Here on the banks of the Patuxent River, 150 miles southwest of Philadelphia, scientists are gearing up to unravel the mysteries of the Chesapeake Bay.
Will toxic red tides spread throughout the bay - killing fish and other marine wildlife?Will mercury poison the flesh of bass, muskie and other fish?
Will oysters recover from the ravages of disease and over-fish-ing?
These are the sorts of questions scientists at the Estuarine Research Center, run by Philadelphia's Academy of Natural Sci-ences, are seeking to answer in a new $4.8 million facility that was dedicated last month. The new lab, located in a parklike setting, contains state-of-the-art chemistry, biology and ecology labs as well as a fleet of research vessels for sampling fish and wildlife in the bay.
"This center is the single most powerful tool needed to restore and enhance the living resources of the Chesapeake Bay and to complement the Philadelphia academy's existing network of laboratories," said Louis E. "Sandy" Sage, vice president and director of the academy's division of environmental research. The lab was built with funding from private individuals, corporations and government grants.
Since 1967, academy scientists have been studying the Chesapeake in rented quarters in a makeshift cluster of labs in Benedict, Md. As the academy's research interest in the bay has grown, its scientists realized they needed more than the converted oyster-shucking shack, a six-room motel and two trailers that made up their original labs.
The academy launched a campaign to build a modern, permanent facility in the early 1980s. Mrs. Jefferson Patterson donated her family's cattle plantation in St. Leonard to the state of Maryland to create a park. Upon this land the new 23,000-square-foot estuarine lab was built.
One of the most unusual features of the new complex is a special "ultra clean room" containing air that is tens of thousands of times cleaner than the air found inside most buildings. To enter, visitors must pass through a series of rooms that are successively cleaner - wearing special boots, gloves and other scientific apparel.
The reason the air in this lab must be so clean is because academy scientists are planning to carry out exceedingly sensitive chemical analyses of wildlife samples here.
"One of the academy's major areas of research is on the extent of mercury contamination on fish and other wildlife," said James Sanders, director of the new lab. "But our tests are so sensitive that they can detect mercury being given off by the fillings in researchers' teeth. For this reason, most of the samples done on mercury contamination until recently are suspect."
In the ultra clean room, special precautions are taken to prevent such contamination problems. Researchers are able to detect as little as a few particles of mercury out of trillions of particles of a sample being measured.
In other sections of the lab, scientists will be able to simulate a variety of conditions found in the bay. Inside one room on the first floor they can alter temperature and light. By doing so, they can fool organisms into acting as they do in summer and winter and conduct a variety of experiments on them. In the basement of the building are "wet labs" - a series of aquariums and metal tanks in which water from the bay has been pumped. Inside these containers scientists will store and experiment on wildlife caught from the bay.
There's even a room containing special scuba gear, because a number of the researchers - such as fish ecologist Denise Breitburg - spend a lot of time underwater. The scientists use a small fleet of research vessels, including a 42-foot-long shallow draft boat known as the R/V Leidy, to travel across the bay, collecting samples and examining the bay's ecology.
Outside the facility, a dozen cylindrical tanks have been set up near a grassy area. Inside these containers Sanders has altered the chemistry of bay water with phosphorus, nitrogen and other chemicals. He is experimenting with the conditions that cause algal blooms, which tend to remove oxygen from bay water.
With a surface area of 2,200 square miles, the Chesapeake Bay is the largest and one of the most productive estuaries in the continental United States. It is also one of the most embattled. Within its 64,000-square-mile watershed live 15 million people - an increase from 8 million in 1950.
The population growth has significantly affected the bay's natural ecosystems. Polluted water that has run off from farms, lawns, roads and shopping centers has turned the water murky and devastated underwater sea-grass meadows. Its oyster reefs are largely gone, as are populations of sturgeons, redhead ducks and the American wigeon (a freshwater duck).
Because of these environmental problems, the U.S. Environmental Protection Agency funded a $25 million study of the bay in the 1970s, Sanders said. In 1983 an agreement was reached between the states, major cities and federal agencies to address the ecological problems.
"Right now, I'd say that the bay is holding its own after a long period of decline," said Kevin Sellner, an academy researcher who has set up a monitoring program for the bay. "But a great deal more work needs to be done."
Sanders and other academy scientists outlined a number of the successes and failures in cleaning up the bay during the last decade:
- Success: The public's awareness of environmental problems in the bay has grown dramatically and, as a result, support for protection measures has increased.
- Failure: Governments surrounding the bay have been unsuccessful in controlling population growth. As the number of people - lured by the love of the water - grows, more pollution from additional cars, motorboats, power plants and factories enters the bay.
- Success: The amount of phosphorus flowing into the bay has declined by about 40 percent because of bans in the use of phosphates in detergents.
- Failure: The amount of nitrogen entering the bay has not dropped. Nitrogen is given off by cars, power plants, fertilizer runoff from lawns and farms, septic tanks and sewage-treatment plants. One of the major sources of nitrogen comes from the runoff of fertilizers from farms in Pennsylvania, Sellner said.
Nitrogen and phosphorus are harmful because they fuel the growth of tiny plankton, which cut off sunlight to marine sea grasses. Because nitrogen levels have not declined, the acreage of sea grasses has plummeted, causing a decline in the number of ducks and other waterfowl that live in the bay.
These two chemicals also indirectly cause the amount of oxygen in the bay to decline. When plankton, stimulated by nitrogen and phosphorus, die and decompose, they remove oxygen from the water. During the summer months, large portions of the Chesapeake Bay lack the oxygen to support marine life - resulting in fish kills and other problems.
- Success: The number of striped bass has increased because of restrictions placed on fishing this species, which is known as rockfish along the bay.
- Failure: The populations of oysters have plummeted because of two oyster parasites, MSX and Dermo, and because of over-har-vest-ing. "The future of oysters is bleak," said George Abbe, a senior scientist. Oysters help to filter plankton and sediments out of the bay.
- Success: The amount of lead, a toxic metal, entering the bay has declined because of the reduction in the use of lead in gasolines.
- Failure: There has been little progress in reducing the amounts of other toxic metals - such as mercury and cadmium - and toxic organic chemicals such as pesticides. In many cases scientists are just beginning to understand how these substances affect wildlife and the bay.
"We are just beginning to learn about these toxics and are working to develop a strategy for reducing these chemicals," Sanders said.
"Our new lab facilities should greatly enhance our ability to learn about these toxics and help us develop a control strategy for dealing with them. But the only way we are really going to restore the bay is to control population growth and the pollution that enters it."