Record Details
Some chronic effects of exposure to kraft mill effluent on juvenile chinook salmon
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Some chronic effects of exposure to kraft mill effluent on juvenile chinook salmon |
| Names |
Tokar, Erick M.
(creator) Chadwick, George G. (advisor) |
| Date Issued | 1968-05-07 (iso8601) |
| Note | Graduation date: 1968 |
| Abstract | The effects of sublethal concentrations of kraft mill effluents (KME) on the growth, food consumption, and swimming ability of juvenile chinook salmon, Oncorhynchus tschawytscha (Walbaum), were studied from February 1966 to May, 1967. The KME used in these studies was obtained from two pulp and paper mills producing paper from unbleached pulp. Samples were collected weekly during the experimental periods from settling lagoons of mill A, and waste outfalls of mill B. Acute toxicity bioassays of these wastes were performed periodically, and 96-hour median tolerance limits (TL[subscript m]) were estimated for the salmon and for guppies (Poecilia reticulata Peters). Water and wastes were introduced into 16 experimental chambers by a system of head boxes and siphons. In each experiment, growth rates of salmon continuously exposed to three waste concentrations and of controls were evaluated at four different feeding levels. The waste concentrations were adjusted so as to provide for nearly constant increments of biochemical oxygen demand (BOD). Tubificid worms were the food organism in all experiments. The feeding levels employed ranged from an unrestricted ration, through several restricted rations, to starvation. The growth rates of salmon were found to be reduced at all concentrations of KME from mill A (0.5 to 4.0 mg/liter BOD) when the ration was unrestricted, and were reduced at all concentrations with BOD increments greater than 0.5 mg/liter when the next lower ration was fed. Some death occurred within 16 days at all feeding levels at concentrations having a BOD increment of 4.0 mg/liter. At low feeding levels, no consistent differences in growth attributable to KME were observed. Dilutions of waste from mill B had only small effects on the growth of chinook salmon. Salmon held in clean water and fed worms which had been exposed to KME from mill A showed only slight decreases in growth rate, except when they were fed worms exposed to 100-percent effluent which reduced the efficiency of food utilization considerably. When salmon were exposed to two concentrations of KME from mill A and then tested for swimming ability, no differences of maximum sustained swimming speeds attributable to the wastes were found. Except at the 4.0 mg/liter BOD level of waste from mill A, no reduction in the appetite of salmon exposed to KME was found in the growth experiments. Any reductions in the growth rates observed can be attributed to KME-caused decreases of the efficiency of food utilization for growth. The higher metabolic rates of the fish kept on the high ration presumably were responsible for the increased effects of the KME on these fish. |
| Genre | Thesis/Dissertation |
| Topic | Chinook salmon |
| Identifier | http://hdl.handle.net/1957/46769 |
