Chapter 7 



Ecology of Uptake by Aquatic Organisms 



71 



first approximation, the chemical constituents 

 may be considered to be much the same in all 

 places. Fairly good approximations of the con- 

 centrations of elements in sea water are listed 

 in Table 1 as the numbers of atoms per million 

 atoms of chlorine. The reported values of con- 

 centrations of elements on which Table 1 is 

 based frequently fail to distinguish between the 

 solid and dissolved phases. 



Whereas the oceans may be considered very 

 roughly as a homogeneous mass, most bodies of 



fresh water must be examined on an individual 

 basis because of the tremendous range in their 

 physical and chemical characteristics. Many of 

 the elements that occur normally in the oceans 

 are in concentrations too small to be detected by 

 present methods or are present in only trace 

 amounts in fresh water. The pH of fresh waters 

 ranges from perhaps as low as 2.2 to a high of 

 about 10.5 although the pH of most lakes and 

 streams falls somewhere between 6.5 and 8.5. 

 The total dissolved solids in fresh waters ranges 



TABLE 1 Chemical Abundances in the Marine H\'drosphere 



mg/1 



H 108,000 



He 0.000005 



Li 0.2 



Be 



B 4.8 



C 28 



N 0.5 



O 857,000 



F 1.3 



Ne 0.0003 



Na 10,500 



Mg 1,300 



Al 0.01 



Si 3 



P 0.07 



S 900 



CI 19,000 



A 0.6 



K 380 



Ca 400 



Sc 0.00004 



Ti 0.001 



V 0.002 



Cr 0.00005 



Mn 0.002 



Fe 0.01 



Co 0.0005 



Ni 0.0005 



Cu 0.003 



Zn 0.01 



Ga 0.0005 



Ge < 0.0001 



As 0.003 



Se 0.004 



Br 65 



Kr 0.0003 



Rb 0.12 



Sr 8 



Y 0.0003 



Zr 



Nb 



Mo 0.01 



Tc 



Ru 



Rh 



Pd 



atoms/ 10^ 

 atoms CI 

 202,000,000 



50 



.002 



830 



4,300 



70 



100,000,000 



130 



0.03 



850,000 



100,000 



0.7 



200 



4 



52,000 



1,000,000 



28.5 



18,000 



19,000 



0.002 

 0.04 

 0.08 

 0.002 

 0.07 

 0.3 

 0.02 

 0.02 

 0.09 

 0.3 

 0.01 

 < 0.003 

 0.07 

 0.1 

 1,500 

 0.007 

 2.2 

 160 

 0.006 



0.2 



atoms/ 10' 

 mg/1 atoms CI 



Ag 0.0003 0.005 



Cd 0.000055 0.0009 



In < 0.02 < 0.3 



Sn 0.003 0.05 



Sb < 0.0005 < 0.008 



Te 



I 0.05 0.7 



Xe 0.0001 0.001 



Q 0.0005 0.005 



Ba 0.0062 0.008 



La 0.0003 0.004 



Ce 0.0004 0.005 



Pr 



Nd 



Pm 



Sm 



Eu 



Gd 



Tb 



Dy 



Ho 



Er 



Tm 



Yb 



Lu 



Hg 



Ta 



W 0.0001 0.001 



Re 



Os 



Ir 



Pt 



Au 0.000004 0.00004 



Hg 0.00003 0.0003 



Tl < 0.00001 < 0.00009 



Pb 0.003 0.03 



Bi 0.0002 0.002 



Po 



At 



Rn 9.0 X 10"'^ 8.0 X 10" 



Fr 



Ra 3.0 X 10"" 2.0 X 10" 



Ac 



Th 0.0007 0.006 



Pa 0.003 0.03 



U 



