22
It is proposed to show that these mechanisms,
operating
selectively between the dissolved and solid phases of sea
water,
can bring about an apparent discrimination,
ecological system,
in a marine
between ‘isotopes of the same heavy element.
The accumulation of zinc ions by fish liver cells
against an apparent 7-fold concentration gradient is considered
by
Saltman and Boroughs
(1960), to be a passive mechanism not
Girectly coupled to metabolic energy,
involving sorption of
zine to binding sites on or within the cells.
The binding
sites were not specifically identified but were shown to be
profoundly altered by changes of temperature,
pH and chemical
environment.
Black and Mitchell
(1952) analyzed spectrographically
some of the common brown algae
(Laminariaceae and Fucaceae)
and sea water samples from the Scottish coast, reporting con~
centration factors of over 1000 for some trace elements, nota~
bly Ti and Zn,
in these algae.
Lagrange and Tchakirian
(1939), using spectrographic
methods in analyses of Lithothamnium, a common reef builder,
detected 15 trace elements in addition to the major constitu-
ents.
Chaberek and Martell
(1959), cite the outer surface of
vertebrate bone as an ion exchange medium capable of adsorbing