Yes temperature can get too warm for active 'feeding'- growth for both plants and animals depending on the adaptation of each specie. Trout are a good example of this feature. Most warm water fish have a relatively high upper active temperature tolerance or limit. Rarely do ponds with some depth and good habitat diversity (cool water refuge) reach those maximums throughout the entire water column for most warm water fish. Continually aerated ponds will have fewer cool water refuge areas. If one is keenly interested in this topic, they can do some homework to learn more about how to adjust the GDD for temperatures that are above the optimum for the specie they are interested in learning more about. This concept or practice is commonly performed for field corn.
The graph and description in the link above and repeated here briefly explain this phenomonon.
http://agron-www.agron.iastate.edu/Courses/agron212/Calculations/GDD.htm
