20
°6
0°
60° 40° 20° 0° –20° –40° –60°
100°
140°
180°
220°
260° Chl a (mg/m
3 )
300°
00
.0
70
.2
0.
40
.6
1.
02
.0
5.
03
5.0
340°
PLATE 7
. The image shows marine productivity, as revealed by chlorophyll concentrations, in the world’s oceans. Generally, productivity,
measured by mg/m
3 is highest (redder tones) at higher latitudes and along continental margins. It is lower (bluer tones) nearer the Equator,
and conspicuously low (black) in mid-
ocean along the Tropics of Cancer and Capricorn (Source: NOAA).