20
"Harvey plant pigment unit", Hart was able to estimate the standing
crop of Antarctic phytoplankton.
In the early 50's, the use of the chlorophyll ~ method in estimating phytoplankton standing crop (Richards and Thompson, 1952) and
the radioactive 14C uptake method in estimating primary production
(Steemann Nielsen, 1952) revolutionized phytoplankton research. Thanks
to the extensive investigations carried out by scientists aboard the
USSR OB and VITIAZ, the USNS ELTANIN, the Argentine SAN MARTIN and
ISLAS o RCADAS, the French COMMANDANTE-CHARCOT and 14ARION DUFRESNE, the
numerous Japanese Antarctic Research Expeditions, and many others in
the 60's and 70's, a large amount of useful data were obtained on the
geographical and temporal distributions of phytoplankton standing crop
and on the magnitude of primary production in the circum-Antarctic
waters (Klyashtorin, 1961; Ichimura and Fukushima, 1963; Mandelli and
Burkholder, 1966; El-Sayed, 1967, 1968).
In this paper we will review the subject of primary productivity
of the Antarctic waters and examine the factors which govern the productivity of these waters in light of the more recent data collected
during the last decade.
Special emphasis will be put on the pelagic
primary producers.
(See El-Sayed, 1970; El-Sayed and Turner, 1977;
Fogg, 1977; Holm-Hansen et al., 1977; for earlier reviews.)
II. STANDING CROP AND PRIMARY PRODUCTION OF ANTARCTIC PHYTOPLANKTON
The bulk of the phytoplankton data show chlorophyll concentra3
.
tions in the range of 0.1 and 1.0 mg/m , with the mean value of
< 0.5 mg/m 3 (Saijo and Kawashima, 1964; El-Sayed and Mandelli, 1965;
El-Sayed, 1970; Fukuchi, 1980). In contrast to the generally oligotrophic oceanic regions, high standing crop values have been frequently reported from inshore waters, e.g. west of the Antarctic
Peninsula, in the Gerlache Strait (El-Sayed, 1967), in the southern
Ross Sea (El-Sayed et al., 1983), near the Kerguelen and Heard Islands
(El-Sayed and Jitts, 1973), off the Crozet Archipelago (El-Sayed et
al., 1979) and in the inshore waters of Signy Islands (Horne et al.,
-
3 - -
1969).
Exceptionally high values (i.e. in excess of 25 mg/m ) were
reported by Mandelli and Burkholder (1966), during a phytoplankton
bloom near Deception Island.
The most extensive and richest of these
blooms, reported by El-Sayed (1971), occurred in the southwestern
Weddell Sea. This bloom (composed entirely of the diatom Thalassiosira
tumida (Janish) Hasle was to cover an area> 15,000 km 2 , with a chlorophyll concentration of about 190 mg/m 3 • Another, but less spectacular
"Harvey plant pigment unit", Hart was able to estimate the standing
crop of Antarctic phytoplankton.
In the early 50's, the use of the chlorophyll ~ method in estimating phytoplankton standing crop (Richards and Thompson, 1952) and
the radioactive 14C uptake method in estimating primary production
(Steemann Nielsen, 1952) revolutionized phytoplankton research. Thanks
to the extensive investigations carried out by scientists aboard the
USSR OB and VITIAZ, the USNS ELTANIN, the Argentine SAN MARTIN and
ISLAS o RCADAS, the French COMMANDANTE-CHARCOT and 14ARION DUFRESNE, the
numerous Japanese Antarctic Research Expeditions, and many others in
the 60's and 70's, a large amount of useful data were obtained on the
geographical and temporal distributions of phytoplankton standing crop
and on the magnitude of primary production in the circum-Antarctic
waters (Klyashtorin, 1961; Ichimura and Fukushima, 1963; Mandelli and
Burkholder, 1966; El-Sayed, 1967, 1968).
In this paper we will review the subject of primary productivity
of the Antarctic waters and examine the factors which govern the productivity of these waters in light of the more recent data collected
during the last decade.
Special emphasis will be put on the pelagic
primary producers.
(See El-Sayed, 1970; El-Sayed and Turner, 1977;
Fogg, 1977; Holm-Hansen et al., 1977; for earlier reviews.)
II. STANDING CROP AND PRIMARY PRODUCTION OF ANTARCTIC PHYTOPLANKTON
The bulk of the phytoplankton data show chlorophyll concentra3
.
tions in the range of 0.1 and 1.0 mg/m , with the mean value of
< 0.5 mg/m 3 (Saijo and Kawashima, 1964; El-Sayed and Mandelli, 1965;
El-Sayed, 1970; Fukuchi, 1980). In contrast to the generally oligotrophic oceanic regions, high standing crop values have been frequently reported from inshore waters, e.g. west of the Antarctic
Peninsula, in the Gerlache Strait (El-Sayed, 1967), in the southern
Ross Sea (El-Sayed et al., 1983), near the Kerguelen and Heard Islands
(El-Sayed and Jitts, 1973), off the Crozet Archipelago (El-Sayed et
al., 1979) and in the inshore waters of Signy Islands (Horne et al.,
-
3 - -
1969).
Exceptionally high values (i.e. in excess of 25 mg/m ) were
reported by Mandelli and Burkholder (1966), during a phytoplankton
bloom near Deception Island.
The most extensive and richest of these
blooms, reported by El-Sayed (1971), occurred in the southwestern
Weddell Sea. This bloom (composed entirely of the diatom Thalassiosira
tumida (Janish) Hasle was to cover an area> 15,000 km 2 , with a chlorophyll concentration of about 190 mg/m 3 • Another, but less spectacular