WASTES IN THE SEA — WALLEN 393 



From the biological standpoint, the disposal of wastes is much more 

 complicated than from geological, physical, or chemical standpoints. 

 The thousands of marine species have differing metabolic requirements, 

 at many different concentration levels, for different chemicals that 

 may or may not be abundant in the sea. Certain trace elements that 

 are required for rapid growth may be present in nuclear wastes. 

 Consideration must be given to the possible use of contaminated fish 

 or seaweed as fertilizers on the land, as well as to the possibility of 

 beach disposition of radioactive materials. Tolerances for radiation 

 and susceptibility to genetic changes vary widely depending on the 

 chromosomal structure, the stage of development, and many other 

 poorly known criteria. 



The scale of allowable concentrations for a single constituent of 

 nuclear wastes is a complex one with variations between 1 and 10"'^, a 

 10 millionfold difference. Living organisms may concentrate certain 

 isotopes to at least 10'' times, a millionfold increase. If radioactive 

 wastes are of known quality and quantity and if the organisms in an 

 area are known to concentrate the specific wastes at a known rate, 

 a reasonable answer could be given to the question concerning poten- 

 tial effects of given disposal rates. In the absence of this information 

 a number of guesses must be compounded on at least a 10 million- 

 million scale in estimating permissible disposal levels. 



The extent of accumulation of a radionuclide is dependent on its 

 availability to the organisms. This is regulated by the abundance of 

 the element, and to some extent, by the abundance of other elements. 

 Not only must the specific elements be considered ; but also it must be 

 remembered that certam radionuclides may be present in chemical 

 combinations not readily available, or, conversely, more available, to 

 the marine biota. 



Most organisms appear to have a greater affinity for certain ele- 

 ments than for others. Goldberg (1957) noted a relationship between 

 concentratability of metallic ions and their chemical stability. In sea- 

 weeds it was found that nickel is concentrated 550 times, zinc 900 times 

 and strontium 23 times that of seawater. Bowen and Sutton (1951) 

 reported concentration in sponges as 1,400 for copper, 420 for nickel, 

 50 for cobalt, 0.07 for magnesium and 3.5 for calcium. 



In the open ocean after massive close-in fallout from nuclear tests, 

 most fission-product isotopes are found within a few hours of detona- 

 tion to be associated with biological organisms, especially plankton, 

 and with particulate suspensoids. Within a week the cation fission 

 products seem to have been mostly removed from living biological 

 surfaces. Induced radioactive isotopes are produced from materials 

 in the containment vessel of a nuclear device or from elements in 

 the water. The biological demand for these materials is such that 



