93
Minor Elements in Seawater
Table 3.1
Speciation, Concentration, and Distribution Types of Elements in Ocean Waters
Element
Probable Species
Range and Average Concentration
Type of Distribution
Li
Li +
25 μM
Conservative
Be
BeOH + , Be(OH) 2
4–30 pM, 20 pM
Nutrient type
B
B(OH) 3 , B(OH) 4
0.416 mM
Conservative
C
HCO 3
– , CO 3
2–
2.0–2.5 mM, 2.3 mM
Nutrient type
N
NO 3
– , (N 2 )
0–45 μM
Nutrient type
F
F – , MgF + , CaF +
68 μM
Conservative
Na
Na +
0.468 M
Conservative
Mg
Mg 2+
53.2 mM
Conservative
Al
Al(OH) 4
– , Al(OH) 3
5–40 nM, 2 nM
Mid- depth minima
Si
Si(OH) 4
0–180 μM
Nutrient type
P
HPO 4
2– , MgHPO 4
0–3.2 μM
Nutrient type
S
SO 4
2– , NaSO 4
– , MgSO 4
28.2 mM
Conservative
Cl
Cl –
0.546 M
Conservative
K
K +
10.2 mM
Conservative
Ca
Ca 2+
10.3 mM
Conservative
Sc
Sc(OH) 3
8–20 pM, 15 pM
Surface depletion
Ti
Ti(OH) 4
Few pM
?
V
HVO 4
2– , H 2 VO 4
–
20–35 nM
Surface depletion
Cr
Cr O 4
2–
2–5 nM, 4 nM
Nutrient type
Mn
Mn 2+
0.2–3 nM, 0.5 nM
Depletion at depth
Fe
Fe(OH) 3
0.1–2.5 nM, 1 nM
Surface and depth depletion
Co
Co 2+ , CoCO 3
0.01–0.1 nM, 0.02 nM
Surface and depth depletion
Ni
NiCO 3
2–12 nM, 8 nM
Nutrient type
Cu
CuCO 3
0.5–6 nM, 4 nM
Nutrient type, scavenging
Zn
Zn 2+ , ZnOH +
0.05–9 nM, 6 nM
Nutrient type
Ga
Ga(OH) 4
–
5–30 pM
?
As
HAsO 4
2–
15–25 nM, 23 nM
Nutrient type
Se
SeO 4
2– , SeO 3
2–
0.5–2.3 nM, 1.7 nM
Nutrient type
Br
Br –
0.84 nM
Conservative
Rb
Rb+
1.4 μM
Conservative
Sr
Sr 2+
90 μM
Conservative
Y
YCO 3
+
0.15 nM
Nutrient type
Zr
Zr(OH) 4
0.3 nM
?
Nb
NbCO 3
+
50 pM
Nutrient type (?)
Mo
MoO 4
2–
0.11 μM
Conservative
Tc
TcO 4
–
No stable isotope
?
Ru
?
<0.05 pM
?
Rh
?
?
?
Pd
PdCl 4
0.2 pM
?
Ag
AgCl 2
–
0.5–35 pM, 25 pM
Nutrient type
Cd
CdCl 2
–
0.001–1.1 nM, 0.7 nM
Nutrient type
In
In(OH) 3
1 pM
?
Sn
Sn(OH) 4
1–12 pM, 4 pM
Surface input
continued