110
Chemical Oceanography, 4th Edition
5. Heavy group elements of a particular class are taken up more strongly than lighter
elements.
6. The affinity of organisms for anions increases with increasing ionic charge and in
a given group with increasing weight of the central atom:
F – < Cl – < Br – < I –
SO 4
2– < MoO 4
2– < WO 4
2–
7. The lower organisms concentrate elements more strongly than higher organisms.
8. Heavy metals are frequently concentrated in the digestive or renal organs.
The biosphere can affect minor elements by the following:
1. The regulation of dissolved and particulate organic material as a function of
time and space. This material can interact with minor elements and change their
reactivity.
2. The concentration of elements in living and nonliving organic material. The active
and inactive uptake can redistribute elements from surface to deep waters. The
concentration of organics on nonliving particles may also increase the adsorption
on these particles.
Fe, nmol kg –1
0.0
0.2
0.4
0.6
0.8
1.0
Depth, m
0
1000
2000
3000
4000
5000
Atlantic
Pacific
Figure 3.15
Profiles of Fe in the Atlantic and Pacific Oceans.