134
S. Z. EL-SAYED and H. R. JITIS:
2. Distribution of Plant Pigments
The data for surface and integrated (i.e. within the euphotic zone, and/or to 200 m)
chlorophyll a, phaeopigments, primary productivity, and nutrient salts are included in
Table 1. Surface chlorophyll a values at most of the stations occupied during "Eltanin"
cruise 46 were moderate; the average value was 0.28 mg m- 3 • High chlorophyll a values
were found at station 4, located just to the north of the Polar Front, and in the region
between Heard and Kerguelen Islands. The highest surface chlorophyll a values during
this cruise (0.73 mg m -3) were recorded at station 16, off Heard Island, and at station
E
.I:. 150
l
200
250
[I CHI.OROPHYlL Ii!
B PHA[O ·PlOMEHTS
~ ~==~==~===c===c===c==~ o
(}I
0 2
0 -3
004
0 5
Chlorophyll a and Phaeo-pigments Img m-3)
Fig. 4. Vertical distribution of chlorophyll a and phaeopigments based on average values of all
stations combined during "Eltanin" cruise 46 (20 Nov. 1970 - 20 Jan. 1971)
17 A, situated to the SE of the Kerguelen Islands. The chlorophyll a values at these
stations are as high, or even higher, than those reported from the highly productive
regions in the northern and western Arabian Sea. (KREY, 1973; MCGILL and LAWSON,
1966.)
The vertical distribution of chlorophyll a (Fig. 3) shows that at the majority of the
stations, maximum chlorophyll a concentrations were found at subsurface depths; these
depth maxima varied between 10 m at station 17 A and 120 m at station 7. Maximum
chlorophyll a values, in general, occurred at depths corresponding to 25 - 12 % of surface
Fig. 3. Vertical distribution of chlorophyll a and phaeopigments (mg m- 3 ) at stations occupied
during "Eltanin" cruise 46. Position of arrows indicate depth of euphotic zone