Introduction This book contains papers given at a NATO Advanced Research
Institute (A.R.I.) held at Caiscais, Portugal, in November, 1981. The
subject of the A.R.I. was marine heterotrophy; this is defined as the
process by which the carbon autotrophically fixed into organic compounds
by photosynthesis is transformed and respired. Obviously all animals and
many microbes are heterotrophs but here we will deal only with the
microbes. Also, we restricted the A.R.I. primarily to microbial
heterotrophy in the water column even though we recognize that a great
deal occurs in sediments. Most of the recent advances have, in fact,
been made in the water column because it is easier to work in a fluid,
apparently uniform medium. The reason for the A.R.I. was the rapid
development of this subject over the past few years. Methods and
arguments have flourished so it is now time for a review and for a
sorting out. We wish to thank the NATO Marine Science Committee for
sharing this view, F. Azam, A.-L. Meyer-Reil, L. Pomeroy, C. Lee, and B.
Hargrave for organizational help, and H. Lang and S. Semino for valuable
editing aid.