Sampling Equipment You Can Build
Secchi Disk:Used to visually measure the turbidity (suspended solids) of a body of water. This is done by lowering the disk into the water until you lose sight of it. Allow the disk to go several feet deeper and then begin to slowly pull it back up. Watch closely as you bring the disk up and mark the depth when you first see it again by grabbing the rope or marking the rope at the surface of the water. You can then measure the distance of visibility from your mark on the rope to the surface of the disk after you bring it back up. A useful tool when comparing bodies of water.
1 circular disk 8-10 inches in diameter (stiff plastic lid, thin metal or plywood, etc.)
Drill with 1/2 or 3/8 inch bit 1/2 or 3/8 inch eye bolt (3-4 inches long) with 2 nuts and washers 6-8 large, heavy washers to act as sinkers (make sure the washers for the eye bolt will not go through the hole of the larger washers)
Approx. 50 feet of thin nylon rope
Black and white enamel paint with appropriate brushes
Meter or yard stick
- Cut the lid, piece of tin, or plywood into a disk 8-10 inches in diameter.
- Drill a hole in the center of the disk with the appropriate bit (match the dia. of the eye bolt)
- Paint the top of disk as shown and allow to dry (If your disk is plywood make sure the top, sides, and bottom are well covered with paint)
- Screw one of the nuts all the way down to the eye of the eye bolt.
- Place one of the small washers onto the eye bolt and insert the bolt through the top of the disk.
- Place the large washers onto the eyebolt on the underside of the disk followed by a small washer and then a nut. Tighten the nut to hold it together.
- Tie the rope securely to the eye of the eyebolt.
- Use the meter or yard stick and permanent marker to mark desired units on the rope from the surface of the disk up the rope for depth measurements.
Plankton Net:used to collect samples of macroscopic and microscopic plankton organisms. Net is usually cast out into the water or trolled behind a boat for a given distance then retrieved. If the diameter of the net and the distance "towed" is known then the volume of water being sampled can be determined. Upon retrieving the net the collecting bottle can be removed for direct observation or sealed and stored for later investigation.
1 round, plastic embroidery hoop (6-8 inches in dia.)
At least 4 feet of relatively thin, strong wire
1 pair of panty hose or old shirt sleeve (support panty hose work best)
1 large snap swivels (the kind used in fishing)
25-30 feet of strong nylon cord
1 small jar, vial, or test tube
Several strong rubber bands
Pair of scissors and needle nose pliers
- Cut two pieces of wire approx. 24 inches long
- Bend the two wires over to form two U-shaped wires and twist together at the top to form a loop( this will be the yoke of the net)
- Cut one of the legs of the panty hose off at the top of the thigh region and cut off the tip of the toe(If using a sleeve, cut off up by shoulder and cut off just above cuff)
- Attach top of the panty hose leg or sleeve to the embroidery hoop by going over the outside of the larger hoop and tucking the top edge of the "net" into the inside of the hoop and then inserting the smaller inner hoop and lock.
- Attach the free ends of the yoke wires to the embroidery hoop by passing the wire around the hoop passing through the net and twisting(yolk wires must be equally spaced around the hoop and the same length from the rim of hoop to the twisted loop)
- Attach the collecting bottle by inserting into "netting" at the opening in the bottom and securing with several wraps of a strong rubber band.
- Tie the fishing snap swivel to the nylon cord and connect the snap swivel to the yoke loop. Now you're ready to sample!
Insect Sweep Net:
used to literally sweep through grasses and other vegetation very rapidly to knock insects from their hiding and into the net. After a couple of quick sweeps have been made the net should be grasped from the outside and gathered below it's opening to keep the insects from escaping. A wide-mouth collecting jar can then be carefully inserted into the open end of the net(where you are grasping it) and the catch allowed to fall or be shaken into the jar for observation. Don't try to sweep nets through thorny or very tough, stiff vegetation, it will only tangle and tear the netting. Be careful when netting butterflies or moths, young children usually injure these delicate insects when netting them. Net the butterflies and moths yourself and show them to the children!
1 old or inexpensive standard pillow case
At least 48 inches of very stiff wire (should be at least 2 if not 3 times thicker than a good wire coat hanger)
1 wooden dowel rod or old broom handle(approximately 36 inches)
Roll of electrical or duct tape
Pair of pliers and wire clippers
Drill with 1/8-3/16 in. bit
- Make round hoop with the wire and bend as shown in the drawing (the hoop must be the same circumference as the opening of the pillow case, twice the width of pillow case and subtract 1in. for the width of handle)
- The wire extensions of the hoop (for attachment to the handle) should be at least 4 inches long and bent inward on the ends to insert into holes in the handle.
- Drill a shallow hole on opposite sides of the handle approximately 4 inches from the end.
- Cut a V-shaped wedge out of the edge of the casing at the seam of the pillow case. This will serve as the opening to insert the wire hoop.(You may want to sew down the middle of the casing so the casing hole will not be so large)
- Slide the casing of the pillow case over the wire hoop
- Attach the extensions of the wire hoop to the handle by inserting the bent ends of the wire into the shallow holes in the handle and then securely wrapping the wire extensions with electrical or duct tape
used for collecting aquatic invertebrates and fish from the bank of a body of water. Net may be used to scoop up aquatic organisms, swept rapidly through aquatic vegetating, or pulled toward you rapidly as you scrape the bottom. Organisms caught should be quickly released into collecting pans for observation, Identification, and counting.
2-24in.X18in. pieces of plastic or fiberglass
Window screen material
1-47in.X6in. strip of canvas or heavy, durable material
At least 54in. of heavy, stiff wire or similar material
Wooden dowel rod or old broom handle (at least 4 feet)
Electrical or duct tape
Pliers, wire cutters, and scissors
Drill with drill bit to match diameter of wire
Sewing machine with durable needle and tread
- Bend the heavy wire into a triangular hoop with the handle extensions at the top of the triangle (base side 18.in., other two sides 14in. each, and handle extensions 4 in. each)
- Lay the two pieces of window screen material directly on top of each other and sew together as shown in the drawing(double stitch for strength) to make the "net bag" and trim off the excess screen material within 1/4 inch of your seam.
- Fold the strip of canvas in half length-wise(pressing with an iron would be helpful) to form the casing to be sewn to open top of the "net bag".
- Sew the casing around the top of the "net bag" and remember to leave the ends open to insert the wire. Turn the net right side out(seam rough edges to inside) and insert the wire hoop through the casing.
- Drill a shallow hole on opposite sides of the handle approximately 4 inches from the end.
- Attach the extensions of the wire hoop to the handle by inserting the bent ends of the wire into the shallow holes in the handle and then securely wrapping the wire extensions with electrical or duct tape(See insect sweep net directions)
used for sifting leaf litter, organic humous, or aquatic bottom samples. Material collected is placed into the sifting screen and the organisms and small debris fall through The screen when it is shaken and into an observation pan (if the organisms are aquatic there must be a little "pond" water in the pan).
Plastic bucket or pail
Wire mesh (1/8in. hardware cloth)
Tube of silicon caulking
Tin shears or wire cutters
- Place the bucket or pail on top of the piece of wire mesh and mark on the mesh the perimeter of the container.
- Cut out the pattern on the wire mesh approximately 1/8 inch smaller than the actual pattern marked on the wire so it will fit smugly in the bottom of the container.
- Cut out the bottom of the bucket or pail leaving an inward lip of the bottom approx. 1/2 in. wide to attach and support the mesh on the inside of the bucket.
- Apply a generous amount of silicon caulk around the inside of the bucket bottom on top of inner lip and press the wire mesh into the caulk. Wipe the caulk smooth with a damp cloth and allow to dry.
Collection Pans & Scoops:
Collection pans are used to put sifted leaf litter, bottom sample, or netted organisms in for viewing purposes (identification, counting, etc.). Scoops are used to collect leaf litter, soil, or bottom samples. There a variety of light colored pans you have around the house which could be used for collection pans( Tupper ware containers, pie tins, etc.) which should be spray painted white if not already to enhance viewing. Small shovels or trowels may be used to collect leaf litter, soil, or bottom samples. The problem comes with having enough of these for the various collecting groups. Here is possible solution to that problem.
1-empty gallon plastic
Clorox or milk container with the lid securely on
Sharp knife or single edge razor blade
- Mark the plastic container as shown in the example all the way around the sides of the container.
- Cut along your markings with the knife or razor blade
**The bottom part is a collection pan and the upper portion a scoop with a handle**
bugbios - http://www.bugbios.com/
More Texas Butterflies - http://www.butterflies.com/guide.html