The students waded through slimy, green algae in water as high as their hips. They slid through a low tunnel, banging their heads in the dark. They climbed over tree trunks and sloshed down concrete culverts.
Five hours later, they had tracked a stream from behind Aberdeen Middle School to where it connects with Swann Creek, a few miles beyond U.S. Route 40.
Lannell Ward, one of 23 Aberdeen High students on an environmental field trip last week, had one conclusion: "Uggh! Everything's so dirty!"
Which was precisely the point of the expedition, sponsored by the Chesapeake Bay Foundation: To show students that small streams connect to creeks that feed into the bay, and if the streams are dirty, the bay will be dirty.
Last week's trip was one of 30 coordinated by the foundation with schools in the Baltimore and Washington areas this spring. The State Department of Education contracted with CBFto conduct the trips in Maryland public schools this year. Students from at least three more Harford schools will go on the trips, calledStream Restoration Projects.
"These students are learning that it's not just big companies that pollute the bay," said Claudia Donegan, manager of the Stream Restoration Project. "It's us -- the way we pack our lunch and what we put down the drain."
"The problems with the bay start in streams and rivers. Streams are like veins. You clogthe bay's veins, and eventually it will die," she told the students on the trip, showing them a map of the bay and its tributaries.
Students spend the first day in the two-day field trips studying a stream or river up close. The second day, they conduct a project, such asplanting seedlings along the stream, that will improve the water quality.
On a cold, cloudless morning last week, the ninth- and 10th-graders of Aberdeen Middle -- members of an honors biology class -- gathered behind the school. After a brief discussion about water pollution, they slipped into thigh-high rubber boots, walked about half a mile and waded into a concrete culvert.
The students hiked 2 milesupstream, mud splattering from head to toe as they looked for signs of pollution.
Donegan and another Stream Restoration educator, Mike DiMisa, showed the teen-agers how to to assess the health of a stream by collecting fish, insects and microscopic plants.
"Bugs are dependent on the water quality of the stream," Donegan explained. "There are certain bugs if the quality is good, like mayflies and stoneflies, and certain bugs if it's bad, like leeches and aquatic worms."
After spreading screens across the creek to gather aquatic life, the students found little life -- a few fish and some small slippery frog eggs.
"I found a dead aquatic worm!" announced Wendy Wagman, 16.
"I found a bad snail. Another bad snail. Four bad snails!" yelped Dan Taylor, 15, picking the creatures out of a sludge-like mud. "That was fun."
"There's not much life," concluded DiMisa. "There's no food chain. Usually a stream would be teeming with insects that feed the birds and fish."
Later in the day, the students tested the stream for chemicals, including dissolved oxygen, nitrates and phosphates.
"Just because the water looks clean doesn't mean it is clean," Donegan said.
Biology teacher Victoria Cunningham had a tough day learning about dirty water. She'd slipped in the mud, chipping a tooth, dropping her camera and getting dirt in her contacts.
But shethought it was worth it.
"You can give them the theory, but they have to get out and do it," she said. "Young people need to be aware of what's going on environmentally."
On Friday, the second day of the field trip, the Aberdeen students planned to hike the stream, collecting trash and planting seedlings along the way.
They also would paint "Don't Dump. Chesapeake Bay Drainage" on storm drains.
"We'll ask, 'How did this stuff get here?' It will make the students more conscientious about what they're dumping," Donegan said.
Splashing through the creek was a big adventure, too.
"I've hit my head 12 times!" said Kris Collins, as she emerged from an underground cistern.
"I feel like I'm Jane and Tarzan. This is really gross!" said Tracy Dunne, swinging over a tree trunk and wiping mud off her face.
Said Kris, "You wouldn't think this little creek would be so polluted. This is the most interesting, exhilarating trip I've ever taken."