Urban Effects On Inshore Plankton
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Arnam, Steve Roosevelt H.S
3436 W. Wilson Ave.
This lab activity in counting plankton, reinforces the use of the microscope.
Differences encountered in count may lead to an exercise in graphing the observed
results and stimulate discussion concerning plankton count variation from selected
collection sites. The Phenomenological Goal of the lab is the realization of urban
water pollution problems. A recognition of cause and effect relationships in an urban
area is a concern I feel students should have early in high school biology. Students
should arrive at certain conclusions through inquiry rather than being told answers.
This microscope lab will have students critically thinking about the discrepancies of
plankton counts along our shore and through problem solving techniques they will
arrive at a few hypotheses.
Equipment and Materials
Projecting microscope Microscope
Slides (gridded,see Preparation) Coverslips
Beral pipet (eye dropper) Plankton collector (see Preparation)
Plankton samples (preserved) Lab notebook or data sheets w/graph
Preparation and Strategies
You could either purchase a plankton net (approx. $45.00) or make one. In order to
make one you should use a 3 lb. coffee can with both ends removed. Cover one of the
ends with fine mesh netting (50 mesh or smaller) and surround the outside with an
embroidery hoop that fits (approx. $0.75). Tighten the hoop while periodically
pulling the mesh so there is no sagging. Ideally the mesh must must be taut over
the bottom. Tape the embroidery hoop and net along the sides with duct tape to
ensure its tight fit. You may have to remove the duct tape and retighten the mesh
if it begins to sag. Take the tape with you on the collection trip. The collecting
can nets are easy to make and are really inexpensive. Using the plankton net you
can now sample any aquatic community. For this lab I used Chicago beaches from
31st Street north to Evanston and then took samples in both Highland Park and
Zion, IL. Students can repeat this experiment by resampling beaches along Chicago
or areas along Lake Michigan or even their own projects. The possibilities are
endless! As a beginning microscope activity the "Urban effects" lab can be used
during the first weeks of school focusing on manipulation and viewing skills. This
lab could also be used in plankton studies further into the semester. Gridded
slides for counting plankton can be made by copying graph paper onto acetate,
using Xerox or thermofax process. Cut the desired size and tape the acetate to one
side of a slide.
1. Take specified labeled (site designation) Beral pipet and shake thoroughly.
2. Immediately place 2 drops on your slide.
3. Make a wet mount (glass slide up if using acetate grid on slide).
4. Place slide under the microscope and count the number of plankton.
5. Record the number on your data sheet.
6. Have your partner count the same slide or repeat your count.
7. Record the number on your data sheet.
8. Average the 2 plankton counts and record.
9. Repeat the following procedures with a different sample.
Station A B C D E F G H I J .