Decisions and Scientific Research for Water Quality Management

Since scientists are trained to identify questions in need of additional research, it is natural for the scientific community to focus on gaps in understanding and talk about uncertainty when discussing the state of scientific knowledge concerning an issue of public concern. It is perhaps plausible, then, for the public and for decision makers to interpret that quest for better understanding as a declaration that the scientific basis for decision is inadequate. This interpretation is premature, and in many instances, incorrect.

For years, federal, state, and university scientists have been engaged in research that addresses key scientific questions of concern for the management of water quality in Chesapeake Bay. There is now, and will continue to be, a need for the scientific or technical assessment of water quality impacts of proposed management actions in the Chesapeake. This scientific assessment will be uncertain, regardless of the confidence with which it is expressed. Unfortunately, uncertainty is likely to cause confusion, leading decision makers to wonder how a decision can be made on a proposed management option when the scientists are unsure. The result may be that the science is pronounced useless, irrelevant, or in need of improvement.

There are two key points I would like to briefly discuss - both dealing with the scientific understanding, or conversely the uncertainty, in water quality studies. The first point is:

There is almost always enough scientific knowledge to make an informed decision.

This is an important message, because, as noted, scientists frequently emphasize issues that are not fully understood and are in need of more research. For example, what will be achieved with a 100 ft. riparian buffer strip as opposed to a 50 ft. buffer strip? Or, will two acre lot zoning achieve water quality goals? These are questions that cannot be answered with certainty. However, just because scientific analysis cannot give a confident, precise answer to questions like these does not mean that decisions should be deferred pending results of additional scientific study. This is an important point. There will almost always be scientific uncertainty about expected water quality impacts of proposed management actions, but there is almost always sufficient information to act.

This leads to my second point:

Decision makers need to understand how to use the scientific uncertainty so that they can distinguish situations calling for new management actions from situations calling for more research.

While I just noted that we almost always know enough to make a decision and take action, there certainly are situations where the uncertainty is so great and the consequences of bad decisions so severe that it is wise to defer action and support more scientific study. We do this in "everyday life" as all of us have attitudes about risky actions that reflect the uncertainty in the outcome and the cost if we’re wrong. In addition, though, there are also situations where an immediate decision is prudent, while at the same time additional scientific study should be supported in expectation of "mid-course corrections." This is basically the approach for the Chesapeake Bay water quality problems - immediate actions are being implemented by state and local governments, while at the same time a number of research projects are being funded. Decision making will be more effective if decision makers can distinguish between these two situations; to do this, decision makers must request an understandable statement of the uncertainty in the scientific studies (e.g., in the water quality predictions).

Fortunately, there is an approach to decision making informed by uncertain science in Chesapeake Bay which should eventually improve decisions. This involves “adaptive management” or “learning while doing.” In the Chesapeake Bay, this strategy is begun with a properly designed water quality monitoring program to assess the water quality response in the Chesapeake Bay and Watershed to the initial management actions. Careful observation of the water quality response can then lead to “mid-course” improvements in management that are more exactly tailored to the system. For example, it may be discovered through monitoring that certain sources of nitrogen and phosphorus are more (less) responsible to water quality degradation, leading to focused management actions.

No one likes the fact that our science is imperfect, but no one should ignore this fact. If we acknowledge the limitations - the uncertainty - in scientific studies, we will end up with more informed, and better, decisions in the long run.