Have you ever looked at beach sand to discover the empty shells of microscopic animals? ... ever seen a water bear crawling through a patch of moss? ... watched a hydra feeding? ... or compared a 'water flea' to a dog flea?

This section is devoted to activity ideas for exploring the world of small living things. The activities are ideal for classroom or home, using readily-available equipment and materials.

Background/Preparation:
Here's an activity to encourage science observation skills among your students -- and it may provide you with a good excuse for a tropical holiday.
Even if you can't get away this year to the tropics, you can have friends traveling to Hawaii or tropical locations collect small containers of white beach sand. A film canister full of sand is enough for classroom use for several years. The sand collector should note a few details about the sample such as: a) location of the beach, b) amount of wave action c) is it near coral reefs?, d) directional exposure of the beach, and so forth. One teacher in Oregon has collected sand samples from hundreds of locations aroung the world.

Materials:
One or more tropical white beach sand samples
Discovery Scopes
transparent tape
Notebook, pencils, etc.

Proceedure:

- Place a piece of transparent (or 'frosted') tape across the posts of the Discovery Scope chamber holder.
- Hold the tape flat, sticky side up, and pour a small amount of a beach sand from one of the samples on the tape.
- Hold the posts vertically and tap them very gently to remove excess sand, recovering the excess sand. (You may need to first press the sand lightly with a clean soft cloth.)
- On the tape outside one of the posts, attach a small piece of paper with information about the sand sample including a sample number.
- Carefully examine the sample. Students should be encouraged to take careful notes according to their level of observation abilities. Counting types of objects, drawing the objects, conjecturing about the source of the object and noting details that provide evidence for their conjectures.

Observations/Discussions:
The 'BINGO' part of this activity is that students may come up with some surprising rewards as they scan their samples. Sand from many 'white' tropical beaches is made entirely of tiny shells and bits of coral or larger shells. On some beaches, there is a profusion of tiny shells from single-cell organisms called foraminiferans. These can be beautifully sculptured or multichambered, and they are a joy to discover. Shells of tiny snails, clams and worms may also be found. Much of the sand on many beaches will be pieces of coral rubble. Students will discover the openings in the coral that house the coral polyp. Every sand sample is a 'mystery with a history', and it can be enjoyable and instructive science to discover evidence that may help to reveal that mystery.

Among the many skills that can be emphasized are: descrimination between different types of shells and pieces of shell; descrimination between shells, shell fragments, and minerals not from living sources; observation of details; classification and categorization of different shell-types; counting individual types of shells; estimation of the total numbers of a single type of object from the count on a portion of the sample; estimation of percentages; and so forth.

Extensions:
Compare beach sands from North America or other temperate locations with tropical beach sands. Why the differences?

Compare black tropical beach sand with white tropical beach sand. Why the differences?

You can also investigate many other grainy materials with this procedure. Students can compare sand samples from a variety of locations for: types of minerals, the degree of roundness of the grains (indicating weathering), the percentage of transparent minerals, and so forth. Students can compare and contrast a variety of crystals such as table salt, alum, epsom salts, and sugar.

Background/Preparation:
Plankton is a term used to indicate organisms that spend their entire lives, or a portion of their lives, drifting about in the waters of oceans, lakes or ponds. The word comes from the Greek word, planktos, meaning 'to wander'. In this activity, you take a close look at the many different types of planktonic organisms that live in freshwater lakes or ponds. This is really a year-round activity (although you may have to chip a hole in the ice to get to pond water in the winter).

Materials:
nylon stocking
metal coat hanger
Thread and needle
Discovery Scopes and chambers
an eye dropper or turkey baster

Proceedure
- First, make a plankton net using the coat hanger and nylon stocking. Straighten the hanger and form a loop about 6 inches (15cm) in diameter. Stretch the nylon stocking opening over the loop and sew it firmly to the loop. Use the remaining part of the hanger as a 'dip-net' handle, or attach the net to the end of a stick, dowel, or broom handle so that it is rigid and does not twist when dragged through the water.
- Collect pond samples using your plankton net, by dragging the net through the water for a few seconds to minutes, depending on density of plankton. Invert the net into a jar of pond water to make a sample of concentrated plankton. Keep the sample cool, in order to keep the plankton alive as long as possible.
- Students can use a turkey baster to remove samples. Observations can be recorded in notebooks or even on videotape.

Filling the Chamber without Capturing a Bubble 1. Fill the chamber until the water 'mounds up', almost to the point of breaking surface tension. 2. Place lid on the edge of the chamber and carefully tilt it into position, pressing down on the aligned edge. 3. Squeeze the lid on and wipe the chamber surfaces clean and dry with a clean cloth, being careful not to scratch the viewing surface.

Observations/Discussions:
Individuals of most planktonic species survive only a few days at the most. Populations grow and diminish depending on sunlight, food supplies, and predation. Thus, the planktonic organisms present in any body of water change from week to week or even more rapidly.
Notebooks can be filled with observations about the plankton species found -- drawings, notes on swimming behavior, interactions with other plankton species, observations about reproduction, etc.
It is not necessarily to precisely identify each type, but is useful to make drawings of the different species. It is very helpful to examine a good reference on the micro-life of ponds.This may lead to identification and will definitely add to an appreciation of the diversity of micro-life. We recommend the excellent guidebook - Guide To Microlife, by Kenneth Rainis and Bruce Russell.

Extensions:

Try comparing plankton samples from different ponds, ...from different depths within a pond, ... from rivers or lakes. If you are near the seashore, collect plankton samples from the ocean or an estuary.

Keep an ongoing account of the species variety of plankton in a pond over several months or even years.

Link to the Plankton Net site for more information and pictures of plankton.

Great lessons on pond life can be organized around combining student investigations with video or multimedia from BioMEDIA ASSOCIATES such as The Biology of Lakes, Ponds and Wetlands Video, the Biology of Nematodes, Rotifers, Bryozoans and some "Minor Phyla" video, or the Wetlands Explorer CD-ROM.

Tell us about a DiscoveryScope Activity you've designed! - We'd like to post activities here to be shared with other educators. Send your activity via e-mail to ddenning@saltspring.com.

A fascinating site about worms - great subjects for discoveryscope classrooms.

Link here to great environmental education resources for teachers.

Tons of great links for biology, education and other topics.

Watch Over Washington is a great model resource about conservation in the State of Washington.

The Ugly Bug page. How can you beat this for microscopy (scanning electron) and education?

Buckman Elementary School has some neat images they have made with a simple digital camera setup.

Life, the Universe, and Everything. A nice jump-off place to many biology and education resources.

Education Index/Biology. An essential site for any educator interested in teaching about living organisms.

The Sea. Pictures, games, teacher resources, and more.

Find a list of good references on microscopes and small life at the Exploratorium.

Skowronski's Science Connection has an excellent set of links to science sites, chosen and posted by a student. Good work!

An excellent jump-off point for links to information on microscopy: Microscopy Internet Related Resources: Education.

Microscope Neat Links is exactly what it says. And they are neat! With a number of sites particularly interesting to educators.

Bagheera is a huge site sponsored by Microsoft. It provides classroom activities about endangered species.