474
Fig. 22.1. An example of HPLC
spectrum of amino acids in a
sea water sample; 1: aspartic
acid; 2: glutamic acid; 3: aspar- .
agine; 4: serine; s: histidine;
6: glutamine; To glycine;
8: threonine; 9: arginine;
10: alanine; 11: tyrosine;
12: r-aminobutyric acid (internal standard); 13: valine;
14: phenylalanine; IS: isoleucine;
16: leucine; 17: ornithine;
18: lysine; methioninsulphone,
methionine, tryptophane and
norvaline were not detected in
this sample
4
7
2
5
10
15
M. Pettine . 1. Patrolecco . S. Capri
8
10
20
t(min)
i.s.
12
25
13
14
16
30
17
35
ings feasible (see Pettine et al. 1999 for more details). Furthermore, polysaccharides
determined by this method would more directly reflect changes in the concentration
of exuded polymers (Benner 1998), which include transparent exopolymer particles
actively involved in the aggregate formation (Passow and Alldredge 1994; Passow 2000).
Samples were analyzed in triplicate against glucose standard solutions, and results were
expressed in terms of glucose-carbon equivalents (TDCHO-C), by assuming 6 moles of
carbon per mole of hexose. The relative standard deviation between replicate samples
was usually below 5%.
22.3
Role of Organic Matter Dynamics in NA Environmental Problems
The dynamics of the DOC pool in the northern Adriatic basin are involved in hypoxic
and anoxic crises in bottom waters and massive occurrences of mucilaginous aggregates in the water column.
Anoxic phenomena occur during summer in the western coastal waters, which are
influenced by the Po River discharge. Since 1975, when nutrient loads discharged by
the Po showed an abrupt increase (Marchetti 1990) as happened in other European
rivers (Kempe et al.1991), large algal blooms have occurred regularly, causing episodes
of diffused anoxia at the sea bottom, which resulted in mass mortalities of benthic
organisms. The spatial and temporal extensions of areas affected by anoxia have diminished in recent years (Degobbis et al. 1999), probably as a consequence of the reduction and banning of phosphorus in Italian detergents. Toxic algal species on occasion also developed, causing severe damages to mollusc cultures and threatening human health. In addition to these environmental deterioration problems that are typical of eutrophicated systems, the northern Adriatic has experienced a peculiar phe-
Fig. 22.1. An example of HPLC
spectrum of amino acids in a
sea water sample; 1: aspartic
acid; 2: glutamic acid; 3: aspar- .
agine; 4: serine; s: histidine;
6: glutamine; To glycine;
8: threonine; 9: arginine;
10: alanine; 11: tyrosine;
12: r-aminobutyric acid (internal standard); 13: valine;
14: phenylalanine; IS: isoleucine;
16: leucine; 17: ornithine;
18: lysine; methioninsulphone,
methionine, tryptophane and
norvaline were not detected in
this sample
4
7
2
5
10
15
M. Pettine . 1. Patrolecco . S. Capri
8
10
20
t(min)
i.s.
12
25
13
14
16
30
17
35
ings feasible (see Pettine et al. 1999 for more details). Furthermore, polysaccharides
determined by this method would more directly reflect changes in the concentration
of exuded polymers (Benner 1998), which include transparent exopolymer particles
actively involved in the aggregate formation (Passow and Alldredge 1994; Passow 2000).
Samples were analyzed in triplicate against glucose standard solutions, and results were
expressed in terms of glucose-carbon equivalents (TDCHO-C), by assuming 6 moles of
carbon per mole of hexose. The relative standard deviation between replicate samples
was usually below 5%.
22.3
Role of Organic Matter Dynamics in NA Environmental Problems
The dynamics of the DOC pool in the northern Adriatic basin are involved in hypoxic
and anoxic crises in bottom waters and massive occurrences of mucilaginous aggregates in the water column.
Anoxic phenomena occur during summer in the western coastal waters, which are
influenced by the Po River discharge. Since 1975, when nutrient loads discharged by
the Po showed an abrupt increase (Marchetti 1990) as happened in other European
rivers (Kempe et al.1991), large algal blooms have occurred regularly, causing episodes
of diffused anoxia at the sea bottom, which resulted in mass mortalities of benthic
organisms. The spatial and temporal extensions of areas affected by anoxia have diminished in recent years (Degobbis et al. 1999), probably as a consequence of the reduction and banning of phosphorus in Italian detergents. Toxic algal species on occasion also developed, causing severe damages to mollusc cultures and threatening human health. In addition to these environmental deterioration problems that are typical of eutrophicated systems, the northern Adriatic has experienced a peculiar phe-