ID:__________Password:__________Names:_______________________________ WATER CLARITY ACTIVITY REPORT Record all observations and answers on this sheet. Be sure to also type all information into your Data Log book on the computer. Trout, Salmon, Warm water sport fish Large, exotic Zooplankton Alewife Juvenile Fish Gobies Sturgeon Zooplankton (Tiny animals) Zebra Mussels Quagga Mussels Phytoplankton (Microscopic Plants) Sunlight Nutrients Use the boxes to fill in information about the different species found in lake Ontario.

ID:__________Password:__________Names:_______________________________ Record all observations and answers on this sheet. Be sure to also type all information into your Data Log book on the computer. 1.Name four things that can affect visibility in a body of water. _________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ 2.Before you touch the secchi disk apparatus, describe its appearance. What color is the water? Does it appear clear? ________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ 3.You took measurements of the length of string to measure the visibility in the water. Your measurements should be taken to the nearest millimeter. (the small lines on the meter stick) Record your measurements in the space provided. First Loose Length ____________ (cm) Second Loose Length ___________ (cm) 4.You can use subtraction to determine the depth of visibility in the water column. Enter the second length here _____________ (cm) Enter the first length here - _____________ (cm) The depth of visibility in the Sample water column is: _____________ (cm) 5. The Lake Sturgeon is one of the only creatures that eats zebra mussels, and is an endangered species. What do you think would happen if the only creature that eats zebra mussels died off completely? _____________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ BIOLOGY TEAM DATA LOG

1.Your Secchi disk apparatus is similar to the picture at right. Take the ruler from your cabinet and measure the length of loose string attached to the Secchi disk. Record your measurements on your activity worksheet. The apparatus should look like the picture labeled “Figure 1.” 2.Pull the string until the disk comes to the top of the water column. 3.Lower the disk into the water until it disappears. After it disappears, pull up on the string until it is just slightly visible. Hold the string here and have your partner measure the loose length now. Record the second loose length on your worksheet now. The apparatus should look something like Figure 2. 4.On your worksheet there is a section for you to calculate the visibility in the water column. Do this now. 5.You can see in the picture labeled “figure 3” that visibility in water is affected by what is in the water. Take a moment to look back at your activity worksheet to find some things that affect visibility in water. 6.Once you are finished calculating the visibility using the Secchi disk you may return to your workstation and proceed with your instruction cards. Figure 3. Figure 1.Figure 2. The diagram shows how far light can travel through pure water. The water sample in the Secchi disk apparatus in the lab is obviously not pure water. This diagram is only meant to illustrate how far light can travel through pure water. Your sample has a certain degree of “Turbidity,” or cloudiness in the water.