Bull trout spawn in streams and tend to be extremely selective when picking a spawning site. In some systems a whole population spawns in one small area, ignoring other apparently suitable habitat. The presence of ground water may be a critical requirement. Large deep pools, often bedrock controlled, adjacent to appropriate spawning habitat may also be important. Small, very high gradient tributary streams and ground water seepage channels are often utilized for spawning and rearing.
Juveniles require one to four years of stream rearing.
Juveniles prefer pools and runs, up to 1.0 m in depth, with cobble and boulder substrate and overhead cover. Access to spawning and juvenile rearing habitat is critical. Selected references Anonymous. A strategic plan for the conservation and management of char in British Columbia. Large Lakes Committee.