THE P R O D U C T I O N O F M A R I N E P L A N K T O N
157
net hauls, more recent work such as t,hat of Burkholder and Sieburth
(1961) indicates that in the waters of Antarctica diatoms are probably
all-important; the only other organism which bulked large in the
phytoplankton was Phaeocystis.
It is perhaps in the warmer seas that the nanoplankton algae,
including the coccolithophores, become of particular significance. The
investigations of Lohmann and of Bernard (1953) in the Mediterranean,
of Riley (1957) for the Sargasso Sea and of Bsharah (1957) for the
Florida Current call attention to the importance of nanoplankton in
warmer waters. Hulburt, Ryther, and Guillaxd (1960) report on the
prevalence of coccolithophores in waters off Bermuda; though the nanoplankton was not quantitatively measured, small coccolithophores,
flagellates and other nanoplankton forms made a considerable contribution to the total crop. Hulburt (1962), dealing with the tropical
north Atlantic finds that small flagellates and coccolithophores are
fairly regularly distributed in these warmer waters together with diatoms and dinoflagellates. Wood (1 963a) considers that the nanoplankton
generally becomes increasingly important in tropical seas, although
there are exceptions, such as a considerable abundance of diatoms
occurring off the Australian coast, end also off the western coast of
India. On the other hand, north and south oS the subtropical convergences, and above all, at really high latitudes, especially south of the
Antarctic Convergence, diatoms become all-im portant.
A comparison between the nanoplankton and larger net phytoplankton has recently been made by Teixeira (1963) and Teixeira and
Kutner (1963) for Brazilian waters. In the shitllow lagoon waters, the
net plankton, consisting mainly of large diatoms, comprised only about
3% of the total which was dominated by the nmoplankton; but even in
offshore waters up to 400 miles from the coast the dominance of the
nanoplankton was still very clear, with the net plankton contributing
less than a fifth to the total standing crop. A f13w nanoplankton species
seem characteristic of polluted waters with high organic content (e.g.
Ryther, 1954), but in general these very small algae are particularly
adapted to oligotrophic waters where they may contribute considerably
to the overall production. Thus in Teixeira's investigations, it appeared
that the net plankton contributed only 10% to total photosynthetic
activity in offshore waters when the 14C method. was used.
IV. PHYTOPLANKTON CROP AND ANNUAL PRODUCTION
The size of standing crop is a most significant factor in total production since rate is reckoned as the amount of cai-bon (or organic matter)
synthesized per unit of carbon (or organic mcitter) present as phytoplankton. In general, as Steemann Nielsen has pointed out (1958b;
F
'
157
net hauls, more recent work such as t,hat of Burkholder and Sieburth
(1961) indicates that in the waters of Antarctica diatoms are probably
all-important; the only other organism which bulked large in the
phytoplankton was Phaeocystis.
It is perhaps in the warmer seas that the nanoplankton algae,
including the coccolithophores, become of particular significance. The
investigations of Lohmann and of Bernard (1953) in the Mediterranean,
of Riley (1957) for the Sargasso Sea and of Bsharah (1957) for the
Florida Current call attention to the importance of nanoplankton in
warmer waters. Hulburt, Ryther, and Guillaxd (1960) report on the
prevalence of coccolithophores in waters off Bermuda; though the nanoplankton was not quantitatively measured, small coccolithophores,
flagellates and other nanoplankton forms made a considerable contribution to the total crop. Hulburt (1962), dealing with the tropical
north Atlantic finds that small flagellates and coccolithophores are
fairly regularly distributed in these warmer waters together with diatoms and dinoflagellates. Wood (1 963a) considers that the nanoplankton
generally becomes increasingly important in tropical seas, although
there are exceptions, such as a considerable abundance of diatoms
occurring off the Australian coast, end also off the western coast of
India. On the other hand, north and south oS the subtropical convergences, and above all, at really high latitudes, especially south of the
Antarctic Convergence, diatoms become all-im portant.
A comparison between the nanoplankton and larger net phytoplankton has recently been made by Teixeira (1963) and Teixeira and
Kutner (1963) for Brazilian waters. In the shitllow lagoon waters, the
net plankton, consisting mainly of large diatoms, comprised only about
3% of the total which was dominated by the nmoplankton; but even in
offshore waters up to 400 miles from the coast the dominance of the
nanoplankton was still very clear, with the net plankton contributing
less than a fifth to the total standing crop. A f13w nanoplankton species
seem characteristic of polluted waters with high organic content (e.g.
Ryther, 1954), but in general these very small algae are particularly
adapted to oligotrophic waters where they may contribute considerably
to the overall production. Thus in Teixeira's investigations, it appeared
that the net plankton contributed only 10% to total photosynthetic
activity in offshore waters when the 14C method. was used.
IV. PHYTOPLANKTON CROP AND ANNUAL PRODUCTION
The size of standing crop is a most significant factor in total production since rate is reckoned as the amount of cai-bon (or organic matter)
synthesized per unit of carbon (or organic mcitter) present as phytoplankton. In general, as Steemann Nielsen has pointed out (1958b;
F
'