Submitted to: American Fisheries Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/16/2004
Publication Date: 8/5/2004
Citation: Danley, M., Mazik, P., Silverstein, J. 2004. Effects of feed frequency on the metabolic responses of hypercapnic rainbow trout. American Fisheries Society Annual Meeting 2004.
Technical Abstract: Rainbow trout (Oncorhynchus mykiss) grown in waters with elevated free carbon dioxide (CO2) have reduced growth rates. It was hypothesized that CO2-exposed trout may have reduced growth rates because of acute recurring respiratory distress during and following high-level activities such as feeding. The following study was conducted to determine if continuous feeding from sunrise to dusk during chronic CO2 exposure would reduce feeding activity, and subsequent respiratory distress, compared to intermittent feeding of 2h at sunrise and 1 h at dusk. Two CO2 treatments were tested (<20 mg/L and 35-45 mg/L) in combination with the two feed treatments for a total of four treatment combinations, each replicated three times. Results are expected to show that low CO2 treated fish will have significantly (P < 0.05) higher oxygen consumption and ammonia excretion rates compared to the high CO2 treated fish, since low CO2 treated fish should have minimal CO2-induced respiratory distress. It is also expected that oxygen consumption and ammonia excretion rates will be higher in high CO2 treated trout fed continuously compared to those fed intermittently. Such results will provide valuable insight for optimizing management practices and selecting fish species/strains for culture environments which contain elevated CO2.