Thermal Thresholds for Growth of Bighead CARP Juveniles – Modelling for Great Lakes Seasonal Temperatures

Information regarding water temperatures requirements, such as upper and lower limits as well as optimal temperatures, for survival and growth of Asian carp is scare and contradictory. This information must address lethal, critical, and optimal thermal limits for individual species, ontogenetic stages, and acclimation conditions. Such information is vital for understanding the potential growth of Asian carp in the Great Lakes, as well the potential competition these species may exert on native species. Lethal conditions can be defined as either “instantaneous mortality”, mortality occurring over a long period of time or violent muscular spasms without killing the individual but with irreversible damage. Critical limits mark the “zone of resistance” in which behavior induced by stress is only marginally exhibited, however physiological functions are affected. For instance, critical temperature marks the point where oxygen consumption might decreases sharply, ultimately limiting the fish’s scope of growth. We will illustrate limits and optimal temperatures with preliminary growth results using bighead carp (Hypophthalmichthys nobilis) juveniles subjected to a range of increasing and decreasing temperature changes. Furthermore, we will use data obtained on growth rates to model and determine potential growth rates for bighead carp in the Great Lakes, using multi-year  average seasonal water temperatures.