contaminants on birds of prey and waterfowl. Poultry husbandry was of little help 

 for these groups. For aquatic life, fish culture which provided large numbers of a 

 variety of fishes for stocking gave a head start to experimentalists. However, this was 

 clearly not the case for saltwater species. 



Development of economical and reliable dosing equipment required substantial 

 effort, especially for aquatic life where maintenance of water concentrations was a 

 problem. Many pesticides in particular were not very water soluble, and difficulty 

 was encountered in maintaining desired exposure concentrations. Late in the decade. 

 Mount and Brungs' developed a simple, inexpensive device that enabled researchers 

 to achieve adequate dosing. Figure 1 shows a modern apparatus for testing toxicity of 

 substances to aquatic life. 



Little is known about handling invertebrates in the laboratory and development of 

 methods for maintaining them lagged behind those for fish. Gradually, however. 



Figure 1. A modern aquatic toxicity testing system for hazardous materials. 



144 



