Water Ecology Lab
Curtis High School, Staten Island
Summer Research Program for Science Teachers
This lab gets students out of the classroom and into the field. In this lab, students apply many concepts they have learned thus far in their scientific exploration and puts their skills to use. This lab can easily be modified so students could test ponds, lakes or rivers. Allow students to construct their own kits with low cost materials found in the classroom or their homes. Groups of 4 should spend approximately one class period preparing for the lab by collecting, labeling, and reviewing the equipment and lab worksheets. The other class period is spent at the site, and the third class period is spent observing organisms in the water and agar, and cleaning up the equipment. The only thing that the teacher will have to prepare would be the test tubes with nutrient agar. You may help supply the low cost equipment or ask your lab technician to help round up supplies.
Materials Needed for Field Work:
Fishing line on thermometer
5m fishing line on float (bobber)
Eye dropper (plastic pipet)
String on wood spool
Plastic collecting jar
Stoppered agar test tube
Meter sticks or large measuring tape on spool
Materials Need for Lab Work:
Slides, cover slips
Students will determine physical and chemical characteristics of a stream ecosystem
Students will observe organisms present and their relative abundance.
Students will determine the relative quality of a water ecosystem.
Materials Needed for Each Lab Group:
Clipboard: holds data sheets and procedures
Thermometer: measures surface and bottom water temperature
Fishing line: 5 meters is needed for placement of the thermometer in the water and for determining the flow speed of the water
Rubber bands 2: loop around the top and bottom of the thermometer. The top rubber band allows the fishing line to be secured to the thermometer. The bottom rubber band protects the thermometer
Meter sticks: measures the depth and width of the stream, pond, or river
Calculator: calculates the average depth, water flow speed, and volume of water flow
String on a spool: measures the width of the stream (with the meter stick)
Float (cork or fishing float): This will be attached to the 5 meters of fishing line
Stopwatch: times the movement of the float. This determines the water flow speed
Collecting jar: collects water sample for turbidity test, pH test, and test for life forms
pH paper: needed to test the pH of the water
Pipet: aids in the pH and life form test
Hand lens: used to observe organisms in the water
Test tube with nutrient agar: used to grow microscopic organisms found in the water
Microscope/slides/coverslip: used for preparation and observation of microscopic life forms
Inoculating loop: transfers organisms from test tube with nutrient agar to microscope
· Fishing line and 2 rubber bands
1. Wrap one rubber band loosely around the bottom of the thermometer.
2. Wrap the second rubber band tightly around the top of the thermometer, then tie the fishing line through the rubber band at the top of the thermometer.
3. Place thermometer bulb near the stream bottom; be careful not to hit rocks. Leave the thermometer in the bottom of the water for 2 minutes. Record as bottom temperature on data sheet.
4. Place thermometer bulb just under the surface of the water. Leave in for 2 minutes. Record as surface temperature on data sheet.
Water Flow Speed and Flow Capacity
String on spool
Float with 5 meters of fishing line
1. Use the meter stick to measure the depth of the stream at points that are approximately Ό, ½, and Ύ of the distance across the stream. Record your measurements on data sheet.
2. Using a calculator, average the depth measurements (add and divide by 3). Record on data sheet as average depth.
3. Stretch string on spool across the stream and mark the width of the stream on the string with a pencil. On shore, measure the length of the string with a meter stick. Record on data sheet as stream width.
4. Attach the 5 meter fishing line to the float. Spool the rest of the line around a stick.
5. Set your watch and drop the float in the water, while still holding the end of the fishing line. Start timing as soon as the float hits the water. Let the float go downstream and stop the clock as soon as the float has traveled the full length of the fishing line (5 meters). Record on data sheet as float time trial 1.
6. Repeat step 5 two more times and record on data sheet as float time trial 2, and 3.
7. Compute the average time for all three trials. Record on data sheet as average time of float.
8. Compute the average flow speed. 5 meters/average time =flow speed (meters/second). Record on data sheet as water flow speed.
9. Compute the volume of water flow speed: stream width x average depth x average flow speed x 0.8 =0.8 is a constant to compensate for bottom drag. Record on data sheet as volume of water flow speed.
10. 0.8 is a constant to compensate for bottom drag. Record on data sheet as volume of water flow speed.
1. Fill your collecting jar with a sample of the stream water
2. Allow to settle for 3 minutes.
3. Hold the jar in front of the lettering on this page, and choose one of the following terms to describe the turbidity of the sample. Record on data sheet as water appearance.
Cannot see any print ---------------Opaque
Print barely visible ------------------Very Cloudy
Print visible, but not readable-----Cloudy
Text readable, but blurry----------Slightly Cloudy
Easily read through water --------Clear
4. Smell the water sample and record any odor present such as, fishy, metallic, woody, or none. Record on data sheet as odor of water.
5. Take water from your sampling jar and pipet two drops of water onto a dry piece of pH paper. Compare your results to the color chart on the side of the jar. Record on the data sheet as pH of water.
5. Presence of Life Forms
Stoppered test tube of agar
First note any organisms that you notice by sight in the stream. Draw what you see on data sheet.
Examine your collected sample with the hand lens. Note any small creatures found. Draw what you see on data sheet.
With the pipet, transfer 5 drops of the water sample to your stoppered test tube, and cap the test tube. Allow to sit for 24 hours.
1. In Lab
Observe your agar tube for any signs for bacterial growth. Using the inoculating loop, prepare two slides with the growth on the agar. Draw your observations on data sheet.
Using water from collecting jar, prepare 2 microscope slides. Draw your observations on data sheet.
Why is it it important to monitor streams, and ponds in the environment?
2. Does fines.
2. Doesour local community have laws about dumping and polluting this particular stream or pond? List the laws and the
3. What is the EPA? What is its
3. What is the EPA? What is its purpose?
New York State Standards
Earth Science Core Curriculum
Standard 1 Analysis, Inquiry, and Design
Key Idea 2: Deductive and inductive reasoning are used to reach mathematical conclusions.
Determine the relationships among: velocity, slope, sediment size, channel shape, and volume of a stream