The bigmouth buffalo, Ictiobus cyrinellus, is the most important commercial species in Lake Oahe, a reservoir in the upper Missouri RIver. The population was dominated by three strong year classes (1959, 1960, and 1962). Successful reproduction appeared to be associated with flooding of shoreline vegetation during spring and early summer. Growth rate was high during the first few years of impoundment and then declined. Inasmuch as little such flooding is expected in the future, annual landings of bigmouth buffalo will probably continue to decline sharply.

A bibliography comprising annotated citations of 2037 scientific and technical publications from ten series issued by the U.S. Fish and Wildlife Service. Includes a six-page introduction containing a history of the Service and a description of the research and development series.

A laboratory method of measuring the accumulation, transfer, elimination, and degradation of xenobiotic contaminants is described for organisms in a freshwater food chain (microorganisms, filter-feeder, and fish). A flow-through diluter-syste, C14-labeled contaminants, gas and thin-layer chromatography, autoradiography, and liquid scintillation spectrometry are used in making residue determinations. Accumulation factors and various index values are developed for measuring and estimating potential accumulation of xenobiotic contaminants by aquatic organisms. The laboratory procedure is economical, simple, reproducible, and ecologically relevant.