Primary Productivity of Phytoplankton
223
Table 14.2. Distribution of underwater light."
A
B
Red
Yellow
Green
Blue
DownwardNeutral
(460facing
facing
Depth (m)
filter
720nm)
590nm)
580nm)
500nm)
hemisphere
hemisphere
Surface (air)
100
100
100
100
100
100
100
0.1
75.0
62.9
90.6
79.4
81.3
65.0
97.8
1
45.5
42.9
40.4
50.5
46.0
47.5
93.6
2
30.4
25.9
28.9
32.4
28.4
37.5
91.7
3
17.8
18.5
21.9
24.0
21.0
30.0
80.0
4
13.5
13.2
16.6
17.6
11.1
23.0
61.9
5
9.6
9.7
11.9
12.3
7.9
17.3
50.0
6
6.8
4.4
9.1
7.0
5.6
13.5
36.9
7
4.9
3.1
6.8
5.0
4.0
10.3
27.4
8
3.4
2.2
3.8
2.6
3.0
8.0
22.6
9
1.8
1.6
2.8
2.3
2.1
6.0
19.0
10
1.2
1.1
2.1
2.0
1.6
4.8
17.9
11
0.8
0.8
1.6
1.4
1.1
3.5
20.2
12
0.5
0.6
1.0
0.8
0.8
1.3
21.4
a A: Underway photometer equipped with neutral and restricted spectral filters. B: Photometer that measures
incident-scattered light from the upper hemisphere and reflected-scattered light from the lower hemisphere.
All values in percent of the surface value.
Table 14.3. Concentrations of phytoplanktonic pigments.
Plant
Depth
Chlorophyll a
Chlorophyll b
Chlorophyll c
carotenoids
Phaeopigments
(m)
0
2
3
4
5
7
10
12
(mgjm 3 )
(mgjm 3 )
(mgjm 3 )
(mgjm 3 )
(mgjm 3 )
0.38
0.17
0.00
0.38
0.13
1.08
0.23
0.57
1.08
0.00
2.00
0.37
0.52
1.82
1.05
1.86
0.16
0.72
1.60
2.06
4.17
0.39
2.05
3.29
2.15
6.07
0.13
2.52
6.73
4.18
5.18
0.42
2.27
4.18
5.23
1.11
0.49
0.88
1.26
3.98
0.75
0.13
1.35
3.47
3.56
Note: When the true rate of photosynthesis is measured by the differential dp/dt, where
PI is the amount of fixed carbon at time t and Po the amount at a zero reference time, then
the rate as measured experimentally is (Strickland, 1960)
PI-PO D
where D is the increase in carbon found in the light bottle. When plant growth
is approximately exponential, the true rate at time to is given by:
dp = (po) (2.3 log D + po)
dt
t
Po
This expression requires the value of Po, which is rarely known.
How would duration of incubation affect this relationship?
Note: When a fractional increase in the size of a population of algae does not exceed
about 20% during the measurement, the true rate at zero time, dp/dt, is equal to D/t to
within a few percent (Strickland and Parsons, 1968). The true rate at a time (t - t o )/2,
however, is still close to the value for D/t with D as much as Po (i.e., when the population
223
Table 14.2. Distribution of underwater light."
A
B
Red
Yellow
Green
Blue
DownwardNeutral
(460facing
facing
Depth (m)
filter
720nm)
590nm)
580nm)
500nm)
hemisphere
hemisphere
Surface (air)
100
100
100
100
100
100
100
0.1
75.0
62.9
90.6
79.4
81.3
65.0
97.8
1
45.5
42.9
40.4
50.5
46.0
47.5
93.6
2
30.4
25.9
28.9
32.4
28.4
37.5
91.7
3
17.8
18.5
21.9
24.0
21.0
30.0
80.0
4
13.5
13.2
16.6
17.6
11.1
23.0
61.9
5
9.6
9.7
11.9
12.3
7.9
17.3
50.0
6
6.8
4.4
9.1
7.0
5.6
13.5
36.9
7
4.9
3.1
6.8
5.0
4.0
10.3
27.4
8
3.4
2.2
3.8
2.6
3.0
8.0
22.6
9
1.8
1.6
2.8
2.3
2.1
6.0
19.0
10
1.2
1.1
2.1
2.0
1.6
4.8
17.9
11
0.8
0.8
1.6
1.4
1.1
3.5
20.2
12
0.5
0.6
1.0
0.8
0.8
1.3
21.4
a A: Underway photometer equipped with neutral and restricted spectral filters. B: Photometer that measures
incident-scattered light from the upper hemisphere and reflected-scattered light from the lower hemisphere.
All values in percent of the surface value.
Table 14.3. Concentrations of phytoplanktonic pigments.
Plant
Depth
Chlorophyll a
Chlorophyll b
Chlorophyll c
carotenoids
Phaeopigments
(m)
0
2
3
4
5
7
10
12
(mgjm 3 )
(mgjm 3 )
(mgjm 3 )
(mgjm 3 )
(mgjm 3 )
0.38
0.17
0.00
0.38
0.13
1.08
0.23
0.57
1.08
0.00
2.00
0.37
0.52
1.82
1.05
1.86
0.16
0.72
1.60
2.06
4.17
0.39
2.05
3.29
2.15
6.07
0.13
2.52
6.73
4.18
5.18
0.42
2.27
4.18
5.23
1.11
0.49
0.88
1.26
3.98
0.75
0.13
1.35
3.47
3.56
Note: When the true rate of photosynthesis is measured by the differential dp/dt, where
PI is the amount of fixed carbon at time t and Po the amount at a zero reference time, then
the rate as measured experimentally is (Strickland, 1960)
PI-PO D
where D is the increase in carbon found in the light bottle. When plant growth
is approximately exponential, the true rate at time to is given by:
dp = (po) (2.3 log D + po)
dt
t
Po
This expression requires the value of Po, which is rarely known.
How would duration of incubation affect this relationship?
Note: When a fractional increase in the size of a population of algae does not exceed
about 20% during the measurement, the true rate at zero time, dp/dt, is equal to D/t to
within a few percent (Strickland and Parsons, 1968). The true rate at a time (t - t o )/2,
however, is still close to the value for D/t with D as much as Po (i.e., when the population