688
K. M. G. Mostofa et al.
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 published 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 production of autochthonous DOM by photoinduced degradation of Chl a or phytoplankton
biomass, under both photoinduced and microbial (bacterial) metabolism/assimilation/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 substantially high, varying from about 1,000 g C m −2 for evergreen tropical rain forests 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 μg 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;
Vilic ˇic ´ 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 production 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 photoinduced and microbial processes, thereby producing a number of pigments and colourless 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.
K. M. G. Mostofa et al.
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 published 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 production of autochthonous DOM by photoinduced degradation of Chl a or phytoplankton
biomass, under both photoinduced and microbial (bacterial) metabolism/assimilation/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 substantially high, varying from about 1,000 g C m −2 for evergreen tropical rain forests 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 μg 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;
Vilic ˇic ´ 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 production 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 photoinduced and microbial processes, thereby producing a number of pigments and colourless 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.