most difficult to prove. Since the availability of prespill biological data 

 is unlikely, the best estimate of the normal variation of the impacted system 

 will probably be obtained after the spill from measurements taken on a similar, 

 unimpacted control system. Once some estimate of the normal variation of the 

 impacted population or community system is obtained the significance of the 

 observed postspill changes in that population or community can be determined. 

 Significant alterations of both populations and communities may occur as 

 short-term and/or long-term effects of a spill. Unfortunately, present state- 

 of-the-art monitoring techniques are inadequate for separation of ecosystem 

 perturbations brought about by natural processes from all but the most obvious 

 effects of spill incidents (Topping 1976). The emphasis placed on assessment 

 of environmental damage by the Clean Water Act of 1977 should stimulate needed 

 research in this area. 



Returning to the legal aspects of analytical documentation, analytical 

 data derived from a spill would be significant in establishing causation, 

 this is, that the spilled substance actually did cause the environmental damage 

 ascribed to the spill. Good arguments can be made that a particular spill 

 caused a particular set of environmental perturbations based only on the tem- 

 poral and spatial relationships between the spill and the environmental per- 

 turbations. Placing the spilled substance in the tissues of dead organisms 

 collected at the spill site, however, would establish a direct link between 

 the spill and the observed damage. 



It is unlikely that analytical data will be influential in establishing 

 the cost of cleanup and restoration of the natural resources. If estimates 

 of plankton and pelagic organism kills based on evaluation of laboratory bio- 

 assay data, field survey data, and quantitative analytical (water column) data 

 (Hi rota et al . 1977) prove to be legally acceptable, this situation would, of 

 course, change somewhat. The cost of cleanup and restoration and/or replace- 

 ment of damaged resources should be assessed by teams of biologists and econo- 

 mists utilizing all pertinent information. The courts, however, will probably 

 make the ulitmate determination of the costs of cleanup and restoration to 

 the discharger. 



CHAIN OF CUSTODY 



Availability of a "chain of custody" for samples taken at a spill site is 

 particularly important to an attorney trying to establish that the samples 

 were analyzed in as near their original state as possible. A "chain of cus- 

 tody" is simply a documentation of the general rule that spill site samples 

 should always be either under observation or locked up. Samples taken for 

 documentation of a spill should be labeled according to accepted scientific 

 procedures as they are collected in the field. In addition, the taking of 

 each documentation sample should also be witnessed by a second person. 

 Thereafter, every time that the sample changes hands a record of the transfer 

 should be kept both on a custody tag attached to the sample itself and in a 

 comprehensive set of sample records maintained by the party coordinating the 

 documentation efforts. The comprehensive record set should indicate who has 

 custody of every sample at all times. 



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