24
provides a means for the concentration of metallic trace elements on the bottom.
Fish samples,
taken from atolls in the vicinity of the
Pacific Proving Ground following nuclear tests, have consistently revealed divalent, cationic radionuclides in various
tissues in concentrations considerably in excess of the levels
in the water of the atoll lagoons
Rice and Price
(Welander,
1957).
Chipman,
(1958) demonstrated in laboratory experiments
the uptake of dissolved zinc from sea water by fish and its
early concentration in the gastro-intestinal tract and the
hepatopancreas.
Joyner
(1961) made similar observations in
experiments with fresh-water fish.
Joyner and Eisler
(1961)
demonstrated the translocation of zinc, taken up from fresh
water by chinook salmon fingerlings,
from the viscera to the
bone of the vertebral colum.
3.2
The Biological Significance of Trace Metals
3.21
Heavy metals in general.
A review of the physi-
cal and chemical bases for the behavior of metal ions in blological systems has been presented by Williams
(1953).
Metal-
containing enzymes and compounds of biological interest can be
divided into two categories.
In the first, the metal ion is
an indispensable part of a protein from which it cannot be dissociated except by destructive chemical attack, and cannot be