Presentation at AFS on Fish Response to Fluctuating Temperatures
Results from EPRI’s study of fish response to fluctuating temperatures were presented at the 137th annual meeting of the American Fisheries Society, held Sep. 2–6 in San Francisco.  The study has included lab experiments, to better define the relationships between exposure magnitude/duration and thermal stress in fish, and the role of recovery; and modeling, to simulate stress accumulation during dynamic temperature exposure.  The presentation discussed the following results:

• Slower rates of increase resulted in earlier loss of equilibrium.
• Acclimation that increases thermal tolerance can happen quickly.
• The potential for acclimation and stress accumulation to occur simultaneously complicates understanding of both.
• Fluctuating temperatures are not necessarily detrimental (depending on the range) and often produce increased acclimation, resulting in higher upper limits.
• Thermal stress accumulation is not always intuitive.
• The thermal stress model should be a useful tool for evaluating the protectiveness of various types of thermal standards.

For more information, contact Robert Goldstein, (650) 855-2593, rogoldst@epri.com.