U.S. Department of the InteriorU.S. Geological Survey

Robert M. Hirsch, Research Hydrologist, USGSMay 20, 2009

Some thoughts on designs for monitoring and assessing Chesapeake Bay progress

We must start from a conceptual model

• The system responds to many forces, only some of which Bay and watershed managers can influence

• The data we collect, if thoughtfully analyzed, can help us learn how the system is changing and why

• This leads to improved decisions for the future (adaptive management)

A very important premise• It has taken more than half a century to

get to the degraded state the Bay is in today.

• It will not be solved in a few years.

• But, we must be sure we have the data we need to observe and track change, if we expect to succeed.

• Decisions must be based on the reality of what is actually happening.

Conditions in the Bay

Actions in the watershed

Actions in the Bay

Natural variability: floods, droughts…

History – stored N & P

Economic drivers: Agricultural & urban

Surprise: invasives, disease…

Models will help

• They are intended to predict how these factors will influence the Bay

• But, we know they are imperfect

• They need to be coupled with long-term data

Just one example:

• A great success story: the Patuxent, point source controls

• The long term data show the history of progress and the huge role of natural variability in total phosphorus loadings

• Most of the watershed stories will be much more subtle than this

“The only way to figure out what is happening to our planet is to measure it.

And this means tracking changes decade after decade,

And poring over the results.”(Ralph Keeling, Science Magazine, 2008, p.

1771-2)

We need data on the watershed and Bay, to see what is actually happening.

To improve our understanding (test our models).

And improve our management strategies over time.

The measurements need to be:

• Consistent over space and time

• Cover a diversity of settings in the watershed and the Bay

• Measure under diverse conditions

• Broad in scope – physical, chemical, and biological – all are important and linked

• Must be sustainable

Data must be coupled with analysis:• An ongoing, high priority process

• Consistent with the conceptual model, recognizing the many drivers

• Designed to extract the signal from the considerable amount of noise

• Feed back to improving our understanding

We must be realistic about:

• How long restoration may take

• How important natural variability and surprise can be

• How long it will take before new monitoring investments pay off

• But, none of these are legitimate excuses for failing to act.

And we must communicate about these realities:

• We must communicate them to senior managers, policy makers, and the interested public

• The message must come across as a call for: action, patience, and the need to continue to learn and adjust.