Bacteria and Microalgae in Reef Bottom Sediments
Fig. 4.2. Redox potential (Eh , mv) in columns of
soft sediments of the Majuro atoll, Marshalls; 1
mucous sediment under the thicket of living coral;
2 coral sand of the lagoonal slope; H depth in
column of sediment, cm. (Data by Sorokin 1973c)
-2tltl
II, em
2
6'
133
Eh,mtr
o 20tl .lftltl
~
0'"
/ p ' /
fl2
I
J
I
I
ttl L....:O-_----"-l ____ -.J
The rate of respiration of microbial populations in coral sands is
correspondingly very high (Table 4.4). Measured by different methods, it
ranges in coral sands within 0.1-0.6 mg O 2 g-1 day-I. It means that only
10-20 g of sand could consume all oxygen from 11 of the oxygen-saturated
sea water during one day. Per 1 m 2 the respiration of bottom communities
(including other microbenthic plant and animal elements) in the coral sand
areas varied within 0.8-8 g O 2 m -2 day-I. The microbial populations take up
70-80% of these values. Thus average values of microbial respiration in
coral sand after measurements in situ or in vitro are either at the level of
0.1-0.3 mg 02g- 1 day-l or of 0.5-5 g 02m-2 (Table 4.5).
Intensive respiration in coral sands results in the developing of anaerobic
conditions within a few centimeters of sediment cores (Figs. 4.2, 4.3). A
Table 4.4. Rates of respiration (M) of micro heterotrophic organisms In reef bottom
sediments, as measured by different methods
Sites
Types of sediments
Method' M, day-l
Reference
mg 0 2g- 1
g 0 2m-2
Kaneohe bay,
Detrital sediment
rwr
2.4-12.0
4.8-24.0
Di Salvo (1971b)
Hawaii
Detrital sediment
bod
1.2
2.4
Sorokin (1978b)
Coral sand
bod
0.05-0.1
0.7-15
Sorokin (1978b)
Majuro atoll,
Coral sand
km
0.17-0.65
2.5-9.5
Sorokin (1978b)
Marshalls
Fanning atoll, Lain
Coral sand
km
0.13
2.0
Sorokin (1970)
Heron I., GBR
Coral sand
bod
0.05-0.1
0.7-1.5
Sorokin (1984a)
Coral sand
enc
0.05
0.8
Propp et al. (1983)
Coral sand with rubble
bod
0.07-0.12
1.0-1.8
Sorokin (1984a)
Moorea I., Society I. Coral sand
enc
0.20
3.0
Sournia (1976b)
Coastal fringing
Carbonaceous silt
bod
0.65
3.2
Original data
reefs, central
Silted coral sand
enc
0.26-0.55 2.6-5.5
Original data
Vietnam
Coral sand
bod
0.13-0.53 2.0-8.0
Original data
Sinton atoll and
Coral sand
enc
0.13-0.26 2.0-3.5
Original data
Spratley, South
Coral sand with rubble
enc
0.21-0.23
4.2-4.5
Original data
China Sea
'km - Indirect calculation using data on production rate of bacteria and Krcoefficient of efficiency of use of
assimilated food for growth; bod - bottle oxygen method; rwr - use of flow water respirometer; enc - use of
in situ enclosures.
Fig. 4.2. Redox potential (Eh , mv) in columns of
soft sediments of the Majuro atoll, Marshalls; 1
mucous sediment under the thicket of living coral;
2 coral sand of the lagoonal slope; H depth in
column of sediment, cm. (Data by Sorokin 1973c)
-2tltl
II, em
2
6'
133
Eh,mtr
o 20tl .lftltl
~
0'"
/ p ' /
fl2
I
J
I
I
ttl L....:O-_----"-l ____ -.J
The rate of respiration of microbial populations in coral sands is
correspondingly very high (Table 4.4). Measured by different methods, it
ranges in coral sands within 0.1-0.6 mg O 2 g-1 day-I. It means that only
10-20 g of sand could consume all oxygen from 11 of the oxygen-saturated
sea water during one day. Per 1 m 2 the respiration of bottom communities
(including other microbenthic plant and animal elements) in the coral sand
areas varied within 0.8-8 g O 2 m -2 day-I. The microbial populations take up
70-80% of these values. Thus average values of microbial respiration in
coral sand after measurements in situ or in vitro are either at the level of
0.1-0.3 mg 02g- 1 day-l or of 0.5-5 g 02m-2 (Table 4.5).
Intensive respiration in coral sands results in the developing of anaerobic
conditions within a few centimeters of sediment cores (Figs. 4.2, 4.3). A
Table 4.4. Rates of respiration (M) of micro heterotrophic organisms In reef bottom
sediments, as measured by different methods
Sites
Types of sediments
Method' M, day-l
Reference
mg 0 2g- 1
g 0 2m-2
Kaneohe bay,
Detrital sediment
rwr
2.4-12.0
4.8-24.0
Di Salvo (1971b)
Hawaii
Detrital sediment
bod
1.2
2.4
Sorokin (1978b)
Coral sand
bod
0.05-0.1
0.7-15
Sorokin (1978b)
Majuro atoll,
Coral sand
km
0.17-0.65
2.5-9.5
Sorokin (1978b)
Marshalls
Fanning atoll, Lain
Coral sand
km
0.13
2.0
Sorokin (1970)
Heron I., GBR
Coral sand
bod
0.05-0.1
0.7-1.5
Sorokin (1984a)
Coral sand
enc
0.05
0.8
Propp et al. (1983)
Coral sand with rubble
bod
0.07-0.12
1.0-1.8
Sorokin (1984a)
Moorea I., Society I. Coral sand
enc
0.20
3.0
Sournia (1976b)
Coastal fringing
Carbonaceous silt
bod
0.65
3.2
Original data
reefs, central
Silted coral sand
enc
0.26-0.55 2.6-5.5
Original data
Vietnam
Coral sand
bod
0.13-0.53 2.0-8.0
Original data
Sinton atoll and
Coral sand
enc
0.13-0.26 2.0-3.5
Original data
Spratley, South
Coral sand with rubble
enc
0.21-0.23
4.2-4.5
Original data
China Sea
'km - Indirect calculation using data on production rate of bacteria and Krcoefficient of efficiency of use of
assimilated food for growth; bod - bottle oxygen method; rwr - use of flow water respirometer; enc - use of
in situ enclosures.