Publication Abstract

The Art of Monitoring. Knowing where to start and when to stop

M.D. Nicholson and R. Fryer

Monitoring programmes are often thought of as a single set of rules that govern sampling, analysis, and decision making, and that are followed from start to finish. Reality, however, is often less simple. The objectives of a programme can change over time, and the rules are likely to evolve accordingly. However, unless explicitly acknowledged, this can lead to poor quality data that give little information about contaminant levels in the environment.

In this paper, we argue that monitoring objectives should be allowed to change, but in a way that responds meaningfully to observed contaminant levels. We show how this can be done by constructing a series of objectives that depend on the current state of contaminant levels. Each objective is phrased within a quantitative framework, and leads to a testable hypothesis that corresponds to a simple, practical question: are contaminant levels too high?, are they changing?, or are they acceptably low? Each hypothesis test allows us to make inferences about contaminant levels, and to decide whether the current monitoring objective is still appropriate.

Reference:

M.D. Nicholson and R. Fryer, 1997. The Art of Monitoring. Knowing where to start and when to stop. Deutsche Hydrographische Zeitschrifte. Supplement 6