NSWC/WOL/TR 76-161 



Although biological monitoring procedures should always be 

 conducted with care, and methods can be made rather elaborate if 

 necessary, it must be recognized that a high degree of accuracy 

 is almost never attainable because of the known variability in the 

 resistance of individual members of a species and because it is 

 physically impossible to isolate a portion of an open body of water 

 and count and weigh every organism in it. One problem is the 

 changing location, population, and behavior of all forms of marine 

 life. Also, the frequent occurrence of wind, currents, rough water, 

 irregular bottoms, and other natural obstacles causes operational 

 difficulties. In addition, conditions may change during the 

 monitoring period, which may be as long as one hour. 



On the other hand, precision is not needed or expected for 

 the purpose of evaluating biological effects. The effects of 

 explosions must be considered in relation to other variable 



It may be noted that similar considerations, and operational 

 difficulties, are involved in the investigation of fish kills 

 resulting from the deliberate or accidental spill of a toxic 

 chemical into a body of water. 9 



2.2 Chemical 



An underwater explosion deposits a fraction of the chemical 

 products of the explosive reaction in the water. After a brief 

 period, these products can be found in a roughly circular surface 

 pool that moves with the current. This pool disappears quickly 

 unless it is marked with a dye tracer, such as fluorescein. The 

 products of a conventional explosive, such as TNT, are generally 

 harmless to the environment in the concentrations in the pool after 

 the rapid turbulent mixing caused by the explosion has subsided. 

 However, some newer explosives produce products that are possibly 

 harmful, and it may be necessary to collect water samples to 

 determine the amounts present. Another reason for chemical 

 monitoring is that the final composition of the products of any 

 explosion may differ from the values determined on the basis of 

 theory. The theoretical calculations usually end at a stage when 

 the products are at a high temperature and before they cool and 

 mix with the surrounding medium. 



Grantham, B. J., 1971: Basic Procedures for Investigating 

 Fish Kills in Streams, pp. 100-104, in Collection of Papers 

 Presented at the Fish Kill Investigation Seminar on 2-4 

 November 1971, Oklahoma State University, Stillwater, Oklahoma, 

 April, 1972. 



