In order of most to least:
| ELEMENT |
MOLECULAR WEIGHT |
PPM IN SEAWATER |
MOLAR CONCENTRATION |
| Chloride |
35.4 |
18980 |
0.536158 |
| Sodium |
23 |
10561 |
0.459174 |
| Magnesium |
24.3 |
1272 |
0.052346 |
| Sulfur |
32 |
884 |
0.027625 |
| Calcium |
40 |
400 |
0.01 |
| Potassium |
39.1 |
380 |
0.009719 |
| Bromine |
79.9 |
65 |
0.000814 |
| Carbon(inorganic) |
12 |
28 |
0.002333 |
| Strontium |
87.6 |
13 |
0.000148 |
| Boron |
10.8 |
4.6 |
0.000426 |
| Silicon |
28.1 |
4 |
0.000142 |
| Carbon (organic) |
12 |
3 |
0.00025 |
| Aluminum |
27 |
1.9 |
0.00007 |
| Fluorine |
19 |
1.4 |
0.000074 |
| N as nitrate |
14 |
0.7 |
0.00005 |
| Nitrogen (organic) |
14 |
0.2 |
0.000014 |
| Rubidium |
85 |
0.2 |
0.0000024 |
| Lithium |
6.9 |
0.1 |
0.000015 |
| P as Phosphate |
31 |
0.1 |
0.0000032 |
| Copper |
63.5 |
0.09 |
0.0000014 |
| Barium |
137 |
0.05 |
0.00000037 |
| Iodine |
126.9 |
0.05 |
0.00000039 |
| N as nitrite |
14 |
0.05 |
0.0000036 |
| N as ammonia |
14 |
0.05 |
0.0000036 |
| Arsenic |
74.9 |
0.024 |
0.00000032 |
| Iron |
55.8 |
0.02 |
0.00000036 |
| P as organic |
31 |
0.016 |
0.00000052 |
| Zinc |
65.4 |
0.014 |
0.00000021 |
| Manganese |
54.9 |
0.01 |
0.00000018 |
| Lead |
207.2 |
0.005 |
0.000000024 |
| Selenium |
79 |
0.004 |
0.000000051 |
| Tin |
118.7 |
0.003 |
0.000000025 |
| Cesium |
132.9 |
0.002 |
0.000000015 |
| Molybdenum |
95.9 |
0.002 |
0.000000021 |
| Uranium |
238 |
0.0016 |
0.0000000067 |
| Gallium |
69.7 |
0.0005 |
0.0000000072 |
| Nickel |
58.7 |
0.0005 |
0.0000000085 |
| Thorium |
232 |
0.0005 |
0.0000000022 |
| Cerium |
140 |
0.0004 |
0.0000000029 |
| Vanadium |
50.9 |
0.0003 |
0.0000000059 |
| Lanthanum |
139.9 |
0.0003 |
0.0000000022 |
| Yttrium |
88.9 |
0.0003 |
0.0000000034 |
| Mercury |
200.6 |
0.0003 |
0.0000000015 |
| Silver |
107.9 |
0.0003 |
0.0000000028 |
| Bismuth |
209 |
0.0002 |
0.00000000096 |
| Cobalt |
58.9 |
0.0001 |
0.0000000017 |
| Gold |
197 |
0.000008 |
0.00000000004 |