310
D. H. uusma
which is rather greater than the estimate of 12 million tons. However,
there is some correspondence between the stocks as estimated by the
present very rough method and those estimated by the techniques of
population dynamics.
D. The transfer coeficients
Steele (1965) has suggested that ecological efficiencies might be considerably greater than 10%. I n the upwelling areas, where populations
increase by many times between generations, growth is less important
than survival. When survival is high during periods of plentiful food,
the population rises, and when survival is low during periods of food 1
lack, the population declines. Steele suggested that if herbivores in- ,
creased under conditions of plentiful food and were themselves eaten
when they stopped growing, ecological efficiencies of up to 25% might
be expected. The transfer coefficients used here are not strictly estimates of ecological efficiency, because they are ratios of production
rather than ratios of yield. The average coefficient is 12.4%. Because
the production cycle in an upwelling area is possibly a temperate one,
the populations of herbivores are increasing ones and so the somewhat
higher transfer coefficients are not unexpected.
Given the increase in transfer coefficient with abundance, the correlation shown in Fig. 15A is fitted by a linear regression (r = 0.77,
P < O-Ol), shown as a full line. But the variance increases sharply
with abundance, because differences in abundance form a geometric
series. The estimates of primary production are as good as the estimated
averages and the estimated lengths of the upwelling seasons ; the estimate of secondary production appears t o be roughly as good as that of
primary production. A straight line drawn through the origin and the
mean does not fit the data so well, which suggests that the best fitting
line would be slightly curved, in a convex manner. This would suggest
that the transfer coefficient decreases with increased primary production. It is the reverse of the conclusion in Gushing (in press) which
was based on limited data from the Pacific Ocean. Another relationship
is that between transfer coefficients and the intensity of primary production (gC/m2 per day), which is shown t o be markedly inverse; it
appears that a greater proportion of material is lost in transfer at high
intensities.
The transfer coefficients tend to be lower in the upwelling areas,
which means that they are relatively inefficient. In effect the coastal
upwellings are compared in Table I11 with the offshore divergences.
Where the intensity of primary production is low ((0.5 gC/m2 per day)
in the offshore divergences, the transfer coefficient is high, where
D. H. uusma
which is rather greater than the estimate of 12 million tons. However,
there is some correspondence between the stocks as estimated by the
present very rough method and those estimated by the techniques of
population dynamics.
D. The transfer coeficients
Steele (1965) has suggested that ecological efficiencies might be considerably greater than 10%. I n the upwelling areas, where populations
increase by many times between generations, growth is less important
than survival. When survival is high during periods of plentiful food,
the population rises, and when survival is low during periods of food 1
lack, the population declines. Steele suggested that if herbivores in- ,
creased under conditions of plentiful food and were themselves eaten
when they stopped growing, ecological efficiencies of up to 25% might
be expected. The transfer coefficients used here are not strictly estimates of ecological efficiency, because they are ratios of production
rather than ratios of yield. The average coefficient is 12.4%. Because
the production cycle in an upwelling area is possibly a temperate one,
the populations of herbivores are increasing ones and so the somewhat
higher transfer coefficients are not unexpected.
Given the increase in transfer coefficient with abundance, the correlation shown in Fig. 15A is fitted by a linear regression (r = 0.77,
P < O-Ol), shown as a full line. But the variance increases sharply
with abundance, because differences in abundance form a geometric
series. The estimates of primary production are as good as the estimated
averages and the estimated lengths of the upwelling seasons ; the estimate of secondary production appears t o be roughly as good as that of
primary production. A straight line drawn through the origin and the
mean does not fit the data so well, which suggests that the best fitting
line would be slightly curved, in a convex manner. This would suggest
that the transfer coefficient decreases with increased primary production. It is the reverse of the conclusion in Gushing (in press) which
was based on limited data from the Pacific Ocean. Another relationship
is that between transfer coefficients and the intensity of primary production (gC/m2 per day), which is shown t o be markedly inverse; it
appears that a greater proportion of material is lost in transfer at high
intensities.
The transfer coefficients tend to be lower in the upwelling areas,
which means that they are relatively inefficient. In effect the coastal
upwellings are compared in Table I11 with the offshore divergences.
Where the intensity of primary production is low ((0.5 gC/m2 per day)
in the offshore divergences, the transfer coefficient is high, where