Environmental Engineering Reference
In-Depth Information
2009
; Grippo et al.
2010
; Isada et al.
2010
; Chen et al.
2011
; Iriarte and González
2004
; Gonzalez et al.
1989
; Mackey et al.
1995
). Detected Chl
a
concentra-
tions are as high as 2080
μ
g L
−
1
in Arabian Sea, <152
μ
g L
−
1
in Yellow Sea,
<148
±
63.1
μ
g L
−
1
in north-western Alboran Sea or W-Mediterranean (0-200 m
depth), <40
μ
g L
−
1
in Chiloé and austral fjord (Chile), <35
μ
g L
−
1
in Concepción
and Mejillones Bay (Chile), <30
μ
g L
−
1
in western subarctic waters of the Pacific
Ocean (0-200 m depth), <23.3
μ
g L
−
1
in Chesapeake Bay (USA), <17
μ
g L
−
1
in Northwest Pacific Ocean, <17
μ
g L
−
1
in North Atlantic Ocean, <16.8
μ
g L
−
1
in upwelling seawater of northern Chile, <15.54
μ
g L
−
1
in Southwest Florida
Shelf, <15.23
μ
g L
−
1
in California Current System, <14.6
μ
g L
−
1
in Scotia Sea
(near South Georgia), <14.5
μ
g L
−
1
in Subtropical coastal waters (Hong Kong:
0-10 m depth), <12.5
μ
g L
−
1
in Baltic Sea, <11.6
μ
g L
−
1
in Southwest Florida
Shelf (Caloosahatchee River: Sts 51-55), <10.88
μ
g L
−
1
in Gulf of St. Lawrence
(Canada), <8.3
μ
g L
−
1
in Southwest coastal waters (India), and 0.0-4.45
μ
g L
−
1
in rest of the coastal and other oceans (Table
1
). Very low values have been found
in Southeast Bering Sea (4.45
μ
g L
−
1
), Atlantic Ocean (<4.0
μ
g L
−
1
) and East
China Sea (<4.14
μ
g L
−
1
) (Table
1
).
Extremely high Chl
a
concentrations at the surface of eastern Arabian Sea (the
highest ever observed in natural water) are responsible for the surface growth of
Trichodesmium
spp. (Parab et al.
2006
). This effect is probably linked to high
water temperature (20.6-29.4 °C) (Parab et al.
2006
) and relatively high DOC
contents, varying from 80 to 300
μ
M C (Menzel
1964
; Dileep Kumar et al.
1990
;
Breves et al.
2003
). High contents of Chl
a
in Yellow seawater are also presum-
ably caused by the occurrence of high contents of DOM (129-268
μ
M C) (Xia et
al.
2010
) and relatively high water temperature (9-20 °C) (Li et al.
2007
) driven
by solar irradiance. High contents of Chl
a
are generally detected in coastal sea-
waters, probably due to high terrestrial input of DOM and POM. Both DOM and
POM can produce DIC, CO
2
and H
2
O
2
upon photoinduced or microbial respira-
tion/degradation, which are responsible for high photosynthesis and high primary
production (see chapter
“
Photosynthesis in Nature: A New Look
” for detailed
mechanisms).
In the Baltic Sea, the Chl
a
concentrations are highest in the water column dur-
ing the spring bloom in late April and during the cyanobacterial bloom in August,
which are the two major bloom events (Bianchi et al.
2002
). In contrast Chl
a
con-
centration is low during the summer period, despite the extensive development of
cyanobacterial surface blooms (Bianchi et al.
2002
). The contents of Chl
a
vary
from 0.3 to 13.5 nmol L
−
1
, whilst those of Chl
b
vary from 0.05 to 0.92 nmol L
−
1
(Bianchi et al.
2002
). Chl
a
is approximately 15 times higher than Chl
b
in the
Baltic Sea.
The observed, relatively low concentrations of Chl
a
in oceanic environments
are presumably due to several facts: (i) Low contents of DOM and POM, partic-
ularly in open Oceanic environments, may cause the occurrence of low contents
of CO
2
, DIC, H
2
O
2
, nutrients, and so on. They are responsible for low photosyn-
thesis and low primary production, as extensively discussed in the photosynthesis
chapter (see chapter
“
Photosynthesis in Nature: A New Look
”). In contrast, high
