324
D. H. UUSHESQ
Then, biologically, the distinction between coastal and oceanic systems
is really in the fish populations, one group of which is retained within the
coastal upwelling system and the other which passes through the
divergences offshore. However, the distinctions must not be pressed
too far, because Ahlstrom’s distributions of eggs and larvae show that
sardine, anchovy (Ahlstrom, 1966) and hake (Alverson and Larkins,
1969), the dominant species of the Californian upwelling, are spread
well beyond the dynamic boundary during their periods of abundance.
I n this paper certain speculative ideas have been put forward on the
nature of the production cycle in upwelling areas and on the consequences of the well-known correlation between phosphorus and zooplankton. The upwelling production cycle appears t o be homologous
with that in temperate waters, in that it is discontinuous and of high
amplitude, generating large quantities of living material ; indeed the
community structure itself has the character of a temperate one. The
correlation between phosphom and zooplankton suggests that production causes the decline of nutrients and not vice versa as was
originally suggested. If the upwelling production cycle is a temperate
one, one would expect that nutrients would decline on a vector offshore
as they do temporarily in a temperate cycle. Then the correlation in
space shown between phosphorus and zooplankton should imply that
in temperate waters the quantities of phosphorus represent regenerated
material, not in the early parts of the cycle, but perhaps so in the later
parts of it. Then the decline of phosphorus (and other nutrients) in
temperate waters is represented as a loss to plant and animal material,
although the residual quantity may be all regenerated. So in the upwelling cycle, as it moves off and as the phosphorus is reduced, it is lost
t o living material and what remains is regenerated.
The methods used in this paper are crude, yet in those areas in
which the fish production has been estimated there is some correspondence between the measures of fish production and of tertiary production. Further, the estimates of primary production were correlated
with those of secondary production, from which it may be concluded
(together with the correspondence with fish production) that they are
quite reliable. It is extraordinary that the average intensities of production (in gC/ma per day) in upwelling areas did not differ very much,
which implies that the processes, in physical terms, could be described
in model terms. I n the same way, the intensities of secondary production were rather similar between the areas of upwelling, so that the
alleged difficulties of estimating zooplankton in terms of sampling and
in terms of patchiness do not really exist. The quantities can be
properly measured and the real obstruction to the improvement of
D. H. UUSHESQ
Then, biologically, the distinction between coastal and oceanic systems
is really in the fish populations, one group of which is retained within the
coastal upwelling system and the other which passes through the
divergences offshore. However, the distinctions must not be pressed
too far, because Ahlstrom’s distributions of eggs and larvae show that
sardine, anchovy (Ahlstrom, 1966) and hake (Alverson and Larkins,
1969), the dominant species of the Californian upwelling, are spread
well beyond the dynamic boundary during their periods of abundance.
I n this paper certain speculative ideas have been put forward on the
nature of the production cycle in upwelling areas and on the consequences of the well-known correlation between phosphorus and zooplankton. The upwelling production cycle appears t o be homologous
with that in temperate waters, in that it is discontinuous and of high
amplitude, generating large quantities of living material ; indeed the
community structure itself has the character of a temperate one. The
correlation between phosphom and zooplankton suggests that production causes the decline of nutrients and not vice versa as was
originally suggested. If the upwelling production cycle is a temperate
one, one would expect that nutrients would decline on a vector offshore
as they do temporarily in a temperate cycle. Then the correlation in
space shown between phosphorus and zooplankton should imply that
in temperate waters the quantities of phosphorus represent regenerated
material, not in the early parts of the cycle, but perhaps so in the later
parts of it. Then the decline of phosphorus (and other nutrients) in
temperate waters is represented as a loss to plant and animal material,
although the residual quantity may be all regenerated. So in the upwelling cycle, as it moves off and as the phosphorus is reduced, it is lost
t o living material and what remains is regenerated.
The methods used in this paper are crude, yet in those areas in
which the fish production has been estimated there is some correspondence between the measures of fish production and of tertiary production. Further, the estimates of primary production were correlated
with those of secondary production, from which it may be concluded
(together with the correspondence with fish production) that they are
quite reliable. It is extraordinary that the average intensities of production (in gC/ma per day) in upwelling areas did not differ very much,
which implies that the processes, in physical terms, could be described
in model terms. I n the same way, the intensities of secondary production were rather similar between the areas of upwelling, so that the
alleged difficulties of estimating zooplankton in terms of sampling and
in terms of patchiness do not really exist. The quantities can be
properly measured and the real obstruction to the improvement of