Environmental Engineering Reference
In-Depth Information
Chl
a
concentrations are greatly variable, ranging from 0.01 to 133.22
μ
g
L
−
1
in 38 Chinese lakes. Most of them are mesotrophic (TN
=
0.31-2.30 mg
L
−
1
; TP
=
0.01-0.11 mg L
−
1
), five lakes are oligotrophic (TN < 0.31 mg L
−
1
;
TP < 0.01 mg L
−
1
), and another four lakes are eutrophic (TN > 2.30 mg L
−
1
;
TP > 0.11 mg L
−
1
) with algal blooms during the summer period (Zhang et al.
2007
). The TN:TP ratio ranged from 2:1 to 253:1 for all 38 lakes (Zhang et al.
2007
). Chl
a
concentrations significantly varied (10-145
μ
g L
−
1
) in two Swedish
lakes. In Lake Börringesjön the highest concentration (145
μ
g L
−
1
) has been found
in September, when light attenuation ranged from 4.61 to 7.81 m
−
1
(Blindow
et al.
2006
). Chl
a
concentrations were low (0.3-1.2
μ
g L
−
1
) in an alpine lake dur-
ing the ice-cover period, but after ice-break the values increased particularly in
the deep layers. The maximum was observed at 9 m depth (8.5
μ
g L
−
1
), whilst
DOC concentrations in the water column ranged from 10 to 54
μ
M C (Sommaruga
and Augustin
2006
). Chl
a
concentrations were also very low (0.14-2.85
μ
g L
−
1
)
in lake water with low WT (1.2-12.4 °C) and low DOC concentrations (such as
~42
μ
M C) (Carrillo et al.
2002
). In Bohai Sea the vertical distribution of Chl
a
and water temperature at depth 0-20 m was approximately 1-2
μ
g L
−
1
and
24.7-25.6 °C. The diffuse attenuation coefficient increased with depth, producing
a DCM at around 5-6 m depth (Xiu et al.
2009
). High temperature and other fac-
tors suggest that this low variation of Chl
a
(1-2
μ
g L
−
1
) might be caused by high
photoinduced decomposition of Chl
a
in the surface layer (0-5 m). This result is not
accounted for by DCM, rather it can be considered as SCM or mixed layer depth.
On the other hand, Chl
a
concentrations in reservoirs are substantially high, rang-
ing from approximately 0.0-919
μ
g L
−
1
(Gálvez et al.
1988
; Foster et al.
1997
; Dasí
et al.
1998
; An and Park
2002
; Almodovar et al.
2004
; Sigareva and Pyrina
2006
;
Mineeva et al.
2008
; Mineeva and Abramova
2009
). The highest Chl
a
concentrations
were detected in several UK reservoirs, such as <120-919
μ
g L
−
1
; Chl
a
was then
found at <54.5-239.8
±
68.2
μ
g L
−
1
in several Russia's reservoirs and <173
μ
g L
−
1
in Taechung Reservoir (South Korea) (Table
1
). The Chl
a
concentrations in Gorky
Reservoir varied from 6.3 to 28.0
μ
g L
−
1
in both right and left banks, and from 5.9
to 20.6
μ
g L
−
1
in riverbed with variation of water temperature (WT) from 19.7 to
21.9 °C. In Cheboksary reservoir, Chl
a
concentrations were 4.2-72.4 and 6.6
±
0.7 - 239.8
±
68.2
μ
g L
−
1
, respectively, with variation of WT from 11.0 to 24.0 °C
(Table
1
) (Mineeva et al.
2008
; Mineeva and Abremova
2009
). The peak Chl
a
levels
in Stanford reservoir exceeded 916
μ
g L
−
1
in June and July, but they remained below
25
μ
g L
−
1
for the remainder of the sampling period (Foster et al.
1997
).
Estuaries
The Chl
a
concentrations are quite high (0.0-220
μ
g L
−
1
) in estuaries (Table
1
)
(Lemaire et al.
2002
; Zhu et al.
2009
; Stross and Stottlemyer
1965
; Pennock
1985
;
Abril et al.
2002
; Hauxwell et al.
2003
; Langston et al.
2003
; Gitelson et al.
2007
;
He et al.
2010
; Craig et al.
2012
; Mallin
1994
; Gaulke et al.
2010
). The highest
Chl
a
concentrations are <220
μ
g L
−
1
in European estuaries; <184
μ
g L
−
1
in
North Carolina estuaries; >101
μ
g L
−
1
in the Exe Estuary SPA; <80
μ
g L
−
1
