letter 

 from the chairman 



THE MEMBERSHIP of the National Techni- 

 cal Advisory Subcommittee on Water Quality 

 Criteria for Fish, Other Aquatic Life, and Wild- 

 life represents training and experience in several 

 phases of freshwater, marine and wildlife ecology, 

 physiology, and toxicology. The task of this Sub- 

 committee is to describe, insofar as possible, un- 

 der present knowledge: (1) the environmental 

 requirements of aquatic life and wildlife, (2) the 

 environmental concentrations of potential toxi- 

 cants that are not harmful under long-term ex- 

 posure, and (3) to suggest indirect methods for 

 determining safe concentrations through bioassays 

 and application factors. Because present knowl- 

 edge of environmental requirements is incomplete 

 and information on safe concentrations of toxi- 

 cants is nonexistent for most organisms, the recom- 

 mendations for water quaUty criteria of necessity 

 are incomplete, tentative, and subject to change as 

 additional information becomes available. In the 

 determination of these criteria, the Subcommittee 

 has utilized the broad knowledge, the many years 

 of experience, and the understanding and com- 

 monsense of the Subcommittee members. 



In order to expedite this task, the Subcommittee 

 was divided into three groups: one for freshwater 

 organisms; one for marine and estuarine orga- 

 nisms; and a third for wildlife. 



Six task forces were set up in each of the first 

 two groups. Each of these task forces was assigned 

 certain environmental factors to review present 

 knowledge and determine environmental condi- 

 tions essential for the survival, growth, reproduc- 

 tion, general well-being, and production of a 

 desired crop of aquatic organisms. Members as- 

 signed to each task force were experts on that 

 particular subject or had wide experience with the 

 factors or materials in question. They were se- 

 lected with this in mind so that the whole subject 

 could be covered most effectively. The composite 

 report thus prepared was reviewed by the full 

 Subcommittee and approved on October 31 and 

 November 1, 1967, in Washington, D.C. 



Clarence M. Tarzwell, 



Chairman. 



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