Observations of substrate selection and spatial distribution of 546 late sac fry, 16 feeding fry and 6-10 trout (age-0, 60-90 mm TL) were made at different times in an indoor tank. The tank was 3. 3 m long, 1. 5 m wide and 0.4 m deep and had a bottom type of sand, gravel, or rubble. Zooplankton provided a limited supply of food for fry, but no food was provided for the larger trout. Early migration was assessed by placing eggs (that were about to hatch) or feeding fry (29-48 mm TL) in central compartments (20-36 cm deep) of four raceways, and observing subsequent migration to adjacent shallower (4-19 cm) or deeper (37-51 cm) areas. The efficiency of Mason jars (1.1 liter) with inverted funnels and plastic minnow traps (5-mm mesh, 45 cm long, 15-22 cm diameter, with inverted funnels at both ends) as sampling tools was tested in a tank (described above) containing 13 feeding fry (45-90 mm TL). Another efficiency test of minnow traps was conducted in an outdoor hatchery pond (26mlong, 4 m wide, and 0. 6 m deep) during January-April. Six groups of age-I lake trout (60-110 mm TL) were placed in the pond at various times during the experiment.

My observations showed that sac fry, feeding fry, and older age-0 trout were benthic in nature. Sac fry and feeding fry did not demonstrate a bottom type preference when given a choice of sand, gravel and rubble although older age-0 trout evidenced a preference for rubble bottom. Sac fry dispersed gradually at random from the location where they had been placed as ready-to-hatch eggs. Dispersal occurred from hatching to about 2 weeks after swim-up, a 12-week period. Within this period, fry showed no preference for deep or shallow water but older fry that had been feeding for a month or so showed a preference for deep water. Minnow traps showed promise as a method of catching small lake trout.