Biological baseline data Youngs Bay, Oregon, 1974

This report presents biological baseline information gathered during the research project, Physical, Chemical and Biological Studies on Youngs Bay.'' Youngs Bay is a shallow embayment located on the south shore of the Columbia River, near Astoria, Oregon. Research on Youngs Bay was motivated by the proposed construction by Alumax Pacific Aluminum Corporation of an aluminum reduction plant at Warrenton, Oregon. The research was designed to provide biological baseline information on Youngs Bay in anticipation of potential harmful effects from plant effluents. The information collected concerns the kinds of animals found in the Youngs Bay area, and their distribution and seasonal patterns of abundance. In addition, information was collected on the feeding habits of selected fish species, and on the life history and behavioral characteristics of the most abundant benthic amphipod, Corophium salmonis. Sampling was conducted at approximately three-week intervals, using commonly accepted methods of animal collection. Relatively few stations were sampled for fish, because of the need to standardize conditions of capture. Data on fish capture are reported in terms of catch-per-unit effort by a particular sampling gear at a specific station. Methods used in sampling invertebrates were generally more quantitative, and allowed sampling at a greater variety of places, as well as a valid basis for the computation of densities. Checklists of invertebrate species and fish species were developed from these samples, and are referred to throughout the report. The invertebrate checklist is more specific taxonomically than are tables reporting invertebrate densities. This is because the methods employed in identification were more precise than those used in counts. 9 refs., 27 figs., 25 tabs