Build a set of sieve screens by constructing three identical square frames using twelve 2 by 2 by 12 inch pieces of lumber. Tack 1/4 inch mesh hardware cloth over one frame, window screening over the second frame, and materials from an old nylon stocking over the third.

Use the screens to separate mud samples by stacking them so that the hardware cloth screen is on top and the stocking screen is on the bottom.

Place a mud sample on the top screen, them sprinkle it with a watering can until all the soil has washed through. When the screens are separated, various materials, plants, and animals can be found and studied.

Some can be organized by texture, color, and size. Live organisms can be kept in pill vials with some water.

Be sure to label samples by original location and type.

If the water bottom along the shoreline is soft, wade along the shore at low tide and collect mud samples with a long- handled shovel. A dredge must be used for deep water specimens. You can construct a dredge by making holes in the center and around the edge of a coffee can. You will also need a second can, one that is slightly smaller in diameter than the first can and that has a plastic lid. Make one hole
in the center of the bottom of the second can and one in the center of the lid. Attach the smaller can to the bottom of the coffee can by threading a nylon string through the center holes in the cans. Tie knots in the string so it won't slip through the holes.

Tie a second string -- the lifting string -- to the open end of the coffee can. Place rocks, nails, or fish weights in the smaller can. Put the lid on the can tightly.

To use the dredge, drop it into the water so that the coffee can embeds itself in the mud on the bottom. When the lifting string is pulled, the coffee can will scoop up a mud sample. The dredge should be pulled out of the water by the lifting string.

(Note: if the lifting cord is marked in feet or decimeters, the sample collection depth can be recorded.)

Use your set of sieves to sort the materials that are found.

Collect samples from different locations, and keep a record for each (e.g., location, depth, number of specimens, number of each type of specimen).