None supplied. From introduction: A study program was prepared in 1963 to obtain the needed information in an orderly fashion. The program had the following stated objectives: (1) Determine the suitability of the Susquehanna River between and above the existing dams to support populations of American shad, Alosa sapidissima. (2) Determine the behavior of young and adult shad between and above impoundments in the river. (3) Determine the tolerance of egg and larval stages of shad to selected potential limiting factors in the environment.