395
Primary Production in the Oceans
waters but not in bottles or in shallow shelf regions. This loss term might be sinking of
large diatoms. If sinking keeps the diatom population low, then the absolute rates of nutrient uptake will be limited because phytoplankton growth is a first- order process.
Iron would also be lost much more rapidly from open ocean systems than from bottles or shallow waters. Iron cannot be lost from a bottle. In shallow waters, sinking iron
–89
–90
–91
Longitude
pCO 2 (µatm)
Nitrate (µm)
Temperature (°C)
Latitude
–92
–93
22
22
21
22
23
24
25
23
20
22
23
24
25
(a)
(b)
(c)
–94
–89
–90
–91
Longitude
–92
–93
–94
–89
–90
–91
Longitude
–92
–93
–94
–1.5
–1.0
–0.5
0.0
0.5
1.0
Latitude
–1.5
–1.0
–0.5
0.0
400
400
450
500
550
350
500
450
2
4
6
8
10 12
12
8
6
4
2
2
6
450
0.5
1.0
Latitude
–1.5
–1.0
–0.5
0.0
0.5
1.0
Figure 9.23
Surface values of temperature, NO 3
– , and pCO 2 in surface waters around the Galapagos Islands.