possible. An active search for such features is of considerable importance to both 

 industry and regulatory agencies. 



These types of applications are occurring now, even though no system or set of 

 systems has been endorsed as a standard. Expert judgment and careful use within 

 acknowledged limits are necessary at present and for the foreseeable future. 

 However, as the relationships between the single species, physiochemical, model 

 ecosystem and field tests are more clearly understood and defined through 

 standardization and criteria development, microcosm technology may yield to 

 structure — activity relationships from powerful computerized data bases. Thus, it 

 will serve as an intermediate technology, both in form and function. 



LOOKING TO THE 1980s 



Several lines of research are currently being followed in concert. Part of the 

 functions of microcosms are transient, in that we expect them to lead us to tools that 

 benefit from the simplest and least expensive measurements possible. These would 

 include "screening microcosms" for rapid assessment of community and ecosystem 

 disruption or for parameterization of mathematical models. Benefits of cross- 

 pollenization from diverse approaches by different agencies and industries have 

 already emerged. 



The most important on-going research is that which provides criteria of a system's 

 validity with respect to (a) the real world, (b) inter-laboratory replicability, and (c) 

 relationship to simpler tests. Establishment of these criteria will then provide means 

 of standardizing operations and interpretation. Achieving these criteria will greatly 

 expand opportunities for investigation of critical ecosystem functions in the 

 microcosm, as a research arena or "field in the laboratory." Questions of physical 

 scale, biological complexity, and whether or not macrofauna may be included will be 

 determined by such criteria. Until these criteria are set forth, microcosm technology 

 will be subject to understandable skepticism. 



Microcosm systems are presently just getting away from the need for extensive and 

 sophisticated laboratory support. It is unlikely that chemical measurements will 

 become less costly in the future, but automation of ecological tests and control of 

 environmental conditions can be anticipated. These advances, coupled to defined 

 criteria for evaluation, can lead to better systems for specific site studies and for 

 generic investigations of ecological processes alike. 



The regulator will continue to seek the ideal microcosm(s) which can be used to test 

 literally thousands of chemicals and real world situations. The research will examine 

 variations in structure and response of a large number of systems to a small group of 

 chemicals, mainly in attempts to understand the world. Success to date tantalizingly 

 hints that both may have their wish, but only if short-term gains can continue to 

 justify the cost in manpower, laboratory space, and other scarce resources. This 

 realistic economic need is well recognized (as if the scientific problems were not 

 enough of a hurdle), so that the first half of the decade is a critical period in the future 

 of microcosm technology. 



Part of that future rests in the overall plan for completing the evaluative bridges 

 through the swamp of chemical and pollutant regulation. Microcosms are presently 

 seen as peripheral to early steps within most assessment schemes. Application in 

 confirmatory and exploratory stages, particularly where microcosms might substi- 

 tute effectively for multiple tests or elaborate field studies, would mean that they have 

 become part of the piers of bridges, cutting short the distance to our goal of rapid, 

 accurate, and cost-effective assessment. 



REFERENCES 



1. Kallet, A., and F. J. Schlink. 1933. 100 Million Guinea Pigs. Vanguard Press. 

 New York, N.Y. 210 pp. 



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