Environmental Engineering Reference
In-Depth Information
and Handa
1987
; Baron et al.
1991
; Søndergaard and Middelboe
1995
; Reitner et
al.
1997
; Malcolm and MacCarthy
1992
; Imai et al.
1998
; Rosenstock and Simon
2001
; Frimmel
2004
; Hayakawa
2004
; Sugiyama et al.
2005
). Biomolecules (e.g.
carbohydrates and proteins) as well as organic acids account for approximately
70 % of high molecular weight (HMW) DOM, and only for approximately 2 %
of (LMW) DOM in lake water (Hama and Handa
1992
). These studies also show
that allochthonous fulvic acids in lakes are largely varied during the summer and
winter season, with winter maxima and summer minima. Their total content is also
low in algal-dominated lakes.
The percentages of major organic substances in bulk DOM in shelf, coastal
and open ocean are: 1-75 % of allochthonous fulvic acids of terrestrial origin;
5-10 % of autochthonous fulvic acids (or marine humic-like: see
Sect. 3.2
and
also FDOM chapter for detailed description) of algal or phytoplankton origin;
10-80 % of carbohydrates (~25 % in deeper layers); 10-28 % of amino acids,
proteins and lipids taken together (amino acids alone account for 7 %); organic
acids; organic peroxides (ROOH); sterols; algal toxins, and so on (Mostofa et al.
2009a
,
b
; Coble
1996
,
2007
; Zhang et al.
2009
; Bronk
2002
; Ogawa and Tanoue
2003
; Ogawa et al.
2001
; Biddanda and Benner
1997
; Harvey and Boran
1985
;
Meyers-Schulte and Hedges
1986
; Druon et al.
2010
; Richardson
2007
; Thurman
1985b
; Alberts and Takács
1999
; Ma et al.
2001
; Beck et al.
1974
; Stuermer and
Harvey
1977
; Gagosian and Stuermer
1977
; Burney et al.
1982
; Thurman and
Malcolm
1983
; Romankevich
1984
; Williams and Druffel
1987
; Moran et al.
1991
; Moran and Hodson
1994
; Pakulski and Benner
1994
; McCarthy et al.
1996
;
Opsahl and Benner
1997
; Gašparovic et al.
1998
; Kirchman et al.
2001
; Aluwihare
et al.
2002
; Benner and Kaiser
2003
; Yamashita and Tanoue
2003
). The con-
tributions of allochthonous humic substances in shelf seawater are 11-75 %, of
which around 38 % of marsh origin and 62 % of river origin (Moran and Hodson
1994
). Carbohydrates can comprise 10-70 % of the organic matter in the plankton
cell (Romankevich
1984
) and are presumably released directly to the water col-
umn by algae or phytoplankton under photo- and microbial respiration (Mostofa
et al.
2009b
; Zhang et al.
2009
; Hellebust
1965
; Ittekkot et al.
1981
; Mopper et
al.
1995
; Cowie and Hedges
1994
,
1996
). Carbohydrates (originally polysaccha-
rides) make up approximately 15-60 % of marine HMW DOM (Druon et al.
2010
;
Burney et al.
1982
; Romankevich
1984
; Pakulski and Benner
1994
; McCarthy et
al.
1996
). Carbohydrates also account for ~5-20 % of particulate material in sea-
water (Pakulski and Benner
1994
; Tanoue and Handa
1987
; Hernes et al.
1996
;
Panagiotopoulos et al.
2002
). Autochthonously produced carbohydrates, proteins
and lipids are vital biochemical organic groups that together constitute approxi-
mately 10-80 % of organic carbon and 15-50 % of the nitrogen assimilated dur-
ing photosynthesis by phytoplankton in natural waters (Sundh
1992
; Bronk et al.
1994
; Braven et al.
1995
; Malinsky-Rushansky and Legrand
1996
; Wakeham et al.
1997
; Slawyk et al.
1998
).
The main organic substances in rainwater are hydrophobic DOM (major frac-
tion; ~<50 %), including allochthonous humic substances (fulvic and humic acids)
or marine humic-like substances, hydrophilic DOM (major fraction; ~>50 %),
