**The title, authors, and abstract for this completion report are provided below.  For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209**

 

 

Effect of Activity on Bioenergetics Model Performance in the Laboratory

Charles P. Madenjian2

 

 

2 U. S. Geological Survey

Great Lakes Science Center

1451 Green Road

Ann Arbor, Michigan  48105

 

 

January 2011

 

ABSTRACT:

We evaluated the performance of the Wisconsin bioenergetics model for lake trout (Salvelinus namaycush) fed ad libitum in laboratory tanks under regimes of low activity and high activity.  In addition, we compared model performance under two different model algorithms: (i) balancing the lake trout energy budget on day t based on lake trout energy density on day t, and (ii) balancing the lake trout energy budget on day t based on lake trout energy density on day t+1.  Results indicated that the model significantly underestimated consumption for both inactive and active lake trout when model algorithm i was used, and the degree of underestimation was similar for the two levels of activity.  In contrast, model performance substantially improved using model algorithm ii, as no detectable bias was found in model predictions of consumption for inactive fish, and only a slight degree of overestimation of consumption was detected for active fish.  Apparently, the energy budget was more accurately balanced using model algorithm ii than using model algorithm i.  Based on the results of this study, we recommended that model algorithm ii be used to estimate food consumption by fish in the field.