Three factors were found to be significantly correlated with the fluctuations and trends in silver salmon production in Oregon. Logging was found to adversely affect the runs of salmon in later years. Exceptional winter floods seem to produce poor resulting runs. Low summer water flows also appear to produce lower...
North American bighorn sheep (Ovis canadensis) have experienced significant declines and population extirpations due to novel pathogens such as Mycoplasma ovipneumoniae. This disease continues to limit the population restoration of bighorn sheep. Therefore, understanding the demographic consequences of pathogen presence and the risk of contact between bighorn populations and potential...
A study was undertaken in the fall of 1948 by the Oregon Fish Commission to determine the possible presence and importance of a delay in the migration of adult chinook salmon (Oncorhynchus tshawytscha) at Bonneville Dam on the Columbia River. Approximately 650 chinook were captured, tagged, and released at the...
1. The Indians at Celilo Falls catch an average of over 2,600,000 pounds of fish each year, in dip nets in a manner very much the same as used by their ancestors. 2. The bulk of the fish caught at Celilo Falls is from the upriver fall run of chinook...
This report contains a series of individual reports within it. The main report continues growth and aging studies on fat gaper clams in Yaquina Bay. This document also includes a report on other Fish Commission activities on the Coast, a summary of razor clam research, the beginning of a survey...
1. Six major types of commercial gear have been used to take salmon and steelhead on the Columbia River; namely, gill nets, set nets, seines, traps, fish wheels and dip nets. 2. The five important commercial species in the Columbia River are chinook, silver, blueback and chum salmon and steelhead...
Project AFS-58 Final Report (part 1).
The first of three reports on a 15-year study to determine the effects of logging on the aquatic resources of three tributaries of the lower Alsea River. The study took place from 1959-1973. Primary objectives included in-depth study of population characteristics of fish species...
In spite of the progressive restrictions of the commercial river fishery during the past fifty years, the trend of the salmon populations of the coastal rivers has been downward. It is almost impossible to isolate and analyze separately the causes of this decline, and any attempt to saddle one factor...
Samples, consisting of scales, length and weight measurements, and sex determinations of chum, pink, and silver salmons, were taken from the commercial catch in the Columbia River in 1914. Five hundred eighteen chum scales were examined. All fish had gone to sea early in their first year; and 70.5 percent...
Project AFS-58 Final Report (part 3). The final of three reports on a 15-year study to determine the effects of logging on the aquatic resources of three tributaries of the lower Alsea River. The study took place from 1959-1973. Primary objectives included in-depth study of population characteristics of fish species...