A growing number of schools in Minnesota are turning to the state's abundant rivers and creeks to teach students about science. The testing of water quality offers practical lessons in chemistry, biology, earth science and math. Biology classes at Eden Prairie High School make several trips a year to the Mississippi River and its tributaries to test water. Teachers say the use of technology and hands-on learning give students a greater appreciation of their environment and science. It's a chilly autumn morning, and the river water has an icy sting.
Some students quickly grab water samples for testing.
Biology teacher Jean Tuschie watches while others stand in the current taking measurements with a device called a calculator-based laboratory. They're taking the levels of dissolved oxygen in the water, and they have to measure it both in percent saturation and milligrams per liter. And then that's one of the indicators of water quality, in fact, dissolved oxygen is one of the most important - the amount of oxygen available to any of the life that's in the water. So dissolved oxygen is the most important test we do. Up on the river bank, other students are huddled around test tubes and chemicals, testing for phosphates and nitrates.