Last month, I was asked to keynote a conference on federally supported science related to the Chesapeake Bay. It gave me the opportunity to put together a number of insights heard from others recently with some concerns of my own about the state of Bay science - about areas where our current state of knowledge as managers calls out for help from the scientific community.

Science has played a key role throughout the history of the Bay's recovery efforts. This has been one of our points of pride as we look to the influence of the Bay Program nationally and internationally. Chesapeake Bay science has not only helped us to understand the Bay, but it has given the world a better understanding of estuarine processes, of how to manage across the ecosystem and of taking a watershedwide approach to restoration.

The Clean Water Action Plan announced last year by President Clinton is to a large degree an effort to carry the Chesapeake Bay Program approach nationwide.

Among our major contributions to science is the basic understanding of the hydrodynamics of an estuarine system - with saltwater moving up along the bottom from the mouth of the Bay as lighter freshwater flows to the sea on the top. It is the circulation and degree of stratification of these waters that creates the conditions for productivity in estuaries. This dynamic was first identified here in the Chesapeake by researchers at the Johns Hopkins Chesapeake Bay Institute under the lead of Don Pritchard.

Another area of Bay scientific pre-eminence is the use of computer models to test management options. Over the years, these interconnected models - one of the airshed, one of watershed nutrient loadings, one of the hydrodynamics of the Bay and one of the effects of loadings and hydrology on the oxygen and living resources - have stayed at the cutting edge worldwide and provided answers that were thought only a few years before to be beyond the capability of the science. Right now, those models are telling Virginians how many grasses and how much oxygen will return to each of their tidal rivers under different levels of nutrient control.

The work that went into the successful recovery of the striped bass in the Chesapeake Bay stands out in the annals of fisheries science. While many of the toughest decisions were political, the scientific underpinnings made them possible.

And the list goes on. Certainly, the leading role of the Chesapeake in proving the importance of air deposition in the overload of nitrogen to coastal estuaries would be on it. As would the latest entry - ground-breaking work by the U.S. Geological Survey's Chesapeake Program staff to quantify groundwater lag time. Because about half of the freshwater entering the Bay comes through the seepage of groundwater into streams, a key question is how long it takes for improved management practices to result in reduced loadings to the Bay. We have learned here that lag times are not as variable as thought, and that preliminary data show the range to be concentrated at 5-10 years.

In addition to these important scientific breakthroughs in estuarine and watershed science, Chesapeake Bay science has led the effort to integrate the disciplines. Nowhere else that I am aware of has a water quality program grown to include the living resource response as a key indicator as well as learned to look to the land to identify and control the sources of pollution upstream and ultimately, upwind (and to try to understand where the effort should focus to get the best results).

So Chesapeake science has a lot to be proud of. Yet I must admit that some disturbing questions remain. Recently, the Bay Program was one of the sponsors of a "Dialogue Across the Generations." This weekend event at Washington College brought together some of our best young scientists from colleges and universities throughout the watershed to meet with seven of the great early scientists of the Bay - those who helped us understand what was wrong with the Chesapeake and what needed to be done. A number of  remarks made that weekend by these early scientists merit our attention.

The aforementioned Don Pritchard was there, and he lamented, "We have lost the fight of reason against environmental hysteria; science is used less and less for policy."

I would characterize things a bit differently. It was easy for science to lead policy when there was little or no policy, as was the case in the early days. It was also easy for science to win out over hysteria when the public was not energized to care and to call the politicians to account. Our challenge today is to assure that the science is as expansive as the policy, and as alert to events and their implications as the public.

This is a much harder task for scientists. As another of the greats at the Dialogue - Reds Wolman of the Johns Hopkins Department of Geography and Environmental Engineering - said, "Science must be ready when the politics is right," when the window of opportunity for action opens up.

This brings us to a second set of issues: What are we managing the Bay for? There are some very serious implications for science depending on how we answer. Reds Wolman asked, "Are we managing for catastrophic events or for small recurring events?" Which is more important to making the system respond or to having it crash? Are we engaged in an effort to restore the Chesapeake to the equilibrium it once knew? Or, are we engaged in an attempt to "reset" the Bay to a perhaps simpler, but cheaper and equally stable system?

What would such a system look like? Grace Brush, another Dialogue participant, asked, "Isn't it really the food web we should be managing?" If she is right, we have a lot of work ahead of us - both scientific and institutional.

These are the critical questions we hear from these early Bay scientists as they look back on careers that in some cases span 60 years. We owe them some answers.

At the same time, new issues and problems rise to meet us every year. Some of them seem intractable. There are at least four in the scientific arena that are on my current list of "Things That Wake Me in the Night."

First is the accumulation of sediments and phosphorous behind the dams on the Susquehanna. I wrote about this a couple of months ago, and the Bay Journal had a lead article on it last month, so I don't want to sound like a broken record. But somebody has got to come up with an idea of what to do about this ticking "time bomb." Or, beginning sometime around 2010 to 2015, Susquehanna loads to the Chesapeake (which comprise half of the freshwater loads in the entire Bay watershed) will increase by 70 percent for phosphorous and 250 percent for sediment. There is currently no affordable technology to deal with this. We had better find it.

Second is the continued loss of forests, wetlands and other resource lands that absorb pollutants. While the losses continue, we are only at the earliest stages of understanding the effects of forest fragmentation and the best ways to create and restore wetlands. We are literally working at the edges of this problem with forest buffers and tidal wetlands protection being our most active tools. Meanwhile, the great mass of our forest ecosystems and our freshwater wetlands go largely unprotected. To give this perspective, consider just one fact: The 60 percent of the watershed currently covered by forests delivers only 17 percent of the nitrogen and a mere 3 percent of the phosphorous that reaches the Bay.

Third, the on-the-ground trends in animal agriculture continue to be all wrong for the Chesapeake. Increasing densities of more and more animals mean higher and higher concentrations of animal wastes in already stressed areas of the watershed. There are already 11 counties in the Bay drainage area that produce more than 250 percent of the phosphorous in manure than can be absorbed by all the crops grown in the county. Phosphorous saturation of the soils is a continuing threat in such areas. We are short of solutions, and the economics are unclear. Even if we reduce manure placement everywhere to levels to provide only the phosphorous needed, how do we pay for the additional nitrogen needed? And how do we assure that we are avoiding the spread of phosphorous saturation when we develop programs to transport manure? We need answers.

Finally, I return to Grace Brush. We really do need to understand the food web of the Bay to manage it. The current debate over rockfish, menhaden and zooplankton interactions is only one case where the reality eludes us. Fisheries statistics, fisheries management plans and fisheries research are all focused on commercial species, usually just one of them at a time. We must move well beyond where we are today to understand how to get a system in balance and keep it there.

Perhaps it is time for a new, "Five Year Study" of the Bay to get at some of these scientific questions with the necessary level of financial resources. The first such study, carried out in 1978-83, helped us to understand what was needed to get the waters of the Chesapeake back to a healthy state. We are well on the way to accomplishing that. But we lack enough understanding to manage the system of living resources we hoped to support with the improved waters. We could very easily restore the Bay but lose all of the living things in it that we value most.

Science is the keystone to success in the Chesapeake Bay Program. There are others whose job it is to fire up the public. There are others whose job it is to take the political heat or reap the political rewards. The job of Chesapeake scientists is to be there with the best information to offer when the windows of opportunity open. As we all know they will.