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Geology topics

Gary Wedemeyer

Publications and source records attributed to Gary Wedemeyer.

At least 37 records · Page 2Linked to original sources
USGS1976

Physiological response to hooking stress in hatchery and wild rainbow trout (Salmo gairdneri)

This study evaluated the physiological response of rainbow trout to hooking stress after being played under standardized conditions (0–5 min) and estimated the time needed for recovery (to 72 h). Plasma osmolality and chloride measurements were used to evaluate osmoregulatory disturbances and gill ion-exchange function, and plasma glucose was used as an index of the generalized nonspecific physiological stress response. Hooking stress caused more severe blood chemistry differences in hatchery fish than in wild trout. Also, hooking stress imposed a greater stress on larger than on smaller hatchery rainbow trout. Higher water temperatures aggravated the delayed hyperglycemia and hyperchloremia in both hatchery and wild trout but only about 3 days were needed for recovery at 4, 10, or 20 C.

Transactions of the American Fisheries Society↗
USGS1973

Some physiological aspects of sublethal heat stress in the juvenile steelhead trout (Salmo gairdneri) and coho salmon (Oncorhynchus kisutch)

A rapid (3 min) but sublethal temperature increase from 10 to 20 imposed a greater stress on juvenile coho salmon ( Oncorhynchus kisutch ) than on juvenile steelhead trout ( Salmo gairdneri ). Both species suffered hyperglycemia, hypocholesterolemia, increased blood hemoglobin, and decreased blood sugar regulatory precision, but the steelhead recovered more quickly. Acid–base equilibrium was essentially unaffected, and only the coho suffered any significant interrenal vitamin C depletion. Vitamin C normalization required about 24 hr.

Journal of the Fisheries Research Board of Canada↗
USGS1973

Computer program for sample sizes required to determine disease incidence in fish populations

A computer program is described for generating the sample size tables required in fish hatchery disease inspection and certification. The program was designed to aid in detection of infectious pancreatic necrosis (IPN) in salmonids, but it is applicable to any fish disease inspection when the sampling plan follows the hypergeometric distribution.

Journal of the Fisheries Research Board of Canada↗
USGS1973

Stress of formalin treatment in juvenile spring chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Salmo gairdneri>)

The physiological stress of 200 ppm formalin treatments at 10 C is more severe in the juvenile steelhead trout ( Salmo gairdneri ) than in the spring chinook salmon ( Oncorhynchus tshawytscha ). In the steelhead, a marked hypochloremia follows a 1-hr treatment and recovery requires about 24 hr. During longer treatments, hypercholesterolemia together with reduced regulatory precision, hypercortisolemia, alkaline reserve depletion, and hypocapnia unaccompanied by a fall in blood p H occur — suggestive of compensated respiratory alkalosis. In the spring chinook, hypochloremia and reduced plasma cholesterol regulatory precision are the significant treatment side effects but recovery requires only a few hours. Formalin treatments also cause epithelial separation, hypertrophy, and necrosis in the gills of both fishes but again, consistent with the physiological dysfunctions, these are more severe in the steelhead.

Journal of the Fisheries Research Board of Canada↗
USGS1972

Some physiological consequences of handling stress in the juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri)

The stress of handling juvenile coho salmon ( Oncorhynchus kisutch ) and steelhead trout ( Salmo gairdneri ) in soft water and in water with added salts was evaluated using blood and tissue chemistry fluctuations as indices of metabolic and endocrine function. Changes in plasma glucose, chloride, calcium, and cholesterol levels indicated that significant osmoregulatory and metabolic dysfunctions can occur and persist for about 24 hr after handling in soft water. Pituitary activation, as judged by lack of interrenal ascorbate depletion, did not occur. Increasing the ambient NaCl and Ca ++ levels to about 100 milliosmols and 75–120 ppm, respectively, partially or completely alleviated the hyperglycemia and hypochloremia indicating that the stress of handling had been reduced.

Journal of the Fisheries Research Board of Canada↗
USGS1971

Some blood chemistry values for the juvenile coho salmon (Oncorhynchus kisutch)

Overlapping Gaussian distribution curves were resolved into normal ranges for 1800 clinical test values obtained from caudal arterial blood or plasma of more than 1000 juvenile coho salmon ( Oncorhynchus kisutch ) held under defined conditions of diet and temperature. Estimated normal blood chemistry ranges were bicarbonate, 9.5–12.6 mEq/liter; blood urea nitrogen (BUN), 0.9–3.4 mg/100 ml; chloride, 122–136 mEq/liter; cholesterol, 88–262 mg/100 ml; p CO 2 , 2.6–6.1 mm Hg (10 C); glucose, 41–135 mg/100 ml; hematocrit, 32.5–52.5%; hemoglobin, 6.5–9.9 g/100 ml; total protein, 1.4–4.3 g/100 ml; blood p H (10 C), 7.51–7.83. The calculated range of normal acid–base balance vs. water temperature is also presented.

Journal of the Fisheries Research Board of Canada↗
USGS1971

The stress of Formalin treatments in rainbow trout (Salmo gairdneri) and coho salmon (Oncorhynchus kisutch)

Changes in gill function, acid–base balance and pituitary activation occurring during standard 200 ppm formalin treatments of juvenile rainbow trout ( Salmo gairdneri ) and coho salmon ( Oncorhynchus kisutch ) were compared. Plasma Cl − , Ca ++ , total CO 2 , and interrenal vitamin C in the trout declined continuously and in proportion to the exposure time, but the salmon were able to maintain these metabolic parameters at approximately initial levels. Blood p H and alkaline reserve regulation of the salmon was also less affected by formalin treatments, especially during prolonged exposures. The oxygen consumption of both species was depressed, but substantially more so in the trout than could be accounted for by decreased ventilation rates. Little frank hemolysis occurred in either species, but there was a significant bilirubinemia in the trout.

Journal of the Fisheries Research Board of Canada↗
USGS1970

Stress of anesthesia with M.S. 222 and Benzocaine in Rainbow Trout (Salmo gairdneri)

Rainbow trout ( Salmo gairdneri ) anesthetized with M.S. 222 for periods up to 12 min experience interrenal ascorbate depletion, uremia, and moderate hypercholesterolemia. Anesthesia with neutralized M.S. 222 ( p H 7) or benzocaine prevented these changes and significantly reduced the variability in plasma glucose, cholesterol, and cortisol, indicating that the stress of anesthesia with M.S. 222 is due to the low p K of the sulfonic acid moiety.

Journal of the Fisheries Research Board of Canada↗