Pj. Braaten et al., DEVELOPMENT AND EVALUATION OF BIOENERGETIC-BASED HABITAT SUITABILITY CRITERIA FOR TROUT, Regulated rivers, 13(4), 1997, pp. 345-356
We constructed energetic models of habitat use for 82-322 g rainbow tr
out (Oncorhynchus mykiss) in a large regulated river, and 8-28 g Color
ado River cutthroat trout (O. clarki pleuriticus) in a small headwater
stream, to determine if observed summer habitat use by these species
could be attributed to net energy acquisition, and to develop habitat
suitability criteria based on net energy gain. Metabolic models of ene
rgy expenditure were derived from literature sources, but measurements
of energy availability were site-specific. From the energy models, we
assigned a suitability value of 1.0 to the entire range of velocities
where positive net energy gains were predicted, and a suitability val
ue of zero to velocities where negative net energy gains were predicte
d. Predicted net energy gain velocities were compared with observed ve
locities used by each species. For rainbow trout, the energetic model
predicted energetically profitable velocities ranging from 5 to 45 cm
s(-1). Predicted velocities were similar to velocities used by rainbow
trout. This indicated that rainbow trout, as a group, were using ener
getically profitable stream locations, but some rainbow trout used non
-profitable velocities. For Colorado River cutthroat trout, the energe
tic model predicted energetically profitable velocities ranging from 5
to 45 cm s(-1). however, Colorado River cutthroat trout used signific
antly lower velocities than predicted. The dissimilarity between veloc
ities predicted and used by Colorado River cutthroat trout may be attr
ibuted to their inability to utilize energetically profitable velociti
es available in the stream because of depth restrictions. The results
suggest that the predictive abilities of energetic models vary between
streams because of differences in depth and velocity availability. (C
) 1997 by John Wiley & Sons, Ltd.