http://hdl.handle.net/1957/16918 <P>A series of research reports published by the Oregon Fish Commission from 1939 to 1944.</P> 2013-05-19T10:35:12Z http://hdl.handle.net/1957/3066 Tuberculosis in Pacific salmon and steelhead trout Wood, James W.; Ordal, Erling Josef, 1906-; Oregon. Fish Commission Tuberculosis in salmonoid fishes was first observed in the 1952 run of fall chinook salmon (Oncorhynchus tshawytscha) returning to the Bonneville Hatchery of the Oregon Fish Commission. In the studies reported here, tuberculosis was found not only in adult spring chinook but in silver salmon (0. kisutch), blueback salmon (0. nerka), and in anadromous and resident strains of rainbow trout (Salmo gairdnerii). Advanced tuberculosis was found in salmonoid fishes held in fresh water for two years or longer, as well as in adults returning from the sea. Lesions were most frequently observed in the liver, and varied in size from small miliary tubercles to huge necrotic areas, filled with characteristic acid-fast bacilli. The typical bacilli were found in stained smears from the kidney, heart, musculature, brain, intestines, pyloric caeca, and roe of infected fish. The disease was originally observed in sexually-underdeveloped fish, and there is indication that it interferes with sexual maturation. It was found that tuberculosis in marked salmon known to be of hatchery origin was extremely high - in some cases 100 percent. Tuberculosis was absent in the small number of silver and chum salmon examined which were known to be the progeny from natural spawning. It is suggested that dissemination of the disease may be due to fish-cultural practices such as the feeding of untreated carcasses and the viscera from tuberculous fish. Since acid-fast bacilli were found in the roe of some fish, it is also suggested that the disease may be transmitted to healthy eggs during the process of fertilization. Tuberculous adult spring chinook were found less capable of surviving to maturity after they reached the spawning grounds than were non-infected fish. It is likely that tuberculosis also influences the ability of salmon to survive during earlier stages of their life history. The incidence of tuberculosis in adult spring chinook entering the Dexter holding ponds on the Middle Fork of the Willamette River in 1955 and 1956 was 8.7 and 6.1 percent, respectively. The increase in incidence to 58.8 percent in 1957 is attributed to the increased dependency of the run on artificial propagation necessitated by the construction of Lookout Point Dam. Among chinook caught in the Columbia River gill-net fishery in. February and in May 1956, 12.3 and 10.5 percent, respectively, of those examined were tuberculous. Although these are spring chinook, it is believed that hatchery reared fall chinook also entered the catch, especially during May, and may have contributed to the number of tuberculous fish taken. 1958-12-01T00:00:00Z http://hdl.handle.net/1957/3065 Analysis of factors affecting the production of chum salmon (Oncorhynchus keta) in Tillamook Bay Henry, Kenneth A.; Oregon. Fish Commission Tillamook Bay chum salmon are caught commercially by gill-nets, both set and drift, and from 1928 through 1949 the landings have averaged 819,689 pounds per season. More chum salmon are caught on Tillamook Bay than on the rest of the Oregon coastal rivers combined. These fish enter the ocean only a few weeks after hatching and return to their native streams to spawn, apparently in the third, fourth, or fifth year of their life. There are numerous factors such as predation, fishing intensity, success of spawning, which may have some effect on the production of Tillamook Bay chum salmon. There was no apparent relationship between total chum landings and lumber production 4 and 8 years previous. It is possible that a relationship between these two factors may exist for some period other than 4 or 8 years previous, but this was not investigated further at this time. Numerous factors, mainly various combinations of stream flow data, were correlated with the size of the commercial landings of chum salmon in an attempt to determine a "predictor" of future abundance. An apparent good relationship, with b = 2.05944 (P = 01), between total chum landings and the minimum stream flow occurring between January 15 and March 20 three years previous was discovered. The regression equation obtained is y = -493.6355 + 2.05944x. The regression of the size of the commercial landings of chum salmon on three variables was computed. These three variables were: (1) minimum stream flow occurring between January 15 and March 20 three years previous; (2) highest air temperature occurring during January or February 3 years previous; and (3) the maximum stream flow occurring between November 1-10 four years previous. The regression equation obtained is y = 346.4554 + 97.3148x[subscript 1] + 66.1037x[subscript 2] — 77.8188x[subscript 3]. The probabilities attached to the results of all the regression functions which were computed are biased because of the manner in which the data were selected to obtain the best relationship. Furthermore, although an apparent good relationship was determined between minimum flows and the size of the commercial landings, it must be realized that these results have some very definite limitations to their actual values. In addition to the biased nature of the probabilities, is the fact that these results have been derived from a very limited amount of data. Also, these analyses have been based on some very important assumptions which, if not true, would almost completely invalidate the results obtained. These assumptions are: (1) catch = a constant X abundance; (2) all the fish mature at 4 years of age; (3) these data can be fitted to a linear model along with the other general assumptions about regression data; (4) fishing intensity has remained relatively constant (implied in 1); and (5) methods of recording flow data have remained consistent from year to year. 1953-09-01T00:00:00Z http://hdl.handle.net/1957/3057 The Indian Dip Net Fishery at Celilo Falls on the Columbia River Schoning, Robert W.; Merrell, Theodore R.; Johnson, Donald R.; Oregon. Fish Commission 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 salmon which spawns in the main Columbia, between Pasco and Rock Island Dam and on the main Snake River between Swan Falls and Marsing. 3. Until the present study, the magnitude of the Indian closed season subsistence catch, averaging 500,000 pounds annually, has been unknown. 4. Most of the fall closed season catch is dried for home use by the Indians during the year although some is sold illegally. 5. The annual average of 50,000 pounds of fish sold directly to tourists is relatively insignificant when compared to the amount sold through regular commercial channels during the open season. 6. The elimination of fixed gear in the Columbia River has increased the percentage of total fish caught by the Indians. In the case of chinooks, the Indian commercial catch increased 8.8 percent. 7. The average annual value of the total Indian catch 1947-1950 is estimated to be $700,000. 1951-11-01T00:00:00Z http://hdl.handle.net/1957/3054 Fisheries statistics of Oregon, 1950-1953 Smith, Harrison S. Document includes fishery statistics for Oregon for the years 1950-1953. 1956-01-01T00:00:00Z