Biologists engaged in pollution investigations and research often work alone and are somewhat isolated. For some time, therefore, there had been recognized a need for a conference of those engaged in the study of biological problems in water pollution control, to acquaint them with current developments and new methods of approach, and to enable them to become acquainted with other workers in the field. The first such gathering was held as a seminar at the Robert A. Taft Sanitary Engineering Center, April 23 - 27, 1956. The seminar consisted of panel discussions and was planned so that most of the time was devoted to commentary from the floor with only short presentations by panel members. Subjects discussed were: (1) Use and Value of Bioassays; (2) Use and Value of Biological Indicators of Pollution; (3) Current Investigations in Water Pollution Biology; (4) Water Quality Criteria for Aquatic Life; and (5) Training of Sanitary Aquatic Biologists.