Impacts of increased tempering lengths on twenty-four-hour survival of hybrid striped bass fry

We evaluated the impacts of different tempering rates on the 24-h survival of 4-d-old palmetto bass (female striped bass Morone saxatilis X male white bass M. chrysops). We used the increase rate of pH as a measure of water q uality change. Four tempering rates were conducted concurrently to determin e the importance of extended tempering time on the survival of fry followin g an adjustment to an increase in pH, alkalinity, and hardness. Fry were te mpered to increases of 0.6-1.9 pH units over periods from 11 to 330 min, pr oducing pH tempering rates of 11.4-0.02/h. The study produced average tempe ring rates and average survival rates for a set of controls and four treatm ent groups. Average fry survival rates ranged from 75% in the control repli cates with a pH tempering rate of +0.01/h to 48% for fry subjected to an in crease of 1.9 pH units in 10 min or a tempering rate of +11.4 pH/h.