The sun glitters off of the stream as a soft breeze rustles and pulls orange and gold leaves off of trees bathed in warm autumn light. More than 70 people wander the area, examining, testing and filming elements of nature, left to flourish in a wilderness untouched by the harshness of the city.
These people are all participants in one of the most widely observed science experiments ever. Bell LIVE!, presented Thursday by the University’s Bell Museum of Natural History, allowed high school students from around the nation to participate in an examination of a Minnesota freshwater ecosystem.
Headed up by local television personalities Joan Steffend of Home and Garden TV and Vineeta Sawker of KSTP, the presentation was broadcast via satellite to about 80,000 middle school students in over 300 schools across the nation and Canada.
Twelve high school freshmen and sophomores helped researchers and scientists test various elements of the ecosystem to determine the health and growth of aquatic life. The students, handpicked by Bell LIVE! coordinators in June, worked together to show how different elements of the system affect one another and work together in an unending cycle.
“Our ultimate goal is to excite and engage kids in environmental science,” said Amy Theisen, director of distance learning at the Bell Museum. “We take them behind the scenes to show them that science is neat and fun — to inspire them to follow their dreams.”
Testing the Water
The experiment began with a test of the water quality in a small Hastings, Minn., stream. Testing water quality is like going to the doctor for a checkup, said Jim Almendinger, who has studied the site for the past year.
In the same way a doctor would check a patient’s pulse and blood, students monitored the flow rate of the stream and measured the particles in the water.
“This is the nicest stream in the metro area,” said Almendinger. All of the components were on par with a high-quality creek.
Students checked oxygen levels, acidity, nitrates, phosphates and the alkalinity of the water. The temperature of the water controls the amounts of oxygen. Higher temperatures and excesses of nutrients lower oxygen levels, which decrease healthy aquatic life.
“Agriculture is the biggest water quality issue in the state because of the runoff,” said Almendinger.
Maintaining a healthy stream requires controlling the watershed area which surrounds the stream, he added.
Protecting the stream and maintaining healthy elements of the water within it enables hundreds of aquatic insects to thrive. These insects, fed by the water, are the second component in a four-part circle.
Maintaining the Bugs
Insects — the lifeblood of the stream — are the most important component of the food chain. As well as providing food for fish, they all work together to keep the stream clean, said Margot Monson, an aquatic entomologist who works part-time at the University.
Divided into four categories based upon the way they feed, there are about 30,000 aquatic insect species associated with freshwater. These are grazers, filterers, shredders and predators.
“Insects are the most interesting part of the day. Each one does a different thing to keep the stream clean,” said Monica Zappa, a freshman at Cumberland High School in Wisconsin.
“A healthy river is full of insects,” said Monson. Bugs of all types were found in the stream; some had pinchers, some had gills and others had camouflage for protection.
Grazers chew on the algae which covers rocks, filterers cling to these rocks and take algae out of water as it flows past, shredders eat dead and decaying organic matter in the stream and predators eat live animal material, sometimes even small fish.
It is important to study insects in their entirety to learn how they function in all of their stages, said Monson. If all of the pieces are known, they can be protected along with their environment.
Protecting insects in the water is, in effect, preserving the fish that feed off of them. If oxygen levels in the water were too low, the insects would die, eliminating the main food source of the fish population.
Shocking the Water
The most concrete determinant of the health of a stream is the amount of fish found within. Collecting and tagging trout in the stream comprised the third step in the examination of the ecosystem.
The favorite activity of the students: sending an electronic current through the stream to stun trout for collection. The current attracts trout without hurting them, said Jerry Grant, a University fisheries and wildlife doctoral student who has been working at the site since 1993.
After being stunned, the trout are anesthetized, their stomachs are pumped and a rice-sized electronic tag containing a micro-chip and antenna is placed inside the abdominal cavity. Once inside, scientists simply need to scan the specimen to identify it. Similar to bar codes in a supermarket, the tag remains in the fish indefinitely, Grant said. He has been able to record individual fish over a four-year period.
The fish, three varieties of trout, don’t feel the shock, and the anesthetic relaxes them for the stomach- pumping and insertion of the chip, said Grant.
The stomach pumping prepares the trout for the insertion of the tag. A small hole is drilled into their abdomen and the tag is inserted. Although no actual tagging was done during the experiment, Grant said he could tag about 100 fish in one day.
Dassel-Cokato High School sophomore Casey Peterson said the shocking was definitely the best part of the day. “It’s pretty neat,” he said.
Catch and Release
Human involvement in the ecosystem rounded off the experiment. This event took the form of a fly-fishing lesson.
Kids need to learn to be involved in taking care of the environment, said Elizabeth Scheurer, vice president of the Twin Cities chapter of Trout Unlimited.
“I’ve done water quality testing before and I wanted to learn how to fly fish,” said Erin McClenahan, a Bloomington-Jefferson sophomore.
Although the fly-fishing season ended about a week ago, students learned the sport on the banks of the stream. The sport requires good timing and a little finesse, said Scheurer.
“Catch and release is our battle cry,” Scheurer. “Admire it, enjoy the sport, but put it back for the next person to enjoy.”