ROANOKE TIMES 
                      Copyright (c) 1997, Roanoke Times

DATE: Saturday, March 29, 1997               TAG: 9703310067
SECTION: VIRGINIA                 PAGE: C-5  EDITION: METRO 
DATELINE: FREDERICKSBURG
SOURCE: ROBERT BURKE THE FREE LANCE-STAR 

TO STUDY THE YORK RIVER, THEY BUILT ANOTHER ONE REPLICA FLOWS IN COLLEGE BASEMENT

The 12-foot-long section of river at Mary Washington College - complete with plants, animals and tides - is kept as close to nature as possible.

The York River is a ways from Mary Washington College's Fredericksburg campus. But a piece of the river flows in the basement of a college classroom building.

Crammed in a narrow room in the basement of Combs Hall is a microcosm of the river - one of the state's most pristine - held in a 12-foot-long tank. The sand, water, plant and animals in the tank come from a spot at the York River State Park in James City County, just north of Williamsburg.

The work of keeping this scoop of river shoreline as close to nature as possible is done by biology students under the watch of assistant biology professor Stephen Gough.

``The idea is that somewhere down the road we can emulate the natural system, and then mess with it'' by adding contaminants, such as pesticides or oil, to help predict the effect on the river, Gough said.

The York is one of the major tributaries to the Chesapeake Bay. It is formed by the Pamunkey and Mattaponi rivers, which drain water from Caroline and Spotsylvania counties.

The York was chosen because ``it seemed to have not been studied too well,'' Gough said. ``Also, the York River State Park is a great natural site to study.''

The college's version of the river is not as scenic as the real thing. Around the main tank are pipes and tubes and smaller tanks, held up by a framework of lumber. A bucket shaped like a window box is filled and emptied into the tank every 15 seconds to create waves.

A barrel nearby is connected to the tank by a pipe, and can raise and lower the water 4 inches on a 12-hour cycle to imitate the tide. Excess nutrients are removed by washing the water over a screen covered with algae. Sunlight comes from three buzzing light panels hanging from the ceiling.

Gough recently began running water through a chiller to cool it to seasonal temperatures. ``We've got fiddler crabs in here, Atlantic river mussels, oyster toadfish, flounder, blue crab, salt marsh snail,'' he said.

There's no sign of the creatures under the intense light. They hide out at the deeper end of the tank when the lights are on.

The system was built three years ago by Gough and biology student Thomas Small to imitate larger models made by scientists at the Smithsonian Institution.

``We wanted to see if we could do a pretty good job with a smaller system,'' Gough said.

It's not a perfect match of the river yet. They can't match the changing water clarity of the river, and pH levels are too high, he said. Also missing are the predators at the top of the food chain, such as osprey.

Gough said students occasionally cull out smaller creatures that would get eaten. For now, though, the microcosm's most valuable role is giving students lab and field work experience.

Since it was built, more than 15 biology seniors have used it for research projects. Most of those have gone on to present their data at conferences hosted by organizations such as the Virginia Academy of Science and the Environmental Protection Agency.

Biology major Laura Babb, 21, plans to begin a research project using the microcosm next fall. This semester, she's one of a handful of students who help keep it running.

Three times a week she checks the water and air temperatures and measures salinity. She also gives the grasses a good soaking with a hand-held shower head.

Babb's research will compare a group of small invertebrates in the tank with those in the river. She must submit an outline of her project to faculty for approval.

She hopes the experience will boost her chances when she applies to graduate school next year.

``Not everyone who is a biology major does research,'' she said. ``But if you have the interest, the opportunity is there for you.''

LENGTH: Medium:   83 lines
ILLUSTRATION: PHOTO:  AP. Laura Babb, a junior biology major, water the 
          grasses in the miniature ecosystem. She's one of a handful of 
          students who help keep it running. She plans to begin a research 
          project using the microcosm next fall.