Detective on the case of the... River Kid Mystery Allie, the equipment manager, packed the ph kit, thermometer, and bug pan for the hike to the creek. She placed the objects in three of the backpacks. One backpack is labeled Chemical Team. One is labeled Bug Team. The other is labeled Temperature Team. But she likes to fool her classmates and has put every single thing in the wrong backpack. The only clue she has given the class is that the ph kit is not in the Temperature Team backpack. Where is the thermometer? Show your work with pictures, diagrams and/or words explaining your solution. 1
Water Quality - Chemical Testing Part 1 1. Dissolved Oxygen Essential for a healthy waterway Lack of DO is a signal of severe pollution If DO level is low, little aquatic life will be present Ex. Trout and pike need a medium to high DO level Catfish and carp can live in waterways with low DO levels. Sources of Dissolved Oxygen Atmosphere Waves Riffles Tumbling water Algae Aquatic plants The level of DO reaches its peak in the late afternoon. AT night photosynthesis stops but plants and animals continue to consume oxygen. As a result, the DO level drops at night. The DO level falls to its lowest point just before dawn. It may even fall below 4, the minimum level to sustain fish such as bass and bluegill. What causes the DO level to change? The volume of the waterway The temperature of the water, as the water temp. rises, the DO level decreases Organic waste anything that was once a part of a living plant or animal. Examples: food, leaves, feces. Organic waste can enter a waterway through sewage, urban and farming runoff, and industrial sources. Bacteria consumes oxygen from the water as it decomposes the organic waste. 2006 Dee Shore. Used with permission. 2
Dissolved Oxygen Alert! DO levels of 2 or lower will not support life. Aquatic life will become stressed at 3 ppm. (parts per measurement) Dissolved oxygen level should be at least 5 to sustain aquatic life. 2. Turbidity Turbidity is the measure of the clarity of water, or in other words, how cloudy it is. Turbidity reduces the amount of sunlight reaching the aquatic life. Causes: Soil erosion Waste discharge Runoff Algae growth The color of the water depends on what it floating in the water. Water is brown when soil particles are floating in the water. If there are algae floating in the water, the water will be green. Problems with too much turbidity: High turbidity causes a rise in the water s temperature Aquatic life find it difficult to survive (When the temperature is up, the DO level goes down.) The inability of sunlight to pass through the water results in photosynthesis slowing down. Solids floating in the water clog the fish s gills. As solids settle on the bottom, the eggs, larvae, and aquatic insects are covered and smothered. 2006 Dee Shore. Used with permission. 3
Water Quality - Chemical Testing Part 2 1. phosphate Phosphorous is necessary for life. All living things have the nutrient, phosphorous. It is found naturally in water as phosphates. One type of phosphate is organic. Organic phosphates include parts of living plants and animals, their byproducts, and their remains. The other type is inorganic phosphates which can be ions attached to soil particles or laundry detergents. The Effects of Phosphorous on Water When there is too much phosphorous: Plants begin to grow rapidly, turns the water a cloudy peagreen Abnormal plant growth causes the DO level to be significantly lower or even depleted This condition produces gases, one of which is hydrogen sulfide, which gives a rotten egg smell. 2. ph measures the acidity of water. The ph scale ranges from 0-14. The lower the number, the more acidic it is. We want our water to be between 6.5-8.5. Every unit represents 10 times greater or less the preceding number. Ex. ph 6 is 10 times greater than ph 7 ph 5 is 100 times greater than ph 7 The range of ph levels that will support specific life: Bacteria 1 13 Plants 6.5-12 Snails, clams, mussels 7-9 Bass, bluegill, crappie 6.6-8.5 Largest # of animals 6.5-7.5 (trout, mayfly nymphs, etc.) Carp, suckers, catfish 6-9 The major effect on ph is acid rain. 2006 Dee Shore. Used with permission. 4
Chemical Team Research Chemical Researched: Name: Describe the chemical: How does this chemical pollute our stream? (How it affects water) 5
Chemical Teams Your job is to complete the chemical assessment each trip. This means you: Will step gently step into the creek. (You do not want to stir up the water.) Will take two creek samples: Follow the directions in your test kit. Will report your results from each test to the group leader. If these do not match, take a third sample to validate the results. Be careful to make sure all pieces, caps to bottles, and directions are returned to the kit. After returning to school: Rinse your equipment, dry and check it with the list on the outside of the backpack. Put a new sheet in the backpack, if necessary. Create a way to display the information on the bulletin board to educate others. 6
Chemical Testing School: Date: Air Temperature: C F Water Temperature: C F Test 1 Test 2 ph Turbidity Dissolved Oxygen Phosphate 2006 Dee Shore. Used with permission. 7
Where Do I Fit In? Reflect on your participation during this group activity. Select and color the fish in this school of fish that is most like you. Explain why. 8