Environmental Engineering Reference
In-Depth Information
it is of 45-68 Gt C year
−
1
and from coastal vegetation it is of 1.9 Gt C year
−
1
(Longhurst et al.
1995
; Box
2004
; Haberl et al.
2007
).
Since the development of techniques for Chl
a
detection in water in the decade
of 1930 and 1940s (Harvey
1934
,
1939
), a number of research works has been pub-
lished to develop analytical methodologies (Richards and Thompson
1952
; Parsons
and Strickland
1963
; Jeffrey and Humphrey
1975
), to elucidate Chl
a
origin (Fennel
and Boss
2003
; Letelier et al.
2004
; Huisman et al.
2006
) and to understand its
photoinduced degradation into various pheopigments (Welschmeyer and Lorenzen
1985
; Barlow et al.
1993
; Stephens et al.
1997
). An additional issue is the produc-
tion of autochthonous DOM by photoinduced degradation of Chl
a
or phytoplankton
biomass, under both photoinduced and microbial (bacterial) metabolism/assimi-
lation/respiration (Kirchman et al.
1991
,
1995
; Tranvik
1993
; Nelson et al.
1998
,
2004
; Hart et al.
2000
; Parlanti et al.
2000
; Carrillo et al.
2002
; Rochelle-Newall and
Fisher
2002
; Nieto-Cid et al.
2006
; Mostofa et al.
2009
; Zhang et al.
2009
).
The spatial variability of the net primary productivity over the globe is sub-
stantially high, varying from about 1,000 g C m
−
2
for evergreen tropical rain for-
ests to less than 30 g C m
−
2
for deserts (Scurlock et al.
1999
). On the other hand,
chlorophyll
a
(Chl
a
) concentrations vary from 0.0 to 2,080
μ
g L
−
1
in a variety
of natural waters. Such a variability in Chl
a
concentration can produce either a
surface/subsurface Chl
a
maximum (SCM) or a deep Chl
a
maximum (DCM) in
natural waters (Huisman et al.
1999
,
2006
; Riley et al.
1949
; Bainbridge
1957
;
Steele and Yentsch
1960
; Anderson
1969
; Derenbach et al.
1979
; Dortch
1987
;
Viliˇi´ 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
;
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 high variation in Chl
a
content is generally used as a universal signature of
cyanobacteria (algae), or of phytoplankton bloom or eutrophication in a variety of
waters (Fielding and Seiderer
1991
; Ondrusek et al.
1991
; Williams and Claustre
1991
; Millie et al.
1993
; Jeffrey et al.
1999
; Bianchi et al.
1993
,
2002
, Blanco et al.
2008
; Kasprzak et al.
2008
). Variations in Chl
a
concentrations or primary produc-
tion is entirely dependent on various environmental factors in natural waters, which
have been extensively discussed before (see also chapter
“
Photosynthesis in Nature:
A New Look
”).
It has been found that Chl
a
bound to phytoplankton can be degraded by photoin-
duced and microbial processes, thereby producing a number of pigments and colour-
less organic compounds in natural waters (Welschmeyer and Lorenzen
1985
; Barlow
et al.
1993
; Stephens et al.
1997
; Zhang et al.
2009
; Bianchi et al.
2002
; Schulte-Elte
et al.
1979
; Falkowski and Sucher
1981
; Pietta et al.
1981
; Mantoura and Llewellyn
1983
; Keely and Maxwell
1991
; Nelson
1993
; Sun et al.
1993
; Rontani et al.
1995
,
1998
,
2003
,
2011
; Rontani and Marchand
2000
; Yacobi et al.
1996
; Cuny et al.
