Primary production: Guidlines for measurement by 14C incorporation.

Abstract

In the years intervening between the preparation and publication of this do- cument, at least two other manuals for use in making primary production de- terminations have been introduced (Nielsen and Bresta, 1984; O'Reilly and Thomas, 1983). The emphasis in these three manuals is different enough to warrant their coexistence in the scientific literature. However, the actual methods outlined in these manuals do differ considerably on some points. Most workers concerned with primary production determinations will find more than one of these manuals coming to rest on their bookshelves. Thus, the flurry of activity in recent years aimed at clarifying and standardizing methods of making primary production estimates may, in some cases, have actually had the opposite effect. While some workers may lament the lack of emergence of a "cookbook' recipe for making primary production measurements, the lack of such a recipe can also be interpreted as a positive step towards the goal of producing more reliable measurements of photosynthesis in aquatic environments. Owing to the different facilities available, the precise de- tails of the primary production measurements made will always differ from laboratory to laboratory. To ensure that reliable results are produced, those responsible for designing the procedures employed by different groups must have a thorough understanding of the processes being measured and an appreciation of the limitations of the method being used. Furthermore, in order to enhance the comparability between results collected by different workers, a number of routine controls must be observed and specific information supp- lied when reporting results. The purpose of this manual is to provide a reference for workers designing programmes incorporating primary production measurements to aid them in producing results which can be used not only in their own research/monitoring programmes but also in the compilation of a database suited to describing the temporal and spatial distribution of primary production in the ICES area. In places where this manual refers to methods or procedures that have been more thoroughly described in another primary production manual, I have taken the editorial liberty of adding references.