apart? Before long you should be able to recognize different frogs based on their calls alone.

Older kids might want to try playing recordings of male frogs singing at ponds at night and see if they can attract female frogs.

Think of ways to design an experiment to find out if only the male frogs sing, or whether the females do too.

3. Eat or be eaten

While you are studying frogs and toads, try to figure out what they eat at each stage and what eats them.

The spadefood toads mentioned above eat insects that swarm at the same time the frogs are active. Both ants and termites tend to produce new queens and males in swarms when the summer monsoons start. At times the air will be filled with flying and mating insects. It is a great time for the toads to store up a lot of food to survive the rest of the year underground. Amazing!

Let us know what you find out.

For more information, try these resources:

Insect Lore Frog Life Cycle Stages

Nonfiction Books for Children:

Face to Face with Frogs (Face to Face with Animals)
by Mark Moffett

Mark Moffett is one of my favorite photographers. His work is often seen in National Geographic, which published this book.

From Tadpole to Frog (Let's-Read-and-Find-Out Science 1)
by Wendy Pfeffer and illustrated by Holly Keller

Frogs by Gail Gibbons, a prolific and award-winning author

Frog (Watch Me Grow)
by DK Publishing

For the younger set.

Book for Adults:
Frog: A Photographic Portrait
by Thomas Marent and Tom Jackson

The Calls of Frogs and Toads
by Lang Elliott
Book and CD

Disclosure:
I am an affiliate for Amazon. If you click through the linked titles or ads and make a purchase, I will receive a small commission at no extra charge to you. Proceeds will be used to maintain this self-hosted blog.

For recent weekend science fun posts we have had a couple of walks: a spring flower walk and a flowering tree walk. Now it is time for a change of pace and do a critter crawl.

Have you ever dug through a pile of leaf litter or looked under a log? How about sifted through a compost heap? Take some time to find a quiet, preferably moist, spot where pieces of dead plants are piled and spend a while getting to know the small, but important animals that live there. Prepare to be amazed at how many different tiny creatures dwell in this often-ignored part of our world.

Before you get started, you might want to gather up a few items:

  • A magnifying lens can help you see more details
  • Tweezers, forceps or a small stick to gently move leaves or bark
  • Small paintbrush to remove dirt and move tiny creatures
  • Paper and pencil to make drawings and record results
  • Gloves (optional but helpful)
  • Identification guides, or take a look at descriptions of compost critters like this one at the Junior Master Gardener website

Locate a compost heap, pile of leaves or logs where you have permission to explore. First survey the area. Make sure you and your family are familiar with common poisonous creatures such as snakes or scorpions that might also be found hiding under leaves, rocks or logs in your community. Bees and wasps sometimes nest in the ground too, so exercise caution.

Gently begin to turn over leaves or peel off loose bark. Pay close attention. What kinds of things might you see?

Expect:

  • Insects such as beetles, crickets, cockroaches, ants or earwigs
  • Snails, slugs
  • Spiders, mites
  • Millipedes, centipedes
  • Worms

If you are lucky you might find a few creatures that are children's favorites, the rolypolies or sowbugs (also called potato bugs, wood lice and various other names). Depending on the type, rolypolies and sowbugs are 1/4- to 1/2-inch-long, gray and relatively hard shelled.

If you find some, gently pick one up. How does it react to being picked up? Does it roll into a tight ball? If so, then it is a rolypoly.
rolypoly

Does it simply try to scamper away? Then it is likely to be a sowbug. Sowbugs look similar to rolypolies, but lack the ability to curl up tightly.

sowbug

The rolypolies and sowbugs belong to a group of animals called the Isopoda. "Iso" means same, and "poda" means foot. Carefully tip yours over and see if this name fits. Does all its feet look the same? How many legs does it have? Insects have six legs and spiders have eight legs, do you think it is either of those?

upside down rolypoly

Does the isopod have eyes? Does it have antennae? What are those small spikes sticking out from the rear part?

When scientists carefully examined isopods, and then compared the isopod appendages and other characteristics to those of other groups of animals, they figured out that isopods are closely related to crabs, shrimp and lobsters. They are crustaceans. Tiny crustaceans in your garden or compost heap, isn't that cool?

What happens when you set your isopod back down? Does it run towards the light or away from the light? Does it try to hide or does it curl up? Try thinking up some more questions to ask.

Keep looking through the litter. You will probably encounter a few things less familiar than the rolypolies, but no less interesting. Have a lot of fun while you observe and learn about this hidden world.

If you can't get outside this weekend, then pick up a few books, like the ones suggested below. After reading them, crawl around the house pretending to be earthworms, crickets and isopods.

Rolypolyology (Backyard Buddies)
by Michael Elsohn Ross, Published by Carolrhoda Books, Inc. Minneapolis, 1995. ISBN 0876149018 contains detailed information and ideas for experiment with isopods.

Compost Critters
by Bianca Lavies, Published by Dutton, 1993. ISBN 0525447636 has absolutely stunning photographs of the inhabitants of a compost heap. Amazing!