4
CORDON A. RILEY
work on this subject but did not lead to any real solution of the major
problems. The validity of the experimental evidence on particle
formation has been challenged. If such particles can indeed be formed
in the sea, their natural rate of production remains essentially unknown. Opinions differ as to the suitability of non-living particulate
matter as food. Menzel and Goering (1966) took the extreme stand that
naturally occurring particles below the immediate surface layer are
neutrally buoyant and refractory, neither sinking out of the water
column nor being utilized. Riley et al. (1965), on the other hand,
proposed the hypothesis that the particulate matter sinks slowly, with
a mean residence time in the water column of the order of four years,
more or less, and is subject during that time to both utilization and
accretion, the two processes existing in a state of dynamic balance.
One interpretation or the other seems necessary in order to explain
the observed fact that the concentration of particulate matter is
relatively uniform with respect to depth and shows no evidence of
decrease in deep water due to biological utilization.
The paper that follows will attempt to resolve some of these difficulties. It will survey existing data on the distribution of particulate
organic matter in the sea, experimental work that has been done on
processes of production and consumption, and the indirect evidence
that is necessary in order t o put the subject into proper oceanographic
perspective. The discussion will mainly deal with non-living particulate
matter but will of necessity also be concerned with its relations with
living organisms and filter-passing organic materials.
11. DISTRIBUTION OF PARTICULATE ORGANIC MATTER IN THE SEA
A. Methods
This section will deal with generalities about methods of collection
and analysis. Details about the methods used by individual investigators will be taken up in later sections in connection with the discussion of their work.
Measurements of particulate organic matter and studies of its
chemical composition require the collection of fairly large water
samples. Our laboratory uses Niskin bottles of 8 and 28 litre capacity,
constructed of polyvinyl chloride. Menzel (1967) has described an all
glass sampler which he built t o avoid any possibility of contamination
by plastic materials. However, Gordon (1969) has used both kinds
of bottles concurrently and has found no significant difference in the
results. Collecting bottles need to be cleaned frequently. There is a
tendency for a bacterial slime film to grow on the inner surfaces, and
CORDON A. RILEY
work on this subject but did not lead to any real solution of the major
problems. The validity of the experimental evidence on particle
formation has been challenged. If such particles can indeed be formed
in the sea, their natural rate of production remains essentially unknown. Opinions differ as to the suitability of non-living particulate
matter as food. Menzel and Goering (1966) took the extreme stand that
naturally occurring particles below the immediate surface layer are
neutrally buoyant and refractory, neither sinking out of the water
column nor being utilized. Riley et al. (1965), on the other hand,
proposed the hypothesis that the particulate matter sinks slowly, with
a mean residence time in the water column of the order of four years,
more or less, and is subject during that time to both utilization and
accretion, the two processes existing in a state of dynamic balance.
One interpretation or the other seems necessary in order to explain
the observed fact that the concentration of particulate matter is
relatively uniform with respect to depth and shows no evidence of
decrease in deep water due to biological utilization.
The paper that follows will attempt to resolve some of these difficulties. It will survey existing data on the distribution of particulate
organic matter in the sea, experimental work that has been done on
processes of production and consumption, and the indirect evidence
that is necessary in order t o put the subject into proper oceanographic
perspective. The discussion will mainly deal with non-living particulate
matter but will of necessity also be concerned with its relations with
living organisms and filter-passing organic materials.
11. DISTRIBUTION OF PARTICULATE ORGANIC MATTER IN THE SEA
A. Methods
This section will deal with generalities about methods of collection
and analysis. Details about the methods used by individual investigators will be taken up in later sections in connection with the discussion of their work.
Measurements of particulate organic matter and studies of its
chemical composition require the collection of fairly large water
samples. Our laboratory uses Niskin bottles of 8 and 28 litre capacity,
constructed of polyvinyl chloride. Menzel (1967) has described an all
glass sampler which he built t o avoid any possibility of contamination
by plastic materials. However, Gordon (1969) has used both kinds
of bottles concurrently and has found no significant difference in the
results. Collecting bottles need to be cleaned frequently. There is a
tendency for a bacterial slime film to grow on the inner surfaces, and