spatial distribution of different forms of sedimentary phosphorus in florida bay: sequential...
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Spatial Distribution of Different Forms of
Sedimentary Phosphorus in Florida Bay:
sequential extraction approach
Jia-Zhong Zhang and Charles Fischer
Ocean Chemistry Division, AOML, NOAA, Miami, FL 33149
Florida Bay
Bottom type
Low phosphate concentration in Florida Bay waterZhang & Chi, 2002
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0
10
20
30
40
50
[PO 4] (nM )
South Florida
Atlantic Ocean
Gulf of Mexico
Sediment sampling station
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
12
34
5
6
78910
11
1213
14
15
16
17
18
19
20
2122
232425
26
27
282930
3132
33
3435
3637
3839 40
Sequential extraction procedure
IP, TP Step 1 Step 2 IP Step 3 IP, TP Step 4 IP Step 5 IP
0.5 g, <124 m dry sediment
50 ml pH8 1 M MgCl2
2 hour
50 ml BD 4 hour
0.5M NaCl Rinse, 2 hour
50 ml Acetate Buffer 6hour
1 M MgCl2 Rinse, 2 hour
50 ml 1 M HCl 16 hour
Ash 550oC 1M HCl 16 hour
Adsorbed inorganic P Leachable organic P
Fe-bound inorganic P
Authegenic Apatite CaCO3-bound P Leachable organic P
Detrital Apaptite
Refractory organic P
Percentage of CaCO3 in Florida Bay sediments
-81 .2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
8 1
8 4
8 7
9 0
9 2
9 4
% C a C O 3
Total Sedimentary Phosphorus in Florida Bay
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
1
3
5
7
9
11
13
Tota l P(um ol/g)
Total exchangeable phosphorus by MgCl2 extraction
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0.1
0.3
0.5
0.7
0.9
1.1
M gC l2-TP(um ol/g)
Exchangeable Inorganic phosphorus by MgCl2 extraction
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0
0.1
0.2
0.3
0.4
0.5
0.6
M gC l2-IP(um ol/g)
Exchangeable organic phosphorus by MgCl2 extraction
-81 .2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0
0.1
0.2
0.3
0.4
0.5
0.6
M gC l2-O P(um ol/g)
Iron-bound Phosphorus by dithionite extraction
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0.2
0.6
1
1.4
1.8
2.2
BD-IP(um ol/g)
Reactive iron in Florida Bay sediments
-81 .2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Long itude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0.5
1
1.5
2
2.5
3
3.5
4
Fe (um ol/g)
Salinity of Florida Bay water during sediment sampling By courtesy of Lee & John
CaCO3-bound total phosphorus by HAc (pH 4) extraction
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0
1
2
3
4
5
6
H AC - TP(um ol/g)
CaCO3-bound inorganic phosphorus
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3L
ati
tud
e
0
1
2
3
4
5
H AC - IP(um ol/g)
CaCO3-bound organic phosphorus
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3L
ati
tud
e
0
0.5
1
1.5
2
H Ac - O P(um ol/g)
Detrital phosphorus by HCl extraction
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0
0.2
0.4
0.6
0.8
1
1.2
H C l-IP(um ol/g)
Residual refractory organic phosphorus by ashing
-81.2 -81.1 -81.0 -80.9 -80.8 -80.7 -80.6 -80.5 -80.4 -80.3
Longitude
24.8
24.9
25.0
25.1
25.2
25.3
La
titu
de
0
0.5
1
1.5
2
2.5
3
Ash-P(um ol/g)
comparison
Fractions of P in Florida Bay sediment
MgCl28.2%
BD18.6%
HAc44.4%
HCl4.6%
Ash24.3%
Percentage of Different Forms of Sedimentary Phosphorus
Eastern Bay
Fe-bound21.0%
CaCO342.3%
Detrital4.5%
R-Org-P23.7%
Leachable8.5%
Central Bay
Leachable8.4%
Fe-bound20.5%
CaCO342.0%
Detrital3.9%
R-Org-P25.2%
Western Bay
Leachable7.6%
Fe-bound14.4%
CaCO348.6%
Detrital5.4%
R-Org-P24.0%
Summary
• Strong W-E spatial gradient in TSP and every forms of sedimentary P
• CaCO3-bound P accounts 44% of TSP
• Refractory organic P constitutes 24% of TSP
• Iron-bound P accounts 19% of TSP• Exchangeable P accounts 8% of
TSP
Sunset
Acknowledgements:
This research was supported by NOAA’s South Florida Ecosystem Restoration, Prediction and Modeling Program
Recent Publications:Zhang, Jia-Zhong, Charles J. Fischer, and Peter B. Ortner, (2004) Potential availability of sedimentary phosphorus to sediment resuspension in Florida Bay, Global Biogeochemical Cycles. 18, GB4008, doi: 10.1029/2004GB002255, 2004. Zhang, J.-Z., J. Chi (2002) Automated analysis of nanomolar concentrations of phosphate in natural waters with liquid waveguide, Environmental Science & Technology, 36(5): 1048-1053.