Breadcrumb

The oxygen transfer coefficient (KLa) will be determined by deaeration with nitrogen gas followed by aeration (0.60 slpm) using a YSI ProODO dissolved oxygen meter. The KLa value will be computed from the ASCE Standard for the Measurement of Oxygen Transfer in Clean Water http://cedb.asce.org/cgi/WWWdisplay.cgi?156576 The measured KLa values will be reported at 20C using a theta = 1.047.

Oxygen uptake of hauling water samples will be determined from the change in dissolved oxygen over a 30 minute period using a YSI ProODO dissolved oxygen meter. Sample will be stirred using a magnetic rod. Oxygen uptake will be determined by fitting a linear regression line through the dissolved oxygen vs time curve and expressed as mg/minute. The oxygen uptake rate will be reported at 20C using a theta = 1.047.

Following simulated hauling, fish from individual tanks will be transferred to 4 in diameter circular tanks for observation. Mortality will be recorded daily for 7 days.

Temperature will be measured using the thermistor sensors in the YSI ProODO or YSI 556 MPS units.

Total ammonia nitrogen will be measured using an Orion Ammonia electrode, calibrated daily with standard solutions (0.1, 1, 10, and 100 mg/Liter), and results expressed as mg/Liter TAN

Un-ionized ammonia will be based on TAN, temperature, salinity, and pH. UIA will be computed from Tables 9 or 10 in http://fisheries.org/hatchery