AMERICAN GEOPHYSICAL UNION, GEOPHYSICAL MONOGRAPH 63

Chapter 3. Major Bioelements Workshop Report

David M. Karl, W. G. Harrison, John Dore

The particulate matter pool in the ocean is comprised of both living and non-living components; the latter includes organic and inorganic fractions. However, most of the particulate matter in the ocean is of biotic origin. Thus biotic processes and transformations largely determine the types, size distributions, abundances and chemical compositions of particles in seawater. Carbon (C), nitrogen (N), oxygen (0), hydrogen (H), phosphorus (P) and sulfur (S) are the major components of living organisms and organic detritus. Accurate measurement of these "bioelements" is particularly important in assessing the chemistry and dynamics of particulate matter in the ocean.

During the discussion of the Bioelements Working Group, it became clear that a consensus exists within the community regarding the best analytical methods for measuring bioelements. Obtaining samples representative of nature and handling them so as not to alter their chemical composition was far more problematic. The following report begins by clarifying the nature of the diverse particle pools in the ocean. Sampling and handling problems unique to bioelements are then discussed. The report concludes with recommendations for the accurate chemical analyses of C, N, P and S.