118
J. E . Q. RAYMONT
significant. However, Sorokin (1964a) points out that the main autotrophic bacteria are probably those oxidizing H,S to sulphate. These are
only abundant at the boundary in the Black Sea between the oxygenated
and de-oxygenated layers. Even in such an atypical sea as the Black
Sea, autotrophic chemosynthesis makes only a small contribution to
overall production.
The second source of autotrophic production, the photosynthetic
activity of green plants, is overwhelmingly the more important. With
solar radiation the plant can build up from carbon dioxide, water and
simple inorganic compounds the complex organic materials of high
potential energy. Some of this organic material, when synthesized,
might be liberated in dissolved form into the sea water. In addition, by
death and decomposition of plankton much larger amounts of dissolved
organic substances are released to sea water. These dissolved organic
materials can be utilized by bacteria, fungi and Protista so synthesizing
particulate living matter, which can be used as food, and thus contribute
to the biomass of marine plankton. But the production of such dissolved organic substances must depend in the first case on autotrophic
synthesis which is due essentially to the photosynthetic activity of
plants. Any consideration of production in the sea therefore, as on
land, immediately focuses attention on the plant life, in this case of the
oceans.
The marine plankton may be regarded as drifting and floating
organisms whose existence is independent of the sea bottom. The community may be thought of as consisting of the green plants, the phytoplankton, and the animals, the zooplankton, together with bacteria,
yeasts, fungi and other similar organisms. There is a continuous flow of
energy through the marine eco-system and it is relatively easy to envisage the transfer of energy through the primary production of the
phytoplankton to the herbivorous zooplankton and thence to the
carnivorous zooplankton and nekton. Even in the plankton itself the
food web is complex, and there is also the interchange of energy
between the plankton and the nekton, and with the various divisions of
the benthos. Although it is artificial, therefore, to separate the plankton
from the remainder of the marine community, for the purposes of this
review production of plankton will be examined as a separate entity.
It is misleading to consider primary production in the marine environment by the phytoplankton without paying some attention also
to those plants which occur in shallow waters fixed or lying on the
bottom, and which may be referred to as the benthic plant population.
These benthic plants, either as living or dead material, are swept into
the waters above the bottom and thus may contribute significantly to
the food of planktonic animals. The benthic plants may be roughly
J. E . Q. RAYMONT
significant. However, Sorokin (1964a) points out that the main autotrophic bacteria are probably those oxidizing H,S to sulphate. These are
only abundant at the boundary in the Black Sea between the oxygenated
and de-oxygenated layers. Even in such an atypical sea as the Black
Sea, autotrophic chemosynthesis makes only a small contribution to
overall production.
The second source of autotrophic production, the photosynthetic
activity of green plants, is overwhelmingly the more important. With
solar radiation the plant can build up from carbon dioxide, water and
simple inorganic compounds the complex organic materials of high
potential energy. Some of this organic material, when synthesized,
might be liberated in dissolved form into the sea water. In addition, by
death and decomposition of plankton much larger amounts of dissolved
organic substances are released to sea water. These dissolved organic
materials can be utilized by bacteria, fungi and Protista so synthesizing
particulate living matter, which can be used as food, and thus contribute
to the biomass of marine plankton. But the production of such dissolved organic substances must depend in the first case on autotrophic
synthesis which is due essentially to the photosynthetic activity of
plants. Any consideration of production in the sea therefore, as on
land, immediately focuses attention on the plant life, in this case of the
oceans.
The marine plankton may be regarded as drifting and floating
organisms whose existence is independent of the sea bottom. The community may be thought of as consisting of the green plants, the phytoplankton, and the animals, the zooplankton, together with bacteria,
yeasts, fungi and other similar organisms. There is a continuous flow of
energy through the marine eco-system and it is relatively easy to envisage the transfer of energy through the primary production of the
phytoplankton to the herbivorous zooplankton and thence to the
carnivorous zooplankton and nekton. Even in the plankton itself the
food web is complex, and there is also the interchange of energy
between the plankton and the nekton, and with the various divisions of
the benthos. Although it is artificial, therefore, to separate the plankton
from the remainder of the marine community, for the purposes of this
review production of plankton will be examined as a separate entity.
It is misleading to consider primary production in the marine environment by the phytoplankton without paying some attention also
to those plants which occur in shallow waters fixed or lying on the
bottom, and which may be referred to as the benthic plant population.
These benthic plants, either as living or dead material, are swept into
the waters above the bottom and thus may contribute significantly to
the food of planktonic animals. The benthic plants may be roughly