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water thickness, and its behaviour can change arbitrarily. Apparently, in the layer
above the thermocline (
0.
Studies of all components in totality will make it possible to determine the
number of changes of the sign of the derivative (
@
p
=@
z)
O
≤
z), which uniquely determines
the number of the phytoplankton maxima. In particular, if
@
p
=@
@
p
=@
z changes the sign
seven times in the layer under study, and (
@
p
=@
z)
z=0
>0and(
@
p
=@
z)
z
→
∞
< 0, then
the function p(z) has four maxima.
Finally, assuming that zooplankton uniformly eat out phytoplankton through the
depth of the layer considered, and neglecting in Eq. (
4.43
) all constituents apart
from the
rst one, based on Eq. (
4.41
) we obtain the following expression for the
speci
c rate of the change of the phytoplankton biomass:
p
1
ð@
p
=@
t
Þ
b
ap
;
ð
4
:
45
Þ
where
2
2
E
10
J
;
b ¼ k
c
E
10
J
Þ
10
Y
a ¼ k
c
;
m ¼ E
max
=
E
0
ð
;
J ¼ m 1
E
=
E
max
ð
Þ;
Y ¼
a
H
max
The Eq. (
4.45
) has the solution:
;
E
10
S
p
ð
t
;
h
Þ
¼
c=
2
þ
exp
tk
c
where
Þ
10
c
S ¼ E
max
=
ð
E
0
;
c ¼
a
H
max
1
E
ð
=
E
max
Þ
E
g
1
Since E
0, at h
→
∞
then pt
ðÞ
½
c=
;
2
þ
Kexp
f
tk
c
;
where
→
K ¼ exp
10
m
f
g
.
4.6.4 Model of the Peruvian Current Ecosystem
Each region of the World Ocean has characteristic hydrophysical and ecological
properties. Therefore, with these properties taken into account, a speci
cation of the
model of the carbon cycle in the World Ocean will raise the reliability of the model
assessment of the role of the ocean systems in the assimilation of excess CO
2
from
the atmosphere. With this aim in view, let us consider the region of the Peruvian
Current characterized by high concentrations of nutrient elements (mkg-at/
'
):
nitrites (0.6
0.8); nitrates (5.5
14.9); phosphates (0.6
1.31); silicic acids (3
45),
-
-
-
-
and large values of primary production (cal/m
2
/day): 17.9
69.3 for phytoplankton;
3.26 for bacteria; 0.12
-
0.73 for zooplankton, and 0.7
-
3 for nekton (mainly,
anchovy). Near the Peruvian coastline there is the most powerful on the Earth
upwelling of deep waters that feeds the photic layer of the bordering region of the
ocean with nutrient elements. Here the main object of the industrial
-
fishing is
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