112
E. 1). 8. CORNER AND ANTHONY G I . DAVIES
was explained by the presence of preformed nutrients, the concentrations of which increased with depth. Broenkow suggested that the
results for the deeper waters might be explained by the mixing of two
water masses, one with a low and the other with a high nutrient
concentration. There would then have been no reason for the AAOU :AP
relationship t o be linear.
Sugiura (1965) suggested that, as the preformed phosphate concentration is a conservative property of sea water, it would be
preferable, in constructing plots of phosphate concentration against
AOU values, to use data for water masses having similar conservative
properties, e.g. temperature and salinity. When this was done,
AAOU :AP values of -272 : 1 were consistently obtained for the waters
of the Oyashio and Kuroshio regions (Sugiura and Yoshimura, 1964).
Although the values for apparent oxygen utilization in many
different regions seem consistent with Fleming’s ( 1940) original ratios,
more recent data has cast doubt on the extent t o which his C :N :P ratios
of 106 :16 :L are truly representative of plankton. Thus, out of eleven
species of phytoplankton grown in culture and analysed by Parsons
el al. (1961), only two-Cricosphuera carterae (Braarud ct Fagerl.)
Braarud [as Syracosphuera carterae] and Coscinodiscus sp.-contained
nitrogen and phosphorus in ratios near 16:1, the majority of values
being much lower (see Table 11). The common diatom Skeletonema
costatum (Greville) Cleve, for example, had a ratio of 7.7 :1. Although it
TABLE 11. THE NITROGEN AND PHOSPHORUS CONTENT AND THE NITROOENPHOSPHORUS RATIO IN SOME CULTURED SPECIES OF MARINE PHYTOPLANKTON.
(Data from Parsons el al., 1901.)
h
yo Dry weight
Tetraaelmia maculata Butch.
Dunaliella salinu (Dunal) Teodor.
Monochrysia lutheri Droop
Syracosphaeru curterae Braarud et Fagerl.
Chaetoceros sp.
Skeletonema costalum (Grovillo) Cleve
Coscinodiactu, sp.
Phaeodactylum tricornutum Bohliti
Amphidinium carterue Hulb.
Exuvietla sp.
A gmen ell um q umlr uplicat um (Meiiogh . ) I3r6 b .
8.3
9.1
7.8
8.9
5.6
5-9
2.7
5.3
4.5
5.0
5.8
3.3
3-3
3.0
1.2
1.6
1.7
0.4
2.0
1.1
1.3
1.4
5.5 :1
6.1 :1
5*8:1
17.4 :1
8*3:1
7.7:1
16*0:1
5-9 :1
13-2:l
12.3:l
10.6:l
E. 1). 8. CORNER AND ANTHONY G I . DAVIES
was explained by the presence of preformed nutrients, the concentrations of which increased with depth. Broenkow suggested that the
results for the deeper waters might be explained by the mixing of two
water masses, one with a low and the other with a high nutrient
concentration. There would then have been no reason for the AAOU :AP
relationship t o be linear.
Sugiura (1965) suggested that, as the preformed phosphate concentration is a conservative property of sea water, it would be
preferable, in constructing plots of phosphate concentration against
AOU values, to use data for water masses having similar conservative
properties, e.g. temperature and salinity. When this was done,
AAOU :AP values of -272 : 1 were consistently obtained for the waters
of the Oyashio and Kuroshio regions (Sugiura and Yoshimura, 1964).
Although the values for apparent oxygen utilization in many
different regions seem consistent with Fleming’s ( 1940) original ratios,
more recent data has cast doubt on the extent t o which his C :N :P ratios
of 106 :16 :L are truly representative of plankton. Thus, out of eleven
species of phytoplankton grown in culture and analysed by Parsons
el al. (1961), only two-Cricosphuera carterae (Braarud ct Fagerl.)
Braarud [as Syracosphuera carterae] and Coscinodiscus sp.-contained
nitrogen and phosphorus in ratios near 16:1, the majority of values
being much lower (see Table 11). The common diatom Skeletonema
costatum (Greville) Cleve, for example, had a ratio of 7.7 :1. Although it
TABLE 11. THE NITROGEN AND PHOSPHORUS CONTENT AND THE NITROOENPHOSPHORUS RATIO IN SOME CULTURED SPECIES OF MARINE PHYTOPLANKTON.
(Data from Parsons el al., 1901.)
h
yo Dry weight
Tetraaelmia maculata Butch.
Dunaliella salinu (Dunal) Teodor.
Monochrysia lutheri Droop
Syracosphaeru curterae Braarud et Fagerl.
Chaetoceros sp.
Skeletonema costalum (Grovillo) Cleve
Coscinodiactu, sp.
Phaeodactylum tricornutum Bohliti
Amphidinium carterue Hulb.
Exuvietla sp.
A gmen ell um q umlr uplicat um (Meiiogh . ) I3r6 b .
8.3
9.1
7.8
8.9
5.6
5-9
2.7
5.3
4.5
5.0
5.8
3.3
3-3
3.0
1.2
1.6
1.7
0.4
2.0
1.1
1.3
1.4
5.5 :1
6.1 :1
5*8:1
17.4 :1
8*3:1
7.7:1
16*0:1
5-9 :1
13-2:l
12.3:l
10.6:l