Determination of photosynthetic pigments in sea-water.

Abstract

The present volume treats various approaches and recommendations for standardization of determinations of photosynthetic pigments, especially chlorophyll in phytoplankton. Standardization of methods in biological oceanography entails more difficulty than in other fields. Regional differences in abundance and composition of marine communities call for quite a considerable variety of methods when one is measuring standing crop and specific composition as well as productivity. The measuring of primary productivity directly or through estimation of the amount of photosynthetic pigments in the phytoplankton of a given body of water is one of the primary objectives of biological oceanography. Problems of standardization do not appear to be insurmountable in this respect, and standardized methods for comparison over a wide range in space and season are of particular interest. If data for regional charts were comparable, such charts, with regional distribution of photosynthetic pigments and their seasonal variation in the ocean, would be most helpful for the mapping of the world ocean's productive areas. The storage and retrieval system for biological data, which is so urgently needed for further progress in our attempts to understand the ocean and its production of living resources, might also suitably include photosynthetic pigment data. The International Council for the Exploration of the Sea (ICES) and the United States National Academy of Science's Committee on Oceanography have established small groups of experts to consider standardization of methods for determination of photosynthetic pigments in sea-water. In December 1963, the Scientific Committee on Oceanic Research and Unesco established a Joint Group of Experts on Determination of Photosynthetic Pigments (SCOR Working Group N o . 17). This latter group met in Paris from 4 to 6 June 1964 under Professor J. Krey's chairmanship and their report is given in the first part of the present volume. A very important background document for the June meeting was a survey of existing methods prepared by Dr. T . R . Parsons (at that time with Unesco) in his capacity as convener of the ICES Working Group on Methods for Measuring Photosynthetic Pigments in Sea-Water. Dr. Parsons' survey makes up the second part of this volume. Two Australian papers, published in the third and fourth parts of the volume, provide additional information on the methods and their limits. Although written after the group's meeting, these two papers relate closely to its deliberations. The need for intercomparability of methods in oceanography has given strong impetus to critical analysis, improvement of accuracy, simplification of methods in use and invention of new methods. In recommending that Unesco publish these four contributions, S C O R was convinced that this would help to achieve world-wide intercomparison of data, provide a reference for intercalibration of other old and new methods, encourage further methodological studies, and give guidance to those laboratories and scientists who work in this field. Any scientific opinions expressed in these papers are, naturally, those of individual scientists or groups of scientists, and should not be interpreted as the views of Unesco.