As the wind whipped waves onto the shore, Cecilia Gaultney and Hallie Burkhard huddled around a cove at Rocky Point Park clutching a lasagna pan full of grass and dirt. The rain pelted their backs until a biologist in a wetsuit signaled to the frigid fifth-graders that it was their turn to go under.
At the count of three, Cecilia stuck her blue-polished fingernails into the pan, grabbed a hunk of grass, then dove into the water so she could mash her plant into the bottom. Hallie went next, her sneakers fluttering above the surface. And so it went until there were no more plants in the pan.
"It's freezing," said a shivering Hallie when the pair finished. "But it's fun to know you're doing it for something good."
The girls, who attend Cecil Manor Elementary School in Elkton, are part of Bay Grasses in Classes, a partnership between Maryland's Department of Natural Resources and the Chesapeake Bay Foundation to reseed the bay with the underwater grasses that form habitat crucial for aquatic life. Every year, thousands of students around the state grow grasses in their classrooms over the winter, planting them in bay waters during May and June.
This year's plantings come as grasses in Maryland's upper bay -- an area that includes the Baltimore County park -- are having a resurgence. The volume of grasses has doubled since 2004, an increase scientists attribute to reductions in pollution from sewage treatment plants and to drier conditions. But grasses are far below historic levels throughout the rest of the bay.
Over the last year, the students have learned that bay grasses are like the canary in the mineshaft: If they can't survive in the water, then chances are other species won't live there either. They have also learned that grasses face a barrage of obstacles, both natural and man-made.
Mute swans eat their lush beds. Strong gusts from storms can destroy whole swaths. But the single biggest factor in their growth is water quality: the murkier the water, the less chance the grasses will flourish.
Nitrogen from sewage plants and runoff from farms and cities are the biggest bay pollutants, and the largest factors in water clarity. As effluent flows, it creates algae blooms that block sunlight and prevent grasses from growing.
"In parts of the bay, like in the tributaries, you see bottles and stuff out there, and that disturbs the animals' habitat," Cecilia said.
Added Hallie: "We've been learning about not polluting or wasting water."
The plantings help make the children aware of the link between what they do on land and how the grasses grow in the water.
"We get some students who really, really see it," said John Rodenhausen, a bay foundation educator. "They know that sunlight is to grasses what pizza is to you and me. If the grasses can't get their favorite food, they're going to die."
The students at Rocky Point yesterday came from farming communities that are quickly turning suburban, with impervious surfaces where open space once stood. Cecil Manor is in Elkton; the other school, Southampton Middle, is in Bel Air.
As her students played "sediment, sediment" -- a tag game in which "bay savers" touch people and "turn" them into trees to stop a pollution blob -- Southampton science teacher Ann Steele said she often points out how changes in Bel Air's landscape are affecting the bay.
"We want to stress stewardship, that one person can make a difference to the bay, and that they have a piece of trying to improve the bay," she said. "I know they've heard it before, but as they see the impact with the planting, I think it makes a better connection."
It did for Colin Stratford, an environmentally conscious seventh-grader who said he already recycles at home and rides his bike around the neighborhood instead of asking for a lift.
"I liked coming in after school and doing the tests on the plants," Colin said. "It's neat now to see where the grasses are going."
The Bay Grasses in Classes program was created in 1998 to get around two problems -- a lack of funding to pay for grass restoration, and a lack of lab space in which to grow the plants. With the help of the bay foundation, 93 schools in the region are now growing plants. The Chesapeake Bay Trust and the National Oceanic and Atmospheric Administration provide grants to pay for supplies.
Students grow grasses in their classrooms using equipment as simple as the lasagna pans. They go to the DNR Web site, enter their data, and compare how their grasses stack up to other schools'. Teachers download class exercises, such as vocabulary lessons.
The grasses that students plant have a 65 percent to 70 percent survival rate. If they don't thrive after a couple of seasons, organizers find a new location.
Rocky Point was considered a good site for practical reasons -- the park has bathrooms, a bus parking lot and good waterfront access. But soon, DNR biologists learned that Baltimore County agreed with the grasses. Within a few seasons, the seedlings grew to 5 feet high. When Maryland and Virginia conducted annual aerial surveys, the Rocky Point grasses were thick enough to spot.
"It was probably less than an acre of grasses, but to see it on a map, bay-wide, it was pretty incredible," said DNR biologist Mark Lewandowski, who wore his wetsuit.
Bay Grasses in Classes helps DNR figure out where to do large-scale plantings. But perhaps the program's greatest benefit, say organizers, is the seed it plants in students' minds.
Before the grass project, Hallie was already an eco-conscious 10-year-old, reminding her mother to turn off lights and not to run the water when brushing her teeth. But after learning about the grasses, she said, she started thinking more about working to help the bay thrive.
"I think the bay is amazing," she said. "Look at the way it gives to people economically and how it gives to nature."