Christopher Clements, Utah Valley University
Physical Sciences
DWR operates the Springville Fish Hatchery raises rainbow trout for stocking lakes and ponds. Since February 2011 the hatchery has observed excessive physical activity among the trout, including jumping out of raceways onto the concrete walkways. Excessive physical activity can result from free carbon dioxide levels above 10 ppm and free carbon dioxide levels in the hatchery water have been measured as high as 17 ppm. They have added some treatment processes before it enters the hatchery and greatly reduced the food intake of the trout, which increase costs and reduce production. This has reduced free carbon dioxide levels to only 15 ppm. The objective of this study is to determine the source of elevated free carbon dioxide and recommend solutions for the problem. The water source for the hatchery is a shallow pond, which is fed by 16 springs, both warm and cold. The objective is being addressed by measuring discharge from each spring and collecting water samples for measurement of free carbon dioxide in addition to other common stressors of rainbow trout. Free carbon dioxide, temperature, pH, electrical conductivity and dissolved oxygen are being measured on-site, while hardness, nitrite, ammonia, copper, iron and zinc are being measured. Free carbon dioxide levels at some warm springs have been measured as high as 25 ppm. Mixing calculations will be carried out to determine whether the discharge and water quality of each spring is consistent with the water quality currently entering the hatchery and whether the removal of one or more springs would result in sufficient water within the acceptable ranges for rainbow trout. If calculations estimate free carbon dioxide significantly lower than the measured free carbon dioxide in the water entering the hatchery, it is possible that additional elevated free carbon dioxide results from the decay of organic matter.