Meeting Abstract
Brook trout (Salvelinus fontinalis) is a cold water species with a narrow range of thermal tolerance. Climate change projections suggest that in addition to increases in average temperatures worldwide, we should expect greater temperature variability. We are investigating growth and metabolic responses of brook trout to daily thermal variation. We reared groups of brook trout under constant temperature to serve as a control, a 4°C daily range as a low variability treatment similar to current conditions, and an 8°C daily range as a high variability treatment mimicking climate change predictions centered on a 6°C for winter or 12°C for summer. Over the two-month treatment exposures, we measured the mass and length of fish from each group to assess growth rates, collected plasma to measure cortisol, T3, and T4, and white muscle for citrate synthase activity. At the end of each treatment exposure series, a subsample of fish from each group was exposed to swimming respirometry to assess active and inactive metabolic rate and metabolic scope. Preliminary results suggest that there was no effect of variability in the daily thermal profile under our winter temperature regimes.
