ABSTRACT
The last decade or two have seen much progress in the transformation of marine ecology from an essentially descriptive discipline towards one of ever increasing quantification. In many cases the ultimate aim seems to be the building of various forms of mathematical model, be they at one extreme wholly empirical or at the other wholly rational, or either deterministic or stochastic (Platt, Mann & Ulanowicz, 1982). No matter what type of quantitative investigation, the general goal ought to be to produce results that, as far as possible, are identical with those in the natural system that one is attempting to mimic. Any deviation from the absolute will either be the result of poor raw data inadequately describing the state of an individual or population, or a poor model for treating the data, or a combination of both. Whatever the cause of deviation from the absolute, it has to be accepted that even the most intricate model is only as good as the data upon which it is built. Unfortunately, there appears to be a general tendency to be less occupied by sources of error in the raw data than in the way in which the data is subsequently treated.
