Environmental Engineering Reference
In-Depth Information
organic substances (see chapter
“
Colored and Chromophoric Dissolved Organic
3 Distribution of Chlorophyll (Chl
a
)
Chl
a
concentrations are significantly varied in the water column, where a given
set of parameters may lead to either a surface or a subsurface Chl
a
maximum
(SCM), or to a deep Chl
a
maximum (DCM) (Huisman et al.
2006
; Riley et al.
1949
; Bainbridge
1957
; Steele and Yentsch
1960
; Anderson
1969
; Derenbach et
al.
1979
; Dortch
1987
; Vilicˇ ic´ et al.
1989
; Bjørnsen and Nielsen
1991
; Donaghay
et al.
1992
; Huisman and Weissing
1995
; Djurfeldt
1994
; Gentien et al.
1995
;
Odate and Furuya
1998
; Huisman et al.
1999
; Dekshenieks et al.
2001
; Franks
and Jaffe
2001
; Klausmeier and Litchman
2001
; Diehl
2002
; Rines et al.
2002
;
Yoshiyama and Nakajima
2002
; Arístegui Ruiz et al.
2003
; Hodges and Rudnick
2004
; Matondkar et al.
2005
; Weston et al.
2005
; Lund-Hansen et al.
2006
;
Beckmann and Hense
2007
; Hense and Beckmann
2008
; Hopkinson and Barbeau
2008
; Whitehouse et al.
2008
; Yoshiyama et al.
2009
; Lu et al.
2010
; Martin et al.
2010
; Ryabov et al.
2010
; Velo-Suárez et al.
2010
). The location of the maximum
is entirely determined by the environmental conditions. The cited studies have
shown that SCM and DCM of phytoplankton can occur in a variety of conditions
in lake and marine waters. They can range in the vertical dimension from centime-
ters to a few meters, and have been observed to extend horizontally for kilometers.
3.1 Surface or Subsurface Chl
a
Maximum
The surface or subsurface Chl
a
maximum (SCM) is detected in the surface layer,
which varies in different waters and may range between 0-25 m in lakes and
0-30 m or more in seawater (Fig.
3
a; Table
1
) (Fu et al.
2010
; Mostofa K et al.
unpublished data; Apollonio
1980
; Vicente and Miracle
1984
; Kimor et al.
1987
;
Pedros-Alio et al.
1987
; Millán-Núñez et al.
1996
; Gomes et al.
2000
; Guildford
and Hecky
2000
; Li and Harrison
2001
; Echevin et al.
2004
; Koné et al.
2005
;
Camacho
2006
; Ediger et al.
2006
; Parab et al.
2006
; Roy et al.
2006
; Satoh
et al.
2006
; Sawatzky et al.
2006
; Yacobi
2006
; Norrbin et al.
2009
; Xiu et al.
2009
; Zhu et al.
2009
; Hamilton et al.
2010
). According to these studies, SCM
can be defined as a zone of maximum photosynthetic activity that shows the high-
est Chl
a
contents. It occurs in the upper surface layer of the euphotic zone in the
presence of strong light, high DOM contents and nutrients, and under high tem-
perature as well as low or high turbulence. It is a remarkable feature of highly tur-
bid water in the surface layer of stagnant natural waters, particularly in lakes and
oceans. High variation with depth of SCM in seawater is presumably caused by an
increase of the surface-water mixing zone, due to strong wind and wave compared
