This tiny Chesapeake lacks only money Budget woes foul ecosystem model

April 20, 1993|By Knight-Ridder News Service

WASHINGTON -- Walter Adey has dominion over the tides and wind and rain.

He decides when the sun will rise and set, whether the days will be cool or hot, and when a storm will blow through and send the hermit crabs scurrying for cover beneath the sandy banks of the bay.

In the basement of the Smithsonian Institution, Mr. Adey has created one of the world's largest and most elaborate models of an ecosystem -- with winds, tides, sunshine, salt marshes and more than 400 species of plants and animals. And it's based on the Chesapeake Bay.

The model is 480 square feet, contains 15,000 gallons of water and is so realistic that the blue crabs actually migrate from salt water to fresh water as the seasons change.

But Mr. Adey must soon give up dominion over his miniature world.

The budget cutters have spoken.

The Smithsonian lacks the money to run it anymore.

[The Army Corps of Engineers has a similar problem with a giant model of the Chesapeake. If Maryland cannot buy the site on Kent Island, it will be sold at auction.]

To keep it going, Mr. Adey has promised to give his ecological Noah's Ark to a group of educators in Newark, Del., who want to use it as a teaching tool.

But there's a catch.

The teachers are $20,000 short of the money they need to move the complex system to Delaware and build a greenhouse to contain it. They have raised about $50,000 since last summer and are seeking support from individuals, schools and corporations in raising the rest.

They hope to use the model to teach high school students from Pennsylvania, New Jersey, Delaware and Maryland how the Delaware Bay works. They also hope to conduct ecological experiments with it.

"This is a phenomenal opportunity for us and students in the Delaware Valley," said Paul Devine, a teacher at Glascow High School who is spearheading the project. Mr. Adey, a Smithsonian ecologist, is a pioneer in a field known as synthetic ecology or microcosmology.

He has created three of the world's largest working models of ecosystems: One is a 20,000-gallon model of the Everglades housed in a greenhouse in Washington. The second is a 750,000-gallon model of the Great Barrier Reef, in Australia.

The third is the model of a mid-Atlantic bay, housed in the Marine Systems Laboratory at the Smithsonian's National Museum of Natural History.

The system consists of eight interconnected Fiberglas tanks. Each tank varies in salinity -- from fresh water at one end of the system to salt water at the other.

Each tank is connected to the next by a circular valve. A computer controls the saltiness of the water in each; the valves allow fish, crabs and marine life to migrate -- just as they do in the Chesapeake.

But the $400,000 model more closely resembles the Delaware Bay than the Chesapeake, Mr. Adey said. That's because fresh water flows into the model from a single source -- a half-inch diameter hose -- much as the Delaware River is the primary source of fresh water entering the Delaware Bay. (The Chesapeake is fed by several rivers, including the James, Potomac and Susquehanna.)

A computer determines when 128 fluorescent lights and 24 thousand-watt metal-halide lamps illuminate the system. By regulating when they go on and off, Mr. Adey simulates the changing of the seasons.

A "dump bucket" simulates waves. Pumps create 6-inch tides. Fans produce winds. Heaters and air conditioners control the temperature of the air and water.

One of the biggest challenges Mr. Adey has faced is controlling the buildup of chemicals, such as nitrogen and phosphorus, in his model. (Such buildups happen in actual estuaries, too. )

He has solved the problem by inventing and patenting a device known as an "algal scrubber," which uses beds of algae growing on screens to filter out chemicals.

"The algal scrubber system is the heart -- or perhaps more accurately, the kidney -- of all of our living ecosystem models," he said.

The model in the Smithsonian's basement contains about 100 species of plants (including goldenrod and honeysuckle), 100 species of algae and about 200 species of animals (including oysters, snails, mussels, bluegill and killifish). He has also had frogs and turtles, but the system is too small to support birds and mammals.

Part of the model looks like an overgrown version of a real-life marsh. It also contains a rocky shore filled with mussels, clams and rocks.

Mr. Adey has introduced predators, such as spotfish and bass, into his model. But these must be carefully managed or they take over, he says.

Mr. Adey said he thinks scientists can create ecological models of virtually any of the world's ecosystems.

His research and that of other ecologists has whetted the interest of many of the 20 million aquarium hobbyists in the United States.

But there are differences.

"In an aquarium, nobody wants their fish to be eaten," he said. "But . . . we want our fish to be eaten. That's because we are trying to duplicate what goes on in real life."

You can contact Paul Devine at (302) 454-2381 or write in care of Glascow High School, 1901 S. College Ave., Newark, Del. 19702.

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